#! /usr/bin/python

# pauseonlock
#
# Script watches xscreensaver status and executes specific commands if given
# requirements are met.
#
# With the default configuration it pauses amarok if it is running and
# continues playing when the screen is no longer locked.
#
# @author: Johannes Rueckert <j.rueckert@gmx.net>
# @license: GPL3 or later
# @version: 1.1
#
# Changelog:
#
# Version 1.1:
# - loop depends on subprocess - if xscreenshot --status is terminated, script ends (previously this caused an
#   infinite loop)

##
# Configuration
##

# Name of the process to check before performing operations
processName = 'amarokapp'

# Command that should be executed on lock (not when the screensaver ist activated!)
commandOnLock = ['amarok', '--pause']

# Command that should be executed on unblank, i.e. when the screen is no longer
# locked
commandOnUnblank = ['amarok', '--play']

##
# Configuration end
##


# import libraries
import subprocess


def isRunning(processName):
  """Test whether given process is running"""

  # try to get pid of process
  pid = subprocess.Popen(["pidof", "-s", processName], stdout=subprocess.PIPE).stdout

  # if pid was found
  if len(pid.readline())>1:
    return 1
  else:
    return 0



# start xscreensaver watcher
process = subprocess.Popen(["xscreensaver-command", "--watch"], stdout=subprocess.PIPE)
pipe = process.stdout


while (process.poll() == None):
  event = pipe.readline()

  if isRunning(processName):
    if event[0:4] == 'LOCK':
      subprocess.call(commandOnLock)
    elif event [0:7] == 'UNBLANK':
      subprocess.call(commandOnUnblank)