RFR: 8349096: Split/MenuButton: exception initializing in a background thread

[Kevin Rushforth]

On Wed, 12 Feb 2025 20:15:03 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

> ## Root Cause
> 
> The ContextMenu (PopupWindow) cannot be shown in a background thread.
> 
> ## Solution
> 
> Bail out of `show()` if in a background thread.

I took another look today, and I am convinced that we need to change the spec and implementation of all `show` and `hide` methods to enforce the threading restriction that they must only be called on the JavaFX Application thread. I filed the following bug to do this:

[JDK-8350048](https://bugs.openjdk.org/browse/JDK-8350048): Enforce threading restrictions for show and hide methods in Window, Control, and Skin

Therefore, this PR should be withdrawn and the bug should be closed as a Duplicate of JDK-8350048.

-------------

PR Comment: https://git.openjdk.org/jfx/pull/1709#issuecomment-2657919263