On CCBitmapFontAtlas effect (Display on by one) - cocos2d-iphone

Question

I'm trying to make a effect using the CCBitmapFontAtlas, here is what I want:
The string say "ABCDEFG" being dispayed one by one, each one won't be displayed
until the one before is completely displayed.
And here is what I tried:
-(id) init
{
if( (self=[super init] )) {
label = [CCBitmapFontAtlas bitmapFontAtlasWithString:#"ABC" fntFile:#"bitmapFontTest.fnt"];
[self addChild:label];
CGSize s = [[CCDirector sharedDirector] winSize];
label.position = ccp(s.width/2, s.height/2);
label.anchorPoint = ccp(0.5f, 0.5f);
label.visible = NO; //hide it first
[[CCTouchDispatcher sharedDispatcher] addTargetedDelegate:self priority:0 swallowsTouches:YES];
}
return self;
}
-(BOOL) ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event
{
CCSprite AChar = (CCSprite) [label getChildByTag:0];
CCSprite BChar = (CCSprite) [label getChildByTag:1];
CCSprite CChar = (CCSprite) [label getChildByTag:2];
id fade_in = [CCFadeIn actionWithDuration:3];
label.visible = YES;
[AChar runAction:fade_in];
[BChar runAction:fade_in];
[CChar runAction:fade_in];
return YES;
}
The effect is the "ABC" will fade in once I touched the screen, then I tried to use the
CallFuncND to call the next string to fade in while the current string is displayed.
But this seems to make things very complex.
Is there a easier way to get this effect done?
Any suggestion will be appreciate.

Answer 1

I feel like you are going in the right direction with this one. You could have each letter be a separate sprite and store them in an array and then run them each one by one.
The call function can be started by:
[self displayNextSprite:spriteArray nextIndex:0];
And the function is:
// Warning, This assumes you are not passing it an empty array, you may want to put in a check for that
-(void)displayNextSprite:(NSMutableArray*)spriteArray nextIndex:(NSUInteger)nextIndex
{
CCSprite *nextSprite = [spriteArray objectAtIndex:nextIndex];
id action1 = [CCFadeIn actionWithDuration:3];
// or = [CCPropertyAction actionWithDuration:3 key:#"opacity" from:0 to:255];
// The last letter
if(nextIndex == ([spriteArray count] - 1))
{
[nextSprite runAction:action1];
}
else // continue to the next letter
{
id callFunc = [CCCallFunc actionWithTarget:self selector:#selector(displayNextSprite:spriteArray nextIndex:nextIndex+1)];
id sequence = [CCSequence actionOne:action1 two:callFunc];
[nextSprite runAction:sequence];
}
}