Draw method for a playlist item that shows the playhead position. Uses path clipping to round corners on top and bottom. (2009)

PlaylistItem.m

#define CORNER_RADIUS 10	

- (void)drawRect:(CGRect)rect {
	CGContextRef context = UIGraphicsGetCurrentContext();
	
	CGContextSetRGBFillColor(context, 0.0, 0.0, 0.0, 0.5); // black
		
	if ([type isEqualToString:@"top"]) {	// curved top
		CGContextBeginPath (context);
		CGContextMoveToPoint(context, 0, self.frame.size.height); // start: bottom-left
		CGContextAddArc (context, 0+CORNER_RADIUS, 0+CORNER_RADIUS, CORNER_RADIUS, M_PI, 3*M_PI/2, 0);  // top-left
		CGContextAddArc (context, self.frame.size.width-CORNER_RADIUS, 0+CORNER_RADIUS, CORNER_RADIUS, 3*M_PI/2, 0, 0);  // top-right
		CGContextAddLineToPoint(context, self.frame.size.width, self.frame.size.height);
		CGContextAddLineToPoint(context, 0, self.frame.size.height);
		CGContextClip(context);
	} else if ([type isEqualToString:@"bottom"]) {	// curved bottom
		CGContextBeginPath (context);
		CGContextMoveToPoint(context, 0, self.frame.size.height); // start: bottom-left
		CGContextAddLineToPoint(context, 0, 0);
		CGContextAddLineToPoint(context, self.frame.size.width, 0);
		CGContextAddArc (context, self.frame.size.width-CORNER_RADIUS, self.frame.size.height-CORNER_RADIUS, CORNER_RADIUS, 0, M_PI/2, 0);  //
		CGContextAddArc (context, 0+CORNER_RADIUS, self.frame.size.height-CORNER_RADIUS, CORNER_RADIUS, M_PI/2, M_PI, 0);  
		CGContextClip(context);		
	} else {
		
		// mid: NOOP //
		
	}
	
	CGContextFillRect(context, CGRectMake(0, 0, self.frame.size.width, self.frame.size.height));
	
	// timeline //
#define TIMELINE_MIN 4
	
	if (isSelected) {
		CGRect frame = CGRectMake(0, 0, TIMELINE_MIN+(self.frame.size.width-TIMELINE_MIN)*playheadPosition, self.frame.size.height);
		CGContextSetRGBFillColor(context, 1.0, 0.49, 0.0, 0.9);
		CGContextFillRect(context, frame);
	}
			
}