diff --git a/TR.html b/TR.html deleted file mode 100644 index 4dece3b..0000000 --- a/TR.html +++ /dev/null @@ -1,10645 +0,0 @@ - - - - UI Events (formerly DOM Level 3 Events) - - - - - - - - - -

Abstract

-

This specification defines UI Events which extend the DOM Event objects defined in - [DOM4]. UI Events are those typically implemented by - visual user agents for handling user interaction such as mouse and keyboard input. -

-

Status of This Document

- - - -

- This section describes the status of this document at the time of its publication. - Other documents may supersede this document. A list of current W3C publications and the - latest revision of this technical report can be found in the W3C technical reports index at - http://www.w3.org/TR/. -

- -

- Implementers should be aware that this document is not stable. - Implementers who are not taking part in the discussions are likely to find the - specification changing out from under them in incompatible ways. - Vendors interested in implementing this document before it eventually reaches - the Candidate Recommendation stage should join the aforementioned mailing lists - and take part in the discussions. -

- -

- The previous version of the UI Events specification was extending DOM Level 3 Events but has been abandoned for now, due to the lack of time to work out the details of 'locale'. Future extensions may also be subsumed by additional work and proposals around the InputDevice API, allowing access to information related to the physical device responsible for an event. -

- - -

- This document was published by the Web Applications Working Group as a Working Draft. - - This document is intended to become a W3C Recommendation. - - - If you wish to make comments regarding this document, please send them to - www-dom@w3.org - (subscribe, - archives). - All comments are welcome. -

- -

- Publication as a Working Draft does not imply endorsement by the W3C - Membership. This is a draft document and may be updated, replaced or obsoleted by other - documents at any time. It is inappropriate to cite this document as other than work in - progress. -

- -

- This document was produced by a group operating under the - 5 February 2004 W3C Patent - Policy. - W3C maintains a public list of any patent - disclosures - made in connection with the deliverables of the group; that page also includes - instructions for disclosing a patent. An individual who has actual knowledge of a patent - which the individual believes contains - Essential - Claim(s) must disclose the information in accordance with - section - 6 of the W3C Patent Policy. -

- -

This document is governed by the 1 August 2014 W3C Process Document. -

- -

Table of Contents

- - - - - -
-

1. Introduction

- -
-

1.1 Overview

-

DOM Events is designed with two main goals. The first goal is the design of an event system which allows registration - of event listeners and describes event flow through a tree structure. Additionally, the specification will provide standard modules of events for user interface - control and document mutation notifications, including defined contextual information for each of these event modules.

- -

The second goal of DOM Events is to provide a common subset of the current event systems used in existing browsers. This is intended to foster interoperability - of existing scripts and content. It is not expected that this goal will be met with full backwards compatibility. However, the specification attempts to achieve - this when possible.

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- -
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1.2 Conformance

-

This section is normative.

- -

Within this specification, the key words MUST, MUST NOT, REQUIRED, - SHALL, SHALL NOT, SHOULD, SHOULD NOT, - RECOMMENDED, MAY, and OPTIONAL are to be interpreted as described in - [RFC2119].

- -

This specification is to be understood in the context of the DOM Level 3 Core specification - [DOM3 Core] and the general - considerations for DOM implementations apply. - For example, handling of namespace URIs is discussed in - XML Namespaces. - For additional information about - conformance, - please see the DOM Level 3 Core specification - [DOM3 Core]. - A user agent is not required to conform - to the entirety of another specification in order to conform to this specification, but it MUST - conform to the specific parts of any other specification which are called out in this specification - (e.g., a conforming UI Events user agent MUST support - the DOMString data type as defined in Web IDL, but need - not support every method or data type defined in Web IDL in order to - conform to UI Events). -

- -

This specification defines several classes of conformance for different - user agents, specifications, and content authors: -

-
-
Web browsers and other dynamic or interactive - user agents -
-
-

A dynamic or interactive user agent, referred to - here as a browser (be it a Web browser, AT (Accessibility Technology) application, - or other similar program), conforms to UI Events if it supports: -

-
    -
  • the Core module defined in - [DOM3 Core] -
  • -
  • the Event dispatch and DOM event flow mechanism -
  • -
  • all the interfaces and events with their associated methods, attributes, and - semantics defined in this specification with the exception of those marked as - deprecated (a conforming user - agent MAY implement the deprecated interfaces, events, or APIs for backwards - compatibility, but is not required to do so in order to be conforming) -
  • -
  • the complete set of key and code values defined in - [DOM3 key Values] and - [DOM3 code Values] - (subject to platform availability), and -
  • -
  • all other normative requirements defined in this specification. -
  • -
-

A conforming browser MUST dispatch events appropriate - to the given EventTarget when the conditions defined - for that event type have been met. -

- -

A browser conforms specifically to UI Events if it implements - the interfaces and related event types - specified in Event Types. -

- -

A conforming browser MUST support scripting, declarative interactivity, or some other means of - detecting and dispatching events in the manner described by this specification, and MUST support - the APIs specified for that event type. -

- -

In addition to meeting all other conformance criteria, a conforming browser MAY implement - features of this specification marked as - deprecated, for backwards compatibility with - existing content, but such implementation is discouraged. -

- -

A conforming browser MAY also support features not found in this specification, but which use - the Event dispatch and DOM event flow mechanism, interfaces, events, - or other features defined in this specification, and MAY implement additional interfaces and - event types appropriate to that implementation. - Such features can be later standardized in future specifications. -

- -

A browser which does not conform to all required portions of this specification MUST NOT claim - conformance to UI Events. - Such an implementation which does conform to portions of this specification MAY claim - conformance to those specific portions. -

- -

A conforming browser MUST also be a conforming implementation of the IDL fragments in this - specification, as described in the Web IDL specification [WEBIDL]. -

-
- -
Authoring tools
-
-

A content authoring tool conforms to UI Events if it produces content which uses the - event types and - Event dispatch and DOM event flow model, consistent in a manner as - defined in this specification. -

-

A content authoring tool MUST NOT claim conformance to UI Events for content it produces - which uses features of this specification marked as - deprecated in this specification. -

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A conforming content authoring tool SHOULD provide to the content author a means to use all - event types and interfaces appropriate to all - host languages in the content document being - produced. -

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Content authors and content
-
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A content author creates conforming UI Events content if that content uses the - event types and - Event dispatch and DOM event flow model, consistent in a manner as - defined in this specification. -

-

A content author SHOULD NOT use features of this specification marked as - deprecated, but SHOULD rely instead upon - replacement mechanisms defined in this specification and elsewhere. -

-

Conforming content MUST use the semantics of the interfaces and - event types as described in this specification. -

- -
Note

Authoring Note: - Content authors are advised to follow best practices as described in - accessibility and - internationalization guideline - specifications. -

-
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Specifications and host languages
-
-

A specification or host language conforms - to UI Events if it references and uses the - Event dispatch and DOM event flow mechanism, interfaces, events, - or other features defined in [DOM4], and does not extend these - features in incompatible ways. -

-

A specification or host language conforms - specifically to UI Events if it references and uses the interfaces and - related event types specified in - Event Types. - A conforming specification MAY define additional interfaces and - event types appropriate to that specification, - or MAY extend the UI Events interfaces and - event types in a manner that does not contradict - or conflict with the definitions of those interfaces and - event types in this specification. -

- -

Specifications or host languages which - reference UI Events SHOULD NOT use or recommend features of this - specification marked as deprecated, but - SHOULD use or recommend the indicated replacement for that the feature (if available). -

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- -
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1.3 Stylistic Conventions

-

This specification follows the Proposed W3C Specification - Conventions, with the following supplemental additions:

- -
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Key and character values
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    -
  • Names of key values are shown as: '=' (e.g., the value of - KeyboardEvent.key). -
  • -
  • Names of key codes are shown as: 'Equal' (e.g., the value of - KeyboardEvent.code). -
  • -
  • Character values of keys are shown as: '\u003d' (e.g., the code point - of the key value). -
  • -
  • Glyphs representing character values are shown as: '=' (e.g., the - key cap or font associated with a character value). -
  • -
-
- -

In addition, certain terms are used in this specification with particular meanings. The term implementation applies to a browser, content authoring tool, - or other user agent that implements this specification, while a content author is a person who writes script or code - that takes advantage of the interfaces, methods, attributes, events, and other features described in this specification in order to make Web applications, and a - user is the person who uses those Web applications in an implementation.

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2. Issues

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Issue 1

Open issues in this specification are called out using this convention.

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3. DOM Event Architecture

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This section is informative.

- -
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3.1 Event dispatch and DOM event flow

- -

This section defines the event dispatch mechanism of the event model defined in this specification. - Applications MAY dispatch event objects using the EventTarget.dispatchEvent() method, and - implementations MUST dispatch event objects as if through this method. The behavior of this method depends on the event flow - associated with the underlying object. An event flow describes how event objects propagate through a data structure. As an example, when an event object - is dispatched to an element in an XML document, the object propagates through parts of the document, as determined by the DOM event flow which is defined at the - end of this section.

- -
- Graphical representation of an event dispatched in a DOM tree using the DOM event flow -
Fig. 1 Graphical representation of an event dispatched in a DOM tree using the DOM event flow
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- -

Event objects are dispatched to an event target. At the beginning - of the dispatch, implementations MUST first determine the event object's propagation path.

- -

The propagation path MUST be an ordered list of current event targets through which - the event object MUST pass. For DOM implementations, the propagation path MUST reflect the hierarchical tree - structure of the document. The last item in the list MUST be the event target. The - preceding items in the list are referred to as the target's ancestors, and the immediately preceding item as the target's parent. Once determined, the - propagation path MUST NOT be changed. For DOM implementations, this applies even if an element in the propagation path is moved within the - DOM or removed from the DOM.

- -
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In the DOM event flow, event listeners might change the position of the - event target in the document while the event object is being dispatched. Such changes do not affect the propagation path.

-
- -

Note that event listeners are not copied over when Node are copied using methods such as - Node.cloneNode or Range.cloneContents - [DOM Range]. -

- -

Exceptions thrown inside event listeners MUST NOT stop the propagation of the event or affect the - propagation path. The exception itself MUST NOT propagate outside the scope of the event - handler.

- -
-
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In the following code, the exception thrown from the call to throw "Error" does not propagate into the parent scope - (which would prevent the console.log statement from executing):

-
var e = document.createEvent("Event");
-e.initEvent("myevent", false, false);
-var target = document.createElement("div");
-target.addEventListener("myevent", function () {
-   throw "Error";
-});
-target.dispatchEvent(e); // Causes the event listener to throw an exception...
-// The previously thrown exception doesn't affect the code that follows:
-console.log("Exceptions? No problem");
-
- -

As the next step, the event object MUST complete one or more event phases. This specification defines - three event phases: capture phase, target phase and bubble phase. Event objects - complete these phases in the specified order using the partial propagation paths as defined below. A phase MUST be skipped if it is not - supported, or if the event object's propagation has been stopped. For example, if the Event.bubbles - attribute is set to false, the bubble phase will be skipped, and if Event.stopPropagation() has been - called prior to the dispatch, all phases MUST be skipped.

- -
    -
  1. The capture phase: The event object MUST propagate through the target's ancestors from the Window to the target's parent. This phase is also known as the capturing phase. Event - listeners registered for this phase MUST handle the event before it reaches its target.
  2. - -
  3. The target phase: The event object MUST arrive at the event object's - event target. This phase is also known as the at-target phase. Event listeners registered for this phase MUST - handle the event once it has reached its target. If the event type indicates that - the event MUST NOT bubble, the event object MUST halt after completion of this phase.
  4. - -
  5. The bubble phase: The event object propagates through the target's ancestors in reverse order, starting - with the target's parent and ending with the Window. This phase is also known as the bubbling phase. - Event listeners registered for this phase MUST handle the event after it has reached its target.
  6. -
- -

Implementations MUST let event objects accomplish an event phase by applying the following steps while there are pending event targets in - the partial propagation path for this phase and the event object's propagation has not been stopped through - Event.stopPropagation().

- -

First, the implementation MUST determine the current target. This MUST be the next pending event target in the partial propagation - path, starting with the first. From the perspective of an event listener this MUST be the event target the listener has been registered on.

- -

Next, the implementation MUST determine the current target's candidate event listeners. - This MUST be the list of all event listeners that have been registered on the current target in their order of registration. [HTML5] defines the ordering of listeners registered through event handler attributes. Once determined, the candidate event listeners - MUST NOT be changed. Adding or removing listeners does not affect the current target's candidate event listeners.

- -

Finally, the implementation MUST process all candidate event handlers in order and trigger - each handler if all the following conditions are met:

- - - -

In the production of the propagation path, the event propagates from the Window - to the document object during the capture phase, and from the document object to the - Window during the bubble phase.

- -

After an event completes all the phases of its propagation path, its - Event.currentTarget MUST be set to null and the Event.eventPhase MUST be - set to 0 (NONE). All other attributes of the Event (or interface derived from Event) - are unchanged (including the Event.target attribute, which MUST continue to reference the - event target).

- -

The model defined above MUST be applied regardless of the specific event flow associated with an event target. Each event flow MUST define how the propagation path - MUST be determined and which event phases are supported. The DOM event flow is an application of this model: the propagation path for a Node - object MUST be determined by its Node.parentNode chain, and if applicable, the document's containing Window. - All events accomplish the capture and target phases. Whether an event accomplishes the bubble phase MUST be defined individually for each - event type. An alternate application of this model can be found in [DOM3 Load and Save].

- -

Implementations of the DOM event model MUST be reentrant. Event listeners MAY perform actions that cause additional events to be dispatched. Such events are handled - in a synchronous manner, the event propagation that causes the event listener to be triggered MUST resume only after the event dispatch of the new event is completed.

- -
- -
-

3.2 Default actions and cancelable events

- -

Events are typically dispatched by the implementation as a result of a user action, in response to the completion of a task, or to signal progress during asynchronous - activity (such as a network request). Some events can be used to control the behavior that the implementation MAY take next (or undo an action that the implementation - already took). Events in this category are said to be cancelable and the behavior they cancel is called their - default action. Cancelable event objects can be associated with one or more default actions. - To cancel an event, call the Event.preventDefault() method.

- -
-
-

A mousedown event is dispatched immediately after the user presses down a button on a - pointing device (typically a mouse). One possible default action taken by the implementation is to set up a state - machine that allows the user to drag images or select text. The default action depends on what happens next — for - example, if the user's pointing device is over text, a text selection might begin. If the user's pointing device is over an image, then an image-drag action could - begin. Preventing the default action of a mousedown - event prevents these actions from occuring.

-
- -

Default actions SHOULD be performed after the event dispatch has been completed, but in exceptional - cases MAY also be performed immediately before the event is dispatched.

- -
-
-

The default action associated with the click event on <input - type="checkbox"> elements toggles the checked IDL attribute value of that element. If the click - event's default action is cancelled, then the value is restored to its former state.

-
- -

When an event is canceled, then the conditional default actions associated with the event MUST be skipped (or - as mentioned above, if the default actions are carried out before the dispatch, their effect MUST be undone). - Whether an event object is cancelable MUST be indicated by the Event.cancelable attribute. - Event.preventDefault() stops all related default actions of an event object. The - Event.defaultPrevented attribute indicates whether an event has already been canceled (e.g., by a prior event listener). If the - DOM application itself initiated the dispatch, then the return value of the EventTarget.dispatchEvent() - method indicates whether the event object was cancelled.

- -
Note

Authoring Note: Many implementations additionally interpret an event listener's return value, such as the value false, to mean - that the default action of cancelable events will be cancelled (though window.onerror handlers are cancelled - by returning true).

- -
Note

Authoring Note: Some cancelable events might not have any observable default actions. For - example, the mousemove event.

- -

This specification does not offer features to programatically query if an event object has any default action associated with - it, or to associate new default actions with an event object. Other specifications SHOULD define what default actions, if any, - are associated with certain event objects. Further, implementations MAY associate default actions with events as necessary and - appropriate for that implementation.

- -
-
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As an example, one implementation might scroll a document view by a certain amount as the - default action of a wheel event, while another implementation might instead zoom the document as its default action.

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- -
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3.3 Synchronous and asynchronous events

- -

Events MAY be dispatched either synchronously or asynchronously.

- -

Events which are synchronous (sync events) MUST be treated as if they are in a virtual queue in a first-in-first-out model, ordered by sequence - of temporal occurrence with respect to other events, to changes in the DOM, and to user interaction. Each event in this virtual queue MUST be delayed until the - previous event has completed its propagation behavior, or been canceled. Some sync events are driven by a specific device or process, such as mouse button events. - These events are governed by the event order algorithms defined for that set of events, and a user agent MUST dispatch - these events in the defined order.

- -
-
-

A user double-clicks a passage of text to select a word, then presses the 'Delete' - key to erase the word, triggering the following synchronous sequence of events: - mousedown, - mouseup, - click, - mousedown, - mouseup, - click, - dblclick, - select, - keydown, - beforeinput, - input, - keyup. - Each of these events are fired in the sequence initiated by the user's actions.

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- -

Events which are asynchronous (async events) MAY be dispatched as the results of the action are completed, with no relation to other events, to - other changes in the DOM, nor to user interaction.

- -
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During loading of a document, an inline script element is parsed and executed. The - load event is queued to be fired asynchronously at the script element. However, because it is an async event, its order with relation to other synchronous - events fired during document load (such as the DOMContentLoaded event from HTML5) is not guaranteed.

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3.3.1 Event order and event loops

- -

Most events take place in a sequential context. [HTML5] defines its event operations in terms - of an event loop mechanism, in which events of all types are fed into different task queues. This specification does not define events in terms of this - event loop mechanism, but it is compatible with this mechanism. Instead, this specification defines several operation-specific - event orders.

- -

Using the terminology of HTML5, each independent device, such as a mouse or keyboard, SHOULD be treated as a task source which feeds into the appropriate - task queue, in the order defined by the event order associated with that device. Each operation, such as - a focus change or composition input, also acts as a task source for the appropriate task queue. The resolution of these event loops is handled - in a manner conforming to the host language, such as HTML [HTML5].

- -
Note

Authoring Note: Certain events, such as hotkeys or control keys pressed in a certain sequence, can be - swallowed by the operating system or the application, interrupting the expected event order.

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3.4 Trusted events

- -

Events that are generated by the user agent, either as a result of user interaction, or as a direct result of changes to the DOM, are trusted by the user agent - with privileges that are not afforded to events generated by script through the DocumentEvent.createEvent("Event") - method, modified using the Event.initEvent() method, or dispatched via the - EventTarget.dispatchEvent() method. The isTrusted attribute of trusted events has a - value of true, while untrusted events have a isTrusted attribute value of false.

- -

Most untrusted events SHOULD NOT trigger default actions, with the exception of the - click event. This event always triggers the - default action, even if the isTrusted attribute is false (this behavior is retained for backward-compatibility). - All other untrusted events MUST behave - as if the Event.preventDefault() method had been called on that event.

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3.5 Activation triggers and behavior

- -

Certain event targets (such as a link or button element) MAY have associated - activation behavior (such a following a link) that implementations perform in response to an activation - trigger (such as clicking a link).

- -

A host language SHOULD indicate which, if any, elements have activation behavior, describe appropriate activation triggers, and define the result of that activation behavior. An implementation which supports a host language SHOULD initiate these activation behavior when the associated - activation trigger occurs.

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Both HTML and SVG have an <a> element which indicates a link. Relevant activation triggers for an <a> element are a - click event on the text or image content of the <a> element, or a keydown - event with a key attribute value of 'Enter' key when the <a> - element has focus. The activation behavior for an <a> element is normally to change the content of the window to the content of the new document, - in the case of external links, or to reposition the current document relative to the new anchor, in the case of internal links.

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- -

An activation trigger is a user action or an event which indicates to the implementation that an activation - behavior SHOULD be initiated. User-initiated activation triggers include clicking a mouse button on an activatable - element, pressing the 'Enter' key when an activatable element has focus, or pressing a key that is somehow - linked to an activatable element (a hotkey or access key) even when that element does not have focus. Event-based - activation triggers MAY include timer-based events that activate an element at a certain clock time or after a certain time period has elapsed, progress - events after a certain action has been completed, or many other condition-based or state-based events.

- -

In some cases, a host language MAY define attributes or even attribute values which add to or change the native - activation trigger or activation behavior of an element. - For example, ARIA [ARIA] defines values for the role attribute that add semantics - to the element to which it is applied, for purposes of enhanced accessibility. In such cases, if the host language - does not explicitly define the activation trigger or activation - behavior, the content author MUST provide the mechanics of the activation trigger (via an event listener) - or activation behavior (such as calling an ECMAScript function) for that element when applying that attribute - or attribute value.

- -
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3.5.1 Activation event synthesis

- -

If the instance of the activation trigger is not an event of event - type click (that is, when it does not result from a user's activation of a button or link - using a mouse or equivalent pointing device), the implementation MUST synthesize and dispatch an event of event type click as one of the default actions of that activation trigger. The value of the Event.target - MUST be set to the event target (normally, the currently focused element), and the event MUST simulate a left - click (i.e., the MouseEvent.button attribute value MUST be 0, and the - MouseEvent.buttons attribute value MUST be 1). Other context information of such a simulated - click event is implementation dependent, but for historical purposes, the interface for the click - event MUST be the MouseEvent interface, regardless of the actual device used to activate the element. Preventing - the default action of the activation trigger, such as - with the Event.preventDefault(), MUST stop the initiation of the - activation behavior.

- -
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When a user activates a hyperlink using a keyboard, such as by focusing the hyperlink element - and pressing the 'Enter' or ' ' key, a click event would be dispatched as the default action of the respective - keydown event.

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- -

Implementations MUST dispatch the synthesized click event as described above even if they do not - normally dispatch such an event (e.g., when activation is requested by a voice command, since this specification does not address - event types for voice input).

- -
Note

Note: The activation of an event target is device dependent, but is also application dependent, e.g., a link in a document can be activated - using a mouse click or a mouse double click.

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3.5.2 Activation event order

- -

Activation triggers and behavior can be defined in part by the events which are dispatched in a set order relative to one another. The following is the typical - sequence of events for an element activated by a pointing device (with only pertinent events listed):

- - - - - - - - - - - - - - - - - -
Event NameNotes
1.click
- All default actions, - including the activation behavior -
- -

The following is the typical sequence of events when a focused element is activated by a key event (with only pertinent events listed):

- - - - - - - - - - - - - - - - - - - - - - -
Event NameNotes
1.keydownMUST be a key which can activate the element, such as the - 'Enter' or ' ' key, - or the element is not activated
2.clickdefault action; synthesized; isTrusted="true"
- All default actions, - including the activation behavior -
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- -
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3.6 Event exceptions

- -

This section is informative.

- -

Event operations can throw a DOMException as specified in their method descriptions.

- -
Note

Note: The exception EventException introduced in DOM Level 2 is - removed in this specification as part of this specification's normative support of Web IDL. EventException formerly defined - an exception code UNSPECIFIED_EVENT_TYPE_ERR which is replaced in this specification by the use of a DOMException of type - InvalidStateError.

- -

The following DOMException types are used in this specification.

- - - - - - - - - - - - - - -
TypeDescription
InvalidStateErrorThrown when the Event.type was not specified by initializing the event before dispatchEvent was - called. Also thrown when the Event object provided to dispatchEvent is already being dispatched.
NotSupportedErrorThrown when DocumentEvent.createEvent() is passed an Event - interface that the implementation does not support.
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- -
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3.7 Constructing Mouse and Keyboard Events

- -

Generally, when a constructor of an Event interface, - or of an interface inherited from the Event interface, - is invoked, the steps described in DOM4 [DOM4] should be followed. - However the KeyboardEvent and - MouseEvent interfaces provide additional - dictionary members for initializing the internal state of the - Event object's key modifiers: specifically, the - internal state queried for using the - KeyboardEvent.getModifierState() - and MouseEvent.getModifierState() - methods. This section supplements the DOM4 steps for intializing a new - Event object with these optional modifier states. -

- -

For the purposes of constructing a KeyboardEvent, - MouseEvent, or object derived from these objects - using the algorithm below, all - KeyboardEvent, - MouseEvent, and derived ojects have - internal key modifier state which can be set and - retreived using the key modifier names: - 'AltGraph' - 'CapsLock' - 'Fn' - 'FnLock' - 'Hyper' - 'NumLock' - 'OS' - 'ScrollLock' - 'Super' - 'Symbol' and - 'SymbolLock'. - -

The following steps supplement the algorithm defined for constructing events in DOM4:

- -
    -
  1. If the Event being constructed is a - KeyboardEvent or - MouseEvent object or an object that - derives from either of these, and a - EventModifierInit - argument was provided to the constructor, then run the following sub-steps: -
      -
    1. For each EventModifierInit - argument, if the dictionary member begins with the string "keyModifierState", then - let the key modifier name be the dictionary member's name - excluding the prefix "keyModifierState", and set the - Event object's - internal key modifier state that - matches the key modifier name to the corresponding value. -
    -
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- - -
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4. Basic Event Interfaces

- -

The basic event interfaces defined in DOM4 - [DOM4] are fundamental to UI Events. - These basic event interfaces MUST always be supported by the implementation: -

- - - -

The event types defined in this specification derive from these basic interfaces, and MUST - inherit all of the attributes, methods, and constants of the interfaces they derive from. -

-

The following chart describes the inheritance structure of interfaces defined in this specification. -

- -
- Graphical representation of inheritance of interfaces defined by this specification -
Fig. 2 Graphical representation of inheritance of interfaces defined by this specification
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- -
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4.1 List of Event Types

- -

Each event MUST be associated with a type, called event type and available as the type - attribute on the event object. The event type MUST be of type DOMString.

