Super key + mouse drag doesn't work in Ubuntu guest and Ubuntu host

[awareness-kindness]

Virtualbox 6.1.18 r142142 Host: Ubuntu 20.04.2 LTS Guest Ubuntu 20.04.2 LTS Laptop: Asus ROG gl552vw Guest additions: Installed by using the by VirtualBox provided ISO file.

SUMMARY:

Guest OS does not receive Super key + mouse drag (i.e. hold left mouse button and move mouse). The mouse movement is received and executed but the holding of the mouse button isn't registered.

What's more, when you finally release the Super key then everything is registered as if you only pressed and released the Super key. This should NOT happen since you simultaneously clicked and dragged the mouse button.

Super key + mouse drag is used by some Ubuntu apps that can't be reconfigured.

This also doesn't work with VirtualBox's virtual keyboard.

STEPS TO REPRODUCE:

1. Start the guest os
2. Open a terminal window
3. Hold down the super key (left windows key in my case) on your hardware keyboard (maintain holding it down during the next steps)
4. Click and hold down the left mouse/mousepad button anywhere on the terminal window (maintain holding it down during the next step)
5. Move/drag the mouse around

EXPECTED RESULT:

The terminal window should be moved around. When you finally release the super key then nothing else should happen.

OBSERVED DEFECT RESULT:

Nothing happens when you move/drag the mouse, and when you release the super key then the guest OS reacts as if all you did was to press and release the super key and so the application overlay is shown (this should NOT happen and instead only the terminal window should be moved)

[awareness-kindness]

I've tried to set the host key combinations to ctrl+super+alt and ctrl+leftShift+alt. The bug happens in both cases.

[janitor]

The problem is that Ubuntu host is very good at intercepting those super-drags. See also e.g. #19625.

OBSERVED DEFECT RESULT:

Nothing happens when you move/drag the mouse,

On Ubuntu 18 host the VM's window will be moved around with super+drag, i.e. it's the host WM that intercepts it and acts upon it. 20 probably uses wayland and misbehaves in slighly different, new creative ways.

One possible workaround is to disable mouse integration. With a real grab in place all keyboard events will be sent to the guest. You can use a Host key shortcut to toggle mouse integration (not set by default) so that you can only toggle it when needed.

[awareness-kindness]

One possible workaround is to disable mouse integration.

@janitor thank you this solved the problem perfectly. If you believe that this isn't VirtualBox's fault then feel free to close this report.

[janitor]

Replying to janitor:

You can use a Host key shortcut to toggle mouse integration (not set by default) so that you can only toggle it when needed.

To clarify, what I meant is assigning a Host-<SomeKey> shortcut to toggle mouse integration. Most of the time you can run with mouse integration enabled, since it's way more convenient in general. When you really need to work around the problem you can quickly toggle it with the shortcut, use Super-<Something> shortcut inside the guest, then toggle mouse integration back on.