Introduction
If you dislike Compiz that much, you don't wish to ever use it despite Compiz having hot corners and its own window picker, as well a whole bevy of other useful productivity features, then you'll be pleased to know there is an alternative to that if you wanted just a means of picking windows with previews which is very easy to install, and easy-enough to implement.
The title is slightly misleading because two programs are in effect here, but after following this tutorial you'll have a means of assigning a window picker to a hot corner, and they'll work together seamlessly.
Glossary
Since @ouroumov mentioned a need for it, may as well include this. Images to come at a later date (i.e. when I feel like it);
Window picker: Also Window Chooser or Window selector, a software that allows for the selection of windows, with or without window previews.
Hot corner: A corner of you screen dedicated to activate a task.
Rationale for use
May as well include this; If you don't want to use Compiz but have something similar to Exposè, then below is a possible solution. Some people like a super-clean, super-minimal desktop, and having a means to choose windows easily with large output and image previews may be something that people looking for a minimalist setup may want.
Skipping around
For this, two programs are required; skippy-xd and brightside. The former is not installable by default, so add the skippy-xd repo as follows;
sudo add-apt-repository ppa:landronimirc/skippy-xd-daily
sudo apt update
Once you've added the PPA for Skippy XD, both programs can be installed;
sudo apt install skippy-xd brightside
You can add in skippy-xd --start-daemon as a command in mate-session-properties or you can make a new autostart entry as follows;
Making the autostart file in pluma
pluma ~/.config/autostart/skippy-xd.desktop
(You can name this whatever you want, MATE doesn't care.)
Autostart file contents
[Desktop Entry]
Type=Application
Exec=skippy-xd --start-daemon
Hidden=false
X-MATE-Autostart-enabled=true
Name[en_US]=Skippy XD
Name=Skippy XD
Comment[en_US]=Executes the Skippy XD window picker daemon.
Comment=Executes the Skippy XD window picker daemon.
You can make this autostart entry appear however you like, the important bit is the command (exec), that shouldn't be changed.
Making it shine
The last part is a GUI bit I can't avoid, so bear with my explanation;
- Open
brightside-properties
- Enable any corner you'd like to use
- For that enabled corner, at the dropdown menu select Custom action...
- Upon selecting it, a dialog pox will pop up.
On entering region: skippy-xd --activate-window-picker
On leaving region: Terminate above application
To test, run skippy-xd --start-daemon manually and go to the corner you activated to try it out. If all you see is a popup with a generic gears icon but no action, then you did it wrong. If you did it right, then next time you sign in, Skippy XD should run automatically as daemon and wait for you to put your mouse in the corner you specified for it to display the window picker.
Other information
Skippy XD will position your cursor on the centre of the last window you were at. Bear that in mind while using it; you may become slightly disoriented when first using it.
Information sources
https://ubuntuforums.org/showthread.php?t=2211109&p=12956710#post12956710