- -

Depending on the level of DOM support, or the devices used for display (e.g., screen) or interaction (e.g., mouse, keyboard, touch screen, or voice), these event - types can be generated by the implementation. When used with an [XML 1.0] or - [HTML5] application, the specifications of those languages MAY restrict the - semantics and scope (in particular the possible event targets) associated - with an event type. Refer to the specification defining the language used in order to find those restrictions or to find event types that are - not defined in this document.

- -

The following table provides an informative summary of the event types defined in this specification.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event TypeSync / AsyncBubbling phaseTrusted event target typesDOM interfaceCancelableDefault Action
abortSyncNoWindow, ElementEventNoNone
beforeinputSyncYesElementInputEventYesUpdate the DOM element
blurSyncNoWindow, ElementFocusEventNoNone
clickSyncYesElementMouseEventYesVaries: - for targets with an associated activation - behavior, executes the activation behavior; - for focusable targets, gives the element focus. -
compositionstartSyncYesElementCompositionEventYesShow a text composition system candidate window
compositionupdateSyncYesElementCompositionEventNoNone
compositionendSyncYesElementCompositionEventNoNone
dblclickSyncYesElementMouseEventNoVaries: - for targets with an associated activation - behavior, executes the activation behavior; - for focusable targets, gives the element focus; - for selectable targets, selects part or all of the - element's content. -
errorAsyncNoWindow, ElementEventNoNone
focusSyncNoWindow, ElementFocusEventNoNone
focusinSyncYesWindow, ElementFocusEventNoNone
focusoutSyncYesWindow, ElementFocusEventNoNone
inputSyncYesElementInputEventNoNone
keydownSyncYesElementKeyboardEventYesVaries: - beforeinput and input events; - launch text composition system; - blur and focus events; - keypress event; - activation behavior; - other event
keyupSyncYesElementKeyboardEventYesNone
loadAsyncNoWindow, Document, ElementEventNoNone
mousedownSyncYesElementMouseEventYesVaries: start a drag/drop operation; start a text selection; start a scroll/pan interaction (in combination with the middle mouse button, if supported)
mouseenterSyncNoElementMouseEventNoNone
mouseleaveSyncNoElementMouseEventNoNone
mousemoveSyncYesElementMouseEventYesNone
mouseoutSyncYesElementMouseEventYesNone
mouseoverSyncYesElementMouseEventYesNone
mouseupSyncYesElementMouseEventYesInvoke a context menu (in combination with the right mouse button, if supported)
resizeSyncNoWindow, ElementUIEventNoNone
scrollAsyncNo / YesDocument, ElementUIEventNoNone
selectSyncYesElementEventNoNone
unloadSyncNoWindow, Document, ElementEventNoNone
wheelAsyncYesElementWheelEventYesScroll (or zoom) the document
- -

For a list of events which are deprecated in this specification, see the Legacy Event Types appendix - at the end of this document.

- -
-
-

The following is one way to interpret the above tables: the load event will - trigger event listeners attached on Element nodes for that event and on the capture and target phases. This event is not cancelable. If an event listener for the - load event is attached to a node other than Window, - Document, or Element nodes, or if it is attached to the bubbling phase only, this event listener would not be triggered.

-
- -
Note

Note: Don't interpret the above tables as definitive for the listed event types. For example, the load event is used in other - specifications, for example, in XMLHttpRequest. Similarly, dispatchEvent can be used to dispatch untrusted events to - listeners on any object that also implements EventTarget.

- -
Note

Note: The event objects associated with the event types described above contain additional context information--refer to the description of the DOM - interfaces for further information.

-
- -
- - -
-

5. Event Types

-

The DOM Event Model allows a DOM implementation to support multiple modules of events. - The model has been designed to allow addition of new event modules in the future. - This document does not attempt to define all possible events. - For purposes of interoperability, the DOM defines a module of user interface events - including lower level device dependent events and a module of document mutation events. -

- -
-

5.1 User Interface Event Types

-

The User Interface event module contains basic event types associated with user - interfaces and document manipulation. -

- -
-

5.1.1 Interface UIEvent

- -

Introduced in DOM Level 2

- -

The UIEvent interface provides specific contextual information associated - with User Interface events. -

- -

To create an instance of the UIEvent interface, use the - DocumentEvent.createEvent("UIEvent") - method call. -

- -
[Constructor(DOMString type, optional UIEventInit eventInitDict)]
-interface UIEvent : Event {
-    readonly    attribute Window? view;
-    readonly    attribute long    detail;
-};
5.1.1.1 Attributes
detail of type long, readonly
-

Specifies some detail information about the Event, depending on the type of event.

- -

The un-initialized value of this attribute MUST be 0.

-
view of type Window, readonly , nullable
-

The view attribute identifies the Window from which the event was generated.

- -

The un-initialized value of this attribute MUST be null.

-
- -
dictionary UIEventInit : EventInit {
-    Window? view = null;
-    long    detail = 0;
-};
5.1.1.2 Dictionary UIEventInit Members
detail of type long, defaulting to 0
-

This value is initialized to a number that is application-specific. -

-
view of type Window, nullable, defaulting to null
-

Should be initialized to the Window object of the global environment - in which this event will be dispatched. If this event will be dispatched - to an element, the view property should be set to the Window object - containing the element's ownerDocument. -

-
- -
- -

The User Interface event types are listed below. Some of these events use the - UIEvent interface if generated from a - user interface, but the Event interface - otherwise, as detailed in each event. -

- - -
-
-
load
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typeload
InterfaceUIEvent if generated from a user interface, Event otherwise.
Sync / AsyncAsync
BubblesNo
Trusted TargetsWindow, Document, Element
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when the DOM implementation finishes loading the resource (such as the document) - and any dependent resources (such as images, style sheets, or scripts). Dependent resources that fail to load MUST NOT prevent this event from firing if the resource - that loaded them is still accessible via the DOM. If this event type is dispatched, implementations are REQUIRED to dispatch this event at least on the Document - node.

- -
Note

Note: For legacy reasons, load events for resources inside - the document (e.g., images) do not include the Window in the propagation path in HTML implementations. See - [HTML5] for more information.

-
-
-
- - -
-
-
unload
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typeunload
InterfaceUIEvent if generated from a user interface, Event otherwise.
Sync / AsyncSync
BubblesNo
Trusted TargetsWindow, Document, Element
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when the DOM Implementation removes from the environment the resource (such - as the document) or any dependent resources (such as images, style sheets, scripts). The document MUST be unloaded after the dispatch of this event type. If this - event type is dispatched, implementations are REQUIRED to dispatch this event at least on the Document node.

-
-
-
- - -
-
-
abort
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typeabort
InterfaceUIEvent if generated from a user interface, Event otherwise.
Sync / AsyncSync
BubblesNo
Trusted TargetsWindow, Element
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when the loading of a resource has been aborted, such as by a user canceling - the load while it is still in progress.

-
-
-
- - -
-
-
error
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typeerror
InterfaceUIEvent if generated from a user interface, Event otherwise.
Sync / AsyncAsync
BubblesNo
Trusted TargetsWindow, Element
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a resource failed to load, or has been loaded but cannot be interpreted - according to its semantics, such as an invalid image, a script execution error, or non-well-formed XML.

-
-
-
- - -
-
-
select
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typeselect
InterfaceUIEvent if generated from a user interface, Event otherwise.
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a user selects some text. This event is dispatched after the selection - has occurred.

- -

This specification does not provide contextual information to access the selected text. Where applicable, a host - language SHOULD define rules for how a user MAY select content (with consideration for international language conventions), at what point the select event is dispatched, and how a content author MAY access the user-selected content.

- -
Note

Note: In order to access to user-selected content, content authors will use native capabilities of the host languages, such as the Document.getSelection() method of the - HTML Editing APIs [HTML Editing].

- -
Note

Note: The select event might not be available - for all elements in all languages. For example, in [HTML5], - select events can be dispatched only on form input and textarea elements. Implementations can dispatch select events in any context deemed appropriate, including text selections outside of form controls, or image or - markup selections such as in SVG.

-
-
-
- - -
-
-
resize
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typeresize
InterfaceUIEvent
Sync / AsyncSync
BubblesNo
Trusted TargetsWindow, Element
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a document view has been resized. This event type is dispatched after - all effects for that occurrence of resizing of that particular event target have been executed by the user agent.

- -

User agents which support continuous reflow of the document's layout during user-initiated resizing MUST dispatch - this event synchronously after each reflow of the document.

- -

The Window object SHOULD always be resizable. A - host language MAY define certain elements to be resizable, and under what conditions (e.g., specific elements like <iframe>, or elements - with particular characteristics like width and height). However, this specification does not define the behavior for elements.

- -
Note

Note: The resize event is distinct from the - SVG zoom event types, though both can occur at the same time, or as the consequence of the same user action. In particular, browser - font zooming or page zooming will not necessarily trigger a resize event.

- -
Note

Note: In previous DOM Events specifications, the resize - event type was defined to have a bubbling phase, but for performance reasons, this was not implemented in most - user agents, and this specification removes the bubbling phase for this event.

-
-
-
- - -
-
-
scroll
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typescroll
InterfaceUIEvent
Sync / AsyncAsync
BubblesNo / Yes
Trusted TargetsDocument, Element
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a document view or an element has been scrolled. This event type is dispatched - after the scroll has occurred.

- -

When dispatched on the Document element, this event type MUST - bubble to the Window object.

-
-
-
-
- -
-

5.2 Focus Event Types

- -
Note

Note: - This interface and its associated event types and - focus event order - were designed in accordance to the concepts and guidelines defined in - User Agent Accessibility Guidelines 2.0 - [UAAG 2.0], - with particular attention on the - focus mechanism - and the terms defined in the - glossary entry for focus. -

- -
-

5.2.1 Interface FocusEvent

- -

Introduced in this specification

- -

The FocusEvent interface provides specific contextual information associated - with Focus events. -

- -

To create an instance of the FocusEvent interface, use the - DocumentEvent.createEvent("FocusEvent") - method call. -

- -
[Constructor(DOMString typeArg, optional FocusEventInit focusEventInitDict)]
-interface FocusEvent : UIEvent {
-    readonly    attribute EventTarget? relatedTarget;
-};
5.2.1.1 Attributes
relatedTarget of type EventTarget, readonly , nullable
-

Used to identify a secondary EventTarget - related to a Focus event, depending on the type of event. -

- -

For security reasons with nested browsing contexts, when tabbing into or out of a nested - context, the relevant EventTarget SHOULD be null. -

- -

The un-initialized value of this - attribute MUST be null. -

-
- -
dictionary FocusEventInit : UIEventInit {
-    EventTarget? relatedTarget = null;
-};
5.2.1.2 Dictionary FocusEventInit Members
relatedTarget of type EventTarget, nullable, defaulting to null
-

The relatedTarget should be initialized to the element - whose bounds the mouse pointer just left (in the case of a - mouseover or mouseenter event) or the element - whose bounds the mouse pointer is entering (in the case of a - mouseout or mouseleave - or focusout event). For other events, this value need not - be assigned (and will default to null). -

-
- -
- -
-

5.2.2 Focus Event Order

-

- The focus events defined in this specification occur in a set order relative to one another. The following is the typical sequence of events when a focus is shifted - between elements (this order assumes that no element is initially focused):

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameNotes
User shifts focus
1.focusinSent before first target element receives focus
2.focusSent after first target element receives focus
User shifts focus
3.focusoutSent before first target element loses focus
4.focusinSent before second target element receives focus
5.blurSent after first target element loses focus
6.focusSent after second target element receives focus
- -
Note

Note: This specification does not define the behavior of focus events when interacting with methods such as focus() or - blur(). See the relevant specifications where those methods are defined for such behavior.

-
- -
-

5.2.3 Document Focus and Focus Context

- -

This event module includes event types for notification of changes in document - focus. - There are three distinct focus contexts that are relevant to this discussion: -

- -
    -
  • The operating system focus context which MAY be on one of many different applications currently - running on the computer. One of these applications with focus can be a browser. -
  • -
  • When the browser has focus, the user can switch (such as with the tab key) the - application focus context among the different browser user interface fields (e.g., the - Web site location bar, a search field, etc.). One of these user interface fields can be the - document being shown in a tab. -
  • -
  • When the document itself has focus, the document focus context can be set to any of the - focusable elements in the document. -
  • -
- -

The event types defined in this specification deal exclusively with document focus, and the - event target identified in the event details - MUST only be part of the document or documents in the window, never a part of the browser or - operating system, even when switching from one focus context to another. -

- -

Normally, a document always has a focused element (even if it is the document element itself) and a persistent focus - ring. When switching between focus contexts, the document's currently focused element and focus ring normally remain in their current state. For example, - if a document has three focusable elements, with the second element focused, when a user changes operating system focus to another application and then back to - the browser, the second element will still be focused within the document, and tabbing will change the focus to the third element. A - host language MAY define specific elements which might receive focus, the conditions under which an element MAY receive focus, the means by which - focus MAY be changed, and the order in which the focus changes. For example, in some cases an element might be given focus by moving a pointer over it, while other - circumstances might require a mouse click. Some elements might not be focusable at all, and some might be focusable only by special means (clicking on the element), - but not by tabbing to it. Documents MAY contain multiple focus rings. Other specifications MAY define a more complex focus model than is described in this specification, - including allowing multiple elements to have the current focus. -

-
- -

The Focus event types are listed below.

- - -
-
-
blur
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typeblur
InterfaceFocusEvent
Sync / AsyncSync
BubblesNo
Trusted TargetsWindow, Element
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when an event target loses - focus. The focus MUST be taken from the element before the dispatch of this event type. This event type is similar to - focusout, but is dispatched after focus is shifted, and does not bubble.

-
-
-
- - -
-
-
focus
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typefocus
InterfaceFocusEvent
Sync / AsyncSync
BubblesNo
Trusted TargetsWindow, Element
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when an event target receives - focus. The focus MUST be given to the element before the dispatch of this event type. This event type is similar to - focusin, but is dispatched after focus is shifted, and does not bubble.

-
-
-
- - -
-
-
focusin
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typefocusin
InterfaceFocusEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsWindow, Element
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when an event target is about - to receive focus. This event type MUST be dispatched before the element is given focus. The event target MUST - be the element which is about to receive focus. This event type is similar to focus, but is dispatched - before focus is shifted, and does bubble.

- -
Note

Note: When using this event type, the content author can use the event's - FocusEvent.relatedTarget attribute (or a host-language-specific method or means) to get the currently focused element before the focus shifts to the - next focus event target, thus having access to both the element losing focus and the element gaining focus - without the use of the blur or focusout event - types.

-
-
-
- - -
-
-
focusout
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typefocusout
InterfaceFocusEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsWindow, Element
CancelableNo
Default actionNone
Context
(trusted events)
- -
-

A user agent MUST dispatch this event when an event target is about - to lose focus. This event type MUST be dispatched before the element loses focus. The event target MUST be the - element which is about to lose focus. This event type is similar to blur, but is dispatched before - focus is shifted, and does bubble.

-
-
-
-
- -
-

5.3 Mouse Event Types

- -

The mouse event module originates from the [HTML 4.01] onclick, ondblclick, - onmousedown, onmouseup, onmouseover, onmousemove, and onmouseout attributes. This event module - is specifically designed for use with pointing input devices, such as a mouse or a trackball.

- -
-

5.3.1 Interface MouseEvent

- -

Introduced in DOM Level 2, modified in this specification

- -

The MouseEvent interface provides specific contextual information - associated with Mouse events. -

- -

In the case of nested elements, mouse events are always targeted at the most deeply - nested element. -

- -
Note

Note: - Ancestors of the targeted element can use event bubbling to obtain notifications - of mouse events which occur within their descendent elements. -

- -

To create an instance of the MouseEvent interface, use the - DocumentEvent.createEvent("MouseEvent") - method call. -

- -
Note

Note: - When initializing MouseEvent objects using initMouseEvent, - implementations can use the client coordinates clientX and clientY - for calculation of other coordinates (such as target coordinates exposed by - DOM Level 0 - implementations or other proprietary attributes, e.g., pageX). -

- -
[Constructor(DOMString typeArg, optional MouseEventInit mouseEventInitDict)]
-interface MouseEvent : UIEvent {
-    readonly    attribute long           screenX;
-    readonly    attribute long           screenY;
-    readonly    attribute long           clientX;
-    readonly    attribute long           clientY;
-    readonly    attribute boolean        ctrlKey;
-    readonly    attribute boolean        shiftKey;
-    readonly    attribute boolean        altKey;
-    readonly    attribute boolean        metaKey;
-    readonly    attribute short          button;
-    readonly    attribute EventTarget?   relatedTarget;
-    // Introduced in this specification
-    readonly    attribute unsigned short buttons;
-    boolean getModifierState (DOMString keyArg);
-};
5.3.1.1 Attributes
altKey of type boolean, readonly
-

Refer to the KeyboardEvent.altKey attribute.

- -

The un-initialized value - of this attribute MUST be false. -

-
button of type short, readonly
-

During mouse events caused by the depression or release of a mouse button, - button MUST be used to indicate which pointer device button - changed state. -

- -

The value of the MouseEvent.button - attribute MUST be as follows: -

- -
    -
  • 0 MUST indicate the primary button of the device - (in general, the left button or the only button on single-button devices, - used to activate a user interface control or select text) or the - un-initialized value.
  • -
  • 1 MUST indicate the auxiliary button - (in general, the middle button, often combined with a mouse wheel).
  • -
  • 2 MUST indicate the secondary button - (in general, the right button, often used to display a context menu).
  • -
- -

Some pointing devices provide or simulate more button states, and values higher than - 2 or lower than 0 MAY be used to represent such buttons. -

- -
Note

Note: - The value of button is not updated for events not caused by the - depression/release of a mouse button. - In these scenarios, take care not to interpret the value 0 as the - left button, but rather as the - un-initialized value. -

- -
Note

Authoring Note: - Some default actions related - to events such as mousedown and - mouseup depend on the specific mouse - button in use. -

- -

The un-initialized value - of this attribute MUST be 0. -

-
buttons of type unsigned short, readonly
-

During any mouse events, buttons MUST be used to indicate - which combination of mouse buttons are currently being pressed, - expressed as a bitmask. -

- -
Note

Note: - Though similarly named, the values for the buttons attribute - and the button - attribute are very different. - The value of button is assumed to be valid during - mousedown / - mouseup event handlers, - whereas the buttons attribute reflects the state of the - mouse's buttons for any trusted MouseEvent object - (while it is being dispatched), because it can represent the - "no button currently active" state (0). -

- -

The value of the MouseEvent.buttons - attribute MUST be as follows: -

- -
    -
  • 0 MUST indicate no button is currently active.
  • -
  • 1 MUST indicate the primary button of the device - (in general, the left button or the only button on single-button devices, - used to activate a user interface control or select text).
  • -
  • 2 MUST indicate the secondary button - (in general, the right button, often used to display a context menu), if present.
  • -
  • 4 MUST indicate the auxiliary button - (in general, the middle button, often combined with a mouse wheel).
  • -
- -

Some pointing devices provide or simulate more buttons. - To represent such buttons, the value MUST be doubled for each successive button - (in the binary series 8, 16, 32, ... ). -

- -
Note

Note: - Because the sum of any set of button values is a unique number, a content - author can use a bitwise operation to determine how many buttons are currently - being pressed and which buttons they are, for an arbitrary number of mouse buttons - on a device. - For example, the value 3 indicates that the left and right button are - currently both pressed, while the value 5 indicates that the left and - middle button are currently both pressed. -

- -
Note

Authoring Note: - Some default actions related - to events such as mousedown and - mouseup depend on the specific mouse button - in use. -

- -

The un-initialized value - of this attribute MUST be 0. -

-
clientX of type long, readonly
-

The horizontal coordinate at which the event occurred relative to the viewport - associated with the event. -

- -

The un-initialized value - of this attribute MUST be 0. -

-
clientY of type long, readonly
-

The vertical coordinate at which the event occurred relative to the viewport - associated with the event. -

- -

The un-initialized value - of this attribute MUST be 0. -

-
ctrlKey of type boolean, readonly
-

Refer to the KeyboardEvent.ctrlKey attribute.

- -

The un-initialized value - of this attribute MUST be false. -

-
metaKey of type boolean, readonly
-

Refer to the KeyboardEvent.metaKey attribute.

- -

The un-initialized value - of this attribute MUST be false. -

-
relatedTarget of type EventTarget, readonly , nullable
-

Used to identify a secondary EventTarget related to a UI event, depending on the type of event.

- -

The un-initialized value of this attribute MUST be null.

-
screenX of type long, readonly
-

The horizontal coordinate at which the event occurred relative to the origin - of the screen coordinate system. -

- -

The un-initialized value - of this attribute MUST be 0. -

-
screenY of type long, readonly
-

The vertical coordinate at which the event occurred relative to the origin - of the screen coordinate system. -

- -

The un-initialized value - of this attribute MUST be 0. -

-
shiftKey of type boolean, readonly
-

Refer to the KeyboardEvent.shiftKey attribute.

- -

The un-initialized value - of this attribute MUST be false. -

-
5.3.1.2 Methods
getModifierState
-

Introduced in this specification

- -

Queries the state of a modifier using a key value. - See Modifier keys for a list of valid (case-sensitive) arguments to this method. -

- -

Returns true if it is a modifier key and the modifier is activated, - false otherwise. -

- - -
ParameterTypeNullableOptionalDescription
keyArgDOMString -

Refer to the KeyboardEvent.getModifierState() method for a description of this parameter.

-
Return type: boolean
- -
dictionary MouseEventInit : EventModifierInit {
-    long           screenX = 0;
-    long           screenY = 0;
-    long           clientX = 0;
-    long           clientY = 0;
-    short          button = 0;
-    unsigned short buttons = 0;
-    EventTarget?   relatedTarget = null;
-};
5.3.1.3 Dictionary MouseEventInit Members
button of type short, defaulting to 0
-

Initializes the button attribute of the MouseEvent - object to a number representing the desired state of the button(s) - of the mouse. -

- -
Note

Note: - The value 0 is used to represent - the primary mouse button, 1 is used to represent the auxiliary/middle - mouse button, and 2 to represent the right mouse button. - Numbers greater than 2 are also possible, but are not specified - in this document. -

-
buttons of type unsigned short, defaulting to 0
-

Initializes the buttons attribute of the MouseEvent - object to a number representing one or more of the button(s) of the mouse - that are to be considered active. -

- -
Note

Note: - The buttons - attribute is a bit-field. If a mask value of 1 is true when applied to - the value of the bit field, then the primary mouse button is down. If a - mask value of 2 is true when applied to the value of the bit field, then - the right mouse button is down. If a mask value of 4 is true when applied - to the value of the bit field, then the auxiliary/middle button is down.

- -
-

In JavaScript, to initialize the - buttons attribute as if the right (2) and middle - button (4) were being pressed simultaneously, the buttons value - can be assigned as either:
- { buttons: 2 | 4 }
- or:
- { buttons: 6 } -

-
-
clientX of type long, defaulting to 0
-

See clientY (substituting "horizontal" for "vertical").

-
clientY of type long, defaulting to 0
-

Initializes the clientY attribute of the MouseEvent - object to the desired vertical position of the mouse pointer - relative to the client window of the user's browser. -

- -

Initializing the event object to the given mouse position must - not move the user's mouse pointer to the initialized position. -

-
relatedTarget of type EventTarget, nullable, defaulting to null
-

The relatedTarget should be initialized to the element - whose bounds the mouse pointer just left (in the case of a - mouseover or mouseenter event) or the element - whose bounds the mouse pointer is entering (in the case of a - mouseout or mouseleave - or focusout event). For other events, this value need not - be assigned (and will default to null). -

-
screenX of type long, defaulting to 0
-

See screenY (substituting "horizontal" for "veritcal").

-
screenY of type long, defaulting to 0
-

Initializes the screenY attribute of the MouseEvent - object to the desired vertical relative position of the mouse - pointer on the user's screen. -

- -

Initializing the event object to the given mouse position must - not move the user's mouse pointer to the initialized position. -

-
- -
- -

Implementations MUST maintain the current click count when generating mouse events. This MUST be a non-negative integer indicating - the number of consecutive clicks of a pointing device button within a specific time. The delay after which the count resets is specific to the - environment configuration.

- -
-

5.3.2 Event Modifier Initializers

- -

The MouseEvent and - KeyboardEvent interfaces share a set - of keyboard modifier attributes and support a mechanism for retrieving additional modifier - states. The following dictionary enables authors to initialize keyboard modifier - attributes of the MouseEvent and - KeyboardEvent interfaces, as well as - the additional modifier states queried via - KeyboardEvent.getModifierState(). - The steps for constructing events using this dictionary are defined in the - event constructors section.

