nixfiles/home-manager/modules/gui/screensaver.py

162 lines
4.5 KiB
Python
Executable File

#!@python@/bin/python
import argparse
import json
import os
import random
import signal
import subprocess
import sys
import filelock
class Screensaver:
def __init__(self, cmd, env=None, weight=1):
self.cmd = cmd
self.weight = weight
if env is not None:
self.env = os.environ.copy()
for k, v in env.items():
self.env[k] = v
else:
self.env = None
self.proc = None
def start(self):
assert self.proc is None
self.proc = subprocess.Popen(self.cmd, env=self.env)
def wait(self):
assert self.proc is not None
self.proc.wait()
def stop(self, kill=False):
assert self.proc is not None
if kill:
self.proc.kill()
else:
self.proc.terminate()
class DoomSaver(Screensaver):
wad = '@doomWad@'
def __init__(self, demo_index, weight=3):
super().__init__(
['@chocoDoom@/bin/chocolate-doom',
'-iwad', self.wad,
'-demoloopi', str(demo_index)],
env={
'SDL_AUDIODRIVER': 'null',
'SDL_VIDEODRIVER': 'caca',
'CACA_DRIVER': 'ncurses',
},
weight=weight,
)
def stop(self):
super().stop(kill=True)
class MultiSaver:
savers = [
DoomSaver(0),
DoomSaver(1),
DoomSaver(2),
]
state_filename = 'screensaver.json'
def __init__(self):
self.state_path = os.path.join(f'/run/user/{os.geteuid()}', self.state_filename)
self.lock = filelock.FileLock(f'{self.state_path}.lock')
self.selected = None
self.cleaned_up = False
def select(self):
assert self.selected is None
with self.lock:
if not os.path.exists(self.state_path):
state = {'instances': []}
else:
with open(self.state_path) as f:
state = json.load(f)
available = set(range(len(self.savers)))
new_instances = []
for instance in state['instances']:
if not os.path.exists(f"/proc/{instance['pid']}"):
continue
new_instances.append(instance)
i = instance['saver']
assert i in available
available.remove(i)
assert available, 'No screensavers left'
available = list(available)
weights = []
for i in available:
weights.append(self.savers[i].weight)
selected_i = random.choices(available, weights=weights)[0]
new_instances.append({'pid': os.getpid(), 'saver': selected_i})
state['instances'] = new_instances
with open(self.state_path, 'w') as f:
json.dump(state, f)
print(f'Selected saver {selected_i}')
self.selected = self.savers[selected_i]
def cleanup(self):
if self.cleaned_up:
return
self.cleaned_up = True
with self.lock:
with open(self.state_path) as f:
state = json.load(f)
for i, instance in enumerate(state['instances']):
if instance['pid'] == os.getpid():
del state['instances'][i]
with open(self.state_path, 'w') as f:
json.dump(state, f)
def run(self):
assert self.selected is not None
self.selected.start()
signal.signal(signal.SIGINT, self._sighandler)
signal.signal(signal.SIGTERM, self._sighandler)
signal.signal(signal.SIGHUP, self._sighandler)
self.selected.wait()
self.cleanup()
def stop(self):
assert self.selected is not None
print('Shutting down')
self.selected.stop()
self.cleanup()
def _sighandler(self, signum, frame):
self.stop()
def main():
parser = argparse.ArgumentParser(description='Wayland terminal-based lock screen')
parser.add_argument('-t', '--terminal', default='alacritty', help='Terminal emulator to use')
parser.add_argument('-i', '--instance', action='store_true', help='Run as instance')
args = parser.parse_args()
if not args.instance:
subprocess.check_call([
'swaylock-plugin', '--command-each',
f'@windowtolayer@/bin/windowtolayer -- {args.terminal} -e {sys.argv[0]} --instance'])
return
ms = MultiSaver()
ms.select()
ms.run()
if __name__ == '__main__':
main()