gistfile1.m

@implementation EGOLoupeView

+ (CFTimeInterval)fadeDuration 
{
    return 0.0;
}

+ (Class)layerClass
{
    return [CATiledLayer class];
}

- (id)init 
{
    if ((self = [super initWithFrame:CGRectMake(0.0f, 0.0f, 127.0f, 127.0f)])) 
    {
        self.backgroundColor = [UIColor clearColor];
    }
    return self;
}

- (void)drawRect:(CGRect)rect 
{    
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    
    [[UIImage imageNamed:@"loupe-lo.png"] drawInRect:rect];
    
    if ((_contentImage!=nil)) {
        
        CGContextSaveGState(ctx);
        CGContextClipToMask(ctx, rect, [UIImage imageNamed:@"loupe-mask.png"].CGImage);
        
        CGContextDrawImage(ctx, rect, _contentImage.CGImage);
//        [_contentImage drawInRect:rect];        
        CGContextRestoreGState(ctx);
        
    }
    
    [[UIImage imageNamed:@"loupe-hi.png"] drawInRect:rect];
    
}

- (void)setContentImage:(UIImage *)image 
{
    @synchronized(self)
    {
        [_contentImage release], _contentImage=nil;
        _contentImage = [image retain];
        [self setNeedsDisplay];
    }
}

- (void)dealloc {
    [_contentImage release], _contentImage=nil;
    [super dealloc];
}

@end