- -
dictionary EventModifierInit : UIEventInit {
-    boolean ctrlKey = false;
-    boolean shiftKey = false;
-    boolean altKey = false;
-    boolean metaKey = false;
-    boolean modifierAltGraph = false;
-    boolean modifierCapsLock = false;
-    boolean modifierFn = false;
-    boolean modifierFnLock = false;
-    boolean modifierHyper = false;
-    boolean modifierNumLock = false;
-    boolean modifierOS = false;
-    boolean modifierScrollLock = false;
-    boolean modifierSuper = false;
-    boolean modifierSymbol = false;
-    boolean modifierSymbolLock = false;
-};
5.3.2.1 Dictionary EventModifierInit Members
altKey of type boolean, defaulting to false
-

Initializes the altKey attribute of the - MouseEvent or - KeyboardEvent - objects to true if the 'Alt' - (alternative) (or 'Option') key modifier - is to be considered active, false otherwise.

-

When true, implementations must also initialize the event object's key modifier - state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with the parameter 'Alt' must - return true.

-
ctrlKey of type boolean, defaulting to false
-

Initializes the altKey attribute of the - MouseEvent or - KeyboardEvent - objects to true if the 'Control' - (control) key modifier is to be considered active, - false otherwise.

-

When true, implementations must also initialize the event object's key modifier - state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with either the parameter 'Control' or - the parameter 'Accel' must return true.

-
metaKey of type boolean, defaulting to false
-

Initializes the metaKey attribute of the - MouseEvent or - KeyboardEvent - objects to true if the 'Meta' - key modifier is to be considered active, false otherwise.

-

When true, implementations must also initialize the event object's - key modifier state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with either the parameter 'Meta' or - the parameter 'Accel' must return true.

-
modifierAltGraph of type boolean, defaulting to false
-

Initializes the event object's key modifier state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with the parameter 'AltGraph' must - return true.

-
modifierCapsLock of type boolean, defaulting to false
-

Initializes the event object's key modifier state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with the parameter 'CapsLock' must - return true.

-
modifierFn of type boolean, defaulting to false
-

Initializes the event object's key modifier state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with the parameter 'Fn' must - return true.

-
modifierFnLock of type boolean, defaulting to false
-

Initializes the event object's key modifier state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with the parameter 'FnLock' must - return true.

-
modifierHyper of type boolean, defaulting to false
-

Initializes the event object's key modifier state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with the parameter 'Hyper' must - return true.

-
modifierNumLock of type boolean, defaulting to false
-

Initializes the event object's key modifier state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with the parameter 'NumLock' must - return true.

-
modifierOS of type boolean, defaulting to false
-

Initializes the event object's key modifier state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with the parameter 'OS' must - return true.

-
modifierScrollLock of type boolean, defaulting to false
-

Initializes the event object's key modifier state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with the parameter 'ScrollLock' must - return true.

-
modifierSuper of type boolean, defaulting to false
-

Initializes the event object's key modifier state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with the parameter 'Super' must - return true.

-
modifierSymbol of type boolean, defaulting to false
-

Initializes the event object's key modifier state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with the parameter 'Symbol' must - return true.

-
modifierSymbolLock of type boolean, defaulting to false
-

Initializes the event object's key modifier state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with the parameter 'SymbolLock' must - return true.

-
shiftKey of type boolean, defaulting to false
-

Initializes the shiftKey attribute of the - MouseEvent or - KeyboardEvent - objects to true if the 'Shift' - key modifier is to be considered active, false otherwise.

-

When true, implementations must also initialize the event object's key modifier - state such that calls to the - MouseEvent.getModifierState() or - KeyboardEvent.getModifierState() - when provided with the parameter 'Shift' must - return true.

-
-
- -
-

5.3.3 Mouse Event Order

- -

Certain mouse events defined in this specification MUST occur in a set order relative to one another. - The following shows the event sequence that MUST occur when a pointing - device's cursor is moved over an element:

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameElementNotes
1.mousemove
Pointing device is moved into element A...
2.mouseoverA
3.mouseenterA
4.mousemoveAMultiple events
Pointing device is moved out of element A...
5.mouseoutA
6.mouseleaveA
- -

When a pointing device is moved into an element A, and then into a nested element B - and then back out again, the following sequence of events MUST occur: -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameElementNotes
1.mousemove
Pointing device is moved into element A...
2.mouseoverA
3.mouseenterA
4.mousemoveAMultiple events
Pointing device is moved into nested element B...
5.mouseoutA
6.mouseoverB
7.mouseenterB
8.mousemoveBMultiple events
Pointing device is moved from element B into A...
9.mouseoutB
10.mouseleaveB
11.mouseoverA
12.mousemoveAMultiple events
Pointing device is moved out of element A...
13.mouseoutA
14.mouseleaveA
- -

Sometimes elements can be visually overlapped using CSS. In the following example, three elements - labeled A, B, and C all have the same dimensions and absolute position on a web page. - Element C is a child of B, and B is a child of A in the DOM: -

- -
- Graphical representation of three stacked elements all on top of each other. The bottom element is labeled A and the top element is C -
Fig. 3 Graphical representation of three stacked elements all on top of each other, with the pointing device moving over the stack.
-
- -

When the pointing device is moved from outside the element stack to the element labeled C and then moved - out again, the following series of events MUST occur:

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameElementNotes
1.mousemove
Pointing device is moved into element C, the topmost element in the stack
2.mouseoverC
3.mouseenterA
4.mouseenterB
5.mouseenterC
6.mousemoveCMultiple events
Pointing device is moved out of element C...
7.mouseoutC
8.mouseleaveC
9.mouseleaveB
10.mouseleaveA
- -
Note

Note: The mouseover/mouseout events are only fired once, while mouseenter/mouseleave - events are fired three times (once to each element).

- -

The following is the typical sequence of events when a button associated with a pointing device (e.g., a mouse button or trackpad) is pressed and released over - an element:

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameNotes
1.mousedown
2.mousemoveOPTIONAL, multiple events, some limits
3.mouseup
4.click
5.mousemoveOPTIONAL, multiple events, some limits
6.mousedown
7.mousemoveOPTIONAL, multiple events, some limits
8.mouseup
9.click
10.dblclick
- -
Note

Note: The lag time, degree, distance, and number of mousemove - events allowed between the mousedown and - mouseup events while still firing a click or dblclick event will be implementation-, device-, and platform-specific. This tolerance can aid users that have physical - disabilities like unsteady hands when these users interact with a pointing device.

- -

Each implementation will determine the appropriate hysteresis - tolerance, but in general SHOULD fire click - and dblclick events when the event target - of the associated mousedown and - mouseup events is the same element with no - mouseout or - mouseleave events intervening, and SHOULD - fire click and - dblclick events on the nearest common inclusive - ancestor when the associated mousedown and - mouseup event targets are different.

- -
-
-

If a mousedown event was targeted at an - HTML document's body element, and the corresponding - mouseup event was targeted at the - root element, then the - click event will be dispatched to the - root element, since it is the nearest common inclusive ancestor.

-
- -

If the event target (e.g. the target element) is removed from the DOM during the mouse events sequence, the remaining - events of the sequence MUST NOT be fired on that element.

- -
-
-

If the target element is removed from the DOM as the result of a - mousedown event, no events for that element will be dispatched for mouseup, - click, or dblclick, nor any default - activation events. However, the mouseup event will still be dispatched on the element that is exposed - to the mouse after the removal of the initial target element. Similarly, if the target element is removed from the DOM during the dispatch of a mouseup event, the click and subsequent events will - not be dispatched.

-
- -
- -

The Mouse event types are listed below. In the case of nested elements, mouse event types are always targeted at the most deeply nested element. Ancestors of the - targeted element MAY use bubbling to obtain notification of mouse events which occur within its descendent elements.

- - -
-
-
click
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typeclick
InterfaceMouseEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableYes
Default actionVaries
Context
(trusted events)
- -
- -

The click event type MUST be dispatched on the - topmost event target indicated by the pointer, when - the user presses down and releases the primary pointer button, - or otherwise activates the pointer in a manner that simulates such an action. - The actuation method of the mouse button depends upon the pointer device and the environment configuration, - e.g., it MAY depend on the screen location or the delay between the press and release of the pointing device button. -

- -

The click event should only be fired for the primary - pointer button (i.e., when MouseEvent.button value is 0, - MouseEvent.buttons value is 1). - Secondary buttons (like the middle or right button on a standard mouse) MUST NOT fire - click events. -

- -

The click event MAY be preceded by the mousedown - and mouseup events on the same element, disregarding changes between other node types (e.g., text - nodes). Depending upon the environment configuration, the click event MAY be dispatched if one or - more of the event types mouseover, mousemove, - and mouseout occur between the press and release of the pointing device button. The click event MAY also be followed by the dblclick - event.

- -
-
-

If a user mouses down on a text node child of a <p> element which has been styled with - a large line-height, shifts the mouse slightly such that it is no longer over an area containing text but is still within the containing block of that <p> - element (i.e., the pointer is between lines of the same text block, but not over the text node per se), then subsequently mouses up, this will likely still trigger - a click event (if it falls within the normal temporal hysteresis for a - click), since the user has stayed within the scope of the same element. Note that user-agent-generated mouse events are not dispatched on text nodes. -

-
- -

In addition to being associated with pointer devices, the click event type MUST be dispatched as - part of an element activation, as described in Activation triggers and behavior.

- -
Note

Note: For maximum accessibility, content authors are encouraged to use the - click event type when defining activation - behavior for custom controls, rather than other pointing-device event types such as - mousedown or - mouseup, which are more device-specific. - Though the click event type has its origins - in pointer devices (e.g., a mouse), subsequent implementation - enhancements have extended it beyond that association, and it can be considered a device-independent event - type for element activation. -

- -

The default action of the - click event type varies - based on the event target of the event and the value of the - MouseEvent.button - or MouseEvent.buttons attributes. - Typical default actions - of the click event type are as follows: -

- - -
-
-
- - -
-
-
dblclick
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typedblclick
InterfaceMouseEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableYes
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when the primary button - of a pointing device is clicked twice over an element. The definition of a double click depends on the environment - configuration, except that the event target MUST be the same between - mousedown, - mouseup, and - dblclick. - This event type MUST be dispatched after the event type - click - if a click and double click occur simultaneously, - and after the event type mouseup otherwise. -

- -

As with the click event, the dblclick event - should only be fired for the primary pointer button. - Secondary buttons MUST NOT fire dblclick events. -

- -
Note

Note: Canceling the - click event does not affect the firing - of a dblclick event. -

- -

As with the click event type, the - default action - of the dblclick event type varies based on the - event target of the event and the value of the - MouseEvent.button or - MouseEvent.buttons attributes. - Normally, the typical default actions of the - dblclick event type match those of the - click event type, with the following additional - behavior: -

- -
    -
  • If the event target is selectable, the default action MUST - be to select part or all of the selectable content. Subsequent clicks MAY select additional selectable portions of that content.
  • -
-
-
-
- - -
-
-
mousedown
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typemousedown
InterfaceMouseEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableYes
Default actionVaries: Start a drag/drop operation; start a text selection; start a scroll/pan interaction (in combination with the middle mouse button, if supported)
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a pointing device button is pressed over an element.

- -
Note

Note: Many implementations use the mousedown event to begin a variety of contextually dependent default actions. These default actions can be prevented if this event is canceled. Some of these default actions could include: beginning - a drag/drop interaction with an image or link, starting text selection, etc. Additionally, some implementations provide a mouse-driven panning feature that is activated when - the middle mouse button is pressed at the time the mousedown event is dispatched.

- -
-
-
- - -
-
-
mouseenter
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typemouseenter
InterfaceMouseEvent
Sync / AsyncSync
BubblesNo
Trusted TargetsElement
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a pointing device is moved onto the boundaries of an element or one of - its descendent elements. This event type is similar to mouseover, but differs in that it does - not bubble, and MUST NOT be dispatched when the pointer device moves from an element onto the boundaries of one of its descendent elements.

- -
Note

Note: There are similarities between this event type and the CSS :hover pseudo-class [CSS2.1]. See also the - mouseleave event type.

- -
-
-
- - -
-
-
mouseleave
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typemouseleave
InterfaceMouseEvent
Sync / AsyncSync
BubblesNo
Trusted TargetsElement
CancelableNo
Default actionNone
Context
(trusted events)
- -
-

A user agent MUST dispatch this event when a pointing device is moved off of the boundaries of an element and all - of its descendent elements. This event type is similar to mouseout, but differs in that does - not bubble, and that it MUST NOT be dispatched until the pointing device has left the boundaries of the element and the boundaries of all of its children.

- -
Note

Note: There are similarities between this event type and the CSS :hover pseudo-class [CSS2.1]. See also the - mouseenter event type.

-
-
-
- - -
-
-
mousemove
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typemousemove
InterfaceMouseEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableYes
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a pointing device is moved while it is over an element. The frequency - rate of events while the pointing device is moved is implementation-, device-, and platform-specific, but multiple consecutive - mousemove events SHOULD be fired for sustained pointer-device movement, rather than a single event for each instance of mouse movement. Implementations - are encouraged to determine the optimal frequency rate to balance responsiveness with performance. -

- -
Note

Authoring Note: In some implementation environments, such as a browser, mousemove events can continue - to fire if the user began a drag operation (e.g., a mouse button is pressed) and the pointing device has left the boundary of the user agent. -

- -
Note

Note: This event was formerly specified to be non-cancelable in DOM Level 2 Events - [DOM2 Events], but was changed to reflect existing interoperability between - user agents. -

-
-
-
- - -
-
-
mouseout
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typemouseout
InterfaceMouseEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableYes
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a pointing device is moved off of the boundaries of an element. This - event type is similar to mouseleave, but differs in that does bubble, and that it MUST be dispatched - when the pointer device moves from an element onto the boundaries of one of its descendent elements.

- -
Note

Note: See also the mouseover event type.

-
-
-
- - -
-
-
mouseover
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typemouseover
InterfaceMouseEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableYes
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a pointing device is moved onto the boundaries of an element. This event - type is similar to mouseenter, but differs in that it bubbles, and that it MUST be dispatched - when the pointer device moves onto the boundaries of an element whose ancestor element is the event target for - the same event listener instance.

- -
Note

Note: See also the mouseout event type.

-
-
-
- - -
-
-
mouseup
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typemouseup
InterfaceMouseEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableYes
Default actionInvoke a context menu (in combination with the right mouse button, if supported)
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a pointing device button is released over an element.

- -
Note

Note: Many implementations will invoke a context menu as the default action of this event if the right mouse button is being released.

- -
Note

Authoring Note: In some implementation environments, - such as a browser, a mouseup event - can be dispatched even if the pointing device has left the boundary of the user - agent, e.g., if the user began a drag operation with a mouse button pressed.

-
-
-
-
- -
-

5.4 Wheel Event Types

-

Wheels are devices that can be rotated in one or more spatial dimensions, and which can be associated with a pointer device. The coordinate system depends on the - environment configuration.

- -
-
-

The user's environment might be configured to associate vertical scrolling - with rotation along the y-axis, horizontal scrolling with rotation along - the x-axis, and zooming with rotation along the z-axis. -

-
- -

The deltaX, deltaY, and deltaZ attributes of - WheelEvent objects indicate a - measurement along their respective axes in units of pixels, lines, or pages. - The reported measurements are provided after an environment-specific algorithm - translates the actual rotation/movement of the wheel device into the appropriate - values and units. -

- -
Note

Authoring Note: - A user's environment settings can be customized to interpret actual rotation/movement - of a wheel device in different ways. - One movement of a common dented mouse wheel can produce a measurement of 162 pixels - (162 is just an example value, actual values can depend on the current screen - dimensions of the user-agent). - But a user can change their default environment settings to speed-up their mouse wheel, - increasing this number. - Furthermore, some mouse wheel software can support acceleration (the faster the wheel - is rotated/moved, the greater the delta of each measurement) or even sub-pixel rotation - measurements. - Because of this, authors can not assume a given rotation amount in one user agent will - produce the same delta value in all user agents. -

- -

The sign (positive or negative) of the values of the deltaX, deltaY, and deltaZ attributes - MUST be consistent between multiple dispatches of the - wheel event while the - motion of the actual wheel device is rotating/moving in the same direction. - If a user agent scrolls as the default action of the - wheel event then the sign - of the delta SHOULD be given by a right-hand coordinate system where positive X, - Y, and Z axes are directed towards the right-most edge, bottom-most edge, and farthest - depth (away from the user) of the document, respectively. -

- -
Note

Note: - Individual user agents can (depending on their environment and hardware configuration) - interpret the same physical user interaction on the wheel differently. - For example, a vertical swipe on the edge of a trackpad from top to bottom can be - interpreted as a wheel action intended to either scroll the - page down or to pan the page up (i.e., resulting in either a positive or negative - deltaY value respectively). -

- -
-

5.4.1 Interface WheelEvent

- -

Introduced in this specification

- -

The WheelEvent interface provides specific contextual information - associated with wheel - events. -

- -

To create an instance of the WheelEvent interface, use the - DocumentEvent.createEvent("WheelEvent") - method call. -

- -
[Constructor(DOMString typeArg, optional WheelEventInit wheelEventInitDict)]
-interface WheelEvent : MouseEvent {
-    // DeltaModeCode
-    const unsigned long DOM_DELTA_PIXEL = 0x00;
-    const unsigned long DOM_DELTA_LINE = 0x01;
-    const unsigned long DOM_DELTA_PAGE = 0x02;
-    readonly    attribute double        deltaX;
-    readonly    attribute double        deltaY;
-    readonly    attribute double        deltaZ;
-    readonly    attribute unsigned long deltaMode;
-};
5.4.1.1 Attributes
deltaMode of type unsigned long, readonly
-

The deltaMode attribute contains an indication of the units of measurement for the - delta values. - The default value is - DOM_DELTA_PIXEL - (pixels). -

- -

This attribute MUST be set to one of the DOM_DELTA constants to indicate the units of measurement - for the delta values. The precise measurement - is specific to device, operating system, and application configurations. -

- -

The un-initialized value of this attribute - MUST be 0. -

-
deltaX of type double, readonly
-

In user agents where the default action of the - wheel event is to scroll, - the value MUST be the measurement along the x-axis (in pixels, lines, or pages) to be scrolled - in the case where the event is not cancelled. Otherwise, this is an implementation-specific - measurement (in pixels, lines, or pages) of the movement of a wheel device around the x-axis. -

- -

The un-initialized value of this attribute - MUST be 0.0. -

-
deltaY of type double, readonly
-

In user agents where the default action of the - wheel event is to scroll, the value - MUST be the measurement along the y-axis (in pixels, lines, or pages) to be scrolled in the case - where the event is not cancelled. Otherwise, this is an implementation-specific - measurement (in pixels, lines, or pages) of the movement of a wheel device around the y-axis. -

- -

The un-initialized value of this attribute - MUST be 0.0. -

-
deltaZ of type double, readonly
-

In user agents where the default action of the - wheel event is to scroll, the value - MUST be the measurement along the z-axis (in pixels, lines, or pages) to be scrolled in the case - where the event is not cancelled. Otherwise, this is an implementation-specific - measurement (in pixels, lines, or pages) of the movement of a wheel device around the z-axis. -

- -

The un-initialized value of this attribute - MUST be 0.0. -

-
5.4.1.2 Constants
DOM_DELTA_LINE of type unsigned long
-

The units of measurement for the delta MUST be - individual lines of text. This is the case for many form controls. -

-
DOM_DELTA_PAGE of type unsigned long
-

The units of measurement for the delta MUST be - pages, either defined as a single screen or as a demarcated page. -

-
DOM_DELTA_PIXEL of type unsigned long
-

The units of measurement for the delta MUST be - pixels. This is the most typical case in most operating system and implementation - configurations. -

-
- -
dictionary WheelEventInit : MouseEventInit {
-    double        deltaX = 0.0;
-    double        deltaY = 0.0;
-    double        deltaZ = 0.0;
-    unsigned long deltaMode = 0;
-};
5.4.1.3 Dictionary WheelEventInit Members
deltaMode of type unsigned long, defaulting to 0
-

Initializes the deltaMode attribute on the WheelEvent - object to the enumerated values 0, 1, or 2, which represent the amount - of pixels scrolled - (DOM_DELTA_PIXEL), - lines scrolled - (DOM_DELTA_LINE), - or pages scrolled - (DOM_DELTA_PAGE) - if the rotation of the wheel would - have resulted in scrolling. -

-
deltaX of type double, defaulting to 0.0

See deltaZ attribute.

deltaY of type double, defaulting to 0.0

See deltaZ attribute.

deltaZ of type double, defaulting to 0.0
-

Initializes the deltaZ attribute of the WheelEvent object. - Relative positive values for this attribute (as well as the - deltaX and deltaY attributes) are given by - a right-hand coordinate system where the X, Y, and Z axes are - directed towards the right-most edge, bottom-most edge, and farthest - depth (away from the user) of the document, respectively. Negative - relative values are in the respective opposite directions. -

-
- -
- -

The Wheel event types are listed below.

- - -
-
-
wheel
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typewheel
InterfaceWheelEvent
Sync / AsyncAsync
BubblesYes
Trusted TargetsElement
CancelableYes
Default actionScroll (or zoom) the document
Context
(trusted events)
-
    -
  • Event.target: - topmost event target
  • -
  • UIEvent.view: - Window
  • -
  • UIEvent.detail: - 0
  • -
  • MouseEvent.screenX: - if the wheel is associated with a pointing device, the value based on the pointer position on the screen, otherwise 0
  • -
  • MouseEvent.screenY: - if the wheel is associated with a pointing device, the value based - on the pointer position on the screen, otherwise 0
  • -
  • MouseEvent.clientX: - if the wheel is associated with a pointing device, the value based - on the pointer position within the viewport, otherwise 0
  • -
  • MouseEvent.clientY : - if the wheel is associated with a pointing device, the value - based on the pointer position within the viewport, otherwise 0
  • -
  • MouseEvent.altKey: - true if 'Alt' - modifier was active, otherwise false
  • -
  • MouseEvent.ctrlKey: - true if 'Control' modifier was active, otherwise false
  • -
  • MouseEvent.shiftKey: - true if 'Shift' modifier was active, otherwise false
  • -
  • MouseEvent.metaKey: - true if 'Meta' modifier was active, otherwise false
  • -
  • MouseEvent.button: - if wheel is associated with a pointing device, value based on current button pressed, otherwise 0
  • -
  • MouseEvent.buttons: - if wheel is associated with a pointing device, value based on all buttons current depressed, 0 if no buttons pressed
  • -
  • MouseEvent.relatedTarget: - indicates the event target the pointing device is pointing at, if any.
  • -
  • WheelEvent.deltaX: - expected amount that the page will scroll along the x-axis according - to the deltaMode units; or an implemenation-specific value of movement of a wheel around the x-axis
  • -
  • WheelEvent.deltaY: - expected amount that the page will scroll along the y-axis according - to the deltaMode units; or an implemenation-specific value of movement of a wheel around the y-axis
  • -
  • WheelEvent.deltaZ: - expected amount that the page will scroll along the z-axis according - to the deltaMode units; or an implemenation-specific value of movement of a wheel around the z-axis
  • -
  • WheelEvent.deltaMode: - unit indicator (pixels, lines, or pages) for the deltaX, deltaY, and deltaZ attributes
  • -
-
- -

A user agent MUST dispatch this event when a mouse wheel has been rotated around any axis, or when an equivalent - input device (such as a mouse-ball, certain tablets or touchpads, etc.) has emulated such an action. Depending on the platform and input device, diagonal wheel - deltas MAY be delivered either as a single wheel event with multiple non-zero axes or as separate wheel - events for each non-zero axis.

- -

The typical default action of the wheel event - type is to scroll (or in some cases, zoom) the document by the indicated amount. If this event is canceled, the implementation MUST NOT scroll or zoom the document - (or perform whatever other implementation-specific default action is associated with this event type).

- -
Note

Note: In some user agents, or with some input devices, the speed that the wheel has been - turned can affect the delta values, with a faster speed producing a higher delta value.

-
-
-
-
- -
-

5.5 Keyboard Event Types

- -

Keyboard events are device dependent, i.e., they rely on the capabilities of the - input devices and how they are mapped in the operating systems. Refer to - Keyboard events and key values for more details, including - examples on how Keyboard Events are used in combination with Composition Events. - Depending on the - character generation device, keyboard events might not be generated. -

- -
Note

Authoring Note: - Keyboard events are only one modality of providing textual input. - For editing scenarios, consider also using the - InputEvent - as an alternate to (or in addition to) keyboard events. -

- -
-

5.5.1 Interface KeyboardEvent

- -

Introduced in this specification

- -

The KeyboardEvent interface - provides specific contextual information associated with keyboard devices. - Each keyboard event references a key using a value. - Keyboard events are commonly directed at the element that has the focus. -

- -

The KeyboardEvent interface - provides convenient attributes for some common modifiers keys: - KeyboardEvent.ctrlKey, - KeyboardEvent.shiftKey, - KeyboardEvent.altKey, - KeyboardEvent.metaKey. - These attributes are equivalent to using the method - KeyboardEvent.getModifierState(keyArg) - with - 'Control', - 'Shift', - 'Alt', or - 'Meta' - respectively. -

- -

To create an instance of the KeyboardEvent - interface, use the - DocumentEvent.createEvent("KeyboardEvent") - method call. -

- -
[Constructor(DOMString typeArg, optional KeyboardEventInit keyboardEventInitDict)]
-interface KeyboardEvent : UIEvent {
-    // KeyLocationCode
-    const unsigned long DOM_KEY_LOCATION_STANDARD = 0x00;
-    const unsigned long DOM_KEY_LOCATION_LEFT = 0x01;
-    const unsigned long DOM_KEY_LOCATION_RIGHT = 0x02;
-    const unsigned long DOM_KEY_LOCATION_NUMPAD = 0x03;
-    readonly    attribute DOMString     key;
-    readonly    attribute DOMString     code;
-    readonly    attribute unsigned long location;
-    readonly    attribute boolean       ctrlKey;
-    readonly    attribute boolean       shiftKey;
-    readonly    attribute boolean       altKey;
-    readonly    attribute boolean       metaKey;
-    readonly    attribute boolean       repeat;
-    readonly    attribute boolean       isComposing;
-    boolean getModifierState (DOMString keyArg);
-};
5.5.1.1 Attributes
altKey of type boolean, readonly
-

true if the 'Alt' (alternative) (or 'Option') key modifier was active.

