Simplified wheel processing.

web/app.js

@@ -93,6 +93,7 @@ var PDFAttachmentViewer = pdfAttachmentViewerLib.PDFAttachmentViewer;
 var PDFFindController = pdfFindControllerLib.PDFFindController;
 var PDFFindBar = pdfFindBarLib.PDFFindBar;
 var getGlobalEventBus = domEventsLib.getGlobalEventBus;
+var normalizeWheelEventDelta = uiUtilsLib.normalizeWheelEventDelta;
 
 var DEFAULT_SCALE_DELTA = 1.1;
 var MIN_SCALE = 0.25;
@@ -1217,16 +1218,6 @@ var PDFViewerApplication = {
     this.pdfPresentationMode.request();
   },
 
-  /**
-   * @param {number} delta - The delta value from the mouse event.
-   */
-  scrollPresentationMode: function pdfViewScrollPresentationMode(delta) {
-    if (!this.pdfPresentationMode) {
-      return;
-    }
-    this.pdfPresentationMode.mouseScroll(delta);
-  },
-
   /**
    * @typedef UpdateUIToolbarParameters
    * @property {number} pageNumber
@@ -1998,17 +1989,12 @@ function webViewerPageChanging(e) {
 
 var zoomDisabled = false, zoomDisabledTimeout;
 function handleMouseWheel(evt) {
-  var MOUSE_WHEEL_DELTA_FACTOR = 40;
-  var ticks = (evt.type === 'DOMMouseScroll') ? -evt.detail :
-              evt.wheelDelta / MOUSE_WHEEL_DELTA_FACTOR;
-  var direction = (ticks < 0) ? 'zoomOut' : 'zoomIn';
-
   var pdfViewer = PDFViewerApplication.pdfViewer;
   if (pdfViewer.isInPresentationMode) {
-    evt.preventDefault();
+    return;
-    PDFViewerApplication.scrollPresentationMode(ticks *
+  }
-                                                MOUSE_WHEEL_DELTA_FACTOR);
+
-  } else if (evt.ctrlKey || evt.metaKey) {
+  if (evt.ctrlKey || evt.metaKey) {
     var support = PDFViewerApplication.supportedMouseWheelZoomModifierKeys;
     if ((evt.ctrlKey && !support.ctrlKey) ||
         (evt.metaKey && !support.metaKey)) {
@@ -2023,7 +2009,15 @@ function handleMouseWheel(evt) {
 
     var previousScale = pdfViewer.currentScale;
 
-    PDFViewerApplication[direction](Math.abs(ticks));
+    var delta = normalizeWheelEventDelta(evt);
+
+    var MOUSE_WHEEL_DELTA_PER_PAGE_SCALE = 3.0;
+    var ticks = delta * MOUSE_WHEEL_DELTA_PER_PAGE_SCALE;
+    if (ticks < 0) {
+      PDFViewerApplication.zoomOut(-ticks);
+    } else {
+      PDFViewerApplication.zoomIn(ticks);
+    }
 
     var currentScale = pdfViewer.currentScale;
     if (previousScale !== currentScale) {
@@ -2046,8 +2040,7 @@ function handleMouseWheel(evt) {
   }
 }
 
-window.addEventListener('DOMMouseScroll', handleMouseWheel);
+window.addEventListener('wheel', handleMouseWheel);
-window.addEventListener('mousewheel', handleMouseWheel);
 
 window.addEventListener('click', function click(evt) {
   if (!PDFViewerApplication.secondaryToolbar.isOpen) {

web/pdf_presentation_mode.js

@@ -17,13 +17,15 @@
 
 (function (root, factory) {
   if (typeof define === 'function' && define.amd) {
-    define('pdfjs-web/pdf_presentation_mode', ['exports'], factory);
+    define('pdfjs-web/pdf_presentation_mode', ['exports', 'pdfjs-web/ui_utils'],
+      factory);
   } else if (typeof exports !== 'undefined') {
-    factory(exports);
+    factory(exports, require('./ui_utils.js'));
   } else {
-    factory((root.pdfjsWebPDFPresentationMode = {}));
+    factory((root.pdfjsWebPDFPresentationMode = {}), root.pdfjsWebUIUtils);
   }
-}(this, function (exports) {
+}(this, function (exports, uiUtils) {
+var normalizeWheelEventDelta = uiUtils.normalizeWheelEventDelta;
 
 var DELAY_BEFORE_RESETTING_SWITCH_IN_PROGRESS = 1500; // in ms
 var DELAY_BEFORE_HIDING_CONTROLS = 3000; // in ms
@@ -120,16 +122,19 @@ var PDFPresentationMode = (function PDFPresentationModeClosure() {
     },
 
