How do I create a GLKViewController that starts in a paused state?

Question

I create a GLKViewController like this:

// Create a GLK View Controller to handle animation timings
_glkVC = [[GLKViewController alloc] initWithNibName:nil bundle:nil];
_glkVC.preferredFramesPerSecond = 60;
_glkVC.view = self.glkView;
_glkVC.delegate = self;
_glkVC.paused = YES;
NSLog(@"initial state: %@", _glkVC.paused ? @"paused" : @"running");

but it immediately starts calling the delegate update method and the output from the NSLog above is: initial state: running

I am managing my view updates with setNeedsDisplay but I want the GLKViewController to handle animations from time to time so I want to unpause it only when needed. Is there a way to start the controller in a paused state?

I'd like to open this question up again. The FPS workaround is ok, but surely there's a better way? — Ricardo RendonCepeda, Jan 06 '13 at 23:41

score 2 · Answer 1 · answered Nov 16 '12 at 04:01

2

have you tried pausing in the viewDidAppear method instead of the viewDidLoad method? It should look something like this:

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];    
    // self.paused automatically set to NO in super's implementation
    self.paused = YES;
}

Boom, done! If this works then you save an "if" check thousands of times a minute just to pause on launch!

answered Nov 16 '12 at 04:01

mogelbuster

1,066
9
19

This doesn't work. The draw method is fired a couple of times before `viewDidAppear` is hit. – Ricardo Sanchez-Saez Jan 23 '15 at 17:14

Alan Stewart · Answer 2 · 2013-11-02T17:10:22.133

2

The viewDidAppear method works for me, but not optimally. A few frames of visible animation occur before the pause takes effect. Using viewWillAppear worked much better:

- (void) viewWillAppear: (BOOL) animated
{
  [ super viewDidAppear: animated ];
  self.paused = YES;
}

edited Nov 02 '13 at 17:10

answered Nov 02 '13 at 17:04

Alan Stewart

21
3

score 1 · Accepted Answer · answered Oct 25 '12 at 11:34

In lieu of any answers I'm using this work-around:

I set .preferredFramesPerSecond = 1 initially and then in the update method I check if(preferredFramesPerSecond == 1) and set .paused = YES (and also set my real desired value for preferredFramesPerSecond). I can then allow the rest of the update method to run once after initialisation, or return immediately if I don't want it to run yet.

I then trigger redraws manually as needed with setNeedsDisplay and unpause it when I need it to animate.

If anyone has a better solution please answer as usual.

score 1 · Answer 4 · answered May 12 '13 at 08:28

1

Have you tried overriding resumeOnDidBecomeActive to return NO? This should keep the animation paused on any activation, including the first.

answered May 12 '13 at 08:28

Steven McGrath

1,717
11
20

How do I create a GLKViewController that starts in a paused state?

4 Answers4