- -

The un-initialized value of this attribute MUST be false.

-
code of type DOMString, readonly
-

code holds a string that identifies the physical key being pressed. - The value is not affected by the current keyboard layout or modifier state, so a particular - key will always return the same value. -

-

The un-initialized value of this attribute MUST be "" (the empty string).

-
ctrlKey of type boolean, readonly
-

true if the 'Control' (control) key modifier was active.

- -

The un-initialized value of this attribute MUST be false.

-
isComposing of type boolean, readonly
-

true if the key event occurs as part of a composition session, i.e., after a - compositionstart - event and before the corresponding - compositionend - event. -

- -

The un-initialized value of this - attribute MUST be false. -

-
key of type DOMString, readonly
-

key holds the key value of the key pressed. - If the value is has a printed representation, it MUST be a non-empty Unicode character - string, conforming to the algorithm for determining the key value defined in this specification. - If the value is a control key which has no printed representation, it MUST be one of the key values defined in the - key values set, as determined by the algorithm for determining the key value. Implementations that are - unable to identify a key MUST use the key value 'Unidentified'.

- -
Note

Note: The key attribute is not related to the legacy keyCode attribute and does not have the same set of values.

- -

The un-initialized value of this attribute MUST be "" (the empty string).

-
location of type unsigned long, readonly
-

The location attribute contains an indication of the location of the key on the device.

- -

This attribute MUST be set to one of the DOM_KEY_LOCATION constants to indicate the location of a key on the device. In case a DOM implementation wishes to provide a new location value, a - value different from the defined constant values MUST be used.

- -

The un-initialized value of this attribute MUST be 0.

-
metaKey of type boolean, readonly
-

true if the meta ('Meta') key modifier was active.

- -
Note

Note: The 'Command' ('⌘') key modifier on Macintosh systems is represented using this key modifier.

- -

The un-initialized value of this attribute MUST be false.

-
repeat of type boolean, readonly
-

true if the key has been pressed in a sustained manner. Holding down a key MUST result in the repeating the events - keydown, - beforeinput, - input - in this order, at a rate determined by the system configuration. For mobile devices which have long-key-press - behavior, the first key event with a repeat attribute value of 'true' MUST serve as an - indication of a long-key-press. The length of time that the key MUST be pressed in order to begin repeating is configuration-dependent.

- -

The un-initialized value of this attribute MUST be false.

-
shiftKey of type boolean, readonly
-

true if the shift ('Shift') key modifier was active.

- -

The un-initialized value of this attribute MUST be false.

-
5.5.1.2 Methods
getModifierState
-

Queries the state of a modifier using a key value. - See Modifier keys for a list of valid (case-sensitive) arguments to this method. -

- - -
ParameterTypeNullableOptionalDescription
keyArgDOMString -

A modifier key value. Valid modifier keys are defined in the - Modifier Keys table in - [DOM3 key Values]. -

- -

Returns true if it is a modifier key and the modifier is activated, false otherwise.

- -
Note

Note: If an application wishes to distinguish between right and left modifiers, this information could be - deduced using keyboard events and KeyboardEvent.location.

-
Return type: boolean
5.5.1.3 Constants
DOM_KEY_LOCATION_LEFT of type unsigned long
-

The key activated originated from the left key location (when there is more than one possible location for this key).

- -
-
-

The left 'Control' key on a PC 101 Key US keyboard.

-
-
DOM_KEY_LOCATION_NUMPAD of type unsigned long
-

The key activation originated on the numeric keypad or with a virtual key corresponding to the numeric - keypad (when there is more than one possible location for this key). Note that the 'NumLock' - key should always be encoded with a location of - DOM_KEY_LOCATION_STANDARD. -

- -
-
-

The '1' key on a PC 101 Key US keyboard located on the numeric pad.

-
-
DOM_KEY_LOCATION_RIGHT of type unsigned long
-

The key activation originated from the right key location (when there is more than one possible location for this key).

- -
-
-

The right 'Shift' key on a PC 101 Key US keyboard.

-
-
DOM_KEY_LOCATION_STANDARD of type unsigned long
-

The key activation MUST NOT be distinguished as the left or right version of the key, and (other than the - 'NumLock' key) did not originate from the numeric keypad (or did not originate - with a virtual key corresponding to the numeric keypad).

- -
-
-

The 'Q' key on a PC 101 Key US keyboard.

-

The 'NumLock' key on a PC 101 Key US keyboard.

-

The '1' key on a PC 101 Key US keyboard located in the main section of the keyboard.

-
-
- -
dictionary KeyboardEventInit : EventModifierInit {
-    DOMString     key = "";
-    DOMString     code = "";
-    unsigned long location = 0;
-    boolean       repeat = false;
-    boolean       isComposing = false;
-};
5.5.1.4 Dictionary KeyboardEventInit Members
code of type DOMString, defaulting to ""
-

Initializes the code attribute of the KeyboardEvent - object to the unicode character string representing the key that - was pressed, ignoring any keyboard modifications such as keyboard - layout. - This value should be one of the code values defined in - [DOM3 code Values]. -

-
isComposing of type boolean, defaulting to false
-

Initializes the isComposing attribute of the KeyboardEvent - object. This attribute should be set to true if the - event being constructed occurs as part of a composition sequence, - false otherwise. -

-
key of type DOMString, defaulting to ""
-

Initializes the key attribute of the KeyboardEvent - object to the unicode character string representing the meaning of a - key after taking into account all keyboard modifications (such as - shift-state). This value is the final effective value of the key. - If the key is not a printable character, then it should be one of - the key values defined in - [DOM3 key Values]. -

-
location of type unsigned long, defaulting to 0
-

Initializes the location attribute of the KeyboardEvent - object to one of the following location numerical constants: -

-
    -
  • KeyboardEvent.DOM_KEY_LOCATION_STANDARD (numerical value 0)
  • -
  • KeyboardEvent.DOM_KEY_LOCATION_LEFT (numerical value 1)
  • -
  • KeyboardEvent.DOM_KEY_LOCATION_RIGHT (numerical value 2)
  • -
  • KeyboardEvent.DOM_KEY_LOCATION_NUMPAD (numerical value 3)
  • -
-
repeat of type boolean, defaulting to false
-

Initializes the repeat attribute of the KeyboardEvent - object. This attribute should be set to true if the the current KeyboardEvent is - considered part of a repeating sequence of similar events caused - by the long depression of any single key, false otherwise. -

-
- -
- -
Warning
-

Warning!

-

Legacy keyboard event implementations include three additional attributes, - keyCode, charCode, and which. - The keyCode attribute indicates a numeric value associated with - a particular key on a computer keyboard, - while the charCode attribute indicates the - ASCII - value of the character associated with that key (which might be the same as - the keyCode value) and is applicable only to keys that produce a - character value. -

-

In practice, keyCode and charCode are inconsistent across platforms - and even the same implementation on different operating systems or using different localizations. - This specification does not define values for either - keyCode or charCode, or behavior for charCode. - In conforming UI Events implementations, content authors can instead use - KeyboardEvent.key and - KeyboardEvent.code. -

-

For more information, see the informative appendix on - Legacy key attributes. -

-
- -
Note

Note: - For compatibility with existing content, virtual keyboards, such as software keyboards - on screen-based input devices, are expected to produce the normal range of keyboard - events, even though they do not possess physical keys. -

- -
Note

Note: - In some implementations or system configurations, some key events, or their values, - might be suppressed by the IME in use. -

- -
-

5.5.2 Keyboard Event Order

-

The keyboard events defined in this specification occur in a set order relative - to one another, for any given key:

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameNotes
1.keydown
2.beforeinput(only for keys which produce a character value)
Any default actions related to this key, such as inserting a - character in to the DOM.
3.input(only for keys which have updated the DOM)
Any events as a result of the key being held for a sustained period (see below).
4.keyup
- -

If the key is depressed for a sustained period, the following events MAY repeat - at an environment-dependent rate: -

- - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameNotes
1.keydown(with repeat attribute set to true)
2.beforeinput(only for keys which produce a character value)
Any default actions related to this key, such as inserting a - character in to the DOM.
3.input(only for keys which have updated the DOM)
- -
Note

Note: - Typically, any default actions - associated with any particular key are completed before the - keyup event is dispatched. - This might delay the keyup - event slightly (though this is not likely to be a perceptible delay). -

- -

The event target of a key event is - the currently focused element which is processing the keyboard activity. - This is often an HTML input element or a textual element which is editable, - but MAY be an element defined by the - host language to accept keyboard input - for non-text purposes, such as the activation of an accelerator key or trigger of some - other behavior. If no suitable element is in focus, the event target will be the HTML - body element if available, - otherwise the root element. -

- -
Note

Note: - The event target might change between - different key events. - For example, a keydown - event for the 'Tab' key - will likely have a different event target - than the keyup - event on the same keystroke. -

-
- -

The keyboard event types are listed below.

- - -
-
-
keydown
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typekeydown
InterfaceKeyboardEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableYes
Default actionVaries: - beforeinput and input events; - launch text composition system; - blur and focus events; - keypress event; - activation behavior; - other event
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a key is pressed down. The - keydown event type is device dependent and relies on the capabilities of the input devices and how they are mapped in the operating system. This - event type MUST be generated after the key mapping. - This event type MUST be dispatched before the - beforeinput, - input, - and keyup - events associated with the same key.

- -

The default action of the keydown event depends upon the key:

- -
    -
  • If the key is associated with a character, the default action MUST be to dispatch - a beforeinput event - followed by an input - event. - In the case where the key which is associated with multiple characters (such as with a macro or certain sequences of dead keys), the default action MUST - be to dispatch one set of - beforeinput / - input - events for each character
  • - -
  • If the key is associated with a text composition system, the default action MUST be to launch that - system
  • - -
  • If the key is the 'Tab' key, the default action MUST be to shift the document focus from the currently focused - element (if any) to the new focused element, as described in Focus Event Types
  • - -
  • If the key is the 'Enter' or ' ' key and the - current focus is on a state-changing element, the default action MUST be to dispatch a click event, - and a DOMActivate event if that event type is supported by the - user agent (refer to activation triggers and behavior for more details)
  • -
- -

If this event is canceled, the associated event types MUST NOT be dispatched, and the associated actions MUST NOT be performed.

- -
Note

Note: The keydown and - keyup events are traditionally associated with detecting any key, not just those which produce a character - value.

-
-
-
- - -
-
-
keyup
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typekeyup
InterfaceKeyboardEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableYes
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a key is released. - The keyup event type is device dependent and relies on the - capabilities of the input devices and how they are mapped in the operating system. - This event type MUST be generated after the key mapping. - This event type MUST be dispatched after the - keydown, - beforeinput, - and input - events associated with the same key.

- -
Note

Note: the keydown and - keyup events are traditionally associated with detecting any key, not just those which produce a character - value.

-
-
-
-
- -
-

5.6 Composition Event Types

- -

Composition Events provide a means for inputing text in a supplementary or alternate - manner than by Keyboard Events, in order to allow the use of characters that - might not be commonly available on keyboard. - For example, Composition Events might be used - to add accents to characters despite their absence from standard US keyboards, - to build up logograms of many Asian languages from their base components or categories, - to select word choices from a combination of key presses on a mobile device keyboard, - or to convert voice commands into text using a speech recognition processor. - Refer to Keyboard events and key values for examples - on how Composition Events are used in combination with keyboard events. -

- -

Conceptually, a composition session consists of one - compositionstart - event, one or more - compositionupdate - events, and one - compositionend - event, with the value of the data - attribute persisting between each stage of this event chain during each session. -

- -
Note

Note: - While a composition session is active, keyboard events can be dispatched to the DOM - if the keyboard is the input device used with the composition session. - See the compositionstart event details - and IME section for relevent event ordering. -

- -

Not all IME systems or devices expose the necessary - data to the DOM, so the active composition string (the Reading Window - or candidate selection menu option) might not be available through this interface, - in which case the selection MAY be represented by the - empty string. -

- -
-

5.6.1 Interface CompositionEvent

- -

Introduced in this specification

- -

The CompositionEvent interface provides specific contextual information associated with Composition Events.

- -

To create an instance of the CompositionEvent interface, use the DocumentEvent.createEvent("CompositionEvent") - method call.

- -
[Constructor(DOMString typeArg, optional CompositionEventInit compositionEventInitDict)]
-interface CompositionEvent : UIEvent {
-    readonly    attribute DOMString data;
-};
5.6.1.1 Attributes
data of type DOMString, readonly
-

data holds the value of the characters generated by an input method. - This MAY be a single Unicode character or a non-empty sequence of Unicode characters - [Unicode]. - Characters SHOULD be normalized as defined by the Unicode normalization form NFC, - defined in [UAX #15]. - This attribute MAY be the empty string. -

- -

The un-initialized value of this attribute - MUST be "" (the empty string). -

-
- -
dictionary CompositionEventInit : UIEventInit {
-    DOMString data = "";
-};
5.6.1.2 Dictionary CompositionEventInit Members
data of type DOMString, defaulting to ""
-

Initializes the data attribute of the CompositionEvent - object to the characters generated by the IME composition. -

-
- -
- -
-

5.6.2 Composition Event Order

- -

The Composition Events defined in this specification MUST occur in the following set order relative to one another:

- - - - - - - - - - - - - - - - - - - - - - -
Event NameNotes
1.compositionstart
2.compositionupdateMultiple events
3.compositionend
-
- -
-

5.6.3 Handwriting Recognition Systems

-

The following example describes a possible sequence of events when composing a text passage text with a handwriting recognition system, such as on a pen - tablet, as modeled using Composition Events.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameCompositionEvent
data
Notes
1.compositionstart''
User writes word on tablet surface
2.compositionupdate'test'
User rejects first word-match suggestion, selects different match
3.compositionupdate'text'
4.compositionend'text'
-
- -
-

5.6.4 Canceling Composition Events

-

If a keydown event is canceled then any - Composition Events that would have fired as a result of that - keydown SHOULD not be dispatched:

- - - - - - - - - - - - - - - - - - - - - - -
Event NameNotes
1.keydownThe default action is - prevented, e.g., by invoking Event.preventDefault(). -
No Composition Events are dispatched
2.keyup
- -

If the initial compositionstart event is - canceled then the text composition session SHOULD be terminated. Regardless of whether or not the composition - session is terminated, the compositionend - event MUST be sent.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameNotes
1.keydown
2.compositionstartThe default action is - prevented, e.g., by invoking Event.preventDefault(). -
No Composition Events are dispatched
3.compositionend
4.keyup
-
- -
-

5.6.5 Key Events During Composition

-

During the composition session, all keydown - and keyup events MAY be suppressed.

- -
-
5.6.5.1 Including Key Events During Composition
- -

If a user agent does not suppress these events during - composition, then it MUST set the key event's - isComposing - attribute to true for any events that occur during a composition session. -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
isComposing
Notes
1.keydownfalseThis is the key event that initiates the composition.
2.compositionstart
3.compositionupdate
4.keyuptrue
...Any key events sent during the composition session MUST have isComposing set to true.
5.keydowntrueThis is the key event that exits the composition.
6.compositionend
7.keyupfalse
- -
- -
-
5.6.5.2 Suppressing Key Events During Composition
- -

If key events are suppressed between - compositionstart and - compositionend, then the first - or last key pressed might result in unmatched - keydown and - keyup events. - If a user agent suppresses key events during composition, - then it MUST ensure that all keydown and - keyup events occur in matching pairs. -

- -

To ensure that the initial keydown has a - matching keyup, a - user agent might insert an extra - keyup to match the - keydown that initiated a composition session, - as shown in the following example: -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
isComposing
Notes
1.keydownfalseThis is the key event that initiates the composition.
2.compositionstart
3.compositionupdate
4.keyuptrueThis event would normally be suppressed because of the ongoing composition session, but it is sent - to match the previously sent keydown - event.
...Any other key events that occur during the composition session are suppressed.
5.compositionend
- -

To ensure that the composition session doesn't end with a dangling - keyup event, a - user agent can choose either (A) to suppress this - keyup event, or (B) to insert an extra - keydown event.

- -

An example event sequence where both the - keydown and - keyup events have - been suppressed:

- - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
isComposing
Notes
keydown for key that exits IME suppressed - during composition session
1.compositionend
A keyup event would normally be sent - at this time, but it is suppressed to avoid generating an unmatched - keyup event.
- -

An example event sequence where a keydown has been inserted: -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
isComposing
Notes
keydown for key that exits IME suppressed - during composition session
1.compositionend
2.keydownfalseThis is key event that was suppressed earlier. It is sent now to match the upcoming - keyup.
3.keyupfalse
- -
- -
- -
-

5.6.6 Composition Event Types

-

The composition event types are listed below.

- - -
-
-
compositionstart
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typecompositionstart
InterfaceCompositionEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableYes
Default actionStart a new composition session when a text composition system is enabled
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a text composition - system is enabled and a new composition session is about to begin (or has begun, depending on the text composition - system) in preparation for composing a passage of text. This event type is device-dependent, and MAY rely upon the capabilities of the text conversion system and how it is - mapped into the operating system. When a keyboard is used to feed an input method editor, this event type is generated after a keydown event, - but speech or handwriting recognition systems MAY send this event type without keyboard events. Some implementations MAY populate the - data attribute of the compositionstart event - with the text currently selected in the document (for editing and replacement). Otherwise, the value of the data - attribute MUST be the empty string.

- -

This event MUST be dispatched immediately before a text composition system begins a new composition session, and - before the DOM is modified due to the composition process. The default action of this event is for the text - composition system to start a new composition session. If this event is canceled, the text composition system SHOULD - discard the current composition session.

- -
Note

Note: Canceling the compositionstart event type is distinct - from canceling the text composition system itself (e.g., by hitting a cancel button or closing an IME window).

- -
Note

Note: Some IMEs do not support cancelling an in-progress composition session (e.g., such as GTK which doesn't presently have such an API). In these - cases, calling preventDefault will not stop this event's default action.

-
-
-
- - -
-
-
compositionupdate
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typecompositionupdate
InterfaceCompositionEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableNo
Default actionNone
Context
(trusted events)
- -
-

A user agent SHOULD dispatch this event during a composition session when a - text composition system updates its active text passage with a - new character, which is reflected in the string in CompositionEvent.data. -

- -

In text composition systems which keep the ongoing composition in sync - with the input control, the compositionupdate event - MUST be dispatched before the control is updated. -

- -

Some text composition systems might not expose this information to the DOM, - in which case this event will not fire during the composition process. -

- -

If the composition session is canceled, this event will be fired immediately before the - compositionend event, - and the CompositionEvent.data attribute will be set to the - empty string. -

-
-
-
- - -
-
-
compositionend
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typecompositionend
InterfaceCompositionEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableNo
Default actionNone
Context
(trusted events)
- -
-

A user agent MUST dispatch this event when a - text composition system completes or cancels the current composition session, - and the compositionend event MUST be dispatched after the control is updated. -

- -

This event is dispatched immediately after the text composition system completes - the composition session (e.g., the IME is closed, minimized, switched out of focus, or otherwise dismissed, - and the focus switched back to the user agent). -

-
-
-
-
-
- -
- - -
-

6. Keyboard events and key values

- -

This section contains necessary information regarding keyboard events:

- - - -
Note

Note: This section uses Serbian and Kanji characters which could - be misrepresented or unavailable in the PDF version or printed version of this specification. -

- -
-

6.1 Keyboard Input

- -

This section is informative

- -

The relationship of each key to the complete keyboard has three separate aspects, - each of which vary among different models and configurations of keyboards, particularly - for locale-specific reasons: -

- - - -

This specification only defines the functional mapping, in terms of - key values and - code values, - but briefly describes - key legends - for background. -

- -
-

6.1.1 Key Legends

- -

This section is informative

- -

The key legend is the visual marking that is printed or embossed on the key cap (the rectangular - 'cap' that covers the mechanical switch for the key). - These markings normally consist of one or more characters that a keystroke on that key - will produce (such as - 'F', - '8', or - 'ш'), - or names or symbols which indicate that key's function (such as an upward-pointing arrow - indicating 'Shift', - or the string 'Enter'). - Keys are often referred to by this marking - (e.g., Press the 'Shift' and 'F' keys.). - Note, however, that the visual appearance of the key has no bearing on its digital representation, - and in many configurations may be completely inaccurate. - Even the control and function keys, such as 'Enter', MAY be mapped to different - functionality, or even mapped as character keys. -

- -

For historical reasons, the character keys are typically marked with the capital-letter equivalents - of the character value they produce, e.g., the 'F' key (the key marked with the glyph - 'F'), will produce the character value 'f' when - pressed without an active modifier key ('Shift') or modifier state - ('CapsLock'). -

- -
Note

Note: - Many keyboards contain keys that do not normally produce any characters, even though the symbol might - have a Unicode equivalent. - For example, the 'Shift' key might bear the symbol - , which has the - Unicode code point '\u21E7', - but pressing the 'Shift' key will not produce this character value, and - there is no Unicode code point for - 'Shift'. -

-
- -
- -
-

6.2 Key codes

- -

A key code is an attribute of a keyboard event that can be used to identify the physical - key associated with the keyboard event. It is similar to USB Usage IDs in that it provides - a low-level value (similar to a scancode) that is vendor-neutral. -

- -

The primary purpose of the code attribute is to provide a consistent and coherent way - to identify keys based on their physical location. In addition, it also provides a stable name - (unaffected by the current keyboard state) that uniquely identifies each key on the keyboard. -

- -

The list of valid code values is defined in the - DOM Level 3 KeyboardEvent code Values Specification [DOM3 code Values]. -

- -
-

6.2.1 Motivation for Adding the code Attribute

- -

The standard PC keyboard has a set of keys (which - we refer to as writing system keys) - that generate different key values - based on the current keyboard layout selected by the user. - This situation makes it difficult to write code that detects keys based on their physical - location since the code would need to know which layout is in effect in order to know which - key values to check for. - A real-world example of this is a game that wants to use the - 'W', - 'A', - 'S' and - 'D' - keys to control player movement. - The code attribute solves this problem by providing - a stable value to check that is not affected by the current keyboard layout. -

- -

In addition, the values in the key attribute depend as well - on the current keyboard state. - Because of this, the order in which keys are pressed and released in relation to modifier keys - can affect the values stored in the key attribute. - The code attribute solves this problem by providing - a stable value that is not affected by the current keyboard state. -

-
- -
-

6.2.2 The Relationship Between key and code

-
-
key
-
The key attribute is intended for users who are interested in the meaning of the key - being pressed, taking into account the current keyboard layout (and IME; dead keys - are given a unique key value). - Example use case: Detecting modified keys or bare modifier keys (e.g., to perform an action in - response to a keyboard shortcut).
- -
code
-
The code attribute is intended for users who are interested in the key that was pressed - by the user, without any layout modifications applied. - Example use case: Detecting WASD keys (e.g., for movement controls in a game) or trapping all keys - (e.g., in a remote desktop client to send all keys to the remote host). -
-
-
- -
-

6.2.3 code Examples

-
-
-

Handling the Left and Right Alt Keys

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Keyboard LayoutKeyboardEvent
key
KeyboardEvent
code
Notes
US'Alt''AltLeft'DOM_KEY_LOCATION_LEFT
French'Alt''AltLeft'DOM_KEY_LOCATION_LEFT
US'Alt''AltRight'DOM_KEY_LOCATION_RIGHT
French'AltGr''AltRight'DOM_KEY_LOCATION_RIGHT
-

In this example, checking the key attribute permits matching 'Alt' without worrying about which Alt key (left or right) was pressed. - Checking the code attribute permits matching the right Alt key ('AltRight') without worrying about which layout is currently in effect. -

-

Note that, in the French example, the 'Alt' and - 'AltGr' keys retain their left and right location, even through there - is only one of each key. -

-
- -
-
-

Handling the Single Quote Key

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Keyboard LayoutKeyboardEvent
key
KeyboardEvent
code
Notes
US''''Quote'
Japanese':''Quote'
US Intl'Dead''Quote'
-

This example shows how dead key values are encoded in the attributes. The - key values vary based on the current locale, whereas the code attribute - returns a consistent value. -

-
- -
-
-

Handling the '2' Key (with and without Shift pressed)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Keyboard LayoutKeyboardEvent
key
KeyboardEvent
code
Notes
US'2''Digit2'
US'@''Digit2'shiftKey
UK'2''Digit2'
UK'"''Digit2'shiftKey
French'é''Digit2'
French'2''Digit2'shiftKey
-

Regardless of the current locale or the modifier key state, pressing the key labelled '2' - on a US keyboard always results in 'Digit2' in the code attribute. -

-
- -
-
-

Sequence of Keyboard Events : 'Shift' and '2'

-

Compare the attribute values in the following two key event sequences. They both produce the - '@' character on a US keyboard, but differ in the order in which the - keys are released. In the first sequence, the order is: - 'Shift' (down), - '2' (down), - '2' (up), - 'Shift' (up). -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboard LayoutKeyboardEvent
key
KeyboardEvent
code
Notes
1.keydownUS'Shift''ShiftLeft'DOM_KEY_LOCATION_LEFT
2.keydownUS'@''Digit2'shiftKey
3.keypressUS'@'''
4.keyupUS'@''Digit2'shiftKey
5.keyupUS'Shift''ShiftLeft'DOM_KEY_LOCATION_LEFT
-

In the second sequence, the Shift is released before the 2, resulting in the following event order: - 'Shift' (down), - '2' (down), - 'Shift' (up), - '2' (up). -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboard LayoutKeyboardEvent
key
KeyboardEvent
code
Notes
1.keydownUS'Shift''ShiftLeft'DOM_KEY_LOCATION_LEFT
2.keydownUS'@''Digit2'shiftKey
3.keypressUS'@'''
4.keyupUS'Shift''ShiftLeft'DOM_KEY_LOCATION_LEFT
5.keyupUS'2''Digit2'
-

Note that the values contained in the key attribute does not match between - the keydown and keyup events for the '2' key. The code attribute provides a consistent value - that is not affected by the current modifier state. -

-
-
- -
-

6.2.4 code and Virtual Keyboards

-

The usefulness of the code attribute is less obvious for virtual keyboards (and also - for remote controls and chording keyboards). - In general, if a virtual (or remote control) keyboard is mimicking the layout and functionality - of a standard keyboard, then it MUST also set the code attribute as appropriate. - For keyboards which are not mimicking the layout of a standard keyboard, then the code - attribute MAY be set to the closest match on a standard keyboard or it MAY be left undefined. -

-

For virtual keyboards with keys that produce different values based on some modifier state, - the code value should be the key value - generated when the button is pressed while the device is in its factory-reset state. -

-
- -
- -
-

6.3 Keyboard Event key Values

- -

A key value is a DOMString that can be used to indicate any given key on a keyboard, regardless of position or state, by the value it produces. These - key values MAY be used as return values for keyboard events generated by the implementation, or as input values by the content author to specify desired input (such - as for keyboard shortcuts). -

- -

The list of valid key values is defined in the - DOM Level 3 KeyboardEvent key Values Specification [DOM3 key Values]. -

- -

Key values can be used to detect the value of a key which has been pressed, using the KeyboardEvent.key - attribute. Content authors can retrieve the - character value of upper- or lower-case letters, number, symbols, or other character-producing keys, and also the key - value of control keys, modifier keys, function keys, or other keys that do not generate characters. These values can be used for monitoring particular - input strings, for detecting and acting on modifier key input in combination with other inputs (such as a mouse), for creating virtual keyboards, or for any number - of other purposes.

