How to set UILabel non rectangular frame - iphone

Question

Im trying to make a UILabel with the edges looking like the following image.
Here is the drawRect: from my UILabel subclass.
-(void)drawRect:(CGRect)rect{
[super drawRect:rect];
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
CGRect labelRect = self.bounds;
CGPoint bottomPoint = CGPointMake(labelRect.size.width, rect.size.height);
CGPoint topMinus30Point =CGPointMake(labelRect.size.width-30, 0);
CGPoint topPoint = CGPointMake(labelRect.size.width, 0);
CGContextBeginPath (context);
//from bottom to -30 top
CGContextMoveToPoint(context, bottomPoint.x,bottomPoint.y);
CGContextAddLineToPoint(context, topMinus30Point.x,topMinus30Point.y);
//from -30 to top
CGContextMoveToPoint(context, topMinus30Point.x,topMinus30Point.y);
CGContextAddLineToPoint(context, topPoint.x,topPoint.y);
//from top to bottom
CGContextMoveToPoint(context, topPoint.x,topPoint.y);
CGContextAddLineToPoint(context, bottomPoint.x,bottomPoint.y);
CGContextClosePath(context);
CGContextStrokePath(context);
CGContextRestoreGState(context);
}
How do I crop the created path from the current frame ?
[Im just getting started with Core Graphics, so please be gentle :)]
Any pointers on how to achieve this would be really helpful.
Thanks

Answer 1

Try this:
- (void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
// clear drawing rect
CGContextClearRect(context, rect);
// save 1
CGContextSaveGState(context);
CGRect labelRect = self.bounds;
CGPoint bottomPoint = CGPointMake(labelRect.size.width, rect.size.height);
CGPoint topMinus30Point = CGPointMake(labelRect.size.width-30, 0);
CGPoint topPoint = CGPointMake(labelRect.size.width, 0);
CGContextBeginPath(context);
CGContextMoveToPoint(context, 0.0f, 0.0f);
CGContextAddLineToPoint(context, topMinus30Point.x, topMinus30Point.y);
CGContextAddLineToPoint(context, bottomPoint.x, bottomPoint.y);
CGContextAddLineToPoint(context, 0.0f, bottomPoint.y);
CGContextAddLineToPoint(context, 0.0f, 0.0f);
CGContextClosePath(context);
CGContextSetFillColorWithColor(context, [UIColor redColor].CGColor);
CGContextDrawPath(context, kCGPathFill);
// restore 1
CGContextRestoreGState(context);
}
Put this in the init you use:
[self setBackgroundColor:[UIColor clearColor]];

Answer 2

One approach is,
set the background color of label to clear color, and draw the required shape inside your drawRect method using CGContext.
Your drawRect will become like this
- (void)drawRect:(CGRect)rect{
[super drawRect:rect];
CGContextRef context = UIGraphicsGetCurrentContext();
CGRect labelRect = self.bounds;
CGPoint bottomPoint = CGPointMake(labelRect.size.width, rect.size.height);
CGPoint topMinus30Point =CGPointMake(labelRect.size.width-30, 0);
//from bottom to -30 top
CGContextMoveToPoint(context, self.bounds.origin.x,self.bounds.origin.y);
CGContextAddLineToPoint(context, topMinus30Point.x,topMinus30Point.y);
CGContextAddLineToPoint(context, bottomPoint.x,bottomPoint.y);
CGContextAddLineToPoint(context, self.bounds.origin.x,self.bounds.origin.x + self.bounds.size.height);
CGContextAddLineToPoint(context, self.bounds.origin.x,self.bounds.origin.y);
CGContextSetFillColorWithColor(context, [UIColor greenColor].CGColor);
CGContextFillPath(context);
}
Another approach is using the CGContextClip using this approach your drawRect will become like this
CGContextMoveToPoint(context, self.bounds.origin.x,self.bounds.origin.y);
CGContextAddLineToPoint(context, topMinus30Point.x,topMinus30Point.y);
CGContextAddLineToPoint(context, bottomPoint.x,bottomPoint.y);
CGContextAddLineToPoint(context, self.bounds.origin.x,self.bounds.origin.x + self.bounds.size.height);
CGContextAddLineToPoint(context, self.bounds.origin.x,self.bounds.origin.y);
CGContextClip(context);
CGContextSetFillColorWithColor(context, [UIColor greenColor].CGColor);
CGContextFillRect(context, self.bounds);
Hope this helps