Merge pull request #5548 from GaborFarkas/fullscreen_event_enum

Fix CHANGETYPE in ol.control.FullScreen

src/ol/control/fullscreencontrol.js

@@ -162,8 +162,8 @@ ol.control.FullScreen.prototype.handleFullScreenChange_ = function() {
 ol.control.FullScreen.prototype.setMap = function(map) {
   ol.control.Control.prototype.setMap.call(this, map);
   if (map) {
-    this.listenerKeys.push(
+    this.listenerKeys.push(ol.events.listen(ol.global.document,
-        ol.events.listen(ol.global.document, ol.control.FullScreen.CHANGETYPE,
+        ol.control.FullScreen.getChangeType_(),
         this.handleFullScreenChange_, this)
     );
   }
@@ -238,18 +238,24 @@ ol.control.FullScreen.exitFullScreen = function() {
 };
 
 /**
- * @type {string}
+ * @return {string} Change type.
+ * @private
  */
-ol.control.FullScreen.CHANGETYPE = (function() {
+ol.control.FullScreen.getChangeType_ = (function() {
+  var changeType;
+  return function() {
+    if (!changeType) {
       var body = document.body;
       if (body.webkitRequestFullscreen) {
-    return 'webkitfullscreenchange';
+        changeType = 'webkitfullscreenchange';
       } else if (body.mozRequestFullScreen) {
-    return 'mozfullscreenchange';
+        changeType = 'mozfullscreenchange';
       } else if (body.msRequestFullscreen) {
-    return 'MSFullscreenChange';
+        changeType = 'MSFullscreenChange';
       } else if (body.requestFullscreen) {
-    return 'fullscreenchange';
+        changeType = 'fullscreenchange';
       }
-  return undefined;
+    }
+    return changeType;
+  };
 })();