From 64f8a8fd7e69971d59fd5025a6b80a541b2bfdf6 Mon Sep 17 00:00:00 2001
From: Jack Reed <pjreed@stanford.edu>
Date: Sat, 29 Aug 2015 10:38:27 -0700
Subject: [PATCH] only allow zoom beyond native if maxZoom param is provided

---
 examples/iiif-example.js | 3 ++-
 leaflet-iiif.js          | 7 +++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/examples/iiif-example.js b/examples/iiif-example.js
index 716f26d..d8fb4ec 100644
--- a/examples/iiif-example.js
+++ b/examples/iiif-example.js
@@ -7,7 +7,8 @@ map = L.map('map', {
 });
 
 stanfordMlk = L.tileLayer.iiif('https://stacks.stanford.edu/image/iiif/hg676jb4964%2F0380_796-44/info.json', {
-  attribution: '<a href="http://searchworks.stanford.edu/view/hg676jb4964">Martin Luther King Jr. & Joan Baez march to integrate schools, Grenada, MS, 1966</a>'
+  attribution: '<a href="http://searchworks.stanford.edu/view/hg676jb4964">Martin Luther King Jr. & Joan Baez march to integrate schools, Grenada, MS, 1966</a>',
+  maxZoom: 6
 }).addTo(map);
 
 princetonMap = L.tileLayer.iiif('http://libimages.princeton.edu/loris2/pudl0076%2Fmap_pownall%2F00000001.jp2/info.json', {
diff --git a/leaflet-iiif.js b/leaflet-iiif.js
index a68e7fe..59fa715 100644
--- a/leaflet-iiif.js
+++ b/leaflet-iiif.js
@@ -13,6 +13,9 @@ L.TileLayer.Iiif = L.TileLayer.extend({
   },
 
   initialize: function(url, options) {
+    if (options.maxZoom) {
+      this._customMaxZoom = true;
+    }
     options = L.setOptions(this, options);
     this._infoDeferred = new $.Deferred();
     this._infoUrl = url;
@@ -133,8 +136,8 @@ L.TileLayer.Iiif = L.TileLayer.extend({
         _this.maxNativeZoom = Math.max(ceilLog2(_this.x / _this.options.tileSize),
           ceilLog2(_this.y / _this.options.tileSize));
         
-        // Enable zooming further than native if needed
-        if (_this.options.maxZoom && _this.options.maxZoom > _this.maxNativeZoom) {
+        // Enable zooming further than native if maxZoom option supplied
+        if (_this._customMaxZoom && _this.options.maxZoom > _this.maxNativeZoom) {
           _this.maxZoom = _this.options.maxZoom;
         }
         else {