     /**
-     * Switches page when the user scrolls (using a scroll wheel or a touchpad)
+     * @private
-     * with large enough motion, to prevent accidental page switches.
-     * @param {number} delta - The delta value from the mouse event.
      */
-    mouseScroll: function PDFPresentationMode_mouseScroll(delta) {
+    _mouseWheel: function PDFPresentationMode_mouseWheel(evt) {
       if (!this.active) {
         return;
       }
+
+      evt.preventDefault();
+
+      var delta = normalizeWheelEventDelta(evt);
+
       var MOUSE_SCROLL_COOLDOWN_TIME = 50;
-      var PAGE_SWITCH_THRESHOLD = 120;
+      var PAGE_SWITCH_THRESHOLD = 0.1;
       var PageSwitchDirection = {
         UP: -1,
         DOWN: 1
@@ -340,11 +345,13 @@ var PDFPresentationMode = (function PDFPresentationModeClosure() {
     _addWindowListeners: function PDFPresentationMode_addWindowListeners() {
       this.showControlsBind = this._showControls.bind(this);
       this.mouseDownBind = this._mouseDown.bind(this);
+      this.mouseWheelBind = this._mouseWheel.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('wheel', this.mouseWheelBind);
       window.addEventListener('keydown', this.resetMouseScrollStateBind);
       window.addEventListener('contextmenu', this.contextMenuBind);
     },
@@ -356,11 +363,13 @@ var PDFPresentationMode = (function PDFPresentationModeClosure() {
         function PDFPresentationMode_removeWindowListeners() {
       window.removeEventListener('mousemove', this.showControlsBind);
       window.removeEventListener('mousedown', this.mouseDownBind);
+      window.removeEventListener('wheel', this.mouseWheelBind);
       window.removeEventListener('keydown', this.resetMouseScrollStateBind);
       window.removeEventListener('contextmenu', this.contextMenuBind);
 
       delete this.showControlsBind;
       delete this.mouseDownBind;
+      delete this.mouseWheelBind;
       delete this.resetMouseScrollStateBind;
       delete this.contextMenuBind;
     },

web/ui_utils.js

@@ -384,6 +384,28 @@ function getPDFFileNameFromURL(url) {
   return suggestedFilename || 'document.pdf';
 }
 
+function normalizeWheelEventDelta(evt) {
+  var delta = Math.sqrt(evt.deltaX * evt.deltaX + evt.deltaY * evt.deltaY);
+  var angle = Math.atan2(evt.deltaY, evt.deltaX);
+  if (-0.25 * Math.PI < angle && angle < 0.75 * Math.PI) {
+    // All that is left-up oriented has to change the sign.
+    delta = -delta;
+  }
+
+  var MOUSE_DOM_DELTA_PIXEL_MODE = 0;
+  var MOUSE_DOM_DELTA_LINE_MODE = 1;
+  var MOUSE_PIXELS_PER_LINE = 30;
+  var MOUSE_LINES_PER_PAGE = 30;
+
+  // Converts delta to per-page units
+  if (evt.deltaMode === MOUSE_DOM_DELTA_PIXEL_MODE) {
+    delta /= MOUSE_PIXELS_PER_LINE * MOUSE_LINES_PER_PAGE;
+  } else if (evt.deltaMode === MOUSE_DOM_DELTA_LINE_MODE) {
+    delta /= MOUSE_LINES_PER_PAGE;
+  }
+  return delta;
+}
+
 /**
  * Simple event bus for an application. Listeners are attached using the
  * `on` and `off` methods. To raise an event, the `dispatch` method shall be
@@ -529,4 +551,5 @@ exports.getOutputScale = getOutputScale;
 exports.scrollIntoView = scrollIntoView;
 exports.watchScroll = watchScroll;
 exports.binarySearchFirstItem = binarySearchFirstItem;
+exports.normalizeWheelEventDelta = normalizeWheelEventDelta;
 }));