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 # for auto-config: common names of internal connectors
  10 commonInternalConnectorNames = ['LVDS', 'LVDS1']
  11
  12 # Load a section-less config file: maps parameter names to space-separated lists of strings (with shell quotation)
  13 def loadConfigFile(file):
  14         import shlex
  15         result = {}
  16         if not os.path.exists(file):
  17                 return result # no config file
  18         # read config file
  19         linenr = 0
  20         with open(file) as file:
  21                 for line in file:
  22                         linenr += 1
  23                         line = line.strip()
  24                         if not len(line) or line.startswith("#"): continue # skip empty and comment lines
  25                         try:
  26                                 # parse line
  27                                 pos = line.index("=") # will raise exception when substring is not found
  28                                 curKey = line[:pos].strip()
  29                                 value = line[pos+1:]
  30                                 result[curKey] = shlex.split(value)
  31                         except Exception:
  32                                 raise Exception("Invalid config, line %d: Error parsing line (quoting issue?)" % linenr)
  33         # add some convencience get functions
  34         return result
  35
  36 def getXrandrInformation():
  37         p = subprocess.Popen(["xrandr", "-q"], stdout=subprocess.PIPE)
  38         connectors = {} # map of connector names to a list of resolutions
  39         connector = None # current connector
  40         for line in p.stdout:
  41                 # new connector?
  42                 m = re.search(r'^([\w]+) (dis)?connected ', line)
  43                 if m is not None:
  44                         connector = m.groups()[0]
  45                         assert connector not in connectors
  46                         connectors[connector] = []
  47                         continue
  48                 # new resolution?
  49                 m = re.search(r'^   ([\d]+)x([\d]+) +', line)
  50                 if m is not None:
  51                         assert connector is not None
  52                         connectors[connector].append((int(m.groups()[0]), int(m.groups()[1])))
  53         p.communicate()
  54         if p.returncode != 0: raise Exception("Querying xrandr for data failed")
  55         return connectors
  56
  57 def res2xrandr(res):
  58         (w, h) = res
  59         return str(w)+'x'+str(h)
  60
  61 def res2user(res):
  62         (w, h) = res
  63         # get ratio
  64         ratio = int(round(16.0*h/w))
  65         if ratio == 12: # 16:12 = 4:3
  66                 strRatio = '4:3'
  67         elif ratio == 13: # 16:12.8 = 5:4
  68                 strRatio = '5:4'
  69         else: # let's just hope this will never be 14 or more...
  70                 strRatio = '16:%d' % ratio
  71         return '%dx%d (%s)' %(w, h, strRatio)
  72
  73 def findAvailableConnector(tryConnectors):
  74         for connector in tryConnectors:
  75                 if connector in connectors and connectors[connector]: # if the connector exists and is active (i.e. there is a resolution)
  76                         return connector
  77         return None
  78
  79 # load connectors and options
  80 connectors = getXrandrInformation()
  81 config = loadConfigFile(os.getenv('HOME') + '/.dsl.conf')
  82 # find internal connector
  83 if 'internalConnector' in config:
  84         if len(config['internalConnector']) != 1:
  85                 raise Exception("You must specify exactly one internal connector")
  86         internalConnector = config['internalConnector'][0]
  87         if not internalConnector in connectors:
  88                 raise Exception("Connector %s does not exist, there is an error in your config file" % internalConnector)
  89 else:
  90         # auto-config
  91         internalConnector = findAvailableConnector(commonInternalConnectorNames)
  92         if internalConnector is None:
  93                 raise Exception("Could not automatically find internal connector, please use ~/.dsl.conf to specify it manually")
  94 # all the rest is external then, obviously - unless the user wants to do that manually
  95 if 'externalConnectors' in config:
  96         externalConnectors = config['externalConnectors']
  97         for connector in externalConnectors:
  98                 if not connector in connectors:
  99                         raise Exception("Connector %s does not exist, there is an error in your config file" % internalConnector)
 100 else:
 101         externalConnectors = connectors.keys()
 102         externalConnectors.remove(internalConnector)
 103 if not externalConnectors:
 104         raise Exception("No external connector found - either your config is wrong, or your machine has only one connector")
 105
 106 # default: screen off
 107 args = {} # maps connector names to xrand arguments
 108 for c in externalConnectors+[internalConnector]:
 109         args[c] = ["--off"]
 110
 111 # Check what to do
 112 usedExternalConnector = findAvailableConnector(externalConnectors) # *the* external connector which is actually used
 113 if usedExternalConnector is not None: # there's an external screen connected, we need to ask what to do
 114         internalResolutions = connectors[internalConnector]
 115         externalResolutions = connectors[usedExternalConnector]
 116         extPosition = PositionSelection(usedExternalConnector, map(res2user, internalResolutions), map(res2user, externalResolutions))
 117         extPosition.exec_()
 118         if not extPosition.result(): sys.exit(1) # the user canceled
 119         extResolution = res2xrandr(externalResolutions[extPosition.extResolutions.currentIndex()])
 120         intResolution = res2xrandr(internalResolutions[extPosition.intResolutions.currentIndex()])
 121         # build command-line
 122         args[usedExternalConnector] = ["--mode", extResolution] # set external screen to desired resolution
 123         if extPosition.extOnly.isChecked():
 124                 args[usedExternalConnector] += ["--primary"]
 125         else:
 126                 # there are two screens
 127                 args[internalConnector] = ["--mode", intResolution] # set internal screen to desired resolution
 128                 # set position
 129                 if extPosition.posLeft.isChecked():
 130                         args[usedExternalConnector] += ["--left-of", internalConnector]
 131                 else:
 132                         args[usedExternalConnector] += ["--right-of", internalConnector]
 133                 # set primary screen
 134                 if extPosition.primExt.isChecked():
 135                         args[usedExternalConnector] += ["--primary"]
 136                 else:
 137                         args[internalConnector] += ["--primary"]
 138 else:
 139         # use first resolution
 140         args[internalConnector] = ["--mode", res2xrandr(connectors[internalConnector][0]), "--primary"]
 141 # and do it
 142 call = ["xrandr"]
 143 for name in args:
 144         call += ["--output", name] + args[name]
 145 print "Call that will be made:",call
 146 subprocess.check_call(call)