Add destroy method to Playable

[jrouault]

Description

As pointed out in #63, whenever a tween is stopped, its update and complete can still trigger in the same tick.
This PR adds a destroy method to Playable which immediately removes the tween. As the tween is removed immediately, its update and complete do not trigger in the same tick.

poke @ronkorving @cainmartin @bchevalier

[bchevalier]

Yo!

The problem with immediately removing a tween is that it might translate into some weird behaviors if the tween's onComplete or onStop callback is called while some code is looping over the current active tweens.

Also, instead of duplicating the stop method it might be best to wrap the code into a third method? there are other solutions to avoid the issue but I think logic should not be duplicated.

[jrouault]

Thanks for the quick answer 😃

As for the onComplete callback, it's the whole point of the destroy method to ensure it will not be called. I don't see which case could result in a weird behaviour.
As for the onStop callback, it is still called at the end of the destroy method but I don't see how it would result in a weird behaviour either.
Could you detail that a bit please?

I will make the changes to avoid the duplicated logic.

[ronkorving]

If true in both cases, maybe more elegant to move the return statement to after the else?

[jrouault]

Hello,

Is there anything I can do to push this PR forward?
@bchevalier Do you have an example so that I could reproduce the bad behaviour that would be introduced by this feature?

[bchevalier]

Unit tests?
That show that removing tweens immediately do not affect other tweens' updates.

[Tatsujinichi]

@bchevalier I assume this is because doubly list is nulling out the next and previous on the removed node, therefore it may stop iterating? Which, coincidentally, is not included on your 'container-doublylist'