Refactor PDFPresentationMode to be more class-like

web/pdf_presentation_mode.js

@@ -18,9 +18,9 @@
 
 'use strict';
 
+var DELAY_BEFORE_RESETTING_SWITCH_IN_PROGRESS = 1500; // in ms
 var DELAY_BEFORE_HIDING_CONTROLS = 3000; // in ms
 var SELECTOR = 'presentationControls';
-var DELAY_BEFORE_RESETTING_SWITCH_IN_PROGRESS = 1000; // in ms
 
 /**
  * @typedef {Object} PDFPresentationModeOptions
@@ -32,30 +32,25 @@ var DELAY_BEFORE_RESETTING_SWITCH_IN_PROGRESS = 1000; // in ms
  *   to the context menu in Presentation Mode.
  */
 
-var PDFPresentationMode = {
-  initialized: false,
-  active: false,
-  args: null,
-  contextMenuOpen: false,
-  mouseScrollTimeStamp: 0,
-  mouseScrollDelta: 0,
-
 /**
+ * @class
+ */
+var PDFPresentationMode = (function PDFPresentationModeClosure() {
+  /**
+   * @constructs PDFPresentationMode
    * @param {PDFPresentationModeOptions} options
    */
-  initialize: function pdfPresentationModeInitialize(options) {
-    this.initialized = true;
+  function PDFPresentationMode(options) {
     this.container = options.container;
     this.viewer = options.viewer || options.container.firstElementChild;
     this.pdfThumbnailViewer = options.pdfThumbnailViewer || null;
     var contextMenuItems = options.contextMenuItems || null;
 
-    window.addEventListener('fullscreenchange', this._fullscreenChange);
-    window.addEventListener('mozfullscreenchange', this._fullscreenChange);
-//#if !(FIREFOX || MOZCENTRAL)
-    window.addEventListener('webkitfullscreenchange', this._fullscreenChange);
-    window.addEventListener('MSFullscreenChange', this._fullscreenChange);
-//#endif
+    this.active = false;
+    this.args = null;
+    this.contextMenuOpen = false;
+    this.mouseScrollTimeStamp = 0;
+    this.mouseScrollDelta = 0;
 
     if (contextMenuItems) {
       for (var i = 0, ii = contextMenuItems.length; i < ii; i++) {
@@ -66,17 +61,19 @@ var PDFPresentationMode = {
         }.bind(this, item.handler));
       }
     }
-  },
+  }
 
+  PDFPresentationMode.prototype = {
     /**
      * Request the browser to enter fullscreen mode.
      * @returns {boolean} Indicating if the request was successful.
      */
-  request: function pdfPresentationModeRequest() {
-    if (!this.initialized || this.switchInProgress || this.active ||
+    request: function PDFPresentationMode_request() {
+      if (this.switchInProgress || this.active ||
           !this.viewer.hasChildNodes()) {
         return false;
       }
+      this._addFullscreenChangeListeners();
       this._setSwitchInProgress();
       this._notifyStateChange();
 
@@ -105,8 +102,8 @@ var PDFPresentationMode = {
      * with large enough motion, to prevent accidental page switches.
      * @param {number} delta - The delta value from the mouse event.
      */
-  mouseScroll: function pdfPresentationModeMouseScroll(delta) {
-    if (!this.initialized && !this.active) {
+    mouseScroll: function PDFPresentationMode_mouseScroll(delta) {
+      if (!this.active) {
         return;
       }
       var MOUSE_SCROLL_COOLDOWN_TIME = 50;
@@ -119,12 +116,12 @@ var PDFPresentationMode = {
       var currentTime = (new Date()).getTime();
       var storedTime = this.mouseScrollTimeStamp;
 
-    // If we've already switched page, avoid accidentally switching page again.
+      // If we've already switched page, avoid accidentally switching again.
       if (currentTime > storedTime &&
           currentTime - storedTime < MOUSE_SCROLL_COOLDOWN_TIME) {
         return;
       }
-    // If the user changes scroll direction, reset the accumulated scroll delta.
+      // If the scroll direction changed, reset the accumulated scroll delta.
       if ((this.mouseScrollDelta > 0 && delta < 0) ||
           (this.mouseScrollDelta < 0 && delta > 0)) {
         this._resetMouseScrollState();
@@ -137,7 +134,7 @@ var PDFPresentationMode = {
         var page = PDFViewerApplication.page;
         this._resetMouseScrollState();
 
