RFR: 8280993: [XWayland] Popup is not closed on click outside of area controlled by XWayland [v3]

[Phil Race]

On Fri, 19 May 2023 15:58:07 GMT, Alexander Zvegintsev <azvegint at openjdk.org> wrote:

>> On Linux systems, we rely on XGrabPointer (X11 API) to capture mouse input and dismiss popup menus on mouse clicks outside the popup menu.
>> Unfortunately, on Linux systems using the [Wayland](https://wayland.freedesktop.org/) session this only works inside [XWayland(Wayland's X11 server implementation)](https://wayland.freedesktop.org/xserver.html).
>> This means if a user clicks on a part of the screen not controlled by XWayland (e.g. window decorations, other non X11 applications) the popup menu will not be hidden.
>> 
>> As a workaround, we can hide this menu when the parent popup menu window loses focus.
>> However, it does have its drawbacks, which should be described in the documentation.The focus does not change when clicking on the header of its own parent window or on non-focusable windows, .e.g., empty space in system dock, so in this case the popup menu is not hidden.
>> 
>> Third-party applications use a similar approach.
>> 
>> I also have doubts about the need to change the documentation, as I can't find where it is described that the popup menu should be hidden when clicked outside the menu.
>> 
>> <del>CSR: https://bugs.openjdk.org/browse/JDK-8307529</del>
>
> Alexander Zvegintsev has updated the pull request incrementally with one additional commit since the last revision:
> 
>   move to toolkit

Marked as reviewed by prr (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/13830#pullrequestreview-1434815761