external_screen.py

   1 #!/usr/bin/python
   2 import sys, re, subprocess
   3 from PyQt4 import QtGui
   4 from selector_window import PositionSelection
   5 app = QtGui.QApplication(sys.argv)
   6
   7 def getXrandrInformation():
   8         p = subprocess.Popen(["xrandr", "-q"], stdout=subprocess.PIPE)
   9         connectors = {} # map of connector names to a list of resolutions
  10         connector = None # current connector
  11         for line in p.stdout:
  12                 # new connector?
  13                 m = re.search(r'^([\w]+) connected ', line)
  14                 if m is not None:
  15                         connector = m.groups()[0]
  16                         assert connector not in connectors
  17                         connectors[connector] = []
  18                         continue
  19                 # new resolution?
  20                 m = re.search(r'^   ([\d]+)x([\d]+) +', line)
  21                 if m is not None:
  22                         assert connector is not None
  23                         connectors[connector].append((int(m.groups()[0]), int(m.groups()[1])))
  24         p.communicate()
  25         if p.returncode != 0: raise Exception("Querying xrandr for data failed")
  26         return connectors
  27
  28 def res2xrandr(res):
  29         (w, h) = res
  30         return str(w)+'x'+str(h)
  31
  32 def res2user(res):
  33         (w, h) = res
  34         # get ratio
  35         ratio = int(round(16.0*h/w))
  36         if ratio == 12: # 16:12 = 4:3
  37                 strRatio = '4:3'
  38         elif ratio == 13: # 16:12.8 = 5:4
  39                 strRatio = '5:4'
  40         else: # let's just hope this will never be 14 or more...
  41                 strRatio = '16:%d' % ratio
  42         return '%dx%d (%s)' %(w, h, strRatio)
  43
  44 # Check screen setup
  45 internalName = "LVDS1"
  46 externalNames = ["HDMI1", "VGA1"]
  47 connectors = getXrandrInformation()
  48 internalResolutions = connectors[internalName] # there must be a screen assoicated to the internal connector
  49 externalName = None # *the* external connector which is actually used
  50 externalResolutions = None # resultions of the external connector
  51 args = {} # maps connector names to xrand arguments
  52
  53 # look for enabled external screen, disable all the others
  54 for name in externalNames:
  55         if externalResolutions is None and name in connectors:
  56                 externalName = name
  57                 externalResolutions = connectors[name]
  58         else:
  59                 args[name] = ["--off"]
  60
  61 # Check what to do
  62 if externalName is not None: # we need to ask what to do
  63         extPosition = PositionSelection(externalName, map(res2user, internalResolutions), map(res2user, externalResolutions))
  64         extPosition.exec_()
  65         if not extPosition.result(): sys.exit(1) # the user canceled
  66         extResolution = res2xrandr(externalResolutions[extPosition.extResolutions.currentIndex()])
  67         intResolution = res2xrandr(internalResolutions[extPosition.intResolutions.currentIndex()])
  68         # build command-line
  69         args[externalName] = ["--mode", extResolution] # we definitely want an external screen
  70         if extPosition.extOnly.isChecked():
  71                 args[internalName] = ["--off"]
  72                 args[externalName] += ["--primary"]
  73         else:
  74                 # there are two screens
  75                 args[internalName] = ["--mode", intResolution]
  76                 if extPosition.posLeft.isChecked():
  77                         args[externalName] += ["--left-of", internalName]
  78                 else:
  79                         args[externalName] += ["--right-of", internalName]
  80                 if extPosition.primExt.isChecked():
  81                         args[externalName] += ["--primary"]
  82                 else:
  83                         args[internalName] += ["--primary"]
  84 else:
  85         args[internalName] = ["--mode", res2xrandr(internalResolutions[0]), "--primary"]
  86 # and do it
  87 call = ["xrandr"]
  88 for name in args:
  89         call += ["--output", name] + args[name]
  90 print "Call that will be made:",call
  91 subprocess.check_call(call)