It is currently not possible to configure the mouse drag window behavior to any other modifier than Alt/Meta. This is is hindering the window management usability when using the mouse with a left hand, since both Alt and Meta are on the left side of the keyboard in some keyboard layouts. Only Alt-Gr and Ctrl are present on the right-hand side. It would be nice to be able to map at least Alt-Gr to the keyboard behavior to avoid having to move the hand out-of-position when doing the resizing.
STEPS TO REPRODUCE
1. Open System Settings -> Window Management -> Window Behavior -> Window Actions
2. Under the "Inner Window, Titlebar & Frame", change the Modifier key
Only "Alt" and "Meta" are available
Other options are available, at least Alt-Gr.
Linux/KDE Plasma: Kubuntu 16.04
(available in About System)
KDE Plasma Version: 5.5.5
KDE Frameworks Version: 4.14.16 (*)
Qt Version: 5.5.1
(*) checked with "apt-cache show kdelibs5-dev", not sure if this is the correct way
Unfortunately I'm not able to test this on a newer version at the moment (due to work system configuration), but I tried searching for this and did not find any updates to this, so I'm fairly sure this has not been implemented in later kwin versions either.
What keyboard layout do you usually use?
I personally can drag windows by pressing Alt-Gr.
Please, please, PLEASE address this.
I want to switch back to KDE from XFCE for so many reasons. I actually kind of need to. But I can't, because I can't stand being limited to just one of these buttons for this key, and I also can't stand not having this key as a shortcut for move/resize.
In XFCE I am able to go into xfconf and set this shortcut to Ctrl+Alt. I've found that to be a great solution, because that combination almost never interferes with any in-app shortcuts that want to make use of Alt or Meta/Super.
KDE is supposed to be the DE with the most options, which also means the most accessibility, and the reporter of this bug has shown that this is also a straight-up accessibility issue. It really sucks that I can't switch because XFCE's xfwm4 manages to be more configurable in just this one aspect, despite being the opposite in any other.