Merge pull request #392 from msalsbery/Double-Tap

Add Double-Click/Tap Gesture to MouseTracker (#300)

changelog.txt

@@ -48,6 +48,8 @@ OPENSEADRAGON CHANGELOG
     * Added a GestureSettings class for per-device gesture options. Currently has settings to enable/disable zoom-on-scroll, zoom-on-pinch, zoom-on-click, and flick gesture settings.
     * Added GestureSettings objects for mouse, touch, and pen devices to the Viewer options giving users the ability to customize gesture handling in the viewer
     * Added velocity (speed and direction) properties to the "canvas-drag" event
+* Added double-click gesture detection to MouseTracker with corresponding dblClickHandler event callback (#392)
+* Added zoom on double-click feature to Viewer, with corresponding dblClickToZoom option added to the GestureSettings class (#392)
 * Made it possible to run OpenSeadragon from local filesystem on some browsers (#379)
 
 1.0.0:

src/mousetracker.js

@@ -40,10 +40,8 @@
 
     /**
      * @class MouseTracker
-     * @classdesc Provides simplified handling of common pointer device (mouse, touch, pen, etc.) and keyboard
+     * @classdesc Provides simplified handling of common pointer device (mouse, touch, pen, etc.) gestures
-     * events on a specific element, like 'enter', 'exit', 'press', 'release',
+     *            and keyboard events on a specified element.
-     * 'scroll', 'click', and 'drag'.
-     *
      * @memberof OpenSeadragon
      * @param {Object} options
      *      Allows configurable properties to be entirely specified by passing
@@ -54,11 +52,17 @@
      *      A reference to an element or an element id for which the pointer/key
      *      events will be monitored.
      * @param {Number} options.clickTimeThreshold
-     *      The number of milliseconds within which multiple pointer clicks
+     *      The number of milliseconds within which a pointer down-up event combination
-     *      will be treated as a single event.
+     *      will be treated as a click gesture.
      * @param {Number} options.clickDistThreshold
-     *      The distance between pointer click within multiple pointer clicks
+     *      The maximum distance allowed between a pointer down event and a pointer up event
-     *      will be treated as a single event.
+     *      to be treated as a click gesture.
+     * @param {Number} options.dblClickTimeThreshold
+     *      The number of milliseconds within which two pointer down-up event combinations
+     *      will be treated as a double-click gesture.
+     * @param {Number} options.dblClickDistThreshold
+     *      The maximum distance allowed between two pointer click events
+     *      to be treated as a click gesture.
      * @param {Number} [options.stopDelay=50]
      *      The number of milliseconds without pointer move before the stop
      *      event is fired.
@@ -76,6 +80,8 @@
      *      An optional handler for mouse wheel scroll.
      * @param {OpenSeadragon.EventHandler} [options.clickHandler=null]
      *      An optional handler for pointer click.
+     * @param {OpenSeadragon.EventHandler} [options.dblClickHandler=null]
+     *      An optional handler for pointer double-click.
      * @param {OpenSeadragon.EventHandler} [options.dragHandler=null]
      *      An optional handler for the drag gesture.
      * @param {OpenSeadragon.EventHandler} [options.dragEndHandler=null]
@@ -111,17 +117,33 @@
          */
         this.element            = $.getElement( options.element );
         /**
-         * The number of milliseconds within which mutliple pointer clicks will be treated as a single event.
+         * The number of milliseconds within which a pointer down-up event combination 
+         * will be treated as a click gesture.
          * @member {Number} clickTimeThreshold
          * @memberof OpenSeadragon.MouseTracker#
          */
         this.clickTimeThreshold = options.clickTimeThreshold;
         /**
-         * The distance between pointer click within multiple pointer clicks will be treated as a single event.
+         * The maximum distance allowed between a pointer down event and a pointer up event
+         * to be treated as a click gesture.
          * @member {Number} clickDistThreshold
          * @memberof OpenSeadragon.MouseTracker#
          */
         this.clickDistThreshold = options.clickDistThreshold;
+        /**
+         * The number of milliseconds within which two pointer down-up event combinations
+         * will be treated as a double-click gesture.
+         * @member {Number} dblClickTimeThreshold
+         * @memberof OpenSeadragon.MouseTracker#
+         */
+        this.dblClickTimeThreshold = options.dblClickTimeThreshold;
+        /**
+         * The maximum distance allowed between two pointer click events
+         * to be treated as a click gesture.
+         * @member {Number} clickDistThreshold
+         * @memberof OpenSeadragon.MouseTracker#
+         */
+        this.dblClickDistThreshold = options.dblClickDistThreshold;
         this.userData           = options.userData        || null;
         this.stopDelay          = options.stopDelay       || 50;
 
