dock-toggle.sh

#!/bin/bash

set -e -u

EXTERNAL_SCREEN='DP-2-1'
INTERNAL_SCREEN='eDP-1'

# XXX persist windows & pids to a file in case things go *real* wrong?

DRY_RUN=${DRY_RUN:-0}

function die() {
    echo $1 >&2
    exit 1
}

function active-display() {
    xrandr | perl -nle 'print $1 if /^(\S+)\s+\bconnected\b\s+(?:primary\s+)?\d+x\d+/'
}

function restore-tags() {
    quoted_filename=$(echo 'print(string.format("%q", arg[1]))' | lua - "$1")
    awesome-client <<END_LUA
local filename = $quoted_filename

local iterate = require('awful.client').iterate

local f, err = io.open(filename, 'r')
if not f then
  alert("couldn't open state file: " .. tostring(err))
  return
end

for line in f:lines() do
  local window_id, desktop = line:match '(0x%x+)%s+(%d+)'
  if window_id and desktop then
    window_id = tonumber(window_id)
    local tag = tonumber(desktop) + 1

    for c in iterate(function(c) return c.window == window_id end) do
      c:move_to_tag(tags[1][tag])
    end
  end
end
f:close()
END_LUA
}

if ! xrandr | grep -q "$EXTERNAL_SCREEN connected" ; then
    die "External monitor not connected!"
fi

current=$(active-display)

if [[ $DRY_RUN -ne 0 ]] ; then
    echo "dry run - bailing out"
    exit 0
fi

window_state=$(mktemp)
wmctrl -l > "$window_state"

if [[ $current == "$EXTERNAL_SCREEN" ]]; then
    xrandr --output "$INTERNAL_SCREEN" --scale 0.5x0.5 --auto
    xrandr --output "$EXTERNAL_SCREEN" --off || true # for some reason we get a BadMatch?
elif [[ $current == "$INTERNAL_SCREEN" ]] ; then
    xrandr --output "$EXTERNAL_SCREEN" --auto
    xrandr --output "$INTERNAL_SCREEN" --off
fi

sleep 3

echo 'awesome.restart()' | awesome-client || true # awesome won't reply, since it's restarting

sleep 3 # wait for awesome to set itself up

restore-tags "$window_state"

rm "$window_state"