i3expo

Overwiew

Expo is an simple and straightforward way to get a visual impression of all your i3 workspaces that many compositing window managers use. It's not a very powerful approach, but a very intuitive one and especially fits workflows that use lots of temporary windows or those in which the workspaces are mentally arranged in a grid.

i3expo emulates that function within the limitations of a non-compositing window manager. By listening to the IPC, it takes a screenshot whenever a window event occurs. Thanks to a fast C library, this produces negligible overhead in normal operation and allows the script to remember what state you left a workspace in.

The script is run as a background process and reacts to signals in order to open its UI in which you get an overview of the known state of your workspaces and can select another with the mouse or keyboard.

Example output:

Installation

pipx install i3expo

Usage

Launch i3expo from i3 config; alternatively you may prefer to run i3expo in a terminal in order to catch any errors in this pre-alpha stage.

Default configuration is written into $XDG_CONFIG_HOME/i3expo/config. Color values can be specified by using their PyGame names or in #fff or #ffffff hex.

Send SIGUSR1 to i3expo to toggle the Expo UI, for example by adding a bindsym for killall -s SIGUSR1 i3expo to your i3 config. Send SIGHUP to have the application reload its configuration.

Navigate the UI with the mouse or with they keyboard using hjkl, the arrow keys, Return and Escape.

Recommended i3 config:

  exec_always --no-startup-id i3expo
  for_window [class="^i3expo$"] fullscreen enable
  bindsym $mod1+e exec --no-startup-id killall -s SIGUSR1 i3expo

Note the script depends on pre-compiled i3expo/prtscn.so for screen-grabbing. If it doesn't work you may need to compile prtscn.c yourself following the instruction in the file header. In that case add screenshot_lib_path config item, pointing to the compiled prtscn executable.

Limitations

Since it works by taking screenshots, the application cannot know workspaces it hasn't seen yet. Furthermore, the updates are less continuous than you might be used to if you're coming from a compositing WM where they can happen live and in the background.

Caution

This is pre-alpha software and some bugs are still around. It works for my own, single monitor and a common workflow. There is not much input validation and no protection against you screwing up the layout or worse.

Bugs

Stalled windows whose content i3 doesn't know cause interface bugs and could probably be handled better, but this needs more testing.

Daemon's cpu usage raises considerably upon first time UI gets rendered. Believe this has something to do with pygame not de-initing itself properly. Confirm this is still the case

Todo

• It's theoretically feasible to take the window information from i3's tree and allow for dragging of windows from one workspace to another or even from container to container. However, this would be massively complex (especially on the UI side) and it's not clear if it would be worth the effort.
• multimonitor support
• pause screenshotting while screen is locked, eg via i3lock

Credit

• original code from https://gitlab.com/d.reis/i3expo
  • for a time this fork was developed under https://gitlab.com/layr89/i3expo
• Stackoverflow answer for the screenshot library