getMouse is supposed to return mouse position in the current view's coordinate system. When the coordinate system is shifted by xoffset/yoffset, getMouse fails to take this shift into account. This is, I believe, the problem underlying the malfunction of the standard dragger for views that have an offset. For example, in the attached program, the red view jumps everytime you drag it. On the other hand, the blue view drags correctly, because its dragger gets the relative mouse position using a function getRelMouse, which subtracts xoffset/yoffset. I claim that the standard getMouse function should be doing what this getRelMouse function does.