Transitioning from one UIPopoverController to another is slow on iOS8

Question

My app has multiple buttons each of which brings up a different UIPopoverController. We have 'passthroughViews' set so the buttons are still enabled while the popovers are up. Pressing one of the buttons while a popover is displayed dismisses the current popover and brings up the new one. The trouble is, this seems very slow on iOS8. The popovers come up and go away on their own just fine -- it's just when we switch from one to another that there is a pause between when the first one closes and next one starts to show. I'm calling these dismissPopoverAnimated and presentPopoverFromRect: calls back to back, so there is nothing going on between the two. I've tried setting 'animated' to NO for both of these but the pause still remains. Any help is greatly appreciated.

Answer 1

Rather than close the popover, re-purpose the same popover when the 2nd button is pressed. Move the location of the popover, on the screen and load the new content into it. Seems like that would be quicker and avoid whatever contention or latency issues you are experiencing switching from one modal view to the next (I suspect that is what the issue is). You'd lose the disappear/reappear animations, but it should be near instantaneous and provide a good user experience, because users don't really (in the long run) want to wait through animations to see their content when they push a new button anyway.

Answer 2

What's inside these popovers? If they're tied to something running on the main thread, then you are likely seeing that as your lag element. You might want to lean up your viewDidLoad and viewWillAppear methods. Try running largish processes on a background thread and updating it after appearing.

If you are using a core data store then you are likely using the primary context, which always runs on the main thread. Try caching those calls ahead of time, or run your fetches on a child thread and returning those to the main thread after the popover has loaded.

Answer 3

Try this code,

[UIView transitionWithView:pop1.contentViewController.view duration:0 options:UIViewAnimationOptionTransitionCrossDissolve animations:^{

    [pop1 dismissPopoverAnimated:NO];

} completion:^(BOOL finished) {

   [pop2 presentPopoverFromRect:btn.bounds inView:self.view permittedArrowDirections:UIPopoverArrowDirectionLeft animated:NO];

}];

hope it helps.

Answer 4

I had a similar issue that had my head banging on the problem for almost a day: the UIPopoverController was extremely slow to appear on occasion (sometimes it was sluggish, other time almost fine, other it was taking like 4" to appear...), and this happened only on iOs8 (iOs7 was always blink-fast), which leads me to believe that my solution might help you as well.

After much debugging I have come to the conclusion that the problem for me was connected the fact that I showed the popover within the

- (NSIndexPath *) tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath;

method (but I would'n rule out that other similar cases exist).

My solution is running the presentPopoverFromRect: method (my logs showed it was the slow method) just after the willSelectRowAtIndexPath: method ended (as a matter of fact I crammed the whole popover "initialize and show" in the function to delay as well, to be on the safe side, and because my code was already like that).

This boils down to running the UIPopoverController initialization and display code in a block like this one:

dispatch_async(dispatch_get_main_queue(), ^() {
    // Do the popover stuff here
});

Even if you are not using table, other similar problems might exist within iOs8 (because this is an Apple bug!), so I guess this might worth a try...

Hope it helps, Cheers