@@ -132,6 +154,7 @@
         this.moveHandler        = options.moveHandler     || null;
         this.scrollHandler      = options.scrollHandler   || null;
         this.clickHandler       = options.clickHandler    || null;
+        this.dblClickHandler    = options.dblClickHandler || null;
         this.dragHandler        = options.dragHandler     || null;
         this.dragEndHandler     = options.dragEndHandler  || null;
         this.pinchHandler       = options.pinchHandler    || null;
@@ -154,6 +177,7 @@
             setCaptureCapable:     !!this.element.setCapture && !!this.element.releaseCapture,
 
             click:                 function ( event ) { onClick( _this, event ); },
+            dblclick:              function ( event ) { onDblClick( _this, event ); },
             keypress:              function ( event ) { onKeyPress( _this, event ); },
             focus:                 function ( event ) { onFocus( _this, event ); },
             blur:                  function ( event ) { onBlur( _this, event ); },
@@ -207,6 +231,10 @@
             // Legacy mouse event tracking
             capturing:             false,
 
+            // Tracking for double-click gesture
+            lastClickPos:          null,
+            dblClickTimeOut:       null,
+
             // Tracking for pinch gesture
             pinchGPoints:          [],
             lastPinchDist:         0,
@@ -456,7 +484,7 @@
          * @param {OpenSeadragon.Point} event.position
          *      The position of the event relative to the tracked element.
          * @param {Boolean} event.quick
-         *      True only if the clickDistThreshold and clickDeltaThreshold are both passed. Useful for ignoring events.
+         *      True only if the clickDistThreshold and clickTimeThreshold are both passed. Useful for ignoring drag events.
          * @param {Boolean} event.shift
          *      True if the shift key was pressed during this event.
          * @param {Boolean} event.isTouchEvent
@@ -470,6 +498,30 @@
          */
         clickHandler: function () { },
 
+        /**
+         * Implement or assign implementation to these handlers during or after
+         * calling the constructor.
+         * @function
+         * @param {Object} event
+         * @param {OpenSeadragon.MouseTracker} event.eventSource
+         *      A reference to the tracker instance.
+         * @param {String} event.pointerType
+         *     "mouse", "touch", "pen", etc.
+         * @param {OpenSeadragon.Point} event.position
+         *      The position of the event relative to the tracked element.
+         * @param {Boolean} event.shift
+         *      True if the shift key was pressed during this event.
+         * @param {Boolean} event.isTouchEvent
+         *      True if the original event is a touch event, otherwise false. <span style="color:red;">Deprecated. Use pointerType and/or originalEvent instead.</span>
+         * @param {Object} event.originalEvent
+         *      The original event object.
+         * @param {Boolean} event.preventDefaultAction
+         *      Set to true to prevent the tracker subscriber from performing its default action (subscriber implementation dependent). Default: false.
+         * @param {Object} event.userData
+         *      Arbitrary user-defined object.
+         */
+        dblClickHandler: function () { },
+
         /**
          * Implement or assign implementation to these handlers during or after
          * calling the constructor.
@@ -746,7 +798,7 @@
     /**
      * Detect browser pointer device event model(s) and build appropriate list of events to subscribe to.
      */
-    $.MouseTracker.subscribeEvents = [ "click", "keypress", "focus", "blur", $.MouseTracker.wheelEventName ];
+    $.MouseTracker.subscribeEvents = [ "click", "dblclick", "keypress", "focus", "blur", $.MouseTracker.wheelEventName ];
 
