CADisplayLink stops updating when UIScrollView scrolled

Question

Title is quite self explanatory, but I have some animation being done in a loop triggered by CADisplayLink. However, as soon as I scroll a UIScrollView I have added to my view hierarchy, the animation stops immediately, only to return again when scrolling has completely stopped and come to a standstill....

Anyway to cancel this behaviour?

Answer 1

You can also mitigate the effects of this issue by using NSRunLoopCommonModes instead of NSDefaultRunLoopModes:

[displayLink addToRunLoop:[NSRunLoop currentRunLoop]
                  forMode:NSRunLoopCommonModes];

Answer 2

Run the display link (using -addToRunLoop:forMode:) on another thread with another run loop. So create a new thread, create a run loop on that thread, and run the CADisplayLink on that thread/run loop.

Answer 3

Use UITrackingRunLoopMode. It's specifically designed for scrolling stuffs.

Otherwise, just call render & present routine at -scrollViewDidScroll.

UIScrollView broken and halts scrolling with OpenGL rendering (related CADisplayLink, NSRunLoop)

Answer 4

Here you can find a better (and more complex) solution:

Animation in OpenGL ES view freezes when UIScrollView is dragged on iPhone

that allows you to use 'NSRunLoopCommonModes' and avoids OpenGL freezing when holding a finger without scrolling.

This is related to what Doug found (setting the frame interval of CADisplayLink to 2 instead of 1 fixing UIScrollView).

Answer 5

Actually CADisplayLink support multiple RunloopMode. try this:

    [displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:UITrackingRunLoopMode];
    [displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];