fix: get is_focused value dynamically (#191)

* feat: write example to test against

* feat: use `activeApplication` to get focused app

* refactor: leave window creation out of the loop

* refactor(mac): make `is_focused` a computed function

* refactor(linux): make `is_focused` a computed function

* refactor(windows): make `is_focused` a computed function

* fix(windows): add struct closing

examples/focused_window.rs

@@ -0,0 +1,25 @@
+use std::thread;
+use xcap::Window;
+
+fn main() {
+    thread::sleep(std::time::Duration::from_secs(3));
+
+    let windows = Window::all().unwrap();
+
+    loop {
+        windows.iter().filter(|w| w.is_focused()).for_each(|focused| {
+            println!(
+                "Focused Window:\n id: {}\n title: {}\n app_name: {}\n monitor: {:?}\n position: {:?}\n size {:?}\n state {:?}\n",
+                focused.id(),
+                focused.title(),
+                focused.app_name(),
+                focused.current_monitor().name(),
+                (focused.x(), focused.y(), focused.z()),
+                (focused.width(), focused.height()),
+                (focused.is_minimized(), focused.is_maximized(), focused.is_focused())
+            );
+        });
+
+        thread::sleep(std::time::Duration::from_secs(1));
+    }
+}

src/linux/impl_window.rs

@@ -28,7 +28,6 @@ pub(crate) struct ImplWindow {
     pub height: u32,
     pub is_minimized: bool,
     pub is_maximized: bool,
-    pub is_focused: bool,
 }
 
 fn get_atom(conn: &Connection, name: &str) -> XCapResult<Atom> {
@@ -80,14 +79,15 @@ pub fn get_window_pid(conn: &Connection, window: &Window) -> XCapResult<u32> {
         .copied()
 }
 
-fn get_active_window_id(conn: &Connection) -> Option<u32> {
-    let active_window_atom = get_atom(conn, "_NET_ACTIVE_WINDOW").ok()?;
+fn get_active_window_id() -> Option<u32> {
+    let (conn, _) = Connection::connect(None).ok()?;
+    let active_window_atom = get_atom(&conn, "_NET_ACTIVE_WINDOW").ok()?;
     let setup = conn.get_setup();
 
     for screen in setup.roots() {
         let root_window = screen.root();
         let active_window_id =
-            get_window_property(conn, root_window, active_window_atom, ATOM_NONE, 0, 4).ok()?;
+            get_window_property(&conn, root_window, active_window_atom, ATOM_NONE, 0, 4).ok()?;
         if let Some(&active_window_id) = active_window_id.value::<u32>().first() {
             return Some(active_window_id);
         }
@@ -102,7 +102,6 @@ impl ImplWindow {
         window: &Window,
         pid: u32,
         z: i32,
-        is_focused: bool,
         impl_monitors: &Vec<ImplMonitor>,
     ) -> XCapResult<ImplWindow> {
         let title = {
@@ -215,10 +214,15 @@ impl ImplWindow {
             height,
             is_minimized,
             is_maximized,
-            is_focused,
         })
     }
 
+    pub fn is_focused(&self) -> bool {
+        let active_window_id = get_active_window_id();
+
+        active_window_id.eq(&Some(self.pid))
+    }
+
     pub fn all() -> XCapResult<Vec<ImplWindow>> {
         let (conn, _) = Connection::connect(None)?;
         let setup = conn.get_setup();
@@ -227,7 +231,6 @@ impl ImplWindow {
         // https://specifications.freedesktop.org/wm-spec/1.5/ar01s03.html#id-1.4.4
         // list all windows by stacking order
         let client_list_atom = get_atom(&conn, "_NET_CLIENT_LIST_STACKING")?;
-        let active_window_id = get_active_window_id(&conn);
 
         let mut impl_windows = Vec::new();
         let impl_monitors = ImplMonitor::all()?;
@@ -267,10 +270,7 @@ impl ImplWindow {
                         }
                     };
 
-                    let is_focused = active_window_id.eq(&Some(client.resource_id()));
-
-                    if let Ok(impl_window) =
-                        ImplWindow::new(&conn, client, pid, z, is_focused, &impl_monitors)
+                    if let Ok(impl_window) = ImplWindow::new(&conn, client, pid, z, &impl_monitors)
                     {
                         impl_windows.push(impl_window);
                     } else {

src/macos/impl_window.rs

@@ -11,6 +11,7 @@ use objc2_core_graphics::{
     CGDisplayBounds, CGMainDisplayID, CGRectContainsPoint, CGRectIntersectsRect,
     CGRectMakeWithDictionaryRepresentation, CGWindowListCopyWindowInfo, CGWindowListOption,
 };
+use objc2_foundation::{NSNumber, NSString};
 
 use crate::{error::XCapResult, XCapError};
 