- -

Key values can also be used by content authors in string comparisons, as values for markup attributes (such as the HTML accesskey) in conforming host languages, or for other related purposes. A conforming host language - SHOULD allow content authors to use either of the two equivalent string values for a key value: the character value, - or the key value.

- -
Note

Note: While implementations will use the most relevant value for a key independently of the platform or keyboard layout mappings, - content authors can not make assumptions on the ability of keyboard devices to generate them. When using keyboard events and key values for shortcut-key combinations, - content authors can consider using numbers and function keys (F4, F5, and so on) instead of letters ([DWW95]) - given that most keyboard layouts will provide keys for those.

- -

A key value does not indicate a specific key on the physical keyboard, nor does it reflect the character printed on the key. A key - value indicates the current value of the event with consideration to the current state of all active keys and key input modes - (including shift modes), as reflected in the operating-system mapping of the keyboard and reported to the implementation. In other - words, the key value for the key marked 'O' on a QWERTY keyboard - has the key value 'o' in an unshifted state and 'O' in a shifted state. - Because a user can map their keyboard to an arbitrary custom configuration, the content author is encouraged not to assume that a - relationship exists between the shifted and unshifted states of a key and the majuscule form (uppercase or capital letters) - and minuscule form (lowercase or small letters) of a character representation, but is encouraged instead to use the value of the - KeyboardEvent.key attribute. For example, the Standard "102" Keyboard layout - depicted in [DOM3 code Values] illustrates one possible set of - key mappings on one possible keyboard layout. Many others exist, both standard and - idiosyncratic.

- -
Note

Note: To simplify dead key support, when the operating-system - mapping of the keyboard is handling a dead key state, the current state of the dead - key sequence is not reported via the KeyboardEvent.key attribute. Rather, a key value of - 'Dead' is reported. Instead, implementations generate composition events - which contain the intermediate state of the dead key sequence reported via the - CompositionEvent.data attribute. As in the previous example, the key value for - the key marked 'O' on a QWERTY keyboard has a - CompositionEvent.data value of 'ö' in an unshifted - state during a dead-key operation to add an umlaut diacritic, and 'Ö' in a shifted state during a dead-key - operation to add an umlaut diacritic.

- -

It is also important to note that there is not a one-to-one relationship between key event states and key values. A particular key value might be associated with - multiple keys. For example, many standard keyboards contain more than one key with the 'Shift' key value (normally distinguished by the - KeyboardEvent.location values DOM_KEY_LOCATION_LEFT - and DOM_KEY_LOCATION_RIGHT) or '8' key value (normally - distinguished by the KeyboardEvent.location values - DOM_KEY_LOCATION_STANDARD - and DOM_KEY_LOCATION_NUMPAD), and user-configured - custom keyboard layouts MAY duplicate any key value in multiple key-state scenarios (note that KeyboardEvent.location - is intended for standard keyboard layouts, and cannot always indicate a meaningful distinction).

- -

Finally, the meaning of any given character representation is context-dependent and complex. For example, in some contexts, the asterisk (star) glyph ('*') represents a footnote or emphasis (when bracketing a passage of text). However, in some documents or executable programs it is equivalent - to the mathematical multiplication operation, while in other documents or executable programs, that function is reserved for the multiplication symbol ('×', - Unicode value '\u00D7') or the Latin small letter 'x' (due to the lack of a multiplication key on many keyboards - and the superficial resemblance of the glyphs '×' and 'x'). Thus, the semantic meaning or function of - character representations is outside the scope of this specification.

- -
-

6.3.1 Key Values and Unicode

- -

The character values described in this specification are Unicode [Unicode] - codepoints, and as such, have certain advantages.

- -

The most obvious advantage is that it allows the content author to use the full range of internationalized language functionality available in the implementation, - regardless of the limitations of the text input devices on the system. This opens up possibilities for virtual keyboards and Web-application-based input method editors.

- -

Another benefit is that it allows the content author to utilize the Unicode general category properties programmatically.

- -

With legacy keyboard event attributes such as keyCode and charCode, content authors are forced to - filter key input using cryptic, platform- and implementation-specific numeric codes, with poor internationalization, such as the following pseudocode:

- -
-
-
if ( ( event.charCode == 45 || event.charCode == 36 ) ||
-     ( event.charCode >= 48 && event.charCode <= 57 ) ||
-     ( event.charCode >= 96 && event.charCode <= 105 ) ) {
-   // minus sign, dollar sign, and numeric characters from keyboard and numpad
-   // ...
-}
-else if ( ( event.charCode >= 65 && event.charCode <= 90 ) ||
-          ( event.charCode >= 97 && event.charCode <= 122 ) ) {
-   // alphabetic characters from Latin character set, A-Z, a-z
-   // ...
-}
-else {
-   // ...
-}
-
-
- -

With key values and regular expressions, however, content authors can support selective and intuitive ranges for key-based input, in a cross-platform manner with - advanced internationalization support, such as the following pseudocode:

- -
-
-
if ( event.key == "-" || event.key.match("\p{Sc}") || event.key.match("\p{N}") ) {
-   // minus sign, any currency symbol, and numeric characters (regardless of key location)
-   // ...
-}
-else if ( event.key.match("\p{L}") ) {
-   // alphabetic characters from any language, upper and lower case
-   // ...
-}
-else {
-   // ...
-}
-
-
- -

In addition, because Unicode categorizes each assigned code point into a group of code points used by a particular - human writing system, even more advanced capabilities are possible.

- -
-
-

A content author can match characters from a particular human script (e.g., Tibetan) using a regular expression such as - \p{Tibetan}, to filter out other characters, or discover if a code point is in - a certain code block (range of code points), using a regular expression like \p{InCyrillic}.

-
- -

To facilitate this, implementations SHOULD support Unicode range detection using regular expressions, in a manner such as the Perl Compatible Regular Expressions - (PCRE) [PCRE].

-
- -
-

6.3.2 Modifier keys

- -

Keyboard input uses modifier keys to change the normal behavior of a key. - Like other keys, modifier keys generate - keydown - and - keyup - events, as shown in the example below. - Some modifiers are activated while the key is being pressed down or maintained pressed such as - 'Alt', - 'Control', - 'Shift', - 'AltGraph', - or - 'Meta'. - Others modifiers are activated depending on their state such as - 'CapsLock', - 'NumLock', - or - 'ScrollLock'. - Change in the state happens when the modifier key is being pressed down. - The - KeyboardEvent - interface provides convenient attributes for some common modifiers keys: - KeyboardEvent.ctrlKey, - KeyboardEvent.shiftKey, - KeyboardEvent.altKey, - KeyboardEvent.metaKey. - Some operating systems simulate the - 'AltGraph' - modifier key with the combination of the - 'Alt' - and - 'Control' - modifier keys. - Implementations are encouraged to use the - 'AltGraph' - modifier key. -

- -

The following example describes a possible sequence of events associated with the generation of the Unicode character Q (Latin Capital Letter Q, Unicode code point '\u0051') on a US keyboard using a US mapping:

- -
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
key
ModifiersNotes
1.keydown'Shift'shiftKey
2.keydown'Q'shiftKeyLatin Capital Letter Q
3.beforeinput'Q'
4.input
5.keyup'Q'shiftKey
6.keyup'Shift'
-
- -

The following example describes an alternate sequence of keys to the example above, where the 'Shift' key is released before the 'Q' key. The key value for the key labeled 'Q' will revert to its unshifted value for the - keyup event:

- -
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
key
ModifiersNotes
1.keydown'Shift'shiftKey
2.keydown'Q'shiftKeyLatin Capital Letter Q
3.beforeinput'Q'
4.input
5.keyup'Shift'
6.keyup'q'Latin Small Letter Q
-
- -

The following example describes a possible sequence of keys that does not generate a Unicode character (using the same configuration):

- -
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
key
ModifiersNotes
1.keydown'Control'ctrlKey
2.keydown'v'ctrlKeyLatin Small Letter V
No beforeinput or input events are generated.
3.keyup'v'ctrlKeyLatin Small Letter V
4.keyup'Control'
-
- -

The following example shows the sequence of events when both 'Shift' and - 'Control' are pressed:

- -
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
key
ModifiersNotes
1.keydown'Control'ctrlKey
2.keydown'Shift'ctrlKey - shiftKey
3.keydown'V'ctrlKey - shiftKeyLatin Capital Letter V
No beforeinput or input events are generated.
4.keyup'V'ctrlKey - shiftKeyLatin Capital Letter V
5.keyup'Shift'ctrlKey
6.keyup'Control'
-
- -

For non-US keyboard layouts, the sequence of events is the same, but the value of the key is based on the current - keyboard layout. The following example shows a sequence of events when an Arabic keyboard layout is used:

- -
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
key
ModifiersNotes
1.keydown'Control'ctrlKey
2.keydown'ر'ctrlKeyArabic Letter Reh
3.keyup'ر'ctrlKeyArabic Letter Reh
4.keyup'Control'
-
- -
Note

Note: - The value in the keydown and keyup events varies based on the current keyboard - layout in effect when the key is pressed. - This means that the 'v' key on a US layout and the - 'ر' key on an Arabic layout will generate different - events even though they are the same physical key. - To identify these events as coming from the same physical key, you will need - to make use of the code attribute. -

- -

In some cases, modifier keys change the key value value for a key event. - For example, on some MacOS keyboards, the key labeled 'delete' - functions the same as the 'Backspace' key on the - Windows OS when unmodified, but when modified by the 'Fn' - key, acts as the 'Delete' key, and the value of the - key value will match the most appropriate function of the key in its current - modified state. -

- -
- -
-

6.3.3 Dead keys

- -

Some keyboard input uses dead keys for the input of composed character sequences. Unlike the handwriting sequence, - in which users enter the base character first, keyboard input requires to enter a special state when a dead key is - pressed and emit the character(s) only when one of a limited number of legal base character is entered.

- -
Note

Note: The MacOS and Linux operating systems use input methods to process - dead keys. -

- -

The dead keys (across all keyboard layouts and mappings) are represented by the - key value 'Dead'. In response to any dead key press, - composition events must be dispatched by the user agent and the - compositionupdate event's - CompositionEvent.data value must be the character value of the current state - of the dead key combining sequence.

- -

While Unicode combining characters always follow the handwriting sequence, with the - combining character trailing the corresponding letter, typical dead key input MAY reverse the sequence, with the - combining character before the corresponding letter. For example, the word naïve, using the combining diacritic - ¨, would be represented sequentially in Unicode as nai¨ve, but MAY be typed na¨ive. The sequence - of keystrokes '\u0302' (Combining Circumflex Accent key) and '\u0065' - (key marked with the Latin Small Letter E) will likely produce (on a French keyboard using a french mapping and without - any modifier activated) the Unicode character 'ê' (Latin Small Letter E With Circumflex), as - preferred by the Unicode Normalization Form NFC:

- -
Note

Note: The keydown and keyup events shown in these - examples would normally be suppressed during the composition session. - They are included in these examples to make the user actions (pressing and releasing keys) more apparent. -

- -
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
key
KeyboardEvent
isComposing
CompositionEvent
data
Notes
1.keydown'Dead'falseCombining Circumflex Accent (Dead Key)
2.compositionstart''
3.compositionupdate'\u0302'
4.keyup'Dead'true
5.keydown'ê'true
6.compositionupdate'ê'
7.compositionend'ê'
8.keyup'e'falseLatin Small Letter E
-
- -
Note

Note: In the second keydown event (step 5), the key value - (assuming the event is not suppressed) will - not be 'e' (Latin Small Letter E key) under normal circumstances - because the value delivered to the user agent will already be modified by the dead key operation.

- -

This process might be aborted when a user types an unsupported base character (that is, a base character for which the which the active diacritical mark is not - available) after pressing a dead key:

- -
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
key
KeyboardEvent
isComposing
CompositionEvent
data
Notes
1.keydown'Dead'falseCombining Circumflex Accent (Dead Key)
2.compositionstart''
3.compositionupdate'\u0302'
4.keyup'Dead'true
5.keydown'q'trueLatin Small Letter Q
6.compositionupdate''
7.compositionend''
8.keyup'q'false
-
-
- -
-

6.3.4 Input Method Editors

- -

This specification includes a model for input method editors (IMEs), through the CompositionEvent - interface and events. However, Composition Events and Keyboard Events do not necessarily map as a one-to-one relationship. As an example, receiving a keydown for the 'Accept' key value does not necessarily imply - that the text currently selected in the IME is being accepted, but indicates only that a keystroke happened, disconnected - from the IME Accept functionality (which would normally result in a - compositionend event in most IME systems). Keyboard events cannot be used to determine the current - state of the input method editor, which can be obtained through the data attribute of the - CompositionEvent interface. Additionally, IME systems and devices vary in their functionality, and in which keys - are used for activating that functionality, such that the 'Convert' and 'Accept' keys MAY be represented - by other available keys. Keyboard events correspond to the events generated by the input device after the keyboard layout mapping.

- -
Note

Note: In some implementations or system configurations, some key events, or their values, might be suppressed - by the IME in use.

- -

The following example describes a possible sequence of keys to generate the Unicode character '市' (Kanji character, part of CJK Unified Ideographs) using Japanese - input methods. This example assumes that the input method editor is activated and in the Japanese-Romaji input mode. The keys 'Convert' - and 'Accept' MAY be replaced by others depending on the input device in use and the configuration of the IME, e.g., it can be respectively - '\u0020' (Space key) and 'Enter'.

- -
Note

Note: '詩' (poem) and '市' (city) are homophones, both - pronounced し (shi), so the user needs to use the 'Convert' key to select the proper option.

- -
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
key
KeyboardEvent
isComposing
CompositionEvent
data
Notes
1.keydown's'falseLatin Small Letter S
2.compositionstart''
3.compositionupdate's'
4.keyup's'true
5.keydown'i'trueLatin Small Letter I
6.compositionupdate'し'
7.keyup'i'true
8.keydown'Convert'trueConvert
9.compositionupdate'詩'
10.keyup'Convert'true
11.keydown'Convert'trueConvert
12.compositionupdate'市'
13.keyup'Convert'true
14.keydown'Accept'trueAccept
15.compositionend'市'
16.keyup'Accept'false
-
- -

IME composition can also be canceled as in the following example, with conditions identical to the previous example. - The key 'Cancel' might also be replaced by others depending on the input device in use and - the configuration of the IME, e.g., it could be '\u001B' (Escape key).

- -
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
key
KeyboardEvent
isComposing
CompositionEvent
data
Notes
1.keydown's'falseLatin Small Letter S
2.compositionstart''
3.compositionupdate's'
4.keyup's'true
5.keydown'i'trueLatin Small Letter I
6.compositionupdate'し'
7.keyup'i'true
8.keydown'Convert'trueConvert
9.compositionupdate'詩'
10.keyup'Convert'true
11.keydown'Convert'trueConvert
12.compositionupdate'市'
13.keyup'Convert'true
14.keydown'Cancel'trueCancel
15.compositionupdate''
16.compositionend''
17.keyup'Cancel'false
-
- -
Note

Note: Some input method editors (such as on the MacOS operating system) might set an - empty string to the composition data attribute before canceling a composition.

- -
-
6.3.4.1 Input Method Editor mode keys
- -

Some keys on certain devices are intended to activate input method editor functionality, or to change the mode of an active - input method editor. Custom keys for this purpose can be defined for different devices or language modes. The keys defined - in this specification for this purpose are: Alphanumeric, CodeInput, FinalMode, HangulMode, HanjaMode, - Hiragana, JunjaMode, KanaMode, - KanjiMode, Katakana, and RomanCharacters. When one of these keys is pressed, and no IME - is currently active, the appropriate IME is expected to be activated in the mode indicated by the key (if available). If - an IME is already active when the key is pressed, the active IME might change to - the indicated mode, or a different IME might be launched, or the might MAY be ignored, on a device- and application-specific - basis.

- -

This specification also defines other keys which are intended for operation specifically with input method editors: - Accept, AllCandidates, Cancel, Convert, Compose, FullWidth, HalfWidth, NextCandidate, - Nonconvert, and PreviousCandidate. The functions of these keys are not defined in this specification — refer to other resources for details - on input method editor functionality.

- -
Note

Note: Keys with input method editor functions are not restricted to that purpose, and can have other device- or implementation-specific - purposes.

-
-
- -
-

6.3.5 Default actions and cancelable keyboard events

- -

Canceling the - default action - of a - keydown - event MUST NOT affect its respective - keyup - event, but it MUST prevent the respective - beforeinput - and - input - (and - keypress - if supported) events from being generated. - The following example describes a possible sequence of keys to generate the Unicode character - Q (Latin Capital Letter Q) on a US keyboard using a US mapping: -

- -
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
key
InputEvent
data
ModifiersNotes
1.keydown'Shift'shiftKey
2.keydown'Q'shiftKeyThe default action is - prevented, e.g., by invoking Event.preventDefault(). -
No - beforeinput - or - input - (or - keypress, - if supported) events are generated -
3.keyup'Q'shiftKey
4.keyup'Shift'
-
- -

If the key is a modifier key, the keystroke MUST still be taken into account for the modifiers states. The following example describes a possible sequence of keys - to generate the Unicode character Q (Latin Capital Letter Q) on a US keyboard using a US mapping:

- -
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
key
InputEvent
data
ModifiersNotes
1.keydown'Shift'shiftKeyThe default action is - prevented, e.g., by invoking Event.preventDefault(). -
2.keydown'Q'shiftKey
3.beforeinput'Q'
4.input
5.keyup'Q'shiftKey
6.keyup'Shift'
-
- -

If the key is part of a sequence of several keystrokes, whether it is a dead key or - it is contributing to an Input Method Editor sequence, the keystroke MUST be ignored (not taken into account) only if the - default action is canceled on the - keydown event. Canceling a - dead key on a - keyup event has no effect on - beforeinput or - input events. - The following example uses the dead key 'Dead' ('\u0302' Combining Circumflex - Accent key) and 'e' ('\u0065', Latin Small Letter E key) on a French - keyboard using a French mapping and without any modifier activated:

- -
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
key
InputEvent
data
Notes
1.keydown'Dead'The default action is - prevented, e.g., by invoking Event.preventDefault(). -
2.keyup'Dead'
3.keydown'e'
4.beforeinput'e'
5.input
6.keyup'e'
-
-
- -
-

6.3.6 Guidelines for selecting key values

- -

This section is normative.

- -

To determine the appropriate key value for a key, use the following algorithm: -

- -
    -
  1. If there exists an appropriate character in the key values set, - then the - KeyboardEvent.key - attribute MUST be a string consisting of the key value of that character. -
  2. -
  3. If the key generates a printable character, - and there exists an appropriate - Unicode code point, - then the - KeyboardEvent.key - attribute MUST be a string consisting of the char value of that character. -
  4. -
  5. If more than one key is being pressed and the key combination includes one or more modifier keys that result in the key - no longer producing a printable character (e.g., 'Control' + 'a'), - then the key value should be the printable key value that would have been - produced if the key had been typed with the default keyboard layout - with no modifier keys except for 'Shift' and 'AltGr' applied. -
  6. -
  7. Otherwise, the special value 'Unidentified' should be used. -
  8. -
- -
-
-
    -
  • On a US keyboard with a right-handed single-hand Dvorak - key mapping, - the key labeled - 'Q' - maps to the key values - '5' (unmodified) - and - '%' (shifted). - The primary function of this key is to generate the character - '5' ('\u0035'). - Since this character is a character (in Unicode general category - Nd), the - KeyboardEvent.key - attribute value for the unmodified key will be '5'. -
  • -
  • On the same US Dvorak keyboard layout as the previous example, - pressing 'Control' and the key labeled 'Q' - will produce a key value of 'q'. -
  • -
  • On a French PC keyboard with a standard French mapping, the primary function of the - '^' - key is to act as a - dead key - for the combining circumflex diacritical mark. - The value for this key is 'Dead'. -
  • -
  • Also on a French PC keyboard with a standard French mapping, the - 'é' - key (which corresponds to the '2' key on a US keyboard) - generates a key value of 'é' ('\u00e9'). -
  • -
  • On a Korean PC keyboard with a standard Korean mapping, the primary function of the - 'Ha/En' - key is to switch between Hangul and English input. - The predefined key value list has an appropriate entry for this key, - 'HangulMode', - so this will be the key value. -
  • -
  • On some mobile devices, there are special keys to launch specific applications. - For a standard application like Calendar, there is a predefined key value of - 'LaunchCalendar'. -
  • -
-
- -

While every attempt has been made to make this list of key values as complete as possible, new key values - will periodically need to be defined as new input devices are introduced. - Rather than allowing user agents to define their own key values (which may not work across multiple user - agents), bugs should be filed so that this specification can be updated. -

- -
-
- -
- - -
-

A. Legacy Event Initializers

- -

This section is informative

- -

Early versions of this specification included an initialization method on the - interface (for example initMouseEvent) that required a long list of parameters - that, in most cases, did not fully initialize all attributes of the event object. - Because of this, event interfaces which were derived from the basic Event interface - required that the initializer of each of the derived - interfaces be called explicitly in order to fully initialize an event. -

- -
-
-

Initializing all the attributes of a MutationEvent requires calls to two initializer methods: - initEvent and initMutationEvent. -

-
- -

Due in part to the length of time in the development of this standard, some implementations MAY have - taken a dependency on these (now deprecated) initializer methods. - For completeness, these legacy event intializers are described in this Appendix. -

- -
-

A.1 Legacy Event Initializer Interfaces

-

This section is informative

- -

This section documents legacy initializer methods that were introduced in earlier - versions of this specification. -

- -
-

A.1.1 Initializers for interface CustomEvent

- -
partial interface CustomEvent {
-    // Originally introduced (and deprecated) in this specification
-    void initCustomEvent (DOMString typeArg, boolean bubblesArg, boolean cancelableArg, any detailArg);
-};
A.1.1.1 Methods
initCustomEvent
-

Initializes attributes of a CustomEvent object. This method has the - same behavior as Event.initEvent(). -

- -
Warning

Warning! - The initCustomEvent method is deprecated. -

- - -
ParameterTypeNullableOptionalDescription
typeArgDOMString

Refer to the Event.initEvent() method for a description of this parameter.

bubblesArgboolean

Refer to the Event.initEvent() method for a description of this parameter.

cancelableArgboolean

Refer to the Event.initEvent() method for a description of this parameter.

detailArgany

Specifies CustomEvent.detail.

