make the drag handler and drag feature control tidy up after themselves - as a bonus, give the drag feature control an onStart method. Thanks for the review crschmidt (closes #950).

git-svn-id: http://svn.openlayers.org/trunk/openlayers@4147 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/DragFeature.js

@@ -24,6 +24,19 @@ OpenLayers.Control.DragFeature = OpenLayers.Class(OpenLayers.Control, {
      */
     geometryTypes: null,
     
+    /**
+     * APIProperty: onStart
+     * {Function} Define this function if you want to know when a drag starts.
+     *     The function should expect to receive two arguments: the feature
+     *     that is about to be dragged and the pixel location of the mouse.
+     *
+     * Parameters:
+     * feature - {OpenLayers.Feature.Vector} The feature that is about to be
+     *     dragged.
+     * pixel - {OpenLayers.Pixel} The pixel location of the mouse.
+     */
+    onStart: function(feature, pixel) {},
+
     /**
      * APIProperty: onDrag
      * {Function} Define this function if you want to know about each move of a
@@ -154,6 +167,9 @@ OpenLayers.Control.DragFeature = OpenLayers.Class(OpenLayers.Control, {
         // the return from the handlers is unimportant in this case
         this.dragHandler.deactivate();
         this.featureHandler.deactivate();
+        this.feature = null;
+        this.dragging = false;
+        this.lastPixel = null;
         return OpenLayers.Control.prototype.deactivate.apply(this, arguments);
     },
 
@@ -189,8 +205,8 @@ OpenLayers.Control.DragFeature = OpenLayers.Class(OpenLayers.Control, {
      * pixel - {OpenLayers.Pixel} Location of the mouse event.
      */
     downFeature: function(pixel) {
-        this.dragHandler.dragging = true;
         this.lastPixel = pixel;
+        this.onStart(this.feature, pixel);
     },
 
     /**

lib/OpenLayers/Handler/Drag.js

@@ -282,7 +282,10 @@ OpenLayers.Handler.Drag = OpenLayers.Class(OpenLayers.Handler, {
     deactivate: function() {
         var deactivated = false;
         if(OpenLayers.Handler.prototype.deactivate.apply(this, arguments)) {
+            this.started = false;
             this.dragging = false;
+            this.start = null;
+            this.last = null;
             deactivated = true;
         }
         return deactivated;