Marker drag event after dragend event

[DennisSchiefer]

I encountered the following problem when dragging a Marker object over the map:
When I quickly drag the marker and release the mouse button, frequently the dragend event is fired before the last drag event. The final position of the Marker is that of the last drag event and not that of the dragstop event.

Thus, one cannot rely on the dragend event to correctly tell the end position of a drag operation.

EDIT: Tested on Windows XP, Firefox 10, Leaflet 0.3.1 stable, MS Mouse Explorer 3 with maximum mouse speed

[DennisSchiefer]

I narrowed the issue down to the following basic problem:

The drag event is fired by L.Draggable._updatePosition(). This function is called L.Util.requestAnimFrame() which delays the call for a short amount of time. Now, if a dragend event is processed during that time, a drag event is fired after the dragend event. This is not only inconsistent behaviour, it also causes errors, for example if the dragged object is removed during the dragend event.

Possible fixes:

• Change the behaviour of L.Util.requestAnimFrame() when immediate==true to alwyas perform the callback immediately and to only if an requestAnimationFrame function is missing in the browser
• prevent the execution of L.Draggable._updatePosition() when no longer dragging

[DennisSchiefer]

Leaflet 0.4 offers yet another even better solution:
Simply call Util.cancelAnimFrame(this._animRequest); in L.Draggable._onUp();

[mourner]

Sorry for a late response and thanks for a great catch, I'll fix it using your suggestion for 0.4.