make the Navigation control support pinch-zoom, r=bbinet (closes #3273)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@11961 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/Navigation.js

@@ -37,6 +37,18 @@ OpenLayers.Control.Navigation = OpenLayers.Class(OpenLayers.Control, {
      */
     dragPanOptions: null,
 
+    /**
+     * Property: pinchZoom
+     * {<OpenLayers.Control.PinchZoom>}
+     */
+    pinchZoom: null,
+
+    /**
+     * APIProperty: pinchZoomOptions
+     * {Object} Options passed to the PinchZoom control.
+     */
+    pinchZoomOptions: null,
+
     /**
      * APIProperty: documentDrag
      * {Boolean} Allow panning of the map by dragging outside map viewport.
@@ -124,6 +136,12 @@ OpenLayers.Control.Navigation = OpenLayers.Class(OpenLayers.Control, {
             this.zoomBox.destroy();
         }
         this.zoomBox = null;
+
+        if (this.pinchZoom) {
+            this.pinchZoom.destroy();
+        }
+        this.pinchZoom = null;
+
         OpenLayers.Control.prototype.destroy.apply(this,arguments);
     },
     
@@ -139,6 +157,9 @@ OpenLayers.Control.Navigation = OpenLayers.Class(OpenLayers.Control, {
         if (this.zoomBoxEnabled) {
             this.zoomBox.activate();
         }
+        if (this.pinchZoom) {
+            this.pinchZoom.activate();
+        }
         return OpenLayers.Control.prototype.activate.apply(this,arguments);
     },
 
@@ -146,6 +167,9 @@ OpenLayers.Control.Navigation = OpenLayers.Class(OpenLayers.Control, {
      * Method: deactivate
      */
     deactivate: function() {
+        if (this.pinchZoom) {
+            this.pinchZoom.deactivate();
+        }
         this.zoomBox.deactivate();
         this.dragPan.deactivate();
         this.handlers.click.deactivate();
@@ -188,6 +212,11 @@ OpenLayers.Control.Navigation = OpenLayers.Class(OpenLayers.Control, {
                                     this, {"up"  : this.wheelUp,
                                            "down": this.wheelDown},
                                     this.mouseWheelOptions );
+        if (OpenLayers.Control.PinchZoom) {
+            this.pinchZoom = new OpenLayers.Control.PinchZoom(
+                OpenLayers.Util.extend(
+                    {map: this.map}, this.pinchZoomOptions));
+        }
     },
 
     /**