.xrandr-toggle

#!/usr/bin/python3

import sys

from re import findall, MULTILINE
from subprocess import check_output

##################
## CONFIG BEGIN ##
##################
# what position to set other screen relative to first screen. Leave blank to
# skip non-cloned dual screen ouptput
# valid options are left-of, right-of, above, below, and same-as
POSITION_CONFIG = 'left-of'
VERBOSE = True
##################
### CONFIG END ###
##################

##################
## GLOBAL STATE ##
##################
LAPTOP_ONLY = 'laptop_only'
CLONED = 'cloned'
EXTERNAL_ONLY = 'external_only'
POSITION = 'position'

class Monitor(object):
    def __init__(self, name, x, y, horiz, vert):
        self.name = name
        self.x = int(x) if x else 0
        self.y = int(y) if y else 0
        self.horiz = int(horiz) if horiz else 0
        self.vert = int(vert) if vert else 0
    def __repr__(self):
        return "Monitor(%s, %d, %d, %d, %d)" % (self.name, self.x, self.y,
                                                self.horiz, self.vert) 

def get_monitor_data():
    state_src = check_output(['xrandr']).decode(sys.stdout.encoding)
    monitors = [Monitor(*x) for x in
            findall(r"^(\w+) connected (?:(\d+)x(\d+)\+(\d+)\+(\d+))?",
                    state_src, MULTILINE)]
    screen = [tuple(int(y) for y in x) for x in
              findall("^Screen.* current (\d+) x (\d+),.*", state_src)]
    return monitors, screen

def clone(mons):
    """
        Clone output to both monitors.
    """
    check_output(['xrandr', '--output', mons[0].name, '--auto', '--output',
                  mons[1].name, '--auto']) # , '--same-as' ?

def external_only(mons):
    """
        Set the output to the external monitor only.
    """
    check_output(['xrandr', '--output', mons[0].name, '--off', '--output',
                  mons[1].name, '--auto'])

def posof(mons, position):
    """
        Set secondary monitor relative to primary monitor.
    """
    check_output(['xrandr', '--output', mons[0].name, '--auto', '--output',
                  mons[1].name, '--auto', "--%s" % position, mons[0].name])

def laptop_only(mons):
    """
        Show only the laptop (primary) display.
    """
    check_output(['xrandr', '--output', mons[0].name, '--auto', '--output',
                  mons[1].name, '--off'])

def laptop_on(mons):
    """
        Force the first output on and hope for the best
    """
    if len(mons) > 1:
        append = ['--output', mons[1].name, '--off']
    else:
        append = []
    check_output(['xrandr', '--output', mons[0].name, '--auto'] + append)

def get_current(mons, screen):
    """
    left of: 2720 x 900; 1280x800+1440+0; 1440x900+0+0
    clone: 1440 x 900; 1280x800+0+0; 1440x900+0+0
    """
    if not mons[0].x and mons[1].x:
        return EXTERNAL_ONLY
    elif mons[0].x and not mons[1].x:
        return LAPTOP_ONLY
    elif mons[0].vert or mons[0].horiz:
        return POSITION
    elif not (mons[0].vert or mons[0].horiz or mons[1].vert or mons[1].horiz):
        return CLONED
    else:
        print("Undefined monitor state!", file=sys.stderr)
        return None # undefined state!


# We assume the first output is always the laptop LCD output (when we care).
# We want to cycle like so:
    # Laptop Only
    # Laptop External Clone
    # External Only
    # Laptop posof External (if posof set)
    # to the top

def main():
    monitors, screen = get_monitor_data()
    if len(monitors) == 1:
        if VERBOSE:
            print("Forcing laptop")
        laptop_on(monitors)
    else:
        state = get_current(monitors, screen)
        if VERBOSE:
            print(state)
        if state == LAPTOP_ONLY:
            if VERBOSE:
                print('switching to clone')
            clone(monitors)
        elif state == CLONED:
            if VERBOSE:
                print('switching to external only')
            external_only(monitors)
        elif state == EXTERNAL_ONLY:
            if POSITION_CONFIG:
                if VERBOSE:
                    print('switching to %s' % POSITION_CONFIG)
                posof(monitors, POSITION_CONFIG)
            else:
                if VERBOSE:
                    print('switching to laptop only')
                laptop_only(monitors)
        elif state == POSITION:
            if VERBOSE:
                print('switching to laptop only')
            laptop_only(monitors)
        else:
            print("Illegal state: %s" % state, sys.stderr)
            laptop_on(monitors) # fail safe option, maybe clone?

if __name__ == "__main__":
    main()