dsl.py

   1 #!/usr/bin/python
   2 # DSL - easy Display Setup for Laptops
   3
   4 import os, sys, re, subprocess
   5 from PyQt4 import QtGui
   6 from selector_window import PositionSelection
   7 app = QtGui.QApplication(sys.argv)
   8
   9 # Load a section-less config file: maps parameter names to space-separated lists of strings (with shell quotation)
  10 def loadConfigFile(file):
  11         import shlex
  12         # read config file
  13         linenr = 0
  14         with open(file) as file:
  15                 result = {}
  16                 for line in file:
  17                         linenr += 1
  18                         line = line.strip()
  19                         if not len(line) or line.startswith("#"): continue # skip empty and comment lines
  20                         try:
  21                                 # parse line
  22                                 pos = line.index("=") # will raise exception when substring is not found
  23                                 curKey = line[:pos].strip()
  24                                 value = line[pos+1:]
  25                                 result[curKey] = shlex.split(value)
  26                         except Exception:
  27                                 raise Exception("Invalid config, line %d: Error parsing line (quoting issue?)" % linenr)
  28         # add some convencience get functions
  29         return result
  30
  31 def getXrandrInformation():
  32         p = subprocess.Popen(["xrandr", "-q"], stdout=subprocess.PIPE)
  33         connectors = {} # map of connector names to a list of resolutions
  34         connector = None # current connector
  35         for line in p.stdout:
  36                 # new connector?
  37                 m = re.search(r'^([\w]+) connected ', line)
  38                 if m is not None:
  39                         connector = m.groups()[0]
  40                         assert connector not in connectors
  41                         connectors[connector] = []
  42                         continue
  43                 # new resolution?
  44                 m = re.search(r'^   ([\d]+)x([\d]+) +', line)
  45                 if m is not None:
  46                         assert connector is not None
  47                         connectors[connector].append((int(m.groups()[0]), int(m.groups()[1])))
  48         p.communicate()
  49         if p.returncode != 0: raise Exception("Querying xrandr for data failed")
  50         return connectors
  51
  52 def res2xrandr(res):
  53         (w, h) = res
  54         return str(w)+'x'+str(h)
  55
  56 def res2user(res):
  57         (w, h) = res
  58         # get ratio
  59         ratio = int(round(16.0*h/w))
  60         if ratio == 12: # 16:12 = 4:3
  61                 strRatio = '4:3'
  62         elif ratio == 13: # 16:12.8 = 5:4
  63                 strRatio = '5:4'
  64         else: # let's just hope this will never be 14 or more...
  65                 strRatio = '16:%d' % ratio
  66         return '%dx%d (%s)' %(w, h, strRatio)
  67
  68 def findAvailableConnector(tryConnectors, availableConnectors):
  69         for connector in tryConnectors:
  70                 if connector in availableConnectors: return connector
  71         return None
  72
  73 # load options
  74 config = loadConfigFile(os.getenv('HOME') + '/.dsl.conf')
  75 if len(config['internalConnector']) != 1:
  76         raise Exception("You must specify exactly one internal connector")
  77 if len(config['externalConnectors']) < 1:
  78         raise Exception("You must specify at least one external connector")
  79 # use options
  80 internalConnector = config['internalConnector'][0]
  81 externalConnectors = config['externalConnectors']
  82 connectors = getXrandrInformation()
  83 usedExternalConnector = findAvailableConnector(externalConnectors, connectors) # *the* external connector which is actually used
  84
  85 # default: screen off
  86 args = {} # maps connector names to xrand arguments
  87 for c in externalConnectors+[internalConnector]:
  88         args[c] = ["--off"]
  89
  90 # Check what to do
  91 if usedExternalConnector is not None: # there's an external screen connected, we need to ask what to do
  92         internalResolutions = connectors[internalConnector]
  93         externalResolutions = connectors[usedExternalConnector]
  94         extPosition = PositionSelection(usedExternalConnector, map(res2user, internalResolutions), map(res2user, externalResolutions))
  95         extPosition.exec_()
  96         if not extPosition.result(): sys.exit(1) # the user canceled
  97         extResolution = res2xrandr(externalResolutions[extPosition.extResolutions.currentIndex()])
  98         intResolution = res2xrandr(internalResolutions[extPosition.intResolutions.currentIndex()])
  99         # build command-line
 100         args[usedExternalConnector] = ["--mode", extResolution] # set external screen to desired resolution
 101         if extPosition.extOnly.isChecked():
 102                 args[usedExternalConnector] += ["--primary"]
 103         else:
 104                 # there are two screens
 105                 args[internalConnector] = ["--mode", intResolution] # set internal screen to desired resolution
 106                 # set position
 107                 if extPosition.posLeft.isChecked():
 108                         args[usedExternalConnector] += ["--left-of", internalConnector]
 109                 else:
 110                         args[usedExternalConnector] += ["--right-of", internalConnector]
 111                 # set primary screen
 112                 if extPosition.primExt.isChecked():
 113                         args[usedExternalConnector] += ["--primary"]
 114                 else:
 115                         args[internalConnector] += ["--primary"]
 116 else:
 117         # use first resolution
 118         args[internalConnector] = ["--mode", res2xrandr(connectors[internalConnector][0]), "--primary"]
 119 # and do it
 120 call = ["xrandr"]
 121 for name in args:
 122         call += ["--output", name] + args[name]
 123 print "Call that will be made:",call
 124 subprocess.check_call(call)