Calling replaceScene:
with a CCScene
on CCDirector
which is during a CCTransition
results in dealloc
not being called on any scene used, moreover, after this operation any scene is not being displayed.
Here is a link to the sample project
Shortest way to obtain this behavior is such method (I mean reproducing the problem):
SceneOne *destScene = [SceneOne node];
CCTransitionFade *transition = [[CCTransitionFade alloc]initWithDuration:2 scene:destScene];
[[CCDirector sharedDirector]replaceScene:transition];
double delayInSeconds = 1.0;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
[[CCDirector sharedDirector]replaceScene:[SceneTwo node]];
});
My question is: is there any feasible way to replace scenes when the CCTransition
is being performed by the CCDirector
?
I have implemented a delegate callback from CCDirector
informing me about ending scene replacement, but this is never called if I push the iPhone home button during CCTransition
.
If the answer is no, is there a cocos2d-iphone way to achieve goal described below?
Originally, this problem arised when I wanted to add "loading scene" when applicationDidEnterBackground
(as a background task) or applicationWillEnterForeground
, but I realized it has nothing to do with background execution. My ultimate goal is to provide seamless user experience while a game is waiting for Game Center authentication handler being called, and a "loading scene" being displayed from the very start of the app awaked from background would be sufficient (not only preventing user interaction which can be done many ways, but not showing previous game UI to the user). However, this solution is susceptible to the problem described above - if user taps the home button during scene transition he is going to get a very strange screen after bringing the game from background.
EDIT: After some more research I didn't find any satisfactory solution to replacing scene during CCTransition
, however, problem described above was solved by not calling replaceScene
but by adding a "loading" CCLayer
to the visible CCScene
, as @LearnCocos2D (thanks Steffen) suggested. This is not perfect, since adding a child during scene transition still has some narrow window (in the sense of running time) when strange results occur, but it is much better than replacing the scene. I would like to mention that it only concerns me when testing my game on 3GS, since newer devices are significantly faster and it is very difficult to reproduce the problem of "home button" clicking during CCTransition
on something faster than 3GS.