Question

I created a UIView Subclass and are using drawing rounded rects with UIBezierpath and fill it with some gradient.

In short this is what the subclass draw rect looks like:

CGRect frame1 = //size of Frame 1

CGRect frame2 = //size of Frame 2



//gradientingStart
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

if (options == false) {
    self.color = [self createRandomColor];
}



NSArray *gradientColors = [NSArray arrayWithObjects:
                           (id)[UIColor colorWithHue:color saturation:saturationVal brightness:brightnessVal alpha:1].CGColor,
                           (id)[UIColor colorWithHue:color+0.04 saturation:saturationVal+0.15 brightness:brightnessVal-0.15 alpha:1].CGColor, nil];

CGFloat gradientLocations2[] = {0.25,1};
CGGradientRef gradient2 = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef)gradientColors, gradientLocations2);
CGContextSaveGState(context);
//gradientingEnd

UIBezierPath *result =
[UIBezierPath bezierPathWithRoundedRect: frame1 cornerRadius:radius];
[result appendPath:
 [UIBezierPath bezierPathWithRoundedRect: frame2 cornerRadius:radius]];
[result setLineWidth:3];
[[UIColor blackColor]setStroke];
[result stroke];
[result fill];
[result addClip];
CGContextDrawLinearGradient(context, gradient2, CGPointMake(0, 0), CGPointMake(0, self.bounds.size.height), 0);

//important to prevent leaks
CGGradientRelease(gradient2);
CGColorSpaceRelease(colorSpace);
//-------
UIImage *texture = [UIImage imageNamed:@"texture2.png"];
[texture drawInRect:CGRectMake(self.bounds.origin.x, self.bounds.origin.y, self.bounds.size.width, self.bounds.size.height)];

Now I’m creating several instances of this in my view controller and trying the move them with animations like this:

[UIView animateWithDuration:0.5 delay:0 options:0 animations:^{
    costumview.alpha = 0;
    [costumview setFrame:CGRectMake(320,0,320,420)];
    [self reorderViewsFrom:costumview.intValue];
    overlay.alpha = 0;
}completion:^(BOOL finished){
}];

But unfortunately the animation is on a device very laggy and the more (5-10) costum views are display the worse it gets.

How can i improve the performance and provide smooth animations? I think changing the costum view is not an alternative because this would destroy the sense of the application. Are there any faster ways to animate the costum view?

Answer 1

I pointed out that using some CALayer transformation (rounding corners) causing the lag – unfournately this wasn’t in the snippet I posted.

I avoided it by creating the rounded corners with a own uiview subclass. This makes the app a lot smoother. All these rasterization stuff didn’t do it for me…