Fade in/Fade out for MAAttachedWindow - objective-c

Question

I'm using Matt Gemmell's MAAttachedWindow (http://mattgemmell.com/source) with an NSStatusItem to display a custom view in the menu bar. I'm confused as to how to get it to fade in and fade out. Normally I'd do something like this:
[window makeKeyAndOrderFront:self];
[[window animator] setAlphaValue:1.0];
and to fade out:
[[window animator] setAlphaValue:0.0];
However this code seems to have no effect with MAAttachedWindow. Any ideas?
Thanks

Answer 1

Sorry to drudge up an old post, but I thought it worthwhile mentioning that it works just fine for me to set the alpha value directly, with no need to add accessors/getters.
Simply doing (depending on your setup, or course):
[[self window] addChildWindow:attachedWindow ordered:NSWindowAbove];
[attachedWindow setAlphaValue:0.0];
[NSAnimationContext beginGrouping];
[[NSAnimationContext currentContext] setDuration:0.5];
[attachedWindow makeKeyAndOrderFront:self];
[[attachedWindow animator] setAlphaValue:1.0];
[NSAnimationContext endGrouping];
Works just fine.

Answer 2

I'm not especially well versed in CoreAnimation and the usage of implicit animations. However, I was able to get the MAAttachedWindow to fade in by adding an explicit alphaValue property to the MAAttachedWindow class:
#interface MAAttachedWindow : NSWindow {
CGFloat _alphaValue;
...
}
-(CGFloat) alphaValue;
-(void) setAlphaValue:(CGFloat)windowAlpha;
...
#implementation MAAttachedWindow
- (CGFloat) alphaValue {
return _alphaValue;
}
- (void) setAlphaValue:(CGFloat)windowAlpha {
_alpha = windowAlpha;
[super setAlphaValue:windowAlpha];
}
...
By adding that, I was able to get the implicit animation for setAlphaValue to work:
(below code cribbed from Matt's Sample "NSStatusItemTest" code)
- (void)toggleAttachedWindowAtPoint:(NSPoint)pt
{
...
[attachedWindow makeKeyAndOrderFront:self];
[[attachedWindow animator] setAlphaValue:1.0];
I am not sure why explicitly defining the alphaValue property works. I would expect the inherited version from NSWindow would be invoked for the implicit animation. It doesn't appear to though.