Return type: void
-
- -
-

A.1.2 Initializers for interface UIEvent

- -
partial interface UIEvent {
-    // Deprecated in this specification
-    void initUIEvent (DOMString typeArg, boolean bubblesArg, boolean cancelableArg, Window? viewArg, long detailArg);
-};
A.1.2.1 Methods
initUIEvent
-

Initializes attributes of an UIEvent object. - This method has the same behavior as Event.initEvent(). -

- -
Warning

Warning! - The initUIEvent method is deprecated, but supported for - backwards-compatibility with widely-deployed implementations. -

- - -
ParameterTypeNullableOptionalDescription
typeArgDOMString -

Refer to the Event.initEvent() method for a description of this parameter.

-
bubblesArgboolean -

Refer to the Event.initEvent() method for a description of this parameter.

-
cancelableArgboolean -

Refer to the Event.initEvent() method for a description of this parameter.

-
viewArgWindow -

Specifies UIEvent.view. This value MAY be null.

-
detailArglong -

Specifies UIEvent.detail.

-
Return type: void
-
- -
-

A.1.3 Initializers for interface FocusEvent

- -
partial interface FocusEvent {
-    // Originally introduced (and deprecated) in this specification
-    void initFocusEvent (DOMString typeArg, boolean bubblesArg, boolean cancelableArg, Window? viewArg, long detailArg, EventTarget? relatedTargetArg);
-};
A.1.3.1 Methods
initFocusEvent
-

Initializes attributes of a FocusEvent object. - This method has the same behavior as - UIEvent.initUIEvent(). -

- -
Warning

Warning! - The initFocusEvent method is deprecated. -

- - -
ParameterTypeNullableOptionalDescription
typeArgDOMString

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

bubblesArgboolean

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

cancelableArgboolean

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

viewArgWindow

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

detailArglong

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

relatedTargetArgEventTarget

Specifies FocusEvent.relatedTarget. This value MAY be null.

Return type: void
-
- -
-

A.1.4 Initializers for interface MouseEvent

- -
partial interface MouseEvent {
-    // Deprecated in this specification
-    void initMouseEvent (DOMString typeArg, boolean bubblesArg, boolean cancelableArg, Window? viewArg, long detailArg, long screenXArg, long screenYArg, long clientXArg, long clientYArg, boolean ctrlKeyArg, boolean altKeyArg, boolean shiftKeyArg, boolean metaKeyArg, short buttonArg, EventTarget? relatedTargetArg);
-};
A.1.4.1 Methods
initMouseEvent
-

Initializes attributes of a MouseEvent object. - This method has the same behavior as UIEvent.initUIEvent(). -

- -
Warning

Warning! - The initMouseEvent method is deprecated, but supported for - backwards-compatibility with widely-deployed implementations. -

- - -
ParameterTypeNullableOptionalDescription
typeArgDOMString -

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

-
bubblesArgboolean -

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

-
cancelableArgboolean -

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

-
viewArgWindow -

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

-
detailArglong -

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

-
screenXArglong -

Specifies MouseEvent.screenX.

-
screenYArglong -

Specifies MouseEvent.screenY.

-
clientXArglong -

Specifies MouseEvent.clientX.

-
clientYArglong -

Specifies MouseEvent.clientY.

-
ctrlKeyArgboolean -

Specifies MouseEvent.ctrlKey.

-
altKeyArgboolean -

Specifies MouseEvent.altKey.

-
shiftKeyArgboolean -

Specifies MouseEvent.shiftKey.

-
metaKeyArgboolean -

Specifies MouseEvent.metaKey.

-
buttonArgshort -

Specifies MouseEvent.button.

-
relatedTargetArgEventTarget -

Specifies MouseEvent.relatedTarget. This value MAY be null.

-
Return type: void
-
- -
-

A.1.5 Initializers for interface WheelEvent

- -
partial interface WheelEvent {
-    // Originally introduced (and deprecated) in this specification
-    void initWheelEvent (DOMString typeArg, boolean bubblesArg, boolean cancelableArg, Window? viewArg, long detailArg, long screenXArg, long screenYArg, long clientXArg, long clientYArg, short buttonArg, EventTarget? relatedTargetArg, DOMString modifiersListArg, double deltaXArg, double deltaYArg, double deltaZArg, unsigned long deltaMode);
-};
A.1.5.1 Methods
initWheelEvent
-

Initializes attributes of a WheelEvent object. - This method has the same behavior as - MouseEvent.initMouseEvent(). -

- -
Warning

Warning! - The initWheelEvent method is deprecated. -

- - -
ParameterTypeNullableOptionalDescription
typeArgDOMString

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

bubblesArgboolean

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

cancelableArgboolean

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

viewArgWindow

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

detailArglong

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

screenXArglong

Refer to the MouseEvent.initMouseEvent() method for a description of this parameter.

screenYArglong

Refer to the MouseEvent.initMouseEvent() method for a description of this parameter.

clientXArglong

Refer to the MouseEvent.initMouseEvent() method for a description of this parameter.

clientYArglong

Refer to the MouseEvent.initMouseEvent() method for a description of this parameter.

buttonArgshort

Refer to the MouseEvent.initMouseEvent() method for a description of this parameter.

relatedTargetArgEventTarget

Refer to the MouseEvent.initMouseEvent() method for a description of this parameter.

modifiersListArgDOMString -

A white space - separated list of modifier key values to be activated on this object. - As an example, "Control Shift" marks the control and shift modifiers as activated - (the MouseEvent.ctrlKey and - MouseEvent.shiftKey inherited attributes - will be true on the initialized WheelEvent object). -

-
deltaXArgdouble

Specifies WheelEvent.deltaX.

deltaYArgdouble

Specifies WheelEvent.deltaY.

deltaZArgdouble

Specifies WheelEvent.deltaZ.

deltaModeunsigned long

Specifies WheelEvent.deltaMode.

Return type: void
-
- -
-

A.1.6 Initializers for interface KeyboardEvent

-
Note

Note: The argument list to this legacy KeyboardEvent initializer does not include - the detailArg (present in other initializers) and adds the locale argument (see - Changes between different drafts of this specification); it is necessary - to preserve this inconsistency for compatibility with existing implementations.

-
partial interface KeyboardEvent {
-    // Originally introduced (and deprecated) in this specification
-    void initKeyboardEvent (DOMString typeArg, boolean bubblesArg, boolean cancelableArg, Window? viewArg, DOMString keyArg, unsigned long locationArg, DOMString modifiersListArg, boolean repeat, DOMString locale);
-};
A.1.6.1 Methods
initKeyboardEvent
-

Initializes attributes of a KeyboardEvent object. - This method has the same behavior as UIEvent.initUIEvent(). - The value of UIEvent.detail remains undefined. -

- -
Warning

Warning! - The initKeyboardEvent method is deprecated. -

- - -
ParameterTypeNullableOptionalDescription
typeArgDOMString

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

bubblesArgboolean

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

cancelableArgboolean

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

viewArgWindow

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

keyArgDOMString

Specifies KeyboardEvent.key.

locationArgunsigned long

Specifies KeyboardEvent.location.

modifiersListArgDOMString

A white space - separated list of modifier key values to be activated on this object. - As an example, "Control Alt" marks the control and alt modifiers as activated. -

-
repeatboolean

Specifies whether the key event is repeating. See KeyboardEvent.repeat.

localeDOMString

Specifies the locale attribute of the KeyboardEvent. -

Issue 2

Should we include locale in this specification now?

Return type: void
-
- -
-

A.1.7 Initializers for interface CompositionEvent

-
Note

Note: The argument list to this legacy CompositionEvent initializer does not include - the detailArg (present in other initializers) and adds the locale argument (see - Changes between different drafts of this specification); it is necessary - to preserve this inconsistency for compatibility with existing implementations.

-
partial interface CompositionEvent {
-    // Originally introduced (and deprecated) in this specification
-    void initCompositionEvent (DOMString typeArg, boolean bubblesArg, boolean cancelableArg, Window? viewArg, DOMString dataArg, DOMString locale);
-};
A.1.7.1 Methods
initCompositionEvent
-

Initializes attributes of a CompositionEvent object. - This method has the same behavior as UIEvent.initUIEvent(). - The value of UIEvent.detail remains undefined. -

- -
Warning

Warning! - The initCompositionEvent method is deprecated. -

- - -
ParameterTypeNullableOptionalDescription
typeArgDOMString

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

bubblesArgboolean

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

cancelableArgboolean

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

viewArgWindow

Refer to the UIEvent.initUIEvent() method for a description of this parameter.

dataArgDOMString

Specifies CompositionEvent.data.

localeDOMString

Specifies the locale attribute of the CompositionEvent. -

Issue 3

Should we include locale in this specification now?

-
Return type: void
-
- -
-
- - -
-

B. Legacy Key Attributes

-

This section is informative

- -

This section provides a non-normative description of the attributes that are currently used when - handling keyboard events. -

- -

These features were never formally specified and the current browser implementations vary in - significant ways. - The large amount of legacy content, including script libraries, that relies upon detecting the - user agent and acting accordingly means that any - attempt to formalize these legacy attributes and events would risk breaking as much content as - it would fix or enable. - Additionally, these attributes are not suitable for international usage, nor do they address - accessibility concerns. -

- -

Therefore, this specification does not normatively define the events and attributes commonly employed - for handling keyboard input, though they MAY be present in - user agents for compatibility with legacy content. - Authors SHOULD use the KeyboardEvent.key attribute - instead of the charCode - and keyCode attributes. -

- -

However, for the purpose of documenting the current state of these features and their relation to - normative events and attributes, this section provides an informative description. - For implementations which do support these attributes and events, it is suggested that the definitions - provided in this section be used. -

- -
-

B.1 Legacy KeyboardEvent supplemental interface

-

This section is informative

- -

Browser support for keyboards has traditionally relied on three ad-hoc attributes, - keyCode, charCode, - and which.

- -

All three of these attributes return a numerical code that represents some aspect of the key pressed: - keyCode is an index of the key itself. - charCode is the ASCII value of the character keys. - which is the character value where available and otherwise the key index. - The values for these attributes, and the availability of the attribute, is inconsistent across - platforms, keyboard languages and layouts, user agents, - versions, and even event types. -

- -
-
Interface KeyboardEvent (supplemental)
-
-

Introduced in this specification

- -

The partial - KeyboardEvent - interface is an informative extension of the - KeyboardEvent - interface, which adds the - charCode, - keyCode, - and which - attributes.

- -

The partial - KeyboardEvent - interface can be obtained by using the - DocumentEvent.createEvent("KeyboardEvent") - method call in implementations that support this extension.

- -
partial interface KeyboardEvent {
-    // The following support legacy user agents
-    readonly    attribute unsigned long charCode;
-    readonly    attribute unsigned long keyCode;
-    readonly    attribute unsigned long which;
-};

Attributes

charCode of type unsigned long, readonly
-

charCode holds a character value, for - keypress events which - generate character input. - The value is the Unicode reference number (code point) of that character (e.g. - event.charCode = event.key.charCodeAt(0) for printable characters). - For keydown or - keyup events, the - value of charCode is 0. -

-
keyCode of type unsigned long, readonly
-

keyCode holds a system- and implementation-dependent - numerical code signifying the unmodified identifier associated with the key pressed. - Unlike the KeyboardEvent.key - attribute, the set of possible values are not normatively defined in this specification. - Typically, these value of the keyCode - SHOULD represent the decimal codepoint in - ASCII [RFC20][US-ASCII] - or Windows 1252 [WIN1252], - but MAY be drawn from a different appropriate character set. - Implementations that are unable to identify a key use the key value - '0'. -

- -

See Legacy key models for more details on how to - determine the values for keyCode. -

-
which of type unsigned long, readonly
-

which holds a system- and implementation-dependent numerical code - signifying the unmodified identifier associated with the key pressed. - In most cases, the value is identical to - keyCode. -

-
- -
-
- -
-
dictionary KeyboardEventInit (supplemental)
-
-

Browsers that include support for - keyCode, - charCode, - and - which - in KeyboardEvent should also add the following members to the - KeyboardEventInit dictionary. -

- -

The partial - KeyboardEventInit - dictionary is an informative extension of the - KeyboardEventInit - dictionary, which adds - charCode, - keyCode, - and which - members to initialize the corresponding KeyboardEvent attributes.

- -
partial dictionary KeyboardEventInit {
-    unsigned long charCode = 0;
-    unsigned long keyCode = 0;
-    unsigned long which = 0;
-};

Dictionary KeyboardEventInit Members

charCode of type unsigned long, defaulting to 0
-

Initializes the charCode attribute of the - KeyboardEvent to the Unicode code point for the event's character. -

-
keyCode of type unsigned long, defaulting to 0
-

Initializes the keyCode attribute of the - KeyboardEvent to the system- and implementation-dependent - numerical code signifying the unmodified identifier associated with the key pressed. -

-
which of type unsigned long, defaulting to 0
-

Initializes the which attribute of the KeyboardEvent - to the implementation-dependent numerical code - signifying the unmodified identifier associated with the key pressed. - In most cases, the value is identical to - keyCode. -

-
-
-
- -
- -
-

B.2 Legacy key models

-

This section is informative

- -

Implementations differ on which values are exposed on these attributes for different event types. - An implementation MAY choose to expose both virtual key codes and character codes in the - keyCode property (conflated model), or report - separate keyCode and charCode - properties (split model). -

- -
-

B.2.1 How to determine keyCode for keydown and keyup events

- -

The keyCode for - keydown - or keyup events is calculated - as follows: -

- -
    -
  1. Read the virtual key code from the operating system's event information, if such information - is available.
  2. -
  3. If an Input Method Editor is processing key input and the event is - keydown, return 229.
  4. -
  5. If input key when pressed without modifiers would insert a numerical character (0-9), - return the ASCII code of that numerical character.
  6. -
  7. If input key when pressed without modifiers would insert a lower case character in the - a-z alphabetical range, return the ASCII code of the upper case equivalent.
  8. -
  9. If the implementation supports a key code conversion table for the operating system and platform, - look up the value. If the conversion table specifies an alternate virtual key value for the given - input, return the specified value.
  10. -
  11. If the key's function, as determined in an implementation-specific way, corresponds to one of - the keys in the table of fixed virtual key codes, - return the corresponding key code.
  12. -
  13. Return the virtual key code from the operating system.
  14. -
  15. If no key code was found, return 0.
  16. -
-
- -
-

B.2.2 How to determine keyCode for keypress events

- -

The keyCode for - keypress events is - calculated as follows: -

- -
    -
  1. If the implementation supports a conflated model, set keyCode - to the Unicode code point of the character being entered.
  2. -
  3. If the implementation supports a split model, set keyCode to 0.
  4. -
-
- -
-

B.2.3 Fixed virtual key codes

- -

The virtual key codes for the following keys do not usually change with keyboard layouts - on desktop systems: -

- - - - - - - - - - - - - - - - - - - - - - - - - -
KeyVirtual Key
Code
Notes
'Backspace' 8
'Tab' 9
'Enter' 13
'Shift' 16
'Control' 17
'Alt' 18
'CapsLock' 20
'Escape' 27 Esc
' ' 32 Space
'PageUp' 33
'PageDown' 34
'End' 35
'Home' 36
'ArrowLeft' 37
'ArrowUp' 38
'ArrowRight' 39
'ArrowDown' 40
'Delete' 46 Del
-
- -
-

B.2.4 Optionally fixed virtual key codes

- -

The following punctuation characters MAY change virtual codes between keyboard layouts, but reporting - these values will likely be more compatible with legacy content expecting US-English keyboard layout: -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
KeyCharacterVirtual Key
Code
Semicolon ';' 186
Colon ':' 186
Equals sign '=' 187
Plus '+' 187
Comma ',' 188
Less than sign '<' 188
Minus '-' 189
Underscore '_' 189
Period '.' 190
Greater than sign '>' 190
Forward slash '/' 191
Question mark '?' 191
Backtick '`' 192
Tilde '~' 192
Opening square bracket '[' 219
Opening curly brace '{' 219
Backslash '\' 220
Pipe '|' 220
Closing square bracket ']' 221
Closing curly brace '}' 221
Single quote ''' 222
Double quote '"' 222
-
-
-
- - -
-

C. Legacy Event Types

-

This section is informative

- -

This section provides a non-normative description of the event types that are deprecated in - this document. -

- -

The purpose of this section is to document the current state of these features and their relation - to normative events. - For implementations which do support these events, it is suggested that the definitions provided - in this section be used. -

- -

The following table provides an informative summary of the event types which are deprecated in - this specification. - They are included here for reference and completeness. -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event TypeSync / AsyncBubbling phaseTrusted event target typesDOM interfaceCancelableDefault Action
DOMActivateSyncYesElementUIEventYesNone
DOMAttrModifiedSyncYesElementMutationEventNoNone
DOMCharacterDataModifiedSyncYesText, Comment, ProcessingInstructionMutationEventNoNone
DOMFocusInSyncYesWindow, ElementFocusEventNoNone
DOMFocusOutSyncYesWindow, ElementFocusEventNoNone
DOMNodeInsertedSyncYesElement, Attr, Text, Comment, DocumentType, - ProcessingInstructionMutationEventNoNone
DOMNodeInsertedIntoDocumentSyncNoElement, Attr, Text, Comment, DocumentType, - ProcessingInstructionMutationEventNoNone
DOMNodeRemovedSyncYesElement, Attr, Text, Comment, DocumentType, - ProcessingInstructionMutationEventNoNone
DOMNodeRemovedFromDocumentSyncNoElement, Attr, Text, Comment, DocumentType, - ProcessingInstructionMutationEventNoNone
DOMSubtreeModifiedSyncYesWindow, Document, DocumentFragment, Element, Attr - MutationEventNoNone
keypressSyncYesElementKeyboardEventYesVaries: - launch text composition system; - blur and focus events; - DOMActivate event; - other event
- -
-

C.1 Legacy UIEvent events

- - -
-
-
DOMActivate
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
TypeDOMActivate
InterfaceUIEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableYes
Default actionNone
Context
(trusted events)
- -
-

A user agent MUST dispatch this event when a button, link, or other state-changing element is activated. Refer to - Activation triggers and behavior for more details.

- -
Warning

Warning! The DOMActivate event type is defined in this specification for reference and completeness, but this specification - deprecates the use of this event type in favor of the related event type - click. Other specifications MAY define and maintain their own DOMActivate - event type for backwards compatibility.

- -
Note

Note: While DOMActivate and click are not completely equivalent, implemented behavior for the click - event type has developed to encompass the most critical accessibility aspects for which the - DOMActivate event type was designed, and is more widely implemented. Content authors are encouraged - to use the click event type rather than the related - mousedown or mouseup event type to ensure maximum accessibility.

-
-
-
- -

Implementations which support the - DOMActivate - event type SHOULD also dispatch a - DOMActivate - event as a default action of a - click event which is associated - with an activation trigger. - However, such implementations SHOULD only initiate the associated - activation behavior - once for any given occurrence of an - activation trigger. -

- -
-
-

The DOMActivate - event type is REQUIRED to be supported for - XForms [XFORMS], - which is intended for implementation within a host language. - In a scenario where a plugin or script-based implementation of XForms is intended for installation - in a native implementation of this specification which does not support the - DOMActivate - event type, the XForms - user agent has to synthesize and dispatch its own - DOMActivate events based on - the appropriate activation triggers. -

- -

Thus, when a click event is dispatched - by a user agent conforming to UI Events, the - XForms user agent has to determine whether to synthesize - a DOMActivate event with the - same relevant properties as a default action of - that click event. - Appropriate cues might be whether the click - event is trusted, or whether its - event target has a - DOMActivate event listener - registered. -

-
- -
Note

Authoring Note: - Don't rely upon the interoperable support of - DOMActivate - in many user agents. - Instead, the click - event type should be used since it will provide more - accessible behavior due to broader implementation support. -

- -
Warning

Warning! - The DOMActivate - event type is deprecated in this specification. -

- -
-

C.1.1 Activation event order

- -

If the DOMActivate event is supported by the - user agent, then the - events MUST be dispatched in a set order relative to each other: - (with only pertinent events listed): -

- - - - - - - - - - - - - - - - -
1.click
2.DOMActivatedefault action, if supported - by the user agent; synthesized; isTrusted="true" -
3. - All other default actions, - including the activation behavior -
- -

If the focused element is activated by a key event, then the following shows the - typical sequence of events (with only pertinent events listed): -

- - - - - - - - - - - - - - - - - - - - - -
1.keydownMUST be a key which can activate the element, such as the - 'Enter' or ' ' key, - or the element is not activated -
2.clickdefault action; synthesized; isTrusted="true"
3.DOMActivatedefault action, if supported - by the user agent; synthesized; isTrusted="true" -
4. - All other default actions, - including the activation behavior -
-
-
- -
-

C.2 Legacy FocusEvent events

- - -
-
-
DOMFocusIn
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
TypeDOMFocusIn
InterfaceFocusEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsWindow, Element
CancelableNo
Default actionNone
Context
(trusted events)
- -
-

A user agent MUST dispatch this event - when an event target receives focus. - The focus MUST be given to the element before the dispatch of this event type. - This event type MUST be dispatched after the event type - focus. -

- -
Warning

Warning! - The DOMFocusIn event type - is defined in this specification for reference and completeness, but this specification - deprecates the use of this event type in favor - of the related event types focus - and focusin. -

-
-
-
- - -
-
-
DOMFocusOut
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
TypeDOMFocusOut
InterfaceFocusEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsWindow, Element
CancelableNo
Default actionNone
Context
(trusted events)
- -
-

A user agent MUST dispatch this event - when an event target loses focus. - The focus MUST be taken from the element before the dispatch of this event type. - This event type MUST be dispatched after the event type - blur. -

- -
Warning

Warning! - The DOMFocusOut event - type is defined in this specification for reference and completeness, but this specification - deprecates the use of this event type in - favor of the related event types blur - and focusout. -

-
-
-
- -
-

C.2.1 Legacy FocusEvent event order

- -

The following is the typical sequence of events when a focus is shifted between elements, - including the deprecated - DOMFocusIn - and DOMFocusOut - events. The order shown assumes that no element is initially focused. -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
User shifts focus
1.focusinSent before first target element receives focus
2.focusSent after first target element receives focus
3.DOMFocusInIf supported
User shifts focus
4.focusoutSent before first target element loses focus
5.focusinSent before second target element receives focus
6.blurSent after first target element loses focus
7.DOMFocusOutIf supported
8.focusSent after second target element receives focus
9.DOMFocusInIf supported
-
- -
- -
-

C.3 Legacy KeyboardEvent events

- -

The keypress event is the - traditional method for capturing key events and processing them before the DOM is updated - with the effects of the key press. - Code that makes use of the - keypress - event typically relies on the legacy - charCode, - keyCode, - and which - attributes. -

- -

Note that the keypress event - is specific to key events, and has been replaced by the more general event sequence of - beforeinput - and input events. - These new input events are not specific to keyboard actions and can be used to capture - user input regardless of the original source. -

- - -
-
-
keypress
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Typekeypress
InterfaceKeyboardEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableYes
Default actionVaries: - launch text composition system; - blur and focus events; - DOMActivate event; - other event
Context
(trusted events)
- -
- -

If supported by a user agent, this event MUST - be dispatched when a key is pressed down, if and only if that key normally produces a - character value. - The keypress event type - is device dependent and relies on the capabilities of the input devices and how they are - mapped in the operating system. -

- -

This event type MUST be generated after the key mapping. - It MUST NOT be fired when using an input method editor. -

- -

If this event is canceled, it should prevent the - input - event from firing, in addition to canceling the - default action. -

- -

Authors SHOULD use the - beforeinput - event instead of the - keypress - event. -

- -
Note

Note: - The keypress event is traditionally - associated with detecting a character value rather - than a physical key, and might not be available on all keys in some configurations. -

- -
Warning
-

Warning!

-

The keypress event type is defined - in this specification for reference and completeness, but this specification - deprecates the use of this event type. - When in editing contexts, authors can subscribe to the beforeinput event instead. -

-
- -
-
-
- -
-

C.3.1 keypress event order

- -

The keypress - event type MUST be dispatched after the - keydown - event and before the - keyup - event associated with the same key. -

- -

The keypress - event type MUST be dispatched after the - beforeinput - event and before the - input - event associated with the same key. -

- -

The sequence of key events for user-agents the support the - keypress event - is demonstrated in the following example: -

- -
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Event NameKeyboardEvent
key
InputEvent
data
1.keydown'a'
2.beforeinput'a'
3.keypress'a'
Any default actions related to this key, such as inserting a - character in to the DOM. -
4.input
5.keyup'a'
-
-
-
- -
-

C.4 Legacy MutationEvent events

- -

The mutation and mutation name event modules are designed to allow notification of any - changes to the structure of a document, including attribute, text, or name modifications. -

- -
Note

Note: - None of the event types associated with the MutationEvent interface are - designated as cancelable. - This stems from the fact that it is very difficult to make use of existing DOM interfaces - which cause document modifications if any change to the document might or might not take - place due to cancelation of the resulting event. - Although this is still a desired capability, it was decided that it would be better left - until the addition of transactions into the DOM. -

- -

Many single modifications of the tree can cause multiple mutation events to be dispatched. - Rather than attempt to specify the ordering of mutation events due to every possible - modification of the tree, the ordering of these events is left to the implementation. -

- -
Warning
-

Warning!

