Automon

Automon is a tool that uses xrandr to automatically configure monitors as they are connected and disconnected.

Dependencies

Automon uses PyYAML to read configuration files.

Configuration

Automon uses the file ~/.automon.yaml to decide how to configure monitors. The file declares which screen (if any) is the laptop screen, which file to read for lid status, and a collection of profiles for monitors. A profile is a list of configurations for monitors. Multiple profiless can be defined for a given set of monitors, and writing next or prev to the named pipe /tmp/automon_pipe will cause automon to change to the next or previous profile for the connected monitors. Similarly, if the index of a preferred profile is known, then sending set [index] to the pipe will switch directly to that profile. See the following for a sample configuration file:

--- 
laptop-screen: eDP-1
lid: /proc/acpi/button/lid/LID/state
profiles: 
  - - 
      output: HDMI-1
      mode: auto
    - 
      output: eDP-1
      left-of: HDMI-1
      mode: auto
  - - 
      output: HDMI-1
      mode: auto
    - 
      output: eDP-1
      'off': ~ # off is in quotes because it's a reserved word in YAML. ~ shows that this xrandr flag does not have a value
  - -
      output: eDP-1
      mode: 1280x800

This configuration has three defined profiles: two for when HDMI-1 and eDP-1 are connected, and one for when only eDP-1 is connected. If only HDMI-1 is connected, it will default to mode: auto.

In order for config changes to be reloaded, write config to /tmp/automon_pipe.

Running

Run automon with Python 3.

python3 automon.py

It is recommended to configure your window manager to run automon as a background process on startup. Instructions for doing so vary by window manager.

python3 automon.py &