The following defect was noticed from Script.Aculo.us versions 1.5.3 to 1.6.1.
I have a DIV container which has a set width and height. It is set to auto-scroll with "overflow: auto" style. It contains a bunch of Droppable elements (with onHover/onDrop events and some options parameters). I noticed that if I scroll the container to reveal a Droppable element at the bottom, when I drag a Draggable element to it, the code somehow thinks the Droppable element is a certain distance higher in the container. The vertical distance in error is the same as the scrolled distance. Therefore, when I drop the element, it goes to the wrong Droppable area in another location.
I have looked at dragdrop.js, particularly the Droppables.isAffected() and Droppables.show() methods. They are using prototype's Position.within() method to detect if the mouse event position is within any Droppable element's boundaries. However, by default, Position.within() method does not use its "includeScrollOffsets" boolean member. This boolean member is set to false by default and I couldn't find anywhere in the prototype.js that sets it to true.
My work-around for now is to find "Position.prepare();" string within dragdrop.js, and manually add "Position.includeScrollOffsets = true;" at the next line. This seems to have fixed the above issue. The three places I've updated are Droppables.fire(), Draggable.updateDrag(), and Draggable.scroll().
Of course, because of my limited knowledge of prototype and Script.Aculo.us, there may be much better solution to the issue. I'm looking forward to seeing this issue getting resolved in your later releases. Thanks!