     if( $.MouseTracker.wheelEventName == "DOMMouseScroll" ) {
         // Older Firefox
@@ -877,6 +929,12 @@
          * @memberof OpenSeadragon.MouseTracker.GesturePointList#
          */
         this.contacts = 0;
+        /**
+         * Current number of clicks for the device. Used for multiple click gesture tracking.
+         * @member {Number} clicks
+         * @memberof OpenSeadragon.MouseTracker.GesturePointList#
+         */
+        this.clicks = 0;
     };
     $.MouseTracker.GesturePointList.prototype = /** @lends OpenSeadragon.MouseTracker.GesturePointList.prototype */{
         /**
@@ -1164,6 +1222,17 @@
     }
 
 
+    /**
+     * @private
+     * @inner
+     */
+    function onDblClick( tracker, event ) {
+        if ( tracker.dblClickHandler ) {
+            $.cancelEvent( event );
+        }
+    }
+
+
     /**
      * @private
      * @inner
@@ -1453,7 +1522,7 @@
             captureMouse( tracker );
         }
 
-        if ( tracker.clickHandler || tracker.pressHandler || tracker.dragHandler || tracker.dragEndHandler ) {
+        if ( tracker.clickHandler || tracker.dblClickHandler || tracker.pressHandler || tracker.dragHandler || tracker.dragEndHandler ) {
             $.cancelEvent( event );
         }
     }
@@ -1795,7 +1864,7 @@
             $.stopEvent( event );
         }
 
-        if ( tracker.clickHandler || tracker.pressHandler || tracker.dragHandler || tracker.dragEndHandler || tracker.pinchHandler ) {
+        if ( tracker.clickHandler || tracker.dblClickHandler || tracker.pressHandler || tracker.dragHandler || tracker.dragEndHandler || tracker.pinchHandler ) {
             $.cancelEvent( event );
         }
     }
@@ -2210,7 +2279,8 @@
             curGPoint,
             updateGPoint,
             releaseCapture = false,
-            wasCaptured = false;
+            wasCaptured = false,
+            quick;
 
         if ( typeof event.buttons !== 'undefined' ) {
             pointsList.buttons = event.buttons;
@@ -2317,13 +2387,13 @@
                             }
                         }
 
-                        // Click
+                        // Click / Double-Click
-                        if ( tracker.clickHandler && updateGPoint.insideElementPressed && updateGPoint.insideElement ) {
+                        if ( ( tracker.clickHandler || tracker.dblClickHandler ) && updateGPoint.insideElement ) {
-                            var time = releaseTime - updateGPoint.contactTime,
+                            quick = releaseTime - updateGPoint.contactTime <= tracker.clickTimeThreshold &&
-                                distance = updateGPoint.contactPos.distanceTo( releasePoint ),
+                                            updateGPoint.contactPos.distanceTo( releasePoint ) <= tracker.clickDistThreshold;
-                                quick = time <= tracker.clickTimeThreshold &&
-                                            distance <= tracker.clickDistThreshold;
 
