Re: mouseDown Event / locationInWindows always returning (0,0)

FROM : glenn andreas
DATE : Tue Jan 08 23:21:12 2008

On Jan 8, 2008, at 3:53 PM, luc BARREDA wrote:

> Hi,
>
> I've a strange problem  under 10.5,
>
> I subclassed a NSView and declared in it :
>
> - (void)mouseDown:(NSEvent *)theEvent
> {         NSPoint p;
>
>     p = [theEvent locationInWindow];
> }
>
> Under the debugger, the event is trapped and the function gets 
> called, theEvent shows a correct mouseDownEvent type (1),
> the protected '_location' NSEvent member contains the right mouse 
> coord, window is not nil, everything is OK
> BUT locationInWindow always return (0,0)
> I browsed the mailing list before posting and tried to make the same 
> thing in a window subclassing, same result
>
> Has somebody a clue before I loose all my hairs? I'd appreciate a lot



How do you _know_ that it returning (0,0)?

If you are just looking in the debugger at the value of "p", the 
compiler is free to see this and say "hey, they are setting a 
variable, and that variable is never used again, I can just plain not 
generate the code to set the variable and drop the return value and it 
won't change the result of the code, and it will save a few 
instructions and cache hits".

Add an explicit

NSLog(@"Point was %@", NSStringFromPoint(p));

and see what value is printed out...


Glenn Andreas                      <email_removed>
  <http://www.gandreas.com/> wicked fun!
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