I'm building a semi-transparent floating HUD window in my application, which is intended to look like the Quick Look HUD window, specifically using the Enter/Exit full screen image. Cocoa provides the NSEnterFullScreenTemplate (and NSExitFullScreenTemplate) templates, which serve this purpose, and work fine on bordered buttons.
As soon as I remove the border and put the button on a dark background though, it keeps a dark gray color, and makes it difficult to see. I'd like to make it white, like in Quick Look. Is there a built-in way to do this, or do I have to resort to scaling and coloring the image myself?
I ended up writing an NSImage category class method that returns a template image at the desired size and in the desired color (basically doing it myself, as I don't think the API does provide a way to do this).
+(NSImage *)templateImage:(NSString *)templateName
withColor:(NSColor *)tint
andSize:(CGSize)targetSize
{
NSImage *template = [NSImage imageNamed:templateName];
NSSize size = (CGSizeEqualToSize(targetSize, CGSizeZero)
? [template size]
: targetSize);
NSRect imageBounds = NSMakeRect(0, 0, size.width, size.height);
NSImage *copiedImage = [template copy];
[copiedImage setTemplate:NO];
[copiedImage setSize:size];
[copiedImage lockFocus];
[tint set];
NSRectFillUsingOperation(imageBounds, NSCompositeSourceAtop);
[copiedImage unlockFocus];
return [copiedImage autorelease];
}