-      // If we're already on the first/last page, we don't need to do anything.
+        // If we're at the first/last page, we don't need to do anything.
         if ((page === 1 && pageSwitchDirection === PageSwitchDirection.UP) ||
             (page === PDFViewerApplication.pagesCount &&
              pageSwitchDirection === PageSwitchDirection.DOWN)) {
@@ -158,24 +155,11 @@ var PDFPresentationMode = {
     /**
      * @private
      */
-  _fullscreenChange: function pdfPresentationModeFullscreenChange() {
-    var self = PDFPresentationMode;
-    if (self.isFullscreen) {
-      self._enter();
-    } else {
-      self._exit();
-    }
-  },
-
-  /**
-   * @private
-   */
-  _notifyStateChange: function pdfPresentationModeNotifyStateChange() {
-    var self = PDFPresentationMode;
+    _notifyStateChange: function PDFPresentationMode_notifyStateChange() {
       var event = document.createEvent('CustomEvent');
       event.initCustomEvent('presentationmodechanged', true, true, {
-      active: self.active,
-      switchInProgress: !!self.switchInProgress
+        active: this.active,
+        switchInProgress: !!this.switchInProgress
       });
       window.dispatchEvent(event);
     },
@@ -185,14 +169,15 @@ var PDFPresentationMode = {
      * i.e. when the browser is requested to enter fullscreen mode.
      * This timeout is used to prevent the current page from being scrolled
      * partially, or completely, out of view when entering Presentation Mode.
-   * NOTE: This issue seems limited to certain zoom levels (e.g. 'page-width').
+     * NOTE: This issue seems limited to certain zoom levels (e.g. page-width).
      * @private
      */
-  _setSwitchInProgress: function pdfPresentationMode_setSwitchInProgress() {
+    _setSwitchInProgress: function PDFPresentationMode_setSwitchInProgress() {
       if (this.switchInProgress) {
         clearTimeout(this.switchInProgress);
       }
       this.switchInProgress = setTimeout(function switchInProgressTimeout() {
+        this._removeFullscreenChangeListeners();
         delete this.switchInProgress;
         this._notifyStateChange();
       }.bind(this), DELAY_BEFORE_RESETTING_SWITCH_IN_PROGRESS);
@@ -201,7 +186,8 @@ var PDFPresentationMode = {
     /**
      * @private
      */
-  _resetSwitchInProgress: function pdfPresentationMode_resetSwitchInProgress() {
+    _resetSwitchInProgress:
+        function PDFPresentationMode_resetSwitchInProgress() {
       if (this.switchInProgress) {
         clearTimeout(this.switchInProgress);
         delete this.switchInProgress;
@@ -211,7 +197,7 @@ var PDFPresentationMode = {
     /**
      * @private
      */
-  _enter: function pdfPresentationModeEnter() {
+    _enter: function PDFPresentationMode_enter() {
       this.active = true;
       this._resetSwitchInProgress();
       this._notifyStateChange();
@@ -223,11 +209,7 @@ var PDFPresentationMode = {
         PDFViewerApplication.setScale('page-fit', true);
       }.bind(this), 0);
 
-    window.addEventListener('mousemove', this._showControls, false);
-    window.addEventListener('mousedown', this._mouseDown, false);
-    window.addEventListener('keydown', this._resetMouseScrollState, false);
-    window.addEventListener('contextmenu', this._contextMenu, false);
-
+      this._addWindowListeners();
       this._showControls();
       this.contextMenuOpen = false;
       this.container.setAttribute('contextmenu', 'viewerContextMenu');
@@ -241,13 +223,14 @@ var PDFPresentationMode = {
     /**
      * @private
      */
-  _exit: function pdfPresentationModeExit() {
+    _exit: function PDFPresentationMode_exit() {
       var page = PDFViewerApplication.page;
 
