This is a Browser Action API.
_dragDropXY simulates a drag and drop action.
It drags the element and drops it at the given x, y coordinate.
_dragDropXY(draggable, x, y, isRelative)
The parameters are:
If _image(“item”) is located at coordinates (50, 150)
_dragDropXY(_image("item"), 100, 300);
will drag the item and drop it at the coordinate (100, 300)
The end result is that the element’s coordinates will be at (100, 300)
_dragDropXY(_image("item"), 100, 300, true);
will drag the item and drop it at the coordinate (50+100, 150+300)
The end result is that the element’s coordinates will be at (150, 450)
Also look at documentation on _dragDrop