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tic
Member
Hi
How is it possible to chain together a sequence of events with each event executing upon completion of the last event?
I am having trouble achieving this with CCSequence.
For this example I am using CCFadeIn on a background splash screen, CCFadeIn on a CCLabelTTF overlay, and then I wish to fade them both out.
I am just starting and would like to understand best practices
Many thanks
Use blocks..
I don't know the exact order you want, but lets say you want to fadeIn in the bg, then fadeIn the label, then fade them both out.
Not tested but I think something like this would work:
id background = yourBackground;
id label = yourLabel;
id bgFadeIn = [CCCallBlock actionWithBlock:^{
[background runAction:[CCFadeIn actionWithDuration:2.0f];
}];
id labelFadeIn = [CCCallBlock actionWithBlock:^{
[label runAction:[CCFadeIn actionWithDuration:2.0f];
}];
id fadeOutBoth = [CCCallBlock actionWithBlock:^{
[label runAction:[CCFadeOut actionWithDuration:2.0f];
[background runAction:[CCFadeOut actionWithDuration:2.0f];
}];
id seq = [CCSequence actions:bgFadeIn, labelFadeIn, fadeOutBoth, nil];
[self runAction:seq];Try this out, but something is telling me that the seq may not respect the time durations in the blocks, so if that's the case just insert delayTime actions in the seq, make sense?
something like this:
id background = yourBackground;
id label = yourLabel;
float bgFadeTime = 2.0f;
float labelFadeTime = 2.0f;
id bgFadeIn = [CCCallBlock actionWithBlock:^{
[background runAction:[CCFadeIn actionWithDuration:bgFadeTime];
}];
id bgDelay = [CCDelayTime actionWithDuration:bgFadeTime];
id labelDelay = [CCDelayTime actionWithDuration:bgFadeTime];
id labelFadeIn = [CCCallBlock actionWithBlock:^{
[label runAction:[CCFadeIn actionWithDuration:labelFadeTime];
}];
id fadeOutBoth = [CCCallBlock actionWithBlock:^{
[label runAction:[CCFadeOut actionWithDuration:2.0f];
[background runAction:[CCFadeOut actionWithDuration:2.0f];
}];
id seq = [CCSequence actions:bgFadeIn, bgDelay, labelFadeIn, labelDelay, fadeOutBoth, nil];
[self runAction:seq];
tic
Member
That is what I had tried, but the order is completely messed up (the background displays and fades correctly, but doesn't wait in the middle. The label fades in and out several times and starts immediately at full opacity)
When creating your objects, should you addChild them immediately before fading them, as then how do they know to start fading in if they're already added at full opacity?
I've been doing a lot of searching and testing on this sequence issue. It seems very strange that it is so difficult and there is no definitive answer as I would expect that it would be a very common requirement for a game to have multiple objects performing actions one after another.
Thanks again
Huh, sorry I don't know man, logically it seems like that would work. Maybe someone more experienced can provide insight..
To create a sequence with actions that run on different nodes, wrap the actions that have a different target in a CCTargetedAction.
For example
CCJumpBy *jump1 = [CCJumpBy actionWithDuration:2 position:CGPointZero height:100 jumps:3];
CCJumpBy *jump2 = [[jump1 copy] autorelease];
CCRotateBy *rot1 = [CCRotateBy actionWithDuration:1 angle:360];
CCRotateBy *rot2 = [[rot1 copy] autorelease];
CCTargetedAction *t1 = [CCTargetedAction actionWithTarget:kathia action:jump2];
CCTargetedAction *t2 = [CCTargetedAction actionWithTarget:kathia action:rot2];
CCSequence *seq = [CCSequence actions:jump1, t1, rot1, t2, nil];
[aSprite runAction:seq];
//another possibility is to wrap all actions and run them on a third object
tic
Member
Hi araker
I've been trying to play with your code, but I really don't understand what you mean.
With your example, how could I with obj1 and obj2, fadeIn obj1 then fadeIn obj2, wait some time, then fade both out?
Do you know if there is a 'correct' way to do this that is extensible. Say I have 100 actions that I want to run 1 after the other, then how would I do that? There must be a simple way to create synchronous behaviour from this asynchronous methods. I tried to search for anonymous delegates as a callback function oncomplete like most other languages have, but apparently objective-c does not support this.
You're nearly there as long as you understand how targeted actions work. It pretty much allows actions to be handled on the same timeline but the targets to be different so you can apply actions to any node you please.
After that you have to use CCSequence and CCSpawn to simulate serial actions and parallel actions.
Remember that you CAN nest sequences and spawns together.
So your example of "fadeIn obj1 then fadeIn obj2, wait some time, then fade both out" can be done by nesting 1 spawn in your sequence of actions.
The concept would look like this:
sequence=[fadeIn-obj1, fadeIn-obj2, wait, spawn=[fadeOut-obj1, fadeOut-obj2], anotheraction ]
See if you can attempt to create the code by nesting a spawn at the end of the sequence. Remember to use targeted actions for each item.
Nothing really changes since the target of the action doesn't matter on CallFunc's.
So I guess this is a confusion of the term 'target'. CallFunc's use target/selector to refer to object instances so it can find the right message to invoke. CCTargetedActions pass in a target as well but that refers to the CCNode that you apply an action onto.
Just don't wrap a CCTargetAction when you use CallFunc.
tic read Lam's last sentence.
Thanks for explaining this, I learned something too ;)
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