+                            // Click
+                            if ( tracker.clickHandler ) {
                                 propagate = tracker.clickHandler(
                                     {
                                         eventSource:          tracker,
@@ -2341,6 +2411,41 @@
                                     $.cancelEvent( event );
                                 }
                             }
+
+                            // Double-Click
+                            if ( tracker.dblClickHandler && quick ) {
+                                pointsList.clicks++;
+                                if ( pointsList.clicks === 1 ) {
+                                    delegate.lastClickPos = releasePoint;
+                                    /*jshint loopfunc:true*/
+                                    delegate.dblClickTimeOut = setTimeout( function() {
+                                        pointsList.clicks = 0;
+                                    }, tracker.dblClickTimeThreshold );
+                                    /*jshint loopfunc:false*/
+                                } else if ( pointsList.clicks === 2 ) {
+                                    clearTimeout( delegate.dblClickTimeOut );
+                                    pointsList.clicks = 0;
+                                    if ( delegate.lastClickPos.distanceTo( releasePoint ) <= tracker.dblClickDistThreshold ) {
+                                        propagate = tracker.dblClickHandler(
+                                            {
+                                                eventSource:          tracker,
+                                                pointerType:          updateGPoint.type,
+                                                position:             getPointRelativeToAbsolute( updateGPoint.currentPos, tracker.element ),
+                                                shift:                event.shiftKey,
+                                                isTouchEvent:         updateGPoint.type === 'touch',
+                                                originalEvent:        event,
+                                                preventDefaultAction: false,
+                                                userData:             tracker.userData
+                                            }
+                                        );
+                                        if ( propagate === false ) {
+                                            $.cancelEvent( event );
+                                        }
+                                    }
+                                    delegate.lastClickPos = null;
+                                }
+                            }
+                        }
                     } else if ( pointsList.contacts === 2 ) {
                         if ( tracker.pinchHandler && updateGPoint.type === 'touch' ) {
                             // Reset for pinch

