Shortcuts involving the Alt key are not detected in the script editor

[HungryProton]

Godot version:
4.0 - 2410016

OS/device including version:
Ubuntu 20.04

Issue description:
Script editor shortcuts involving the alt key doesn't trigger anything. The associated action does work if you manually click on it. Shortcuts in the 3D view seems to work however (for example, control + alt + 2 to split the viewport works as expected).

One exception is the alt + arrow key (up and down moves the current line, left and right moves through the history). These four shortcuts work so it's only the shortcuts involving alt and a letter.

This issue only happens with Godot 4 (latest commit of master). It does not happen with the 3.x versions, nor on Windows.

Steps to reproduce:

• Open the editor
• Create a new script and open it
• Try any shortcut involving the alt key and a letter like:
  • control + alt + s (Save)
  • shift + alt + s (Save all)

Minimal reproduction project:
Any empty project exhibits this behavior.

[EricEzaM]

Can't repro on Windows 10 - so looks to be a Unix/Linux issue

[Calinou]

This is an issue with most window managers on Linux using Alt by default for window management operations. You need to change your window manager's manipulation key to Meta ("Super") so the Alt + clicK shortcuts work in other applications. For the record, Blender faces the same issue.

It would be great if we could detect this and print a message when the editor starts, but is it possible to detect this programmatically?

[HungryProton]

All my shortcuts are individually defined in the settings panel, some of them uses the Meta key while others uses the Alt key. (There's no global way I could find to switch from one to another.)
None of them conflicts with Godot shortcuts though and these shortcuts work with 3.x so I'm not really sure the WM is to blame here. I tried with Gnome and Plasma but no luck either.

However, I tried changing my keyboard from Azerty to Qwerty and then, the Control + Alt + 2 shortcut in the 3D view worked. Turns out I have to do the same thing in 3.x, I never noticed. That's a different issue though. But Godot 4 did caught that control + alt shortcut in the 3D view, now it's just the shortcuts from the text editor that doesn't trigger anything. alt + arrow key work but everything else involving alt doesn't. I'll update the first post.

[capnm]

@HungryProton There is also a central option for this in gnome-tweaks.
I set it always to super ;)

[Leleat]

I can't reproduce it on Fedora 32 either. I tried setting the "Close All" scripts in the Script Editor to Ctrl+Alt+W and it works in 3.2.2 and current master for me.

[BigZaphod]

Unsure if this is the same problem, but I have a situation like this with Godot 3.2.2 on macOS. Using Alt(Option)-1, 2, 3 works everywhere except when I'm in the script editor which is super annoying. Instead it just inserts some weird character into the source code depending on which key combo I used.

[boruok]

I've got issue with fold/unfold (ALT+F) key doesn't recognized too on my *PopOS 20.10 *based on Ubuntu 20.10

[Cykyrios]

This issue may be caused by #37769, which was also merged in the 3.2 branch on September 24.