Why does Java (XWayland / Weston) resize a Window to 1x1 pixel when HDMI is unplugged (and does not resize back when HDMI is plugged)

[Martin Petzold]

Hi,

Am 08.06.23 um 09:28 schrieb Marius Vlad:
> Hi,
>
> Sort of sounds like might have has been fixed with [1].
>
> The change itself was integrated in weston 12, so you'd need to pick
> that version to test it out. Debian has only only weston 11 in
> experimental so you would need to either grab 12.0 branch from git, or get
> it from [2]. In both case you'd have to compile it yourself. If you
> manage to test it out and still see the issue, suggest to open a gitlab
> ticket.
the related error is a little different. I am not changing any size, it 
happens on HDMI plug and unplug. However, it may be related and the cause.

I am fixed to this Kernel, will be hard to get Weston 12 running. Any 
idea for a work-around?

Thanks,

Martin

> [1] https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/1180
> [2] https://gitlab.freedesktop.org/wayland/weston/-/releases/12.0.1
>
> On Wed, Jun 07, 2023 at 10:25:28PM +0200, Martin Petzold wrote:
>> I guess I have an issue with XWayland (but maybe Weston / Linux). It is very
>> specific and I kindly ask for help.
>>
>> I have a Java application running on:
>>
>> XWayland 2:1.20.11-1+deb11u6, Weston 9.0.0-1, OpenJDK 11.0.18+10-1~deb11u1,
>> Debian 11, Kernel 5.10.52
>>
>> My JFrame (Window) is set to: GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().setFullScreenWindow(this);
>>
>> I can then see my interface on the full screen (in my case it is a TV and I
>> have CEC enabled in the Kernel). However, after I UNPLUG HDMI and then PLUG
>> HDMI again, my interface is gone (black screen). There is only one small 1x1
>> pixel left. It seems the size of the Window is changed by Java / XWayland /
>> (Weston). I am sure, that I am not changing it - I checked all resize
>> methods on JFrame.
>>
>> When I restart my Java application, it is back again - so it is not an issue
>> of the OS (Linux) directly and also - most probably - not Weston.
>>
>> I also don't have this issue with a pure Wayland application (e.g. Weston
>> flower). Using only Wayland (without Java and XWayland) things work.
>>
>> When I PLUG the HDMI there is NO java.awt.event.ComponentEvent
>>
>> When I UNPLUG HDMI, I get the following java.awt.event.ComponentEvent:
>>
>> java.awt.event.ComponentEvent[COMPONENT_RESIZED (0,0 1x1)] on frame0
>> java.base/java.lang.Thread.getStackTrace(Thread.java:1602)
>> java.desktop/java.awt.AWTEventMulticaster.componentResized(AWTEventMulticaster.java:167)
>> java.desktop/java.awt.AWTEventMulticaster.componentResized(AWTEventMulticaster.java:167)
>> java.desktop/java.awt.Component.processComponentEvent(Component.java:6461)
>> java.desktop/java.awt.Component.processEvent(Component.java:6415)
>> java.desktop/java.awt.Container.processEvent(Container.java:2263)
>> java.desktop/java.awt.Window.processEvent(Window.java:2049)
>> java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5011)
>> java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
>> java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2772)
>> java.desktop/java.awt.Component.dispatchEvent(Component.java:4843)
>> java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
>> java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
>> java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
>> java.base/java.security.AccessController.doPrivileged(Native Method)
>> java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
>> java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
>> java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
>> java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
>> java.base/java.security.AccessController.doPrivileged(Native Method)
>> java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
>> java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
>> java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
>> java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
>> java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
>> java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
>> java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
>> java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
>>
>> Unfortunately I also don't know how to manipulate the size after I catched
>> this event. I tried to directly set the size back, but this did not work. I
>> think it may don't work because at this time HDMI is UNPLUGGED.
>>
>> As I don't get any event when the HDMI is PLUGGED again, I also don't know
>> when to (try to) set the size back to "normal".
>>
>> Thanks,
>>
>> Martin