How can I stop the next screen from briefly displaying at the start of a CCTransitionFadeTR?

Question

I am testing transitions in cocos2d, and am running into a problem.

I have a MainMenu screen which contains a button. The idea is that clicking on the button will trigger a CCTransitionFadeTR transition to a WhackMain screen where there is a CCLabelTTF which displays "Hello World".

But when I press the button and start the transition, the WhackMain screen appears at full opacity for a moment before the transition from MainMenu to WhackMain begins. The transition appears to be working correctly, apart from WhackMain being visible for a moment before the transition begins.

How can I keep this from happening?

Here is my code, if it will help identify the problem:

MainMenu.m:

#import "MainMenu.h"
#import "WhackMain.h"

@implementation MainMenu

+(CCScene *) scene1 {
// 'scene' is an autorelease object.
CCScene *scene1 = [CCScene node];

// 'layer' is an autorelease object.
MainMenu *layer1 = [MainMenu node];

// add layer as a child to scene
[scene1 addChild: layer1];

// return the scene
return scene1;
}


-(id) init {
// always call "super" init
// Apple recommends to re-assign "self" with the "super" return value
if( (self=[super init])) {

    CGSize winSize = [[CCDirector sharedDirector] winSize];

    // Create a label for display purposes
    _label = [[CCLabelTTF labelWithString:@"Last button: None" 
                               dimensions:CGSizeMake(320, 50) alignment:UITextAlignmentCenter 
                                 fontName:@"Arial" fontSize:32.0] retain];
    _label.position = ccp(winSize.width/2, 
                          winSize.height-(_label.contentSize.height/2));
    [self addChild:_label];

    // Standard method to create a button
    CCMenuItem *starMenuItem = [CCMenuItemImage 
                                itemFromNormalImage:@"ButtonStar.png" selectedImage:@"ButtonStarSel.png" 
                                target:self selector:@selector(starButtonTapped:)];

    // position the label on the center of the screen
    starMenuItem.position =  ccp( winSize.width /2 , winSize.height/2 );



    CCMenu *starMenu = [CCMenu menuWithItems:starMenuItem, nil];
    starMenu.position = CGPointZero;
    [self addChild:starMenu];
}
return self;
}

- (void)starButtonTapped:(id)sender {
  [_label setString:@"Last button: *"];
  [[CCDirector sharedDirector] replaceScene:[CCTransitionFadeTR
                                           transitionWithDuration:2 scene:[WhackMain scene2]]];
}

// on "dealloc" you need to release all your retained objects
- (void) dealloc {
[super dealloc];
}

@end

WhackMenu.m:

#import "WhackMain.h"
#import "MainMenu.h"

@implementation WhackMain

+(CCScene *) scene2 {
// 'scene' is an autorelease object.
CCScene *scene2 = [CCScene node];

// 'layer' is an autorelease object.
WhackMain *layer2 = [WhackMain node];

// add layer as a child to scene
[scene2 addChild: layer2];

// return the scene
return scene2;
}

-(id) init {
// always call "super" init
// Apple recommends to re-assign "self" with the "super" return value
if( (self=[super init])) {

    // create and initialize a Label
    CCLabelTTF *label = [CCLabelTTF labelWithString:@"Hello World" fontName:@"Marker Felt" fontSize:64];

    // ask director the the window size
    CGSize size = [[CCDirector sharedDirector] winSize];

    // position the label on the center of the screen
    label.position =  ccp( size.width /2 , size.height/2 );

    // add the label as a child to this Layer
    [self addChild: label];
}
return self;
}

// on "dealloc" you need to release all your retained objects
- (void) dealloc {
[super dealloc];
 }


@end

Answer 1

Well I tried to recreate your problem in one my projects but it doesn't appear for my case.

There are 2 things you can do here.
1. Install new cocos2d framework,
2. If 1st one doesn't work you can schedule a timer that initializes all your nodes in the given scene after 1 sec like this

[self schedule:@selector(somefunction:) interval:1.0f];

Which is also not a bad choice as when changing the scene the memory usage is at peak and in this way you will reduce the risk of crashing the app due to low memory warnings.

Mostly people use a loading screen which contains nothing more than a label but if you are have problems in transition than i would say go for the second option even if 1st one works.