To an extent, you have to adapt to the working environment you choose to work with.
1) a grid of workspaces (3 columns, 2 rows to be precise);
You already found the Workspace Grid shell extension
2) the application windows remaining in the workspace I move them to;
Using Gnome Tweaks, which is not installed by default in Ubuntu, you can set workspaces to "Static". With dynamic workspaces, workspaces automatically are removed when they are empty, so indeed an application you placed on workspace 3 may end up on workspace 2 or 1 later in the session.
3)miniatures of the workspaces content in the switch modal;
Gnome-shell provides miniatures of the workspaces in the overview when you press Super. By default, however, you have to hover the right side in the overview to make the miniatures visible. You can make sure the workspaces are always expanded with the extension "Always zoom workspaces"
4) workspace switcher showing the overview of all workspaces.
I do not follow here: in the overview, all workspaces are shown. You may also install a "Workspace switcher" extension that provides a clickable icon on the panel that allows you to switch workspaces from a pull down menu.
Easily find out what is being set
Instead of searching through a whole directory of options:
- Open a terminal window
Run the command:
dconf watch /
Make your changes and see what the terminal shows:
![enter image description here](https://i.stack.imgur.com/G2gxA.png)
...and there you are.
Dconf & gsettings
In the example, you see the output from dconf
. Gsettings is the cli- frontend to dconf. Many times, you can use both a dconf
command or a gsettings
command. In this case either:
dconf write /org/gnome/desktop/background/show-desktop-icons false
or:
gsettings set org.gnome.desktop.background show-desktop-icons false
If the gsettings key exists however, the latter is considered to be better practice, to protect the integrity of your dconf
database.
See also here and here.
Best Answer
After you have disabled "dynamic" workspaces using (GNOME) Tweaks and enabled "static" ones (with a fixed number, 4 in this case), install a GNOME extension called Workspace Grid. It
From the extension's preferences you will be able to set your preferred layout (e.g. 2x2, 2x3, 3x3 etc.).
You may see its GitHub page for more detailed info.
Officially it doesn't support GNOME v3.26 yet, but it should work fine. Otherwise, you may be able to make it work adding
"3.26"
to itsmetadata.json
file.Update from the asker:
It worked out of the box without changing anything. Even my old custom shortcuts worked.
Update 2: Ubuntu 19.04
Currently the extension doesn't work with Gnome 3.32 and it might take a while before (if) it again will, because it's the current maintainer (thanks zakkak) is looking for for volunteers to take over maintainance). Suitable replacement can be Workspace Matrix which has a bit less features, but the main features are present.