Adding a PinchZoom control for smooth zooming on multi-touch devices. p=bbinet,me r=crschmidt (closes #3105)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@11544 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/TouchNavigation.js

@@ -5,14 +5,15 @@
 
 /**
  * @requires OpenLayers/Control/DragPan.js
+ * @requires OpenLayers/Control/PinchZoom.js
  * @requires OpenLayers/Handler/Click.js
  */
 
 /**
  * Class: OpenLayers.Control.TouchNavigation
  * The navigation control handles map browsing with touch events (dragging,
- *     double-tapping, and tap with two fingers).  Create a new navigation
- *     control with the <OpenLayers.Control.TouchNavigation> control.
+ *     double-tapping, tap with two fingers, and pinch zoom).  Create a new 
+ *     control with the <OpenLayers.Control.TouchNavigation> constructor.
  *
  * Inherits:
  *  - <OpenLayers.Control>
@@ -31,6 +32,18 @@ OpenLayers.Control.TouchNavigation = OpenLayers.Class(OpenLayers.Control, {
      */
     dragPanOptions: null,
 
+    /**
+     * Property: pinchZoom
+     * {<OpenLayers.Control.PinchZoom>}
+     */
+    pinchZoom: null,
+
+    /**
+     * APIProprety: pinchZoomOptions
+     * {Object} Options passed to the PinchZoom control.
+     */
+    pinchZoomOptions: null,
+
     /**
      * APIProperty: documentDrag
      * {Boolean} Allow panning of the map by dragging outside map viewport.
@@ -70,6 +83,10 @@ OpenLayers.Control.TouchNavigation = OpenLayers.Class(OpenLayers.Control, {
             this.dragPan.destroy();
         }
         this.dragPan = null;
+        if (this.pinchZoom) {
+            this.pinchZoom.destroy();
+            delete this.pinchZoom;
+        }
         OpenLayers.Control.prototype.destroy.apply(this,arguments);
     },
 
@@ -80,6 +97,7 @@ OpenLayers.Control.TouchNavigation = OpenLayers.Class(OpenLayers.Control, {
         if(OpenLayers.Control.prototype.activate.apply(this,arguments)) {
             this.dragPan.activate();
             this.handlers.click.activate();
+            this.pinchZoom.activate();
             return true;
         }
         return false;
@@ -92,11 +110,12 @@ OpenLayers.Control.TouchNavigation = OpenLayers.Class(OpenLayers.Control, {
         if(OpenLayers.Control.prototype.deactivate.apply(this,arguments)) {
             this.dragPan.deactivate();
             this.handlers.click.deactivate();
+            this.pinchZoom.deactivate();
             return true;
         }
         return false;
     },
-
+    
     /**
      * Method: draw
      */
@@ -119,6 +138,9 @@ OpenLayers.Control.TouchNavigation = OpenLayers.Class(OpenLayers.Control, {
             }, this.dragPanOptions)
         );
         this.dragPan.draw();
+        this.pinchZoom = new OpenLayers.Control.PinchZoom(
+            OpenLayers.Util.extend({map: this.map}, this.pinchZoomOptions)
+        );
     },
 
     /**