collectgarbage() do nothing and related listeners problem in SceneManager

nat12

Hello,

I am using the SceneManager (v1.0.1 with collectgarbage) and discovered the old scenes do remain in memory also after the scene change (also after 3 or more scene changes, if they happen in short succession), it is eventually freed only after a random delay, supposedly when the background garbage collector do its work.

This is not a problem for the memory occupation, but i have also found the event listeners of the old scene are still called until the scene is eventually destroyed for real...
Any suggestion for a workaround? (the only solution I have found is to manually remove all listeners before to call changeScene, but this is tedious and error prone)

atilim

Hi nat,

First of all, upgrade your Scene Manager to v1.0.3 from here: https://github.com/gideros/Scene-Manager

Here, there are 4 types of events that your scene can register:
- enterBegin
- enterEnd
- exitBegin
- exitEnd


The "exitBegin" event is very appropriate for stopping your times, removing your listeners etc. Similarly, "enterEnd" is appropriate for registering your events, starting your timers etc. (here is a bit more explanation: http://www.giderosmobile.com/blog/2011/11/17/gideros-scene-manager/)

Let me given an example:

MyScene = gideros.class(Sprite)   function MyScene:init() self:addEventListener("enterEnd", self.onEnterEnd, self) self:addEventListener("exitBegin", self.onExitBegin, self) end   function MyScene:enterEnd() self:addEventListener(Event.ENTER_FRAME, self.onEnterFrame, self) -- create your timers -- also you can add your player sprite -- and so on... end   function MyScene:exitBegin() self:removeEventListener(Event.ENTER_FRAME, self.onEnterFrame, self) -- stop your timers -- save score -- and so on... end   function MyScene:onEnterFrame() end

On the other hand, ENTER_FRAME event is dispatched even when the sprite is _not_ on the stage. (When the sprite is collected, the dispatching of ENTER_FRAME stops). If you want to dispatch ENTER_FRAME only while the sprite is attached to the stage, you can use this method:

MySprite = gideros.class(Sprite)   function MySprite:init() self:addEventListener(Event.ADDED_TO_STAGE, self.onAddedToStage, self) self:addEventListener(Event.REMOVED_FROM_STAGE, self.onRemovedFromStage, self) end   function MySprite:onAddedToStage() self:addEventListener(Event.ENTER_FRAME, self.onEnterFrame, self) end   function MySprite:onRemovedFromStage() self:removeEventListener(Event.ENTER_FRAME, self.onEnterFrame, self) end   function MySprite:onEnterFrame() end

I've done some initial tests and see my scenes are collected right after they exit from the scene. But I'll do some more tests.

PS: Also I can add a function like "removeAllListeners" to make this easier.

best,

nat12

Thank You,

I was unaware of REMOVED_FROM_STAGE.
removeAllListeners sound good, i do not need it for now but can imagine situations where it can be useful.

I will try version 1.0.3

Maybe for a future release you can consider to add an event ENTER_STAGE_FRAME similar to ENTER_FRAME but dispatched only to objects on stage?

atilim

Maybe for a future release you can consider to add an event ENTER_STAGE_FRAME similar to ENTER_FRAME but dispatched only to objects on stage?

Exactly! I was thinking about adding this event but couldn't find a good name for it. I think the name ENTER_STAGE_FRAME is great.