Question

I have an algorithm that takes a few seconds to load some stuff, and I want to first set the string on a label to say “loading” before the actual loading begins. This is all within the same layer, this is not switching between scenes.

I thought I could simply do this:

-(void)startLoading{

[self unscheduleAllSelectors];//just in case the update is already scheduled

[self.loadingLabel setString:@"Loading...."];

[self scheduleUpdate];

 }

Then, I have this:

-(void)update:(ccTime)delta{
[self unscheduleUpdate];
[self beginLoading];//another method that loads all the stuff

 }

My understanding is that my method beginLoading should not run until the next frame. Thus my label should get updated correctly. However this is not happening. There is a slight freeze while all my assets get loaded and my label never gets updated before the loading begins.

Am I missing a step?

Answer 1

Nope ure not missing anything. I stopped fighting this and now use this kind of ‘delayed’ task catapult. It should make certain you will get a draw in the transition from the first to the second tick:

-(void) startLoading{
    _loadTicker=0; // an NSUInteger iVar declared in the .h
    [self schedule:@selector(tickOffLoading:)];
}

-(void) tickOffLoading:(ccTime) dt{

    _loadTicker++;
    if(_loadTicker==1) {
        [self.loadingLabel setString:@"Loading...."];
    } else {
        [self unschedule:@selector(tickOffLoading:)];
        [self beginLoading];
    }
}