Integrated: 8208088: Memory Leak in ControlAcceleratorSupport

[Ambarish Rapte]

On Wed, 17 Mar 2021 17:35:34 GMT, Ambarish Rapte <arapte at openjdk.org> wrote:

> The method `ControlAcceleratorSupport.doAcceleratorInstall(final List<? extends MenuItem> items, final Scene scene)` adds a `ChangeListener` on `MenuItem.acceleratorProperty()`. This listener is not removed when the MenuItem is removed from scenegraph.
> Adding and removing a MenuItem results in multiple copies of the listener added to MenuItem.acceleratorProperty().
> 
> Fix is to remove the listener when MenuItem is removed.
> Fix can be verified by checking the number of instances of `ControlAcceleratorSupport.lambda` using _jvisualvm_. 
> Without this fix, the number of `ControlAcceleratorSupport.lambda` increase in multiple of number of MenuItems being removed and added back.
> With fix, the count is always same as number of MenuItems in scenegraph.
> 
> Also there is another ListChangeListener added to a `ObservableList<MenuItem> items` in the method `ControlAcceleratorSupport.doAcceleratorInstall(final ObservableList<MenuItem> items, final Scene scene)`. There was a TODO note to remove this listener.
> This listener is added on `MenuBarButton.getItems()` and not on `Menu.getItems()`.  This `MenuBarButton` is created by `MenuBarSkin` to show a `Menu`. This `MenuBarButton` gets disposed when the related `Menu` is removed from scenegraph, and so the added `ListChangeListener` gets GCed. Hence it is not required to explicitly remove the listener. 
> Added a comment explaining this behavior in place of the TODO.

This pull request has now been integrated.

Changeset: 05ab7992
Author:    Ambarish Rapte <arapte at openjdk.org>
URL:       https://git.openjdk.java.net/jfx/commit/05ab7992
Stats:     147 lines in 2 files changed: 135 ins; 10 del; 2 mod

8208088: Memory Leak in ControlAcceleratorSupport

Reviewed-by: kcr, aghaisas

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PR: https://git.openjdk.java.net/jfx/pull/429