Bug 425123

Summary:	Middle mouse-click action not triggered on GTK-based applications
Product:	[Applications] systemsettings	Reporter:	Puspam Adak <puspam12345678>
Component:	kcm_style	Assignee:	Janet Blackquill <uhhadd>
Status:	CONFIRMED ---
Severity:	wishlist	CC:	mail, raul.cheleguini
Priority:	NOR
Version First Reported In:	5.18.5
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Puspam Adak 2020-08-07 19:55:41 UTC

SUMMARY
I have configured the middle mouse button click on a window's title bar to minimize an application. The problem is that it does not work for GTK-based applications such as Google Chrome, Firefox, etc. Not only minimize, but it does not work no matter whatever function I assign to the middle mouse click. I hope that this happens since GTK provides a title bar different than KDE's. But I have used Gnome and this functionality works there, but not in KDE Plasma.

STEPS TO REPRODUCE
1. Configure the Middle mouse click action in System settings. Open any GTK-based application, eg.- Google Chrome and try middle-clicking on its title bar.

OBSERVED RESULT
Middle mouse-click action not triggered on GTK-based applications

EXPECTED RESULT
Middle mouse-click action should have triggered.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 5.18.5
(available in About System)
KDE Plasma Version: 5.18.5
KDE Frameworks Version: 5.68.0
Qt Version: 5.12.8

ADDITIONAL INFORMATION

Comment 1 Mikhail Zolotukhin 2020-08-08 10:43:27 UTC

Seems like we possibly could sync KWin titlebar behavior with GNOME CSD one. There is a `org/gnome/desktop/wm/preferences/action-middle-click-titlebar` and other similar settings available. However, when I change those settings via dconf editor - nothing changes and GTK apps are still using default behavior. Could anyone confirm this and provide any alternative way to apply this settings to GTK applications under Plasma? On GNOME those settings are working fine.

Comment 2 Raul 2021-06-22 17:59:15 UTC

Just wanted to leave a workaround here for readers, you can install the package gtk3-nocsd in your system to enable the KWin window decoration for GTK-based applications. I believe it is available in the major distributions.

After install it, logout and login back and open one GTK-based application. The window is expected to have the Kwin window decoration and the middle button click on title bar action will work as expected.