3

I have a NSControl subview and I want to change the drawing when the control is not on a keyWindow. The problem is that I don't see any property that reflects that state (tried enabled property but that was not it).

In simple terms, can I differentiate between these two states?

disabledenabled

THelper
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gcamp
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1 Answers1

6

You can use NSWindow's keyWindow property, and if you want to check to see if your control is the first responder for keyboard events also test [[self window] firstResponder] == self. I don't believe keyWindow supports KVO, but there is a NSWindowDidBecomeKeyNotification and NSWindowDidResignKeyNotification you can listen for. For instance,

- (id)initWithFrame:(NSRect)frameRect;
{
    if ( self = [super initWithFrame:frameRect] )
    {
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(display) name:NSWindowDidResignKeyNotification object:nil];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(display) name:NSWindowDidBecomeKeyNotification object:nil];
    }

    return self;
}

- (void)drawRect:(NSRect)aRect;
{
    if ( [[self window] isKeyWindow] )
    {
    // one way...
    }
    else
    {
    // another way!
    }
}

- (void)dealloc;
{
    [[NSNotificationCenter defaultCenter] removeObserver:self name:NSWindowDidResignKeyNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:NSWindowDidBecomeKeyNotification object:nil];
    [super dealloc];
}
Marc Charbonneau
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  • Thanks! That did the trick. I decided to add start to look for notification in `viewDidMoveToWindow` and remove it in `viewWillMoveToWindow:`, to avoid notification of every window in the application. (Still seems strange to need to to register for a notification for that simple task... A little hole in a great framework.) – gcamp May 25 '11 at 19:37