@@ -30,7 +31,6 @@ pub(crate) struct ImplWindow {
     pub height: u32,
     pub is_minimized: bool,
     pub is_maximized: bool,
-    pub is_focused: bool,
 }
 
 unsafe impl Send for ImplWindow {}
@@ -117,7 +117,6 @@ impl ImplWindow {
         window_name: String,
         window_owner_name: String,
         z: i32,
-        focused_app_pid: Option<i32>,
     ) -> XCapResult<ImplWindow> {
         let id = get_cf_number_i32_value(window_cf_dictionary, "kCGWindowNumber")? as u32;
         let pid = get_cf_number_i32_value(window_cf_dictionary, "kCGWindowOwnerPID")?;
@@ -154,8 +153,6 @@ impl ImplWindow {
         let is_minimized =
             !get_cf_bool_value(window_cf_dictionary, "kCGWindowIsOnscreen")? && !is_maximized;
 
-        let is_focused = focused_app_pid.eq(&Some(pid));
-
         Ok(ImplWindow {
             id,
             title: window_name,
@@ -169,17 +166,26 @@ impl ImplWindow {
             height: cg_rect.size.height as u32,
             is_minimized,
             is_maximized,
-            is_focused,
         })
     }
 
+    pub fn is_focused(&self) -> bool {
+        let focused_app_pid = unsafe {
+            let workspace = NSWorkspace::sharedWorkspace();
+            let pid_key = NSString::from_str("NSApplicationProcessIdentifier");
+            workspace
+                .activeApplication()
+                .and_then(|dictionary| dictionary.valueForKey(&pid_key))
+                .and_then(|pid| pid.downcast::<NSNumber>().ok())
+                .map(|pid| pid.intValue())
+        };
+
+        focused_app_pid.eq(&Some(self.pid as i32))
+    }
+
     pub fn all() -> XCapResult<Vec<ImplWindow>> {
         unsafe {
             let impl_monitors = ImplMonitor::all()?;
-            let workspace = NSWorkspace::sharedWorkspace();
-            let focused_app_pid = workspace
-                .frontmostApplication()
-                .map(|focused_app| focused_app.processIdentifier());
 
             let mut impl_windows = Vec::new();
 
@@ -236,7 +242,6 @@ impl ImplWindow {
                     window_name.clone(),
                     window_owner_name.clone(),
                     num_windows as i32 - i as i32 - 1,
-                    focused_app_pid,
                 ) {
                     impl_windows.push(impl_window);
                 } else {

src/window.rs

@@ -76,7 +76,7 @@ impl Window {
     }
     /// The window is focused.
     pub fn is_focused(&self) -> bool {
-        self.impl_window.is_focused
+        self.impl_window.is_focused()
     }
 }
 

src/windows/impl_window.rs

@@ -51,7 +51,6 @@ pub(crate) struct ImplWindow {
     pub height: u32,
     pub is_minimized: bool,
     pub is_maximized: bool,
-    pub is_focused: bool,
 }
 
 fn is_window_cloaked(hwnd: HWND) -> bool {
@@ -330,7 +329,6 @@ impl ImplWindow {
             let rc_client = window_info.rcClient;
             let is_minimized = IsIconic(hwnd).as_bool();
             let is_maximized = IsZoomed(hwnd).as_bool();
-            let is_focused = GetForegroundWindow() == hwnd;
 
             Ok(ImplWindow {
                 hwnd,
@@ -347,11 +345,14 @@ impl ImplWindow {
                 height: (rc_client.bottom - rc_client.top) as u32,
                 is_minimized,
                 is_maximized,
-                is_focused,
             })
         }
     }
 
+    pub fn is_focused(&self) -> bool {
+        unsafe { GetForegroundWindow() == self.hwnd }
+    }
+
     pub fn all() -> XCapResult<Vec<ImplWindow>> {
         // (HWND, i32) 表示当前窗口以及层级，既（窗口，层级 z），i32 表示 max_z_order，既最大的窗口的 z 顺序
         // 窗口当前层级为 max_z_order - z