Question

I’m writing some app. I have there some class with custom view. In the view there is timer that is invoking “setNeedsDisplayInRect” method. I need that timer to be very offensive for purposes of the animation (there is no very complex animation). I have set the value for the timer: 0.0001. Is that value not too big? The app is working correctly with it.

Answer 1

Don’t use NSTimer for this. Use CADisplayLink. It will run at the optimal rate for the device.

Set it up like this:

self.displayLink = [self.view.window.screen displayLinkWithTarget:self selector:@selector(setNeedsDisplayForMyView)];
[self.displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

and define a method setNeedsDisplayForMyView:

- (void)setNeedsDisplayForMyView
{
    [self.view setNeedsDisplayInRect:self.dirtyRect];
}