UIView border with fade or blur effect

Question

Hi everyone!

I'm looking for method to add gradually fading or maybe blured border (I don't exactly know how to name this effect) to arbitrary UIView. I don't need animated effect, I need static effect, for example I my UITableView border being partially transparent. I've made the example: http://i46.tinypic.com/14nz76f.png, so you can see what I'm trying to do.

Can anyone help me?

Answer 1

You might try placing a semi-transparent PNG file over the bottom of the UITableView.

Answer 2

I've found a solution - I've useed CALayer's property mask:

 CALayer *viewLayer = [back layer];
 CALayer* maskCompoudLayer = [CALayer layer];

 maskLayer.bounds = viewLayer.bounds;

 [maskLayer setPosition:CGPointMake(160, CGRectGetHeight(maskCompoudLayer.frame)/2.0)];     

 CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
 CGContextRef context = CGBitmapContextCreate (NULL, 320, 480, 8, 0, colorSpace, kCGImageAlphaPremultipliedLast);     

 CGFloat colors[] = {
      0.5, 0.5, 0.5, 0.0, //BLACK
      0.0, 0.0, 0.0, 1.0, //BLACK
 };     

 CGGradientRef gradient = CGGradientCreateWithColorComponents(colorSpace, colors, NULL, sizeof(colors)/(sizeof(colors[0])*4));     
 CGColorSpaceRelease(colorSpace);     

 NSUInteger gradientH = 20;
 NSUInteger gradientHPos = 0;

 CGContextSetFillColorWithColor(context, [UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:1.0].CGColor);
 CGContextFillRect(context, CGRectMake(0, gradientHPos + gradientH, CGRectGetWidth(maskLayer.frame), CGRectGetHeight(maskLayer.frame)));     

 CGContextSetFillColorWithColor(context, [UIColor colorWithRed:0.5 green:0.5 blue:0.5 alpha:0.0].CGColor);
 CGContextFillRect(context, CGRectMake(0, 0, 320, gradientHPos));

 CGContextDrawLinearGradient(context, gradient, CGPointMake(160, gradientHPos), CGPointMake(160, gradientHPos + gradientH), 0);     
 CGGradientRelease(gradient);     

 CGImageRef contextImage = CGBitmapContextCreateImage(context);
 CGContextRelease(context);     

 [maskLayer setContents:(id)contextImage];

 CGImageRelease (contextImage);

 viewLayer.masksToBounds = YES;
 viewLayer.mask = maskCompoudLayer;

Using this code I have UITableView with fading border