       // Ensure that the correct page is scrolled into view when exiting
       // Presentation Mode, by waiting until fullscreen mode is disabled.
       setTimeout(function exitPresentationModeTimeout() {
         this.active = false;
+        this._removeFullscreenChangeListeners();
         this._notifyStateChange();
 
         PDFViewerApplication.setScale(this.args.previousScale, true);
@@ -255,11 +238,7 @@ var PDFPresentationMode = {
         this.args = null;
       }.bind(this), 0);
 
-    window.removeEventListener('mousemove', this._showControls, false);
-    window.removeEventListener('mousedown', this._mouseDown, false);
-    window.removeEventListener('keydown', this._resetMouseScrollState, false);
-    window.removeEventListener('contextmenu', this._contextMenu, false);
-
+      this._removeWindowListeners();
       this._hideControls();
       this._resetMouseScrollState();
       this.container.removeAttribute('contextmenu');
@@ -273,10 +252,9 @@ var PDFPresentationMode = {
     /**
      * @private
      */
-  _mouseDown: function pdfPresentationModeMouseDown(evt) {
-    var self = PDFPresentationMode;
-    if (self.contextMenuOpen) {
-      self.contextMenuOpen = false;
+    _mouseDown: function PDFPresentationMode_mouseDown(evt) {
+      if (this.contextMenuOpen) {
+        this.contextMenuOpen = false;
         evt.preventDefault();
         return;
       }
@@ -296,46 +274,123 @@ var PDFPresentationMode = {
     /**
      * @private
      */
-  _contextMenu: function pdfPresentationModeContextMenu(evt) {
-    PDFPresentationMode.contextMenuOpen = true;
+    _contextMenu: function PDFPresentationMode_contextMenu() {
+      this.contextMenuOpen = true;
     },
 
     /**
      * @private
      */
-  _showControls: function pdfPresentationModeShowControls() {
-    var self = PDFPresentationMode;
-    if (self.controlsTimeout) {
-      clearTimeout(self.controlsTimeout);
+    _showControls: function PDFPresentationMode_showControls() {
+      if (this.controlsTimeout) {
+        clearTimeout(this.controlsTimeout);
       } else {
-      self.container.classList.add(SELECTOR);
+        this.container.classList.add(SELECTOR);
       }
-    self.controlsTimeout = setTimeout(function showControlsTimeout() {
-      self.container.classList.remove(SELECTOR);
-      delete self.controlsTimeout;
-    }, DELAY_BEFORE_HIDING_CONTROLS);
+      this.controlsTimeout = setTimeout(function showControlsTimeout() {
+        this.container.classList.remove(SELECTOR);
+        delete this.controlsTimeout;
+      }.bind(this), DELAY_BEFORE_HIDING_CONTROLS);
     },
 
     /**
      * @private
      */
-  _hideControls: function pdfPresentationModeHideControls() {
-    var self = PDFPresentationMode;
-    if (!self.controlsTimeout) {
+    _hideControls: function PDFPresentationMode_hideControls() {
+      if (!this.controlsTimeout) {
         return;
       }
-    clearTimeout(self.controlsTimeout);
-    self.container.classList.remove(SELECTOR);
-    delete self.controlsTimeout;
+      clearTimeout(this.controlsTimeout);
+      this.container.classList.remove(SELECTOR);
+      delete this.controlsTimeout;
     },
 
