Problem with Timeline keeping references around

[Stephen F Northover]

This looks like a bug.  Timeline should not be holding on to 
references.  Please enter a JIRA.

Steve

On 2013-10-15 6:35 PM, John Hendrikx wrote:
> Hi List,
>
> I just submitted https://javafx-jira.kenai.com/browse/RT-33600 which 
> is asking for the Timeline JavaDocs to be more clear on when and where 
> hard references are being created and how to properly clean up after 
> oneself.  Most of the docs hardly mention anything when it comes to 
> references causing memory leaks, and Timeline is no exception.
>
> However, apart from the docs not really discussing this topic, I 
> actually cannot get proper cleanup to work at all when working with a 
> Timeline.
>
> If my Timeline is referencing properties from a StackPane and the 
> Timeline was run atleast once, I cannot figure out how to get this 
> Pane to be gc'd.  Calling stop() and even doing getKeyFrames().clear() 
> doesn't help.  I'm sure it must be the Timeline because if I remove 
> the KeyFrames that access the StackPane, it will get gc'd properly.  
> If I never run the animation, it also gets gc'd properly.
>
> See code below.  The System.outs will occur exactly as expected when 
> the StackPane becomes part of the Scene and when it is removed from 
> the Scene.  I call stop() on my Timeline and even clear its KeyFrames, 
> but the StackPane refuses to be gc'd (even after hitting the GC button 
> I created for this occasion dozens of times).
>
> Not calling playFromStart() or not using the KeyFrames that refer to 
> detailsOverlay.opacityProperty() will solve the problem, and the 
> finalize() System.out will occur usually after the first or second 
> time I press my GC button.
>
> Anything else I can try or is this a bug?
> --John
>
> public class PlaybackOverlayPane extends StackPane {
>   private final Timeline fadeInSustainAndFadeOut = new Timeline(
>     new KeyFrame(Duration.seconds(0)),
>     new KeyFrame(Duration.seconds(1), new 
> KeyValue(detailsOverlay.opacityProperty(), 1.0)),
>     new KeyFrame(Duration.seconds(6), new 
> KeyValue(detailsOverlay.opacityProperty(), 1.0)),
>     new KeyFrame(Duration.seconds(9), new 
> KeyValue(detailsOverlay.opacityProperty(), 0.0))
>   );
>
>   private final ChangeListener<Scene> sceneChangeListener = new 
> ChangeListener<Scene>() {
>     @Override
>     public void changed(ObservableValue<? extends Scene> observable, 
> Scene oldValue, Scene newValue) {
>       if(newValue != null) {
>         System.out.println(">>> Starting fadeIn anim");
>         fadeInSustainAndFadeOut.playFromStart();
>       }
>       else {
>         System.out.println(">>> Stopping fadeIn anim");
>         fadeInSustainAndFadeOut.stop();
>         fadeInSustainAndFadeOut.getKeyFrames().clear();
>         fadeInSustainAndFadeOut.stop();
>       }
>     }
>   };
>
>   private final GridPane detailsOverlay = GridPaneUtil.create(new 
> double[] {5, 20, 5, 65, 5}, new double[] {45, 50, 5});
>
>  ...
>
>   @Override
>   protected void finalize() throws Throwable {
>     super.finalize();
>     System.out.println(">>> Finalized " + this);
>   }
> }