src/openseadragon.js

@@ -267,12 +267,20 @@
   *     image requests in parallel as allowed by the browsers policy.
   *
   * @property {Number} [clickTimeThreshold=300]
-  *     If multiple mouse clicks occurs within less than this number of
+  *      The number of milliseconds within which a pointer down-up event combination
-  *     milliseconds, treat them as a single click.
+  *      will be treated as a click gesture.
   *
   * @property {Number} [clickDistThreshold=5]
-  *     If a mouse or touch drag occurs and the distance to the starting drag
+  *      The maximum distance allowed between a pointer down event and a pointer up event
-  *     point is less than this many pixels, ignore the drag event.
+  *      to be treated as a click gesture.
+  *
+  * @property {Number} [dblClickTimeThreshold=300]
+  *      The number of milliseconds within which two pointer down-up event combinations
+  *      will be treated as a double-click gesture.
+  *
+  * @property {Number} [dblClickDistThreshold=20]
+  *      The maximum distance allowed between two pointer click events
+  *      to be treated as a double-click gesture.
   *
   * @property {Number} [springStiffness=6.5]
   *
@@ -284,6 +292,8 @@
   *     Settings for gestures generated by a mouse pointer device. (See {@link OpenSeadragon.GestureSettings})
   * @property {Boolean} [gestureSettingsMouse.scrollToZoom=true] - Zoom on scroll gesture
   * @property {Boolean} [gestureSettingsMouse.clickToZoom=true] - Zoom on click gesture
+  * @property {Boolean} [gestureSettingsMouse.dblClickToZoom=false] - Zoom on double-click gesture. Note: If set to true
+  *     then clickToZoom should be set to false to prevent multiple zooms.
   * @property {Boolean} [gestureSettingsMouse.pinchToZoom=false] - Zoom on pinch gesture
   * @property {Boolean} [gestureSettingsMouse.flickEnabled=false] - Enable flick gesture
   * @property {Number} [gestureSettingsMouse.flickMinSpeed=120] - If flickEnabled is true, the minimum speed to initiate a flick gesture (pixels-per-second)
@@ -293,6 +303,8 @@
   *     Settings for gestures generated by a touch pointer device. (See {@link OpenSeadragon.GestureSettings})
   * @property {Boolean} [gestureSettingsTouch.scrollToZoom=false] - Zoom on scroll gesture
   * @property {Boolean} [gestureSettingsTouch.clickToZoom=false] - Zoom on click gesture
+  * @property {Boolean} [gestureSettingsTouch.dblClickToZoom=true] - Zoom on double-click gesture. Note: If set to true
+  *     then clickToZoom should be set to false to prevent multiple zooms.
   * @property {Boolean} [gestureSettingsTouch.pinchToZoom=true] - Zoom on pinch gesture
   * @property {Boolean} [gestureSettingsTouch.flickEnabled=true] - Enable flick gesture
   * @property {Number} [gestureSettingsTouch.flickMinSpeed=120] - If flickEnabled is true, the minimum speed to initiate a flick gesture (pixels-per-second)
@@ -302,6 +314,8 @@
   *     Settings for gestures generated by a pen pointer device. (See {@link OpenSeadragon.GestureSettings})
   * @property {Boolean} [gestureSettingsPen.scrollToZoom=false] - Zoom on scroll gesture
   * @property {Boolean} [gestureSettingsPen.clickToZoom=true] - Zoom on click gesture
+  * @property {Boolean} [gestureSettingsPen.dblClickToZoom=false] - Zoom on double-click gesture. Note: If set to true
+  *     then clickToZoom should be set to false to prevent multiple zooms.
   * @property {Boolean} [gestureSettingsPen.pinchToZoom=false] - Zoom on pinch gesture
   * @property {Boolean} [gestureSettingsPen.flickEnabled=false] - Enable flick gesture
   * @property {Number} [gestureSettingsPen.flickMinSpeed=120] - If flickEnabled is true, the minimum speed to initiate a flick gesture (pixels-per-second)
@@ -311,13 +325,15 @@
   *     Settings for gestures generated by unknown pointer devices. (See {@link OpenSeadragon.GestureSettings})
   * @property {Boolean} [gestureSettingsUnknown.scrollToZoom=true] - Zoom on scroll gesture
   * @property {Boolean} [gestureSettingsUnknown.clickToZoom=false] - Zoom on click gesture
+  * @property {Boolean} [gestureSettingsUnknown.dblClickToZoom=true] - Zoom on double-click gesture. Note: If set to true
+  *     then clickToZoom should be set to false to prevent multiple zooms.
   * @property {Boolean} [gestureSettingsUnknown.pinchToZoom=true] - Zoom on pinch gesture
   * @property {Boolean} [gestureSettingsUnknown.flickEnabled=true] - Enable flick gesture
   * @property {Number} [gestureSettingsUnknown.flickMinSpeed=120] - If flickEnabled is true, the minimum speed to initiate a flick gesture (pixels-per-second)
   * @property {Number} [gestureSettingsUnknown.flickMomentum=0.25] - If flickEnabled is true, the momentum factor for the flick gesture
   *
   * @property {Number} [zoomPerClick=2.0]
-  *     The "zoom distance" per mouse click or touch tap. <em><strong>Note:</strong> Setting this to 1.0 effectively disables the click-to-zoom feature (also see gestureSettings[Mouse|Touch|Pen].clickToZoom).</em>
+  *     The "zoom distance" per mouse click or touch tap. <em><strong>Note:</strong> Setting this to 1.0 effectively disables the click-to-zoom feature (also see gestureSettings[Mouse|Touch|Pen].clickToZoom/dblClickToZoom).</em>
   *
   * @property {Number} [zoomPerScroll=1.2]
   *     The "zoom distance" per mouse scroll or touch pinch. <em><strong>Note:</strong> Setting this to 1.0 effectively disables the mouse-wheel zoom feature (also see gestureSettings[Mouse|Touch|Pen].scrollToZoom}).</em>
@@ -534,6 +550,10 @@
   * @property {Boolean} clickToZoom
   *     Set to false to disable zooming on click gestures.
   *
+  * @property {Boolean} dblClickToZoom
+  *     Set to false to disable zooming on double-click gestures. Note: If set to true
+  *     then clickToZoom should be set to false to prevent multiple zooms.
+  *
   * @property {Boolean} pinchToZoom
   *     Set to false to disable zooming on pinch gestures.
   *
@@ -891,12 +911,14 @@ window.OpenSeadragon = window.OpenSeadragon || function( options ){
             //UI RESPONSIVENESS AND FEEL
             clickTimeThreshold:     300,
             clickDistThreshold:     5,
+            dblClickTimeThreshold:  300,
+            dblClickDistThreshold:  20,
             springStiffness:        6.5,
             animationTime:          1.2,
-            gestureSettingsMouse:   { scrollToZoom: true,  clickToZoom: true,  pinchToZoom: false, flickEnabled: false, flickMinSpeed: 120, flickMomentum: 0.25 },
+            gestureSettingsMouse:   { scrollToZoom: true,  clickToZoom: true,  dblClickToZoom: false, pinchToZoom: false, flickEnabled: false, flickMinSpeed: 120, flickMomentum: 0.25 },
-            gestureSettingsTouch:   { scrollToZoom: false, clickToZoom: false, pinchToZoom: true,  flickEnabled: true,  flickMinSpeed: 120, flickMomentum: 0.25 },
+            gestureSettingsTouch:   { scrollToZoom: false, clickToZoom: false, dblClickToZoom: true,  pinchToZoom: true,  flickEnabled: true,  flickMinSpeed: 120, flickMomentum: 0.25 },
-            gestureSettingsPen:     { scrollToZoom: false, clickToZoom: true,  pinchToZoom: false, flickEnabled: false, flickMinSpeed: 120, flickMomentum: 0.25 },
+            gestureSettingsPen:     { scrollToZoom: false, clickToZoom: true,  dblClickToZoom: false, pinchToZoom: false, flickEnabled: false, flickMinSpeed: 120, flickMomentum: 0.25 },
-            gestureSettingsUnknown: { scrollToZoom: false, clickToZoom: false, pinchToZoom: true,  flickEnabled: true,  flickMinSpeed: 120, flickMomentum: 0.25 },
+            gestureSettingsUnknown: { scrollToZoom: false, clickToZoom: false, dblClickToZoom: true,  pinchToZoom: true,  flickEnabled: true,  flickMinSpeed: 120, flickMomentum: 0.25 },
             zoomPerClick:           2,
             zoomPerScroll:          1.2,
             zoomPerSecond:          1.0,

