Re: Command-Key modified cursor

FROM : John Nairn
DATE : Mon Jan 07 20:55:47 2008

On Jan 7, 2008, at 8:41 AM, Benjamin Stiglitz wrote:

>> I implemented tracking rects and used mouseMove to change the 
>> cursor depending on modifier keys. In this case holding command key 
>> is  zoom in while command and option is zoom out. It works OK, but 
>> pressing the command key does not get the correct curser until the 
>> mouse physically moves again. I tried to find an event for key 
>> press, but could not find one (command key or option key alone do 
>> not generate keyDown event). I didn't try cursor rects, but found 
>> no indication that cursor tracking would update correctly on 
>> command or option key presses.

>
> Check out -[NSResponder flagsChanged:].
>
> -Ben


Thanks Ben,

That handles most of the issue, but since flagsChanged only responds 
to changes, I had to handle special cases where the zoom cursor should 
change even when the modifier flags have not changed (e.g., when mouse 
enters or exits the zoom region, when the window becomes or loses key, 
and also after doing a zoom (because that redisplay also reset the 
cursor)).

One remaining issue is when window becomes key after losing key 
status. I need to reset the cursor using the current state of the 
modifier flags. I was hoping to find an NSEvent class method for those 
flags (e.g. [NSEvent currentModifierFlags]) that would provide the 
same function as [NSEvent mouseLocation], which returns the mouse 
location at any time (i.e., not needing an event to occur), but could 
not find one? Maybe a carbon call could work here?

---------------
John Nairn (1-541-737-4265, FAX:1-541-737-3385)
Professor and Richardson Chair
Web Page: http://woodscience.oregonstate.edu/faculty/Nairn
FEA/MPM Web Page: http://oregonstate.edu/~nairnj