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

FROM : John Stiles
DATE : Tue Jan 08 23:36:52 2008

glenn andreas wrote:
>
> 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".

Maybe when optimization is enabled, but in -O0 the compiler should not
do this; I'd file a bug if it did. I'd hope that the OP is not debugging
a release build.


> 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!
> quadrium | prime : build, mutate, evolve, animate : the next
> generation of fractal art
>
>
>
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