src/viewer.js

@@ -388,7 +388,10 @@ $.Viewer = function( options ) {
         element:               this.canvas,
         clickTimeThreshold:    this.clickTimeThreshold,
         clickDistThreshold:    this.clickDistThreshold,
+        dblClickTimeThreshold: this.dblClickTimeThreshold,
+        dblClickDistThreshold: this.dblClickDistThreshold,
         clickHandler:          $.delegate( this, onCanvasClick ),
+        dblClickHandler:       $.delegate( this, onCanvasDblClick ),
         dragHandler:           $.delegate( this, onCanvasDrag ),
         dragEndHandler:        $.delegate( this, onCanvasDragEnd ),
         releaseHandler:        $.delegate( this, onCanvasRelease ),
@@ -400,6 +403,8 @@ $.Viewer = function( options ) {
         element:               this.container,
         clickTimeThreshold:    this.clickTimeThreshold,
         clickDistThreshold:    this.clickDistThreshold,
+        dblClickTimeThreshold: this.dblClickTimeThreshold,
+        dblClickDistThreshold: this.dblClickDistThreshold,
         enterHandler:          $.delegate( this, onContainerEnter ),
         exitHandler:           $.delegate( this, onContainerExit ),
         pressHandler:          $.delegate( this, onContainerPress ),
@@ -2254,7 +2259,7 @@ function onCanvasClick( event ) {
      * @property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised this event.
      * @property {OpenSeadragon.MouseTracker} tracker - A reference to the MouseTracker which originated this event.
      * @property {OpenSeadragon.Point} position - The position of the event relative to the tracked element.
-     * @property {Boolean} quick - True only if the clickDistThreshold and clickDeltaThreshold are both passed. Useful for differentiating between clicks and drags.
+     * @property {Boolean} quick - True only if the clickDistThreshold and clickTimeThreshold are both passed. Useful for differentiating between clicks and drags.
      * @property {Boolean} shift - True if the shift key was pressed during this event.
      * @property {Object} originalEvent - The original DOM event.
      * @property {?Object} userData - Arbitrary subscriber-defined object.
@@ -2268,6 +2273,40 @@ function onCanvasClick( event ) {
     });
 }
 