-

The MutationEvent interface was introduced in - DOM Level 2 Events, but has not yet been completely and interoperably implemented across - user agents. - In addition, there have been critiques that the interface, as designed, introduces a - performance and implementation challenge. -

-

DOM4 [DOM4] provides a new mechanism using a - MutationObserver interface which addresses the use cases that mutation events - solve, but in a more performant manner. - Thus, this specification describes mutation events for reference and completeness of legacy - behavior, but deprecates the use of the - MutationEvent interface. -

-
- -
-

C.4.1 Interface MutationEvent

- -

Introduced in DOM Level 2, deprecated in this specification

- -

The MutationEvent interface provides specific contextual information associated - with Mutation events. -

- -

To create an instance of the MutationEvent interface, use the - DocumentEvent.createEvent("MutationEvent") - method call. -

- -
interface MutationEvent : Event {
-    // attrChangeType
-    const unsigned short MODIFICATION = 1;
-    const unsigned short ADDITION = 2;
-    const unsigned short REMOVAL = 3;
-    readonly    attribute Node?          relatedNode;
-    readonly    attribute DOMString      prevValue;
-    readonly    attribute DOMString      newValue;
-    readonly    attribute DOMString      attrName;
-    readonly    attribute unsigned short attrChange;
-    void initMutationEvent (DOMString typeArg, boolean bubblesArg, boolean cancelableArg, Node? relatedNodeArg, DOMString prevValueArg, DOMString newValueArg, DOMString attrNameArg, unsigned short attrChangeArg);
-};
C.4.1.1 Attributes
attrChange of type unsigned short, readonly
-

attrChange indicates the type of change which triggered the - DOMAttrModified - event. The values can be MODIFICATION, ADDITION, - or REMOVAL. -

- -

The un-initialized value of this - attribute MUST be 0. -

- -
Note

Note: - There is no defined constant for the attrChange value of 0 (the un-initialized value). -

-
attrName of type DOMString, readonly
-

attrName indicates the name of the changed Attr node in - a DOMAttrModified - event. -

- -

The un-initialized value of this - attribute MUST be "" (the empty string). -

-
newValue of type DOMString, readonly
-

newValue indicates the new value of the Attr node in - DOMAttrModified - events, and of the CharacterData node in - DOMCharacterDataModified - events. -

- -

The un-initialized value of this - attribute MUST be "" (the empty string). -

-
prevValue of type DOMString, readonly
-

prevValue indicates the previous value of the Attr node - in DOMAttrModified - events, and of the CharacterData node in - DOMCharacterDataModified - events. -

- -

The un-initialized value of this - attribute MUST be "" (the empty string). -

-
relatedNode of type Node, readonly , nullable
-

relatedNode MUST be used to identify a secondary node related to a - mutation event. - For example, if a mutation event is dispatched to a node indicating that its parent - has changed, the relatedNode will be the changed parent. - If an event is instead dispatched to a subtree indicating a node was changed - within it, the relatedNode MUST be the changed node. - In the case of the - DOMAttrModified - event, it indicates the Attr node which was modified, added, or removed. -

- -

The un-initialized value of - this attribute MUST be null. -

-
C.4.1.2 Methods
initMutationEvent
-

Initializes attributes of a MutationEvent object. - This method has the same behavior as Event.initEvent(). -

- - -
ParameterTypeNullableOptionalDescription
typeArgDOMString -

Refer to the Event.initEvent() method for a description of this parameter.

-
bubblesArgboolean -

Refer to the Event.initEvent() method for a description of this parameter.

-
cancelableArgboolean -

Refer to the Event.initEvent() method for a description of this parameter.

-
relatedNodeArgNode -

Specifies MutationEvent.relatedNode.

-
prevValueArgDOMString -

Specifies MutationEvent.prevValue. - This value MAY be the empty string. -

-
newValueArgDOMString -

Specifies MutationEvent.newValue. - This value MAY be the empty string. -

-
attrNameArgDOMString -

Specifies MutationEvent.attrName. - This value MAY be the empty string. -

-
attrChangeArgunsigned short -

Specifies MutationEvent.attrChange. - This value MAY be 0. -

-
Return type: void
C.4.1.3 Constants
ADDITION of type unsigned short
-

The Attr was just added.

-
MODIFICATION of type unsigned short
-

The Attr was modified in place.

-
REMOVAL of type unsigned short
-

The Attr was just removed.

-
-
- -

The mutation event types are listed below.

- - -
-
-
DOMAttrModified
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
TypeDOMAttrModified
InterfaceMutationEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event after - an Attr.value has been modified and after an Attr node has been - added to or removed from an Element. - The event target of this event MUST be - the Element node where the change occurred. - It is implementation dependent whether this event type occurs when the children of the - Attr node are changed in ways that do not affect the value of Attr.value. -

- -
Warning

Warning! - The DOMAttrModified - event type is defined in this specification for reference and completeness, but this - specification deprecates the use of this event type. -

-
-
-
- - -
-
-
DOMCharacterDataModified
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
TypeDOMCharacterDataModified
InterfaceMutationEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsText, Comment, ProcessingInstruction
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event - after CharacterData.data or ProcessingInstruction.data - have been modified, but the node itself has not been inserted or deleted. - The event target of this event MUST - be the CharacterData node or the ProcessingInstruction node. -

- -
Warning

Warning! - The DOMCharacterDataModified - event type is defined in this specification for reference and completeness, but this specification - deprecates the use of this event type. -

-
-
-
- - -
-
-
DOMNodeInserted
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
TypeDOMNodeInserted
InterfaceMutationEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement, Attr, Text, Comment, DocumentType, - ProcessingInstruction
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event type when - a node other than an Attr node has been added as a child of another node. - A user agent MAY dispatch this event when - an Attr node has been added to an Element node - (see note below). - This event MUST be dispatched after the insertion has taken place. - The event target of this event MUST be the - node being inserted. -

- -
Note

Note: - For detecting attribute insertion, use the - DOMAttrModified - event type instead. -

- -
Warning

Warning! - The DOMNodeInserted event - type is defined in this specification for reference and completeness, but this specification - deprecates the use of this event type. -

-
-
-
- - -
-
-
DOMNodeInsertedIntoDocument
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
TypeDOMNodeInsertedIntoDocument
InterfaceMutationEvent
Sync / AsyncSync
BubblesNo
Trusted TargetsElement, Attr, Text, Comment, DocumentType, - ProcessingInstruction
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a node - has been inserted into a document, either through direct insertion of the node or insertion of a - subtree in which it is contained. - A user agent MAY treat an Attr - node as part of an Element's subtree. - This event MUST be dispatched after the insertion has taken place. - The event target of this event MUST be the node - being inserted. - If the node is being directly inserted, the event type - DOMNodeInserted - MUST occur before this event type. -

- -
Warning

Warning! - The DOMNodeInsertedIntoDocument - event type is defined in this specification for reference and completeness, but this specification - deprecates the use of this event type. -

-
-
-
- - -
-
-
DOMNodeRemoved
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
TypeDOMNodeRemoved
InterfaceMutationEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsElement, Attr, Text, Comment, DocumentType, - ProcessingInstruction
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a node - other than an Attr node is being removed from its parent node. - A user agent MAY dispatch this event when an - Attr node is being removed from its ownerElement - (see note below). - This event MUST be dispatched before the removal takes place. The - event target of this event MUST be the node being removed. -

- -
Note

Note: - For reliably detecting attribute removal, use the - DOMAttrModified - event type instead. -

- -
Warning

Warning! - The DOMNodeRemoved event type - is defined in this specification for reference and completeness, but this specification - deprecates the use of this event type. -

-
-
-
- - -
-
-
DOMNodeRemovedFromDocument
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
TypeDOMNodeRemovedFromDocument
InterfaceMutationEvent
Sync / AsyncSync
BubblesNo
Trusted TargetsElement, Attr, Text, Comment, DocumentType, - ProcessingInstruction
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

A user agent MUST dispatch this event when a node is - being removed from a document, either through direct removal of the node or removal of a subtree in - which it is contained. - A user agent MAY treat an Attr - node as part of an Element's subtree. - This event MUST be dispatched before the removal takes place. - The event target of this event type MUST be the node - being removed. - If the node is being directly removed, the event type - DOMNodeRemoved - MUST occur before this event type. -

- -
Note

Note: - For reliably detecting attribute removal, use the - DOMAttrModified - event type instead. -

- -
Warning

Warning! - The DOMNodeRemovedFromDocument - event type is defined in this specification for reference and completeness, but this specification - deprecates the use of this event type. -

-
-
-
- - -
-
-
DOMSubtreeModified
-
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
TypeDOMSubtreeModified
InterfaceMutationEvent
Sync / AsyncSync
BubblesYes
Trusted TargetsWindow, Document, DocumentFragment, Element, Attr -
CancelableNo
Default actionNone
Context
(trusted events)
- -
- -

This is a general event for notification of all changes to the document. - It can be used instead of the more specific mutation and mutation name events. - It MAY be dispatched after a single modification to the document or, at the implementation's - discretion, after multiple changes have occurred. - The latter case SHOULD generally be used to accommodate multiple changes which occur either - simultaneously or in rapid succession. - The target of this event MUST be the lowest common parent of the changes which have taken place. - This event MUST be dispatched after any other events caused by the mutation(s) have occurred. -

- -
Warning

Warning! - The DOMSubtreeModified event - type is defined in this specification for reference and completeness, but this specification - deprecates the use of this event type. -

-
-
-
- -
- -
- - -
-

D. Extending Events

-

This section is informative

- -
-

D.1 Introduction

- -

This specification defines several interfaces and many events, however, this is not - an exhaustive set of events for all purposes. - To allow content authors and implementers to add desired functionality, this specification - provides two mechanisms for extend this set of interfaces and events without creating conflicts: - custom events - and implementation-specific extensions. -

-
- -
-

D.2 Custom Events

- -

A script author MAY wish to define an application in terms of functional components, with event - types that are meaningful to the application architecture. - The content author can use the CustomEvent interface - to create their own events appropriate to the level of abstraction they are using. -

- -
-
-

A content author might have created an application which features a dynamically generated bar chart. - This bar chart is meant to be updated every 5 minutes, or when a feed shows new information, or - when the user refreshes it manually by clicking a button. - There are several handlers that have to be called when the chart needs to be updated: - the application has to fetch the most recent data, show an icon to the user that the event is being - updated, and rebuild the chart. - To manage this, the content author can choose to create a custom updateChart event, - which is fired whenever one of the trigger conditions is met: -

-

-var chartData = ...;
-var evt = document.createEvent("CustomEvent");
-evt.initCustomEvent( "updateChart", true, false, { data: chartData });
-document.documentElement.dispatchEvent(evt);
-
-
-
- -
-

D.3 Implementation-Specific Extensions

- -

While a new event is being designed and prototyped, or when an event is intended for implementation-specific - functionality, it is desirable to distinguish it from standardized events. - Implementors SHOULD prefix event types specific to their implementations with a short string to distinguish - it from the same event in other implementations and from standardized events. - This is similar to the - vendor-specific keyword prefixes - in CSS, though without the dashes ("-") used in CSS, since that can cause problems when used - as an attribute name in Javascript. -

- -
-
-

A particular browser vendor, FooCorp, might wish to introduce a new event, jump. - This vendor implements fooJump in their browser, using their - vendor-specific prefix: 'foo'. - Early adopters start experimenting with the event, using - someElement.addEventListener("fooJump", doJump, false ), - and provide feedback to FooCorp, who change the behavior of fooJump accordingly. -

- -

After some time, another vendor, BarOrg, decides they also want the functionality, but implement - it slightly differently, so they use their own vendor-specific prefix, "bar" in their - event type name: barJump. - Content authors experimenting with this version of the jump event type - register events with BarOrg's event type name. - Content authors who wish to write code that accounts for both browsers can either register each event type - separately with specific handlers, or use the same handler and switch on the name of the event type. - Thus, early experiments in different codebases do not conflict, and the early adopter is able to write - easily-maintained code for multiple implementations. -

- -

Eventually, as the feature matures, the behavior of both browsers stabilizes and might converge due to - content author and user feedback or through formal standardization. - As this stabilization occurs, and risk of conflicts decrease, content authors can remove the forked code, - and use the jump event type name (even before it is formally standardized) - using the same event handler and the more generic registration method - someElement.addEventListener( "jump", doJump, false). -

-
- -
-

D.3.1 Known Implementation-Specific Prefixes

- -

At the time of writing, the following event-type name prefixes are known to exist: -

- - - - - - - - - - - - - - - - - - - - - - - - - - -
PrefixWeb Engine (Organization)
moz, MozGecko (Mozilla)
ms, MSTrident (Microsoft)
o, OPresto (Opera Software)
webkitWebKit (Apple, Google, others)
-
-
-
- - -
-

E. Security Considerations

- -

This appendix discusses security considerations for UI Events implementations. - The discussion is limited to security issues that arise directly from implementation of the event - model, APIs and events defined in this specification. - Implementations typically support other features like scripting languages, other APIs and - additional events not defined in this document. - These features constitute an unknown factor and are out of scope of this document. - Implementers SHOULD consult the specifications of such features for their respective - security considerations. -

- -

Many of the event types defined in this specification are dispatched in response to user actions. - This allows malicious event listeners to gain access to information users would typically consider - confidential, e.g., typos they might have made when filling out a form, if they reconsider their - answer to a multiple choice question shortly before submitting a form, their typing rate or primary - input mechanism. - In the worst case, malicious event listeners could capture all user interactions and submit them - to a third party through means (not defined in this specification) that are generally available - in DOM implementations, such as the XMLHttpRequest interface. -

- -

In DOM implementations that support facilities to load external data, events like the - error event can provide access to sensitive information about - the environment of the computer system or network. - An example would be a malicious HTML document that attempts to embed a resource on the local network - or the localhost on different ports. - An embedded DOM application could then listen - for error and load events - to determine which other computers in a network are accessible from the local system or which ports - are open on the system to prepare further attacks. -

- -

An implementation of UI Events alone is generally insufficient to perform attacks of this kind - and the security considerations of the facilities that possibly support such attacks apply. - For conformance with this specification, DOM implementations MAY take reasonable steps to ensure that - DOM applications do not get access to confidential - or sensitive information. - For example, they might choose not to dispatch load events to - nodes that attempt to embed resources on the local network. -

- -
- - -
-

F. Changes

- -
-

F.1 Changes between DOM Level 2 Events and UI Events (formerly DOM Level 3 Events)

- -

Numerous clarifications to the interfaces and event types have been made. - The HTMLEvents module is no longer defined in this document. - The focus and blur - events have been added to the UIEvent - module, and the dblclick event has been added to the - MouseEvent module. - This new specification provides a better separation between the DOM event flow, - the event types, and the DOM interfaces. -

- -
-

F.1.1 Changes to DOM Level 2 event flow

- -

This new specification introduced the following new concepts in the event flow: -

- -
    -
  • Event listeners are now ordered. In DOM Level 2, the event ordering was unspecified.
  • -
  • The event flow now includes the Window, to - reflect existing implementations.
  • -
-
- -
-

F.1.2 Changes to DOM Level 2 event types

- -

Many clarifications have been made on the event types. - The conformance is now explicitly defined against the event types, and not only in terms - of interfaces used by the event types. -

- -

"MutationEvents" have been deprecated. - Support for namespaced events, present in early drafts of this specification, has also been removed. -

- -

For user agents which support the - DOMNodeInserted - and - DOMNodeRemoved - event types, this specification no longer requires that the event type be fired for - Attr nodes. -

- -

The resize event type no longer bubbles and the - mousemove event is now cancelable, reflecting existing - implementations. -

-
- -
-

F.1.3 Changes to DOM Level 2 Events interfaces

- -
-
Interface Event
-
The Event interface has one new attribute, - Event.defaultPrevented, - and one new method, - Event.stopImmediatePropagation(). -
- Event.timeStamp is now a Number - in the ECMAScript binding. - A proposed correction to make the same change in - [DOM3 Core] is forthcoming. -
- This specification considers the Event.type attribute - to be case-sensitive, while DOM Level 2 Events considers - Event.type to be case-insensitive. -
- -
Interface EventTarget
-
The method EventTarget.dispatchEvent() - was modified. -
- -
Interface MouseEvent
-
The MouseEvent interface has one new method - MouseEvent.getModifierState(). -
- -
Exception EventException
-
The exception EventException is removed in this - specification. - The prior DISPATCH_REQUEST_ERR code is re-mapped to a DOMException of type - InvalidStateError. -
-
-
- -
-

F.1.4 New Interfaces

- -

The interfaces - CustomEvent, - FocusEvent, - KeyboardEvent, - CompositionEvent, - and WheelEvent - were added to the Events module. -

-
-
- -
-

F.2 Changes between different drafts of UI Events (formerly DOM Level 3 Events)

- -

The DOM Level 3 Events document was originally developed between 2000 and 2003, and published - as a W3C Note, pending further feedback and interest from implementers. - In 2006, it was picked up for revision and progress on the Recommendation Track, and was - then revised to reflect the current state of implementation and the - needs of script authors. -

- -

Despite its status only as a W3C Note, rather than an official Recommendation, DOM 3 Events - saw some implementation, and was also referenced by other specifications, so care - is being taken to cause minimal disruption, while still adapting the specification to the - current environment. -

- -

The current specification has been reordered significantly from the earlier W3C Note form, - and also from the structure of DOM2 Events, in order to clarify the material. - New diagrams have been put in place to represent hierarchies and events flows more clearly. - Here are some of the more important changes between drafts: -

- - -
-
- - -
-

G. Acknowledgements

- -

Many people contributed to the DOM specifications (Level 1, 2 or 3), including - participants of the DOM Working Group, the DOM Interest Group, - the WebAPI Working Group, and the WebApps Working Group. - We especially thank the following: -

- -

Andrew Watson (Object Management Group), - Andy Heninger (IBM), - Angel Diaz (IBM), - Anne van Kesteren (Opera Software), - Arnaud Le Hors (W3C and IBM), - Arun Ranganathan (AOL), - Ashok Malhotra (IBM and Microsoft), - Ben Chang (Oracle), - Bill Shea (Merrill Lynch), - Bill Smith (Sun), - Björn Höhrmann, - Bob Sutor (IBM), - Charles McCathie-Nevile (Opera Software, Co-Chair), - Chris Lovett (Microsoft), - Chris Wilson (Microsoft), - Christophe Jolif (ILOG), - David Brownell (Sun), - David Ezell (Hewlett-Packard Company), - David Singer (IBM), - Dean Jackson (W3C, W3C Team Contact), - Dimitris Dimitriadis (Improve AB and invited expert), - Don Park (invited), - Doug Schepers (Vectoreal), - Elena Litani (IBM), - Eric Vasilik (Microsoft), - Gavin Nicol (INSO), - Gorm Haug Eriksen (Opera Software), - Ian Davis (Talis Information Limited), - Ian Hickson (Google), - Ian Jacobs (W3C), - James Clark (invited), - James Davidson (Sun), - Jared Sorensen (Novell), - Jeroen van Rotterdam (X-Hive Corporation), - Joe Kesselman (IBM), - Joe Lapp (webMethods), - Joe Marini (Macromedia), - John Robinson (AOL), - Johnny Stenback (Netscape/AOL), - Jon Ferraiolo (Adobe), - Jonas Sicking (Mozilla Foundation), - Jonathan Marsh (Microsoft), - Jonathan Robie (Texcel Research and Software AG), - Kim Adamson-Sharpe (SoftQuad Software Inc.), - Lauren Wood (SoftQuad Software Inc., former Chair), - Laurence Cable (Sun), - Luca Mascaro (HTML Writers Guild), - Maciej Stachowiak (Apple Computer), - Marc Hadley (Sun Microsystems), - Mark Davis (IBM), - Mark Scardina (Oracle), - Martin Dürst (W3C), - Mary Brady (NIST), - Michael Shenfield (Research In Motion), - Mick Goulish (Software AG), - Mike Champion (Arbortext and Software AG), - Miles Sabin (Cromwell Media), - Patti Lutsky (Arbortext), - Paul Grosso (Arbortext), - Peter Sharpe (SoftQuad Software Inc.), - Phil Karlton (Netscape), - Philippe Le Hégaret (W3C, W3C Team Contact and former Chair), - Ramesh Lekshmynarayanan (Merrill Lynch), - Ray Whitmer (iMall, Excite@Home, and Netscape/AOL, Chair), - Rezaur Rahman (Intel), - Rich Rollman (Microsoft), - Rick Gessner (Netscape), - Rick Jelliffe (invited), - Rob Relyea (Microsoft), - Robin Berjon (Expway, Co-Chair), - Scott Hayman (Research In Motion), - Scott Isaacs (Microsoft), - Sharon Adler (INSO), - Stéphane Sire (IntuiLab), - Steve Byrne (JavaSoft), - Tim Bray (invited), - Tim Yu (Oracle), - Tom Pixley (Netscape/AOL), - T.V. Raman (Google). - Vidur Apparao (Netscape) and - Vinod Anupam (Lucent). -

- -

Former editors: - Tom Pixley (Netscape Communications Corporation) until July 2002, - Philippe Le Hégaret (W3C) until November 2003, - Björn Höhrmann (Invited Expert) until January 2008, - Doug Schepers (W3C) from March 2008 to May 2011, - and Jacob Rossi (Microsoft) from March 2011 to October 2011. -

- -

Contributors: - In the WebApps Working Group, the following people made substantial material contributions - in the process of refining and revising this specification: - Bob Lund (Cable Laboratories), - Cameron McCormack (Invited Expert / Mozilla), - Daniel Danilatos (Google), - Gary Kacmarcik (Google), - Glenn Adams (Samsung), - Hallvord R. M. Steen (Opera), - Hironori Bono (Google), - Mark Vickers (Comcast), - Masayuki Nakano (Mozilla), - Olli Pettay (Mozilla), - Takayoshi Kochi (Google) and - Travis Leithead (Microsoft). -

- -

Glossary contributors: - Arnaud Le Hors (W3C) and - Robert S. Sutor (IBM Research). -

- -

Test suite contributors: - Carmelo Montanez (NIST), - Fred Drake, - Mary Brady (NIST), - Neil Delima (IBM), - Rick Rivello (NIST), - Robert Clary (Netscape), - with a special mention to Curt Arnold. -

- -

Thanks to all those who have helped to improve this specification by sending suggestions and - corrections (please, keep bugging us with your issues!), or writing informative books or Web sites: - Al Gilman, - Alex Russell, - Alexander J. Vincent, - Alexey Proskuryakov, - Arkadiusz Michalski, - Brad Pettit, - Cameron McCormack, - Curt Arnold, - David Flanagan, - Dylan Schiemann, - Erik Arvidsson, - Garrett Smith, - Giuseppe Pascale, - James Su, - Jan Goyvaerts (regular-expressions.info), - Jorge Chamorro, - Kazuyuki Ashimura, - Ken Rehor, - Magnus Kristiansen, - Martijn Wargers, - Martin Dürst, - Michael B. Allen, - Mike Taylor, - Misha Wolf, - Ojan Vafai, - Oliver Hunt, - Paul Irish, - Peter-Paul Koch, - Richard Ishida, - Sean Hogan, - Sergey Ilinsky, - Sigurd Lerstad, - Steven Pemberton, - Tony Chang, - William Edney and - Øistein E. Andersen. -

- -
-

G.1 Production Systems

- -

The current drafts of this specification are lovingly hand-crafted in HTML and SVG, using ReSpec - and custom scripts to format the document according to W3C requirements. -

- -

Earlier versions of this specification were written in XML — the HTML, OMG IDL, Java and - ECMAScript bindings were all produced automatically. - Thanks to Joe English, author of cost, - which was used as the basis for producing DOM Level 1. - Thanks also to Gavin Nicol, who wrote the scripts which run on top of cost. - Arnaud Le Hors and Philippe Le Hégaret maintained the scripts. -

- -

After DOM Level 1, - Xerces - was used as the basis DOM implementation and wish to thank the authors. - Philippe Le Hégaret and Arnaud Le Hors wrote the - Java programs - which are the DOM application. -

- -

Thanks also to Jan Kärrman, author of - html2ps, - which was previously used to generate PostScript versions of the specification. -

-
-
- - -
-

H. Glossary

- -

Some of the following term definitions have been borrowed or modified from similar definitions in other W3C or standards documents. See the links within - the definitions for more information.

- -
-
activation behavior
-
The action taken when an event, typically initiated by users through an input device, causes an element to fulfill a - defined task. The task MAY be defined for that element by the host language, or by - author-defined variables, or both. The default task for any given element MAY be a generic action, or MAY be - unique to that element. For example, the activation behavior of an HTML or SVG <a> element is to cause the - user agent to traverse the link specified in the href attribute, with the further optional parameter - of specifying the browsing context for the traversal (such as the current window or tab, a named window, or a new window). The activation behavior of an HTML - <input> element with the type attribute value submit is be to send the values of the form elements to an - author-defined IRI by the author-defined HTTP method. See Activation triggers and behavior for more details.
- -
activation trigger
-
An event which is defined to initiate an activation behavior. Refer to - Activation triggers and behavior for more details.
- -
author
-
In the context of this specification, an author, content author, or script author is a person who writes script or other executable - content that uses the interfaces, events, and event flow defined in this specification. See Content authors and content conformance - category for more details.
- -
body element
-
In HTML or XHTML documents, the body element represents the contents of the document. In a well-formed HTML document, the body element is a first descendant of - the root element.
- -
bubbling phase
-
The process by which an event can be handled by one of the target's ancestors after being handled by the - event target. See the description of the bubble phase in the context - of event flow for more details.
- -
capture phase
-
The process by which an event can be handled by one of the target's ancestors before being handled by the - event target. See the description of the capture phase in the context - of event flow for more details.
- -
candidate event handlers
-
candidate event listeners
-
The list of all event listeners that have been registered on the target object in their order of registration. This - list is captured or frozen before event listeners on the target object are dispatched, and released or un-frozen after this set of candidate event - handlers have been dispatched (allowing these event listeners to add or remove additional listeners on other objects in an event's propagation chain, but not affect - the order of listeners that will be invoked on the target object). - -
Note

Note: Initially capturing the candidate event handlers prevents infinite loops of event listener dispatch on a given target object.