     /**
      * Resets the properties used for tracking mouse scrolling events.
      * @private
      */
-  _resetMouseScrollState: function pdfPresentationModeResetMouseScrollState() {
-    var self = PDFPresentationMode;
-    self.mouseScrollTimeStamp = 0;
-    self.mouseScrollDelta = 0;
+    _resetMouseScrollState:
+        function PDFPresentationMode_resetMouseScrollState() {
+      this.mouseScrollTimeStamp = 0;
+      this.mouseScrollDelta = 0;
+    },
+
+    /**
+     * @private
+     */
+    _addWindowListeners: function PDFPresentationMode_addWindowListeners() {
+      this.showControlsBind = this._showControls.bind(this);
+      this.mouseDownBind = this._mouseDown.bind(this);
+      this.resetMouseScrollStateBind = this._resetMouseScrollState.bind(this);
+      this.contextMenuBind = this._contextMenu.bind(this);
+
+      window.addEventListener('mousemove', this.showControlsBind);
+      window.addEventListener('mousedown', this.mouseDownBind);
+      window.addEventListener('keydown', this.resetMouseScrollStateBind);
+      window.addEventListener('contextmenu', this.contextMenuBind);
+    },
+
+    /**
+     * @private
+     */
+    _removeWindowListeners:
+        function PDFPresentationMode_removeWindowListeners() {
+      window.removeEventListener('mousemove', this.showControlsBind);
+      window.removeEventListener('mousedown', this.mouseDownBind);
+      window.removeEventListener('keydown', this.resetMouseScrollStateBind);
+      window.removeEventListener('contextmenu', this.contextMenuBind);
+
+      delete this.showControlsBind;
+      delete this.mouseDownBind;
+      delete this.resetMouseScrollStateBind;
+      delete this.contextMenuBind;
+    },
+
+    /**
+     * @private
+     */
+    _fullscreenChange: function PDFPresentationMode_fullscreenChange() {
+      if (this.isFullscreen) {
+        this._enter();
+      } else {
+        this._exit();
+      }
+    },
+
+    /**
+     * @private
+     */
+    _addFullscreenChangeListeners:
+        function PDFPresentationMode_addFullscreenChangeListeners() {
+      this.fullscreenChangeBind = this._fullscreenChange.bind(this);
+
+      window.addEventListener('fullscreenchange', this.fullscreenChangeBind);
+      window.addEventListener('mozfullscreenchange', this.fullscreenChangeBind);
+//#if !(FIREFOX || MOZCENTRAL)
+      window.addEventListener('webkitfullscreenchange',
+                              this.fullscreenChangeBind);
+      window.addEventListener('MSFullscreenChange', this.fullscreenChangeBind);
+//#endif
+    },
+
+    /**
+     * @private
+     */
+    _removeFullscreenChangeListeners:
+        function PDFPresentationMode_removeFullscreenChangeListeners() {
+      window.removeEventListener('fullscreenchange', this.fullscreenChangeBind);
+      window.removeEventListener('mozfullscreenchange',
+                                 this.fullscreenChangeBind);
+//#if !(FIREFOX || MOZCENTRAL)
+      window.removeEventListener('webkitfullscreenchange',
+                              this.fullscreenChangeBind);
+      window.removeEventListener('MSFullscreenChange',
+                                 this.fullscreenChangeBind);
+//#endif
+
+      delete this.fullscreenChangeBind;
     }
   };
+
+  return PDFPresentationMode;
+})();

web/viewer.js

@@ -107,6 +107,8 @@ var PDFViewerApplication = {
   pdfThumbnailViewer: null,
   /** @type {PDFRenderingQueue} */
   pdfRenderingQueue: null,
+  /** @type {PDFPresentationMode} */
+  pdfPresentationMode: null,
   pageRotation: 0,
   updateScaleControls: true,
   isInitialViewSet: false,
@@ -189,7 +191,7 @@ var PDFViewerApplication = {
 
     if (this.supportsFullscreen) {
       var toolbar = SecondaryToolbar;
-      PDFPresentationMode.initialize({
+      this.pdfPresentationMode = new PDFPresentationMode({
         container: container,
         viewer: viewer,
         pdfThumbnailViewer: this.pdfThumbnailViewer,
@@ -1342,20 +1344,20 @@ var PDFViewerApplication = {
   },
 
   requestPresentationMode: function pdfViewRequestPresentationMode() {
-    if (!this.supportsFullscreen) {
+    if (!this.pdfPresentationMode) {
       return;
     }
-    PDFPresentationMode.request();
+    this.pdfPresentationMode.request();
   },
 
   /**
    * @param {number} delta - The delta value from the mouse event.
    */
   scrollPresentationMode: function pdfViewScrollPresentationMode(delta) {
-    if (!this.supportsFullscreen) {
+    if (!this.pdfPresentationMode) {
       return;
     }
-    PDFPresentationMode.mouseScroll(delta);
+    this.pdfPresentationMode.mouseScroll(delta);
   }
 };
 //#if GENERIC