+function onCanvasDblClick( event ) {
+    var gestureSettings;
+
+    if ( !event.preventDefaultAction && this.viewport ) {
+        gestureSettings = this.gestureSettingsByDeviceType( event.pointerType );
+        if ( gestureSettings.dblClickToZoom ) {
+            this.viewport.zoomBy(
+                event.shift ? 1.0 / this.zoomPerClick : this.zoomPerClick,
+                this.viewport.pointFromPixel( event.position, true )
+            );
+            this.viewport.applyConstraints();
+        }
+    }
+    /**
+     * Raised when a double mouse press/release or touch/remove occurs on the {@link OpenSeadragon.Viewer#canvas} element.
+     *
+     * @event canvas-double-click
+     * @memberof OpenSeadragon.Viewer
+     * @type {object}
+     * @property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised this event.
+     * @property {OpenSeadragon.MouseTracker} tracker - A reference to the MouseTracker which originated this event.
+     * @property {OpenSeadragon.Point} position - The position of the event relative to the tracked element.
+     * @property {Boolean} shift - True if the shift key was pressed during this event.
+     * @property {Object} originalEvent - The original DOM event.
+     * @property {?Object} userData - Arbitrary subscriber-defined object.
+     */
+    this.raiseEvent( 'canvas-double-click', {
+        tracker: event.eventSource,
+        position: event.position,
+        shift: event.shift,
+        originalEvent: event.originalEvent
+    });
+}
+
 function onCanvasDrag( event ) {
     var gestureSettings;
 

test/events.js

@@ -37,6 +37,7 @@
             origReleaseHandler,
             origMoveHandler,
             origClickHandler,
+            origDblClickHandler,
             origDragHandler,
             origDragEndHandler,
             enterCount,
@@ -45,6 +46,7 @@
             releaseCount,
             moveCount,
             clickCount,
+            dblClickCount,
             dragCount,
             dragEndCount,
             insideElementPressed,
@@ -111,6 +113,15 @@
                     return true;
                 }
             };
+            origDblClickHandler = tracker.dblClickHandler;
+            tracker.dblClickHandler = function ( event ) {
+                dblClickCount++;
+                if (origDblClickHandler) {
+                    return origDblClickHandler( event );
+                } else {
+                    return true;
+                }
+            };
             origDragHandler = tracker.dragHandler;
             tracker.dragHandler = function ( event ) {
                 dragCount++;
@@ -140,6 +151,7 @@
             tracker.releaseHandler = origReleaseHandler;
             tracker.moveHandler = origMoveHandler;
             tracker.clickHandler = origClickHandler;
+            tracker.dblClickHandler = origDblClickHandler;
             tracker.dragHandler = origDragHandler;
             tracker.dragEndHandler = origDragEndHandler;
         };
@@ -188,6 +200,7 @@
             releaseCount = 0;
             moveCount = 0;
             clickCount = 0;
+            dblClickCount = 0;
             dragCount = 0;
             dragEndCount = 0;
             insideElementPressed = false;
@@ -217,6 +230,9 @@
             if ('clickCount' in expected) {
                 equal( clickCount, expected.clickCount, expected.description + 'clickHandler event count matches expected (' + expected.clickCount + ')' );
             }
+            if ('dblClickCount' in expected) {
+                equal( dblClickCount, expected.dblClickCount, expected.description + 'dblClickHandler event count matches expected (' + expected.dblClickCount + ')' );
+            }
             if ('dragCount' in expected) {
                 equal( dragCount, expected.dragCount, expected.description + 'dragHandler event count matches expected (' + expected.dragCount + ')' );
             }
@@ -269,6 +285,7 @@
                 releaseCount:          1,
                 moveCount:             20,
                 clickCount:            0,
+                dblClickCount:         0,
                 dragCount:             0,
                 dragEndCount:          0,
                 insideElementPressed:  false,
@@ -293,6 +310,7 @@
                 releaseCount:          0,
                 moveCount:             20,
                 clickCount:            0,
+                dblClickCount:         0,
                 dragCount:             0,
                 dragEndCount:          0,
                 //insideElementPressed:  false,
@@ -315,6 +333,7 @@
                 releaseCount:          0,
                 moveCount:             20,
                 clickCount:            0,
+                dblClickCount:         0,
                 dragCount:             0,
                 dragEndCount:          0,
                 //insideElementPressed:  false,
@@ -324,7 +343,33 @@
                 //quickClick:            false
             });
 