-
- -
character value
-
In the context of key values, a character value is a string representing one or more Unicode characters, such as a letter or symbol, or a set of letters. In this - specification, character values are denoted as a unicode string (e.g., '\u0020') or a glyph representation of the same code point (e.g., - ' '), and are color coded to help distinguish these two representations. -
Note

Note: In source code, some key values, such as non-graphic characters, can be represented using - the character escape syntax of the programming language in use.

-
- -
current event target
-
In an event flow, the current event target is the object associated with the event handler that is currently being - dispatched. This object MAY be the event target itself or one of its ancestors. The current event target changes as the - event propagates from object to object through the various phases of the event flow. - The current event target is the value of the Event.currentTarget attribute.
- -
dead key
-
A dead key is a key or combination of keys which produces no character by itself, but which in combination or sequence with another key produces a modified character, - such as a character with diacritical marks (e.g., ö, é, â).
- -
default action
-
A default action is an OPTIONAL supplementary behavior that an implementation - MUST perform in combination with the dispatch of the event object. Each event type definition, and each specification, defines the - default action for that event type, if it has one. An instance of an event MAY have more than - one default action under some circumstances, such as when associated with an - activation trigger. A default action MAY - be cancelled through the invocation of the Event.preventDefault() method. For more details, see - Default actions and cancelable events.
- -
delta
-
The estimated scroll amount (in pixels, lines, or pages) that the user agent will scroll or zoom the page in response to the physical movement of an input device that - supports the WheelEvent interface (such as a mouse wheel or touch pad). The value of a delta (e.g., the deltaX, deltaY, or deltaZ attributes) is to be - interpreted in the context of the current deltaMode property. The relationship between the physical movement of - a wheel (or other device) and whether the delta is positive or negative is environment and device dependent. However, if a user - agent scrolls as the default action then the sign of the delta is given by a - right-hand coordinate system where positive X,Y, and Z axes are directed towards the right-most edge, bottom-most edge, and farthest depth (away from the user) of the - document, respectively.
- -
deprecated
-
Features marked as deprecated are included in the specification as reference to older implementations or specifications, but are OPTIONAL - and discouraged. Only features which have existing or in-progress replacements MUST be deprecated in this specification. Implementations - which do not already include support for the feature MAY implement deprecated features for reasons of backwards compatibility with existing - content, but content authors creating content SHOULD NOT use deprecated features, unless there is no other way to solve a use case. - Other specifications which reference this specification SHOULD NOT use deprecated features, but SHOULD - point instead to the replacements of which the feature is deprecated in favor. Features marked as deprecated in this specification are expected to be dropped from - future specifications.
- -
dispatch
-
To create an event with attributes and methods appropriate to its type and context, and propagate it through the DOM tree in the specified manner. Interchangeable - with the term fire, e.g., fire a click event or dispatch - a load event.
- -
document
-
An object instantiating the Document interface - [DOM3 Core], representing the entire HTML or XML text document. Conceptually, it is the root of - the document tree, and provides the primary access to the document's data.
- -
DOM application
-
A DOM application is script or code, written by a content author or automatically generated, which takes advantage of the interfaces, methods, attributes, events, - and other features described in this specification in order to make dynamic or interactive content, such as Web applications, exposed to users in a user agent.
- -
DOM Level 0
-
The term DOM Level 0 refers to a mix of HTML document functionalities, often not formally specified but traditionally supported as de facto standards, implemented - originally by Netscape Navigator version 3.0 or Microsoft Internet Explorer version 3.0. In many cases, attributes or methods have been included for reasons of - backward compatibility with DOM Level 0.
- -
empty string
-
The empty string is a value of type DOMString of length 0, i.e., a string which contains no characters (neither printing nor control - characters).
- -
event
-
An event is the representation of some occurrence (such as a mouse click on the presentation of an element, the removal of child node from an element, or any number - of other possibilities) which is associated with its event target. Each event is an instantiation - of one specific event type.
- -
event focus
-
Event focus is a special state of receptivity and concentration on an particular element or other event target within - a document. Each element has different behavior when focused, depending on its functionality, such as priming the element for activation (as for a button or hyperlink) - or toggling state (as for a checkbox), receiving text input (as for a text form field), or copying selected text. For more details, see - Document Focus and Focus Context.
- -
event focus ring
-
An event focus ring is an ordered set of event focus targets within a document. A - host language MAY define one or more ways to determine the order of targets, such as document order, a numerical index defined per focus target, explicit pointers - between focus targets, or a hybrid of different models. Each document MAY contain multiple focus rings, or conditional focus rings. Typically, for document-order - or indexed focus rings, focus wraps around from the last focus target to the first.
- -
event handler
-
event listener
-
An object that implements the EventListener interface and provides an - EventListener.handleEvent() callback method. Event handlers are language-specific. Event handlers are invoked in the context of a particular object - (the current event target) and are provided with the event object itself. - -
Note

Note: In JavaScript, user-defined functions are considered to implement the EventListener interface. Thus the - event object will be provided as the first parameter to the user-defined function when it is invoked. Additionally, JavaScript objects can also implement - the EventListener interface when they define a handleEvent method.

-
- -
event order
-
The sequence in which events from the same event source or process occur, using the same or related event interfaces. For example, in an environment with a mouse, - a track pad, and a keyboard, each of those input devices would constitute a separate event source, and each would follow its own event order. A mousedown event from the trackpad followed by a mouseup - event from the mouse would not result in a click event. - -
Note

Note: There can be interactions between different event orders. For example, a click event might - be modified by a concurrent keydown event ('Shift'+click). However, the event orders - of these different event sources would be distinct.

- - The event order of some interfaces are device-independent. For example, a user might change focus using the 'Tab' - key, or by clicking the new focused element with the mouse. The event order in such cases depends on the state of the process, not on the state of the device that - initiates the state change.
- -
event phase
-
See phase.
- -
event target
-
The object to which an event is targeted using the DOM event flow. The event target is the - value of the Event.target attribute.
- -
event type
-
An event type is an event object with a particular name and which defines particular trigger conditions, properties, - and other characteristics which distinguish it from other event types. For example, the click event - type has different characteristics than the mouseover or - load event types. The event type is exposed as the Event.type - attribute on the event object. See event types for more details. Also loosely referred to as 'event', such as the click event.
- -
fire
-
A synonym for dispatch.
- -
host language
-
Any language which integrates the features of another language or API specification, while normatively referencing the origin specification rather than redefining - those features, and extending those features only in ways defined by the origin specification. An origin specification typically is only intended to be implemented - in the context of one or more host languages, not as a standalone language. For example, XHTML, HTML, and SVG are host languages for UI Events, and they integrate - and extend the objects and models defined in this specification.
- -
hysteresis
-
A feature of human interface design to accept input values within a certain range of location or time, in order to improve the user experience. For example, allowing - for small deviation in the time it takes for a user to double-click a mouse button is temporal hysteresis, and not immediately closing a nested menu if the user - mouses out from the parent window when transitioning to the child menu is locative hysteresis.
- -
IME
-
input method editor
-
An input method editor (IME), also known as a front end processor, is an application that performs the conversion between keystrokes and ideographs - or other characters, usually by user-guided dictionary lookup, often used in East Asian languages (e.g., Chinese, Japanese, Korean). An - IME MAY also be used for dictionary-based word completion, such as on mobile devices. See Input Method Editors for treatment of - IMEs in this specification. See also text composition system.
- -
key mapping
-
Key mapping is the process of assigning a key value to a particular key, and is the result of a combination of several factors, including the operating system - and the keyboard layout (e.g., QWERTY, Dvorak, Spanish, InScript, Chinese, etc.), and after taking into account all modifier key ('Shift', 'Alt', etc.) and - dead key states.
- -
key value
-
A key value is a character value or multi-character string (such as 'Enter', - 'Tab', or 'MediaTrackNext') associated - with a key in a particular state. Every key has a key value, whether or not it has a character value. This includes - control keys, function keys, modifier keys, dead keys, and any other key. - The key value of any given key at any given time depends upon the key mapping.
- -
local name
-
See local name in [XML Namespaces 1.0].
- -
modifier key
-
A modifier key changes the normal behavior of a key, such as to produce a character of a different case (as with the 'Shift' - key), or to alter what functionality the key triggers (as with the 'Fn' or 'Alt' - keys). Refer to Modifier keys - for a list of modifier keys.
- -
namespace URI
-
A namespace URI is a URI that identifies an XML namespace. This is called the namespace name in [XML - Namespaces 1.0]. See also sections 1.3.2 DOM URIs - and 1.3.3 XML Namespaces regarding URIs and namespace - URIs handling and comparison in the DOM APIs.
- -
phase
-
In the context of events, a phase is set of logical traversals from node to node along the DOM tree, from the Window to the Document object, root element, and down - to the event target (capture phase), at the - event target itself (target phase), and back up the same chain (bubbling - phase).
- -
propagation path
-
The ordered set of current event targets though which an event object will pass - sequentially on the way to and back from the event target. As the event propagates, each current event target in the propagation path is in turn set as the Event.currentTarget. - The propagation path is initially composed of one or more event phases as defined by the - event type, but MAY be interrupted. Also known as an event target chain.
- -
QWERTY
-
QWERTY (pronounced ˈkwɜrti) is a common keyboard layout, so named because the first five character keys on the top row of letter keys are Q, - W, E, R, T, and Y. There are many other popular keyboard layouts (including the Dvorak and Colemak layouts), most designed for localization or ergonomics.
- -
root element
-
The first element node of a document, of which all other elements are children. The document element.
- -
rotation
-
An indication of incremental change on an input device using the WheelEvent interface. On some devices this MAY be a literal - rotation of a wheel, while on others, it MAY be movement along a flat surface, or pressure on a particular button.
- -
target phase
-
The process by which an event can be handled by the event target. - See the description of the target phase in the context of event flow for more details.
- -
text composition system
-
A software component that interprets some form of alternate input (such as a input method editor, a speech processor, or - a handwriting recognition system) and converts it to text.
- -
topmost event target
-
The topmost event target MUST be the element highest in the rendering order which is capable of being - an event target. In graphical user interfaces this is the element under the user's pointing device. A user - interface's hit testing facility is used to determine the target. For specific details regarding hit testing and stacking order, refer to the - host language.
- -
tree
-
A data structure that represents a document as a hierarchical set of nodes with child-parent-sibling relationships, i.e., each node having one or more possible - ancestors (nodes higher in the hierarchy in a direct lineage), one or more possible descendants (nodes lower in the hierarchy in a direct lineage), and one or more - possible peers (nodes of the same level in the hierarchy, with the same immediate ancestor).
- -
Unicode character categories
-
A subset of the General Category values that are defined for each Unicode code point. This subset contains all the - Letter (Ll, - Lm, - Lo, - Lt, - Lu), - Number (Nd, - Nl, - No), - Punctuation (Pc, - Pd, - Pe, - Pf, - Pi, - Po, - Ps) - and Symbol (Sc, - Sk, - Sm, - So) - category values.
- -
Unicode code point
-
A Unicode code point is a unique hexadecimal number signifying a character by its index in the Unicode codespace (or library of characters). In the context of - key values, a Unicode code point is expressed as a string in the format \u followed by a hexadecimal character index in the range 0000 - to 10FFFF, using at least four digits. See also character value.
- -
un-initialized value
-
The value of any event attribute (such as Event.bubbles or - Event.currentTarget) before the event has been initialized with Event.initEvent(). The un-initialized - values of an event apply immediately after a new event has been created using the method - DocumentEvent.createEvent().
- -
user agent
-
A program, such as a browser or content authoring tool, normally running on a client machine, which acts on a user's behalf in retrieving, interpreting, executing, - presenting, or creating content. Users MAY act on the content using different user agents at different times, for different purposes. See the - Web browsers and other dynamic or interactive user agents and Authoring tools for details on the requirements for a conforming - user agent.
- -
Window
-
The Window is the object referred to by the current document's browsing context's Window Proxy object as defined in HTML5 [HTML5].
-
-
- - -
-

I. References

- -

For the latest version of any W3C specification please consult the list of - W3C Technical Reports - available at http://www.w3.org/TR/. -

- -
-

I.1 Normative References

- -
-
[BCP-47] Best Current Practice 47: Tags for Identifying Languages
-
A. Phillips, M. Davis, Editors,
- September 2009.
- The specification for describing the structure, content, construction, and semantics of language tags - to indicate the human language used. - Available at http://www.rfc-editor.org/rfc/bcp/bcp47.txt. -
- -
[DOM2 Events]
-
Document Object Model Level 2 Events Specification,
- T. Pixley, Editor.
- World Wide Web Consortium, November 2000.
- This version of the Document Object Model Level 2 Events Specification is http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113.
- The latest version of Document Object Model Level 2 Events - is available at http://www.w3.org/TR/DOM-Level-2-Events/. -
- -
[DOM3 Core]
-
Document Object Model Level 3 Core Specification,
- A. Le Hors, et al., Editors.
- World Wide Web Consortium, April 2004.
- This version of the Document Object Model Level 3 Core Specification is http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/.
- The latest version of DOM Level 3 Core - is available at http://www.w3.org/TR/DOM-Level-3-Core/. -
- -
[DOM3 code Values]
-
DOM Level 3 KeyboardEvent code Values,
- G. Kacmarcik, T. Leithead, Editors.
- World Wide Web Consortium, April 2014.
- This version of the DOM Level 3 KeyboardEvent code Values is http://www.w3.org/TR/DOM-Level-3-Events-code/.
-
- -
[DOM3 key Values]
-
DOM Level 3 KeyboardEvent key Values,
- G. Kacmarcik, T. Leithead, Editors.
- World Wide Web Consortium, April 2014.
- This version of the DOM Level 3 KeyboardEvent key Values is http://www.w3.org/TR/DOM-Level-3-Events-key/.
-
- -
[ECMAScript]
-
ECMAScript Language Specification,
- 5.1 Edition.
- European Computer Manufacturers Association, Standard ECMA-262, June 2011.
- This version of the ECMAScript Language is available from http://ecma-international.org/ecma-262/5.1/. -
- -
[HTML5]
-
HTML 5,
- I. Hickson, Editor.
- World Wide Web Consortium, W3C Recommendation, October 2014.
- This edition of HTML 5 is http://www.w3.org/TR/2014/REC-html5-20141028/.
- The latest edition of HTML 5 is available at http://www.w3.org/TR/html5/. -
- -
[Java]
-
The Java Language Specification,
- J. Gosling, B. Joy, and G. Steele, Authors.
- Addison-Wesley, September 1996.
- Available at http://java.sun.com/docs/books/jls. -
- - -
[RFC2119] Key words for use in RFCs to indicate Requirement Levels
-
S Bradner, 1997.
- The specification for how to use English to specify normativity, as if it were a technical language. - Available at http://www.ietf.org/rfc/rfc2119.txt. -
- -
[UAX #15]
-
Unicode Normalization Forms,
- The Unicode Standard Annex #15. The Unicode Consortium, 2006.
- The latest version of this annex is available at http://www.unicode.org/reports/tr15/. -
- -
[InputEvents]
-
Input Events,
- Ben Peters, Editor.
- Not yet published. -
- -
[UIEvents]
-
UI Events,
- G. Kacmarcik, T. Leithead, Editors.
- World Wide Web Consortium, W3C Working Group Note, 12 June 2014. -
- -
[Unicode]
-
The Unicode Standard, Version 5.0,
- ISBN 0-321-48091-0, as updated periodically by the publication of new versions.
- See also Versions of the Unicode Standard, - available at http://www.unicode.org/standard/versions/ for - latest version and additional information on versions of the standard and of the Unicode Character Database. -
- -
[WEB IDL]
-
Web IDL,
- C. McCormack. 19 April 2012.
- This version of the Web IDL Candidate Recommendation is: http://www.w3.org/TR/2012/CR-WebIDL-20120419/.
- The latest version of Web IDL is available at - http://heycam.github.io/webidl/. -
- -
[XML Namespaces 1.0]
-
Namespaces in XML 1.0,
- T. Bray, D. Hollander, A. Layman, and R. Tobin, Editors.
- World Wide Web Consortium, 16 August 2006.
- This version of the Namespaces in XML 1.0 Specification is http://www.w3.org/TR/2006/REC-xml-names-20060816.
- The latest version of Namespaces in XML 1.0 - is available at http://www.w3.org/TR/xml-names/. -
-
-
- -
-

I.2 Informative References

-
-
[ARIA]
-
Accessible Rich Internet Applications (WAI-ARIA) Version 1.0,
- J. Craig, M. Cooper, R. Schwerdtfeger, L. Seeman, L. Pappas, Editors.
- World Wide Web Consortium, 18 January 2011.
- This version of the WAI-ARIA Candidate Recommendation is http://www.w3.org/TR/2011/CR-wai-aria-20110118/.
- The latest edition of WAI-ARIA is available at http://www.w3.org/TR/wai-aria/. -
- -
[CSS2.1]
-
Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification,
- B. Bos, T. Çelik, I. Hickson, H.W. Lie, Editors.
- World Wide Web Consortium, 07 June 2011.
- This version of the CSS 2.1 Recommendation is http://www.w3.org/TR/2011/REC-CSS2-20110607/.
- The latest version of CSS 2.1 is available at http://www.w3.org/TR/CSS2/. -
- -
[DOM2 Range]
-
Document Object Model (DOM) Level 2 Traversal and Range Specification,
- J. Kesselman, J. Robie, M. Champion, P. Sharpe, V. Apparao, L. Wood, Editors.
- World Wide Web Consortium, November 2000. -
- -
[DOM3 Load and Save]
-
Document Object Model Level 3 Load and Save Specification,
- J. Stenback, A. Heninger, Editors.
- World Wide Web Consortium, April 2004.
- This version of the DOM Level 3 Load and Save Specification is http://www.w3.org/TR/2004/REC-DOM-Level-3-LS-20040407/.
- The latest version of DOM Level 3 Load and Save - is available at http://www.w3.org/TR/DOM-Level-3-LS/. -
- -
[DOM4]
-
W3C DOM4,
- A. van Kesteren, A. Gregor, Ms2ger, Alex Russell, Robin Berjon, Editors.
- World Wide Web Consortium, Working Draft, 10 July 2014. -
- -
[DWW95]
-
Developing International Software for Windows 95 and Windows NT: A Handbook for International Software Design,
- N. Kano, Author.
- Microsoft Press, 1995. ISBN 1-55615-840-8. -
- -
[HTML 4.01]
-
HTML 4.01 Specification,
- D. Raggett, A. Le Hors, and I. Jacobs, Editors.
- World Wide Web Consortium, December 1999.
- This version of the HTML 4.01 Recommendation is http://www.w3.org/TR/1999/REC-html401-19991224.
- The - latest version of HTML 4 is available at http://www.w3.org/TR/html4/. -
- -
[HTML Editing]
-
HTML Editing APIs,
- A. Gregor, Editor.
- World Wide Web Consortium, work in progress, 13 February 2014. -
- -
[KeyProps]
-
Legacy Keyboard Event Properties,
- D. Schepers, Editor.
- World Wide Web Consortium, work in progress, 04 August 2010.
- This edition of Legacy Keyboard Event Properties is https://dvcs.w3.org/hg/dom3events/raw-file/tip/html/Note-KeyProps.html.
- The latest edition of Legacy Keyboard Event Properties - is available at https://dvcs.w3.org/hg/dom3events/raw-file/tip/html/Note-KeyProps.html. -
- -
[PCRE]
-
Perl Compatible Regular Expressions library.
- Available at http://www.pcre.org/. -
- -
[RFC20] ASCII format for Network Interchange
-
V. Cerf, 1969.
- Available at http://tools.ietf.org/rfc/rfc20.txt -
- -
[US-ASCII] Coded Character Set - 7-Bit American Standard Code for Information Interchange
-
Standard ANSI X3.4-1986, ANSI, 1986. -
- -
[UAAG 2.0]
-
User Agent Accessibility Guidelines (UAAG) 2.0,
- J. Allan, K. Ford, J. Richards, J. Spellman, Editors.
- World Wide Web Consortium, work in progress, 8 March 2010.
- This version of the UAAG 2.0 specfication is http://www.w3.org/WAI/UA/2010/ED-UAAG20-20100308/.
- The latest version of UAAG 2.0 is available at http://www.w3.org/TR/UAAG20/. -
- -
[WIN1252]
-
Windows 1252 a Coded Character Set - 8-Bit.
- Microsoft Corporation. -
- -
[XFORMS]
-
XForms 1.1,
- J. Boyer, Editor.
- World Wide Web Consortium, work in progress, 20 October 2009.
- This edition of XForms 1.1 is http://www.w3.org/TR/2009/REC-xforms-20091020/.
- The latest edition of XForms is available at http://www.w3.org/TR/xforms/. -
- -
[XML 1.0]
-
Extensible Markup Language (XML) 1.0,
- T. Bray, J. Paoli, C. M. Sperberg-McQueen, et. al, Editors.
- World Wide Web Consortium, August 2006.
- This version of the XML 1.0 Recommendation is http://www.w3.org/TR/2006/REC-xml-20060816/.
- The latest version of XML 1.0 is available at http://www.w3.org/TR/xml/. -
-
-
-
- - - diff --git a/w3c-tr.css b/w3c-tr.css deleted file mode 100644 index 9abdf58..0000000 --- a/w3c-tr.css +++ /dev/null @@ -1,200 +0,0 @@ -/*Proposed Typographic Conventions for W3C TR docs*/ - -/* For usage, see http://www.w3.org/StyleSheets/spec-conventions.html */ - -.element, .attr, .prop, .attr-value, .prop-value { - font-family: monospace; - font-weight: bold; - font-size: 1.1em; -} - -.element { - color: brown; -} - -.attr { - color: darkgreen; -} - -.prop { - color: navy; -} - -code.attr-value { - background-color: lightgreen; - color: midnightblue; -} - -code.prop-value { - background-color: powderblue; - color: midnightblue; -} - -.attribute-value { - background-color: lightgreen; - color: midnightblue; -} - -.property-value { - background-color: powderblue; - color: midnightblue; -} - -var { - font-family: monospace; -} - -dfn { - font-style: italic; -} - -.term { - font-style: italic; -} - -.term-ref { - font-style: normal; -} - -a.term-ref { - color: black; -} - -.issue, .atrisk, .proposal, .warning, .idl { - font-style: normal; -} - -.issue, .atrisk, .proposal, .idl { - border-style: solid; - border-width: 1px; - padding: 0.1em 0.2em 0em; -} - -div.note, p.note, -div.issue, p.issue, -.idl { - padding: .5em; - margin: 1.4em 1em; - border-style: none; - border-left: 0.3em solid; -} - -div.note, p.note { - border-left: thick double; -} - -.note { - color: green; -} - -pre { - font-family: monospace; - font-style: normal; -} - -.idl { - font-family: monospace; - color: black; - background-color: aliceblue; - border-color: lightsteelblue; -} - - -/* Warnings */ - -div.warning, p.warning { - padding: 1em; - margin: 1.4em 1em; - border-style: none; - border-left: 0.3em solid; -} - -.warning { - color: darkred; - background-color: mistyrose; -} - -.warning > strong:before, .warning > p > strong:before { - /* - content: "\025BA"; - content: "\02623"; - content: "\026A1"; - */ - content: "\026A0"; -} - - -/* Issues */ - -.issue { - background-color: white; - color: crimson; - border: thin solid crimson; -} - -.issue > strong:before, .issue > p > strong:before { - /* - content: "\025BA \000a0\000a0"; - content: "\02623 \000a0\000a0"; - content: "\026A1 \000a0\000a0"; - content: "\025CA \000a0\000a0"; - */ - content: "\026A1 \000a0\000a0"; -} - -.issue a { - color: gold; -} - - -/* Proposal */ - -.proposal { - border: green dotted 2px; -} - -i.proposal { - border-width: 1px; -} - -.atrisk { - background-color: lavenderblush; - border: red dashed 1.5px; -} - -.change { - background-color: greenyellow; -} - - -/* Example */ - -.example { -/* border-bottom: 1px solid orange; - border-top: 1px solid orange; -*//* background-color: lightyellow;*/ - border-bottom: 1px solid #FF4500; - border-top: 1px solid #FF4500; - background-color: white; -} - -div.example { - margin-top: 1em; - padding: 1em; -} - -p.example > strong, div.example > p > strong { -/* background-color: orange;*/ -/* color: lightyellow;*/ - background-color: #FF4500; - color: white; - padding: 0em 0.2em 0em 0.4em; - letter-spacing: 0.05em; -} - -div.example > p > strong { - display: block; - width: 5em; - margin: -2em 0em 1em -1em; - padding: 0.2em 0.2em 0.1em 0.4em; -}