gistfile1.m

- (void)drawBevelArea
{
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    CGRect frame = self.frame;
        
    CGRect bevelAreaRect = CGRectMake(0, 0, frame.size.width, frame.size.height);
    UIBezierPath* bevelAreaPath = [UIBezierPath bezierPathWithRoundedRect:bevelAreaRect cornerRadius:_cornerRadius];
    [_bevelBackgroundColor setFill];
    [bevelAreaPath fill];
    
    // Inner shadow
    CGRect innerShadowRect = CGRectInset([bevelAreaPath bounds], -_bevelShadowBlurRadius, -_bevelShadowBlurRadius);
    innerShadowRect = CGRectOffset(innerShadowRect, -_bevelShadowOffset.x, -_bevelShadowOffset.y);
    innerShadowRect = CGRectInset(CGRectUnion(innerShadowRect, [bevelAreaPath bounds]), -1, -1);
    
    // Negative path
    UIBezierPath* bevelAreaNegativePath = [UIBezierPath bezierPathWithRect:innerShadowRect];
    [bevelAreaNegativePath appendPath:bevelAreaPath];
    bevelAreaNegativePath.usesEvenOddFillRule = YES;
    
    // Draw shadow
    CGContextSaveGState(context);
    {
        CGFloat xOffset = _bevelShadowOffset.x + round(innerShadowRect.size.width);
        CGFloat yOffset = _bevelShadowOffset.y;
        CGContextSetShadowWithColor(context,
                                    CGSizeMake(xOffset + copysign(0.1, xOffset), yOffset + copysign(0.1, yOffset)),
                                    _bevelShadowBlurRadius,
                                    _bevelShadowColor.CGColor);
        
        [bevelAreaPath addClip];
        CGAffineTransform transform = CGAffineTransformMakeTranslation(-round(innerShadowRect.size.width), 0);
        [bevelAreaNegativePath applyTransform:transform];
        [[UIColor grayColor] setFill];
        [bevelAreaNegativePath fill];
    }
    CGContextRestoreGState(context);
    
    // Draw highlight bottom stroke
    CGContextSaveGState(context);
    
    NSArray* gradientColors = @[(id)[UIColor clearColor].CGColor,
                                (id)[UIColor clearColor].CGColor,
                                (id)[UIColor colorWithWhite:1.0 alpha:0.3].CGColor];
    CGFloat gradientLocations[] = {0, 0.5, 1};
    CGGradientRef gradient = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef)gradientColors, gradientLocations);
    
    CGPathRef strokePath = CGPathCreateCopyByStrokingPath(bevelAreaPath.CGPath, NULL, 1.f, 0.f, 0.f, 0.f);
    
    CGContextAddPath(context, strokePath);
    CGContextClip(context);
    
    CGContextDrawLinearGradient(context, gradient, CGPointMake(0, 0), CGPointMake(0, frame.size.height), 0);
    
    CGContextRestoreGState(context);
    CGGradientRelease(gradient);
}