-            // enter-press-release-exit
+            // enter-press-release-press-release-exit (double click)
+            resetForAssessment();
+            simulateEnter(0, 0);
+            simulateDown(0, 0);
+            simulateUp(0, 0);
+            simulateDown(0, 0);
+            simulateUp(0, 0);
+            simulateLeave(-1, -1);
+            assessGestureExpectations({
+                description:           'enter-press-release-press-release-exit (double click):  ',
+                enterCount:            1,
+                exitCount:             1,
+                pressCount:            2,
+                releaseCount:          2,
+                moveCount:             0,
+                clickCount:            2,
+                dblClickCount:         1,
+                dragCount:             0,
+                dragEndCount:          0,
+                insideElementPressed:  true,
+                insideElementReleased: true,
+                contacts:              0,
+                trackedPointers:       0
+                //quickClick:            true
+            });
+
+            // enter-press-release-exit (click)
             resetForAssessment();
             simulateEnter(0, 0);
             simulateDown(0, 0);
@@ -338,6 +383,7 @@
                 releaseCount:          1,
                 moveCount:             0,
                 clickCount:            1,
+                dblClickCount:         0,
                 dragCount:             0,
                 dragEndCount:          0,
                 insideElementPressed:  true,
@@ -363,6 +409,7 @@
                 releaseCount:          1,
                 moveCount:             200,
                 clickCount:            1,
+                dblClickCount:         0,
                 dragCount:             100,
                 dragEndCount:          1,
                 insideElementPressed:  true,
@@ -389,6 +436,7 @@
                 releaseCount:          1,
                 moveCount:             15,
                 clickCount:            0,
+                dblClickCount:         0,
                 dragCount:             15,
                 dragEndCount:          1,
                 insideElementPressed:  true,
@@ -509,6 +557,8 @@
                 userData: userData,
                 clickTimeThreshold: OpenSeadragon.DEFAULT_SETTINGS.clickTimeThreshold,
                 clickDistThreshold: OpenSeadragon.DEFAULT_SETTINGS.clickDistThreshold,
+                dblClickTimeThreshold: OpenSeadragon.DEFAULT_SETTINGS.dblClickTimeThreshold,
+                dblClickDistThreshold: OpenSeadragon.DEFAULT_SETTINGS.dblClickDistThreshold,
                 focusHandler: onMouseTrackerFocus,
                 blurHandler: onMouseTrackerBlur,
                 enterHandler: onMouseTrackerEnter,

test/legacy.mouse.shim.js

@@ -4,7 +4,7 @@
      * Plugin to force OpenSeadragon to use the legacy mouse pointer event model
      */
 
-    $.MouseTracker.subscribeEvents = [ "click", "keypress", "focus", "blur", $.MouseTracker.wheelEventName ];
+    $.MouseTracker.subscribeEvents = [ "click", "dblclick", "keypress", "focus", "blur", $.MouseTracker.wheelEventName ];
 
     if( $.MouseTracker.wheelEventName == "DOMMouseScroll" ) {
         // Older Firefox