Some drag listener fixes + passing listener reference for convenience

js/listeners/DragListener.js

@@ -29,11 +29,11 @@
  * 3. (optionally) map that to a model location, and (optionally) move that model location to satisfy any constraints of
  *    where the element can be dragged (recomputing the parent/model translation as needed)
  * 4. Apply the required translation (with a provided drag callback, using the locationProperty, or directly
- *    transforming the Node if translateNode:true.
+ *    transforming the Node if translateNode:true).
  *
- * TODO: unit tests
+ * For example usage, see scenery/examples/input.html
  *
- * TODO: add example usage
+ * TODO: unit tests
  *
  * @author Jonathan Olson <[email protected]>
  */
@@ -89,12 +89,12 @@ define( function( require ) {
       //   mapLocation: function( point ) { return dragBounds.closestPointTo( point ); }
       mapLocation: null,
 
-      // {Function|null} - Called as start( event: {Event} ) when the drag is started. This is preferred over passing
-      // press(), as the drag start hasn't been fully processed at that point.
+      // {Function|null} - Called as start( event: {Event}, listener: {DragListener} ) when the drag is started.
+      // This is preferred over passing press(), as the drag start hasn't been fully processed at that point.
       start: null,
 
-      // {Function|null} - Called as end() when the drag is ended. This is preferred over passing release(), as the
-      // drag start hasn't been fully processed at that point.
+      // {Function|null} - Called as end( listener: {DragListener} ) when the drag is ended. This is preferred over
+      // passing release(), as the drag start hasn't been fully processed at that point.
       end: null
     }, options );
 
@@ -168,7 +168,7 @@ define( function( require ) {
         this.reposition( this.pointer.point );
 
         // Notify after positioning and other changes
-        this._start && this._start( event );
+        this._start && this._start( event, this );
 
         sceneryLog && sceneryLog.InputListener && sceneryLog.pop();
       }
@@ -196,7 +196,7 @@ define( function( require ) {
 
       // Notify after the rest of release is called in order to prevent it from triggering interrupt().
       // TODO: Is this a problem that we can't access things like this.pointer here?
-      this._end && this._end();
+      this._end && this._end( this );
 
       sceneryLog && sceneryLog.InputListener && sceneryLog.pop();
     },

js/listeners/PressListener.js

@@ -45,16 +45,16 @@ define( function( require ) {
       // cursor of whatever nodes the pointer may be over).
       pressCursor: 'pointer',
 
-      // {Function|null} - Called as press( event: {Event} ) when this listener's node is pressed (typically
-      // from a down event, but can be triggered by other handlers).
+      // {Function|null} - Called as press( event: {Event}, listener: {PressListener} ) when this listener's node is
+      // pressed (typically from a down event, but can be triggered by other handlers).
       press: null,
 
-      // {Function|null} - Called as release() when this listener's node is released (pointer up/cancel or interrupt
-      // when pressed).
+      // {Function|null} - Called as release( listener: {PressListener} ) when this listener's node is released
+      // (pointer up/cancel or interrupt when pressed).
       release: null,
 
-      // {Function|null} - Called as drag( event: {Event} ) when this listener's node is dragged (move events
-      // on the pointer while pressed).
+      // {Function|null} - Called as drag( event: {Event}, listener: {PressListener} ) when this listener's node is
+      //dragged (move events on the pointer while pressed).
       drag: null,
 
       // {Property.<Boolean>} - If provided, this property will be used to track whether this listener's node is
@@ -290,7 +290,7 @@ define( function( require ) {
       this.pointer.cursor = this._pressCursor;
 
       // Notify after everything else is set up
-      this._pressListener && this._pressListener( event );
+      this._pressListener && this._pressListener( event, this );
 
       sceneryLog && sceneryLog.InputListener && sceneryLog.pop();
 
@@ -325,7 +325,7 @@ define( function( require ) {
 
       // Notify after the rest of release is called in order to prevent it from triggering interrupt().
       // TODO: Is this a problem that we can't access things like this.pointer here?
-      this._releaseListener && this._releaseListener();
+      this._releaseListener && this._releaseListener( this );
 
       sceneryLog && sceneryLog.InputListener && sceneryLog.pop();
     },
@@ -344,7 +344,7 @@ define( function( require ) {
 
       assert && assert( this.isPressed, 'Can only drag while pressed' );
 
-      this._dragListener && this._dragListener( event );
+      this._dragListener && this._dragListener( event, this );
 
       sceneryLog && sceneryLog.InputListener && sceneryLog.pop();
     },