Re: A cursor bug in DragItemAround example

FROM : Quincey Morris
DATE : Sun Apr 20 18:37:41 2008

On Apr 20, 2008, at 03:43, Ling Wang wrote:

> You can see the code at http://developer.apple.com/samplecode/DragItemAround/listing2.html
>  on ADC.
>
> The bug is that the cursor reverts to arrowCursor if the item is 
> dragged off the bound calculated at the mouseDown event just before 
> current mouseDragged event, instead of staying closedHandCursor. 
> Maybe it will be clear till you try to run it.
>
> It seems something happens when the mouse moves out of the cursor 
> rect that is set for the item's bounds in resetCursorRects. This 
> something is out of my knowledge, so I am hoping someone can tell me 
> the cause of the bug and a canonical way to fix it, and I'll 
> feedback the solution together with the bug on ADC after that.


Chances are, calling '[[self enclosingScrollView] setDocumentCursor:
[NSCursor closedHandCursor]]' in 'mouseDown:' will fix the problem 
you're seeing. NSScrollView/NSClipView's way of changing the cursor 
conflicts with autoscrolling or drag-scrolling, but AFAIK there's no 
way of preventing that interference directly.