NSImage - Image With Color Overlay

NSImage+Overlay

- (NSImage *)imageWithColorOverlay:(NSColor *)color {
    
    CGFloat scale = [self recommendedLayerContentsScale:[[NSScreen mainScreen] backingScaleFactor]];
    
    NSImage * overlayedImage = [[NSImage alloc] initWithSize:self.size];
    [self.representations enumerateObjectsUsingBlock:^(NSImageRep * imageRep, NSUInteger idx, BOOL *stop){
        
        CGFloat imageWidth = imageRep.pixelsWide ?: imageRep.size.width * scale;
        CGFloat imageHeight = imageRep.pixelsHigh ?: imageRep.size.height * scale;
        NSRect imageRect = NSMakeRect(0, 0, imageWidth, imageHeight);
        
        CGImageRef imageRef = [imageRep CGImageForProposedRect:&imageRect context:NULL hints:nil];
        
        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
        CGContextRef context = CGBitmapContextCreate(NULL, imageWidth, imageHeight,
                                                     CGImageGetBitsPerComponent(imageRef), 0,
                                                     colorSpace, (CGBitmapInfo)kCGImageAlphaPremultipliedLast);
        CGColorSpaceRelease(colorSpace);
        
        CGContextClipToMask(context, NSRectToCGRect(imageRect), imageRef);
        CGContextSetFillColorWithColor(context, color.CGColor);
        CGContextFillRect(context, NSRectToCGRect(imageRect));
        
        CGImageRef newImage = CGBitmapContextCreateImage(context);
        CGContextRelease(context);
        
        [overlayedImage addRepresentation:[[NSBitmapImageRep alloc] initWithCGImage:newImage]];
        CGImageRelease(newImage);
    }];
    
    return overlayedImage;
}