MATE desktop fixes (updated)

Last week I upgraded my Linux Mint 18 MATE desktop distro to 18.3. With the massive progresses GNU/Linux has done in the desktop, those kind of upgrades use to be simple tasks and no more hassle is to be expected. Except this time where I had several a GUI-related annoyances.

1. MATE panel transparency

I recently became addicted to /r/unixporn and made myself a shiny modern desktop made of MATE and rofi. This desktop use the Arc-Darker theme which used to work nicely with mate-panel version 1.14 but was messing transparency with version 1.18, the one shipped with Mint 18.3.

I fixed this by changing:

background-color: #2b2e37;

to

background-color: transparent;

In the

.gnome-panel-menu-bar.menubar,
PanelApplet > GtkMenuBar.menubar,
PanelToplevel,
PanelWidget,
PanelAppletFrame,
PanelApplet {

section of the ~/.themes/Arc-Darker/gtk-3.0/gtk.css file.

2. Applet padding

To fix the latter, I first switched to the latest version of the theme, in which the new maintainer changed various small details.
Tastes differ, we all know that, and the new Arc-Darker author felt a bigger padding between panel applets was sexier. I have a different opinion. This is the value to change in the same ~/.themes/Arc-Darker/gtk-3.0/gtk.css file:

 -NaTrayApplet-icon-padding: 4;

3. Weird rofi behaviour

I opened an issue about this one. Weird compositing glitches like rofi not appearing until mouse was moved (and thus display refreshed) or sometimes appearing partially, or translucent gnome-terminal not refreshing its content.

I suppose this issue is more about my graphic driver (nvidia-384), yet I found that running marco (MATE window manager) with composition disabled and instead using compton fixes this issue. This configuration choice is really easy to switch to as it is a choice in the Preferences → Windows → Desktop Settings → Window Manager drop down menu.

4. Wrong wallpaper resize

I happen to have 4 monitors. Don’t ask, I like it like that, I see everything I need to see in one small head movement, maybe someday I’ll switch to a 4k monitor but right now this setup is like 4 times cheaper for a 4720 x 3000 resolution.

Now about the bug, from time to time, the wallpaper will be zoomed like it is spread among all screens, except it is zoomed only on the main one. Ugly stuff.
This bug happened randomly, often when opening the file manager, caja, and as a matter of fact, I found in the Arch wiki that it is indeed caja which actually manages the desktop, and thus, the background. Also on their wiki I found how to disable this feature:

$ gsettings set org.mate.background show-desktop-icons false
$ killall caja  # Caja will be restarted by session manager

And then I set my wallpaper using the reknown feh command:

$ feh --bg-fill ~/Pictures/wallpapers/hex-abstract-material-design-ad-3840x2160.jpg

And voila, no more messing with my wallpaper.

I’ll try to keep this list updated if I find anything else.