dsl.py

   1 #!/usr/bin/python
   2 # DSL - easy Display Setup for Laptops
   3 # Copyright (C) 2012 Ralf Jung <post@ralfj.de>
   4 #
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 2 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program (gpl.txt); if not, write to the Free Software
  17 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18
  19 import os, re, subprocess
  20 from selector_window import PositionSelection
  21 import gui
  22
  23 # for auto-config: common names of internal connectors
  24 commonInternalConnectorNames = ['LVDS', 'LVDS0', 'LVDS1', 'LVDS-0', 'LVDS-1']
  25
  26 # Load a section-less config file: maps parameter names to space-separated lists of strings (with shell quotation)
  27 def loadConfigFile(file):
  28         import shlex
  29         result = {}
  30         if not os.path.exists(file):
  31                 return result # no config file
  32         # read config file
  33         linenr = 0
  34         with open(file) as file:
  35                 for line in file:
  36                         linenr += 1
  37                         line = line.strip()
  38                         if not len(line) or line.startswith("#"): continue # skip empty and comment lines
  39                         try:
  40                                 # parse line
  41                                 pos = line.index("=") # will raise exception when substring is not found
  42                                 curKey = line[:pos].strip()
  43                                 result[curKey] = shlex.split(line[pos+1:]) # shlex.split also strips
  44                         except Exception:
  45                                 raise Exception("Invalid config, line %d: Error parsing line (quoting issue?)." % linenr)
  46         # add some convencience get functions
  47         return result
  48
  49 def getXrandrInformation():
  50         p = subprocess.Popen(["xrandr", "-q"], stdout=subprocess.PIPE)
  51         connectors = {} # map of connector names to a list of resolutions
  52         try:
  53                 connector = None # current connector
  54                 for line in p.stdout:
  55                         # screen?
  56                         m = re.search(r'^Screen [0-9]+: ', line)
  57                         if m is not None: # ignore this line
  58                                 connector = None
  59                                 continue
  60                         # new connector?
  61                         m = re.search(r'^([\w\-]+) (dis)?connected ', line)
  62                         if m is not None:
  63                                 connector = m.groups()[0]
  64                                 assert connector not in connectors
  65                                 connectors[connector] = []
  66                                 continue
  67                         # new resolution?
  68                         m = re.search(r'^   ([\d]+)x([\d]+) +', line)
  69                         if m is not None:
  70                                 assert connector is not None
  71                                 connectors[connector].append((int(m.groups()[0]), int(m.groups()[1])))
  72                                 continue
  73                         # unknown line
  74                         raise Exception("Unknown line in xrandr output:\n"+line)
  75         finally:
  76                 # be sure to always proprly finish up with the xrandr
  77                 p.communicate()
  78         # if everything succeededso far, check return code
  79         if p.returncode != 0: raise Exception("Querying xrandr for data failed.")
  80         return connectors
  81
  82 def res2xrandr(res):
  83         (w, h) = res
  84         return str(w)+'x'+str(h)
  85
  86 def res2user(res):
  87         (w, h) = res
  88         # get ratio
  89         ratio = int(round(16.0*h/w))
  90         if ratio == 12: # 16:12 = 4:3
  91                 strRatio = '4:3'
  92         elif ratio == 13: # 16:12.8 = 5:4
  93                 strRatio = '5:4'
  94         else: # let's just hope this will never be 14 or more...
  95                 strRatio = '16:%d' % ratio
  96         return '%dx%d (%s)' %(w, h, strRatio)
  97
  98 def findAvailableConnector(tryConnectors, allConnectors):
  99         for connector in tryConnectors:
 100                 if connector in allConnectors and allConnectors[connector]: # if the connector exists and is active (i.e. there is a resolution)
 101                         return connector
 102         return None
 103
 104 # the main function
 105 def main():
 106         # load connectors and options
 107         connectors = getXrandrInformation()
 108         config = loadConfigFile(os.getenv('HOME') + '/.dsl.conf')
 109         # find internal connector
 110         if 'internalConnector' in config:
 111                 if len(config['internalConnector']) != 1:
 112                         raise Exception("You must specify exactly one internal connector.")
 113                 internalConnector = config['internalConnector'][0]
 114                 if not internalConnector in connectors:
 115                         raise Exception("Connector %s does not exist, there is an error in your config file." % internalConnector)
 116         else:
 117                 # auto-config
 118                 internalConnector = findAvailableConnector(commonInternalConnectorNames, connectors)
 119                 if internalConnector is None:
 120                         raise Exception("Could not automatically find internal connector, please use ~/.dsl.conf to specify it manually.")
 121         # all the rest is external then, obviously - unless the user wants to do that manually
 122         if 'externalConnectors' in config:
 123                 externalConnectors = config['externalConnectors']
 124                 for connector in externalConnectors:
 125                         if not connector in connectors:
 126                                 raise Exception("Connector %s does not exist, there is an error in your config file." % internalConnector)
 127         else:
 128                 externalConnectors = connectors.keys()
 129                 externalConnectors.remove(internalConnector)
 130         if not externalConnectors:
 131                 raise Exception("No external connector found - either your config is wrong, or your machine has only one connector.")
 132
 133         # default: screen off
 134         args = {} # maps connector names to xrand arguments
 135         for c in externalConnectors+[internalConnector]:
 136                 args[c] = ["--off"]
 137
 138         # Check what to do
 139         usedExternalConnector = findAvailableConnector(externalConnectors, connectors) # *the* external connector which is actually used
 140         if usedExternalConnector is not None: # there's an external screen connected, we need to ask what to do
 141                 internalResolutions = connectors[internalConnector]
 142                 externalResolutions = connectors[usedExternalConnector]
 143                 extPosition = PositionSelection(usedExternalConnector, map(res2user, internalResolutions), map(res2user, externalResolutions))
 144                 extPosition.exec_()
 145                 if not extPosition.result(): sys.exit(1) # the user canceled
 146                 extResolution = res2xrandr(externalResolutions[extPosition.extResolutions.currentIndex()])
 147                 intResolution = res2xrandr(internalResolutions[extPosition.intResolutions.currentIndex()])
 148                 # build command-line
 149                 args[usedExternalConnector] = ["--mode", extResolution] # set external screen to desired resolution
 150                 if extPosition.extOnly.isChecked():
 151                         args[usedExternalConnector] += ["--primary"]
 152                 else:
 153                         # there are two screens
 154                         args[internalConnector] = ["--mode", intResolution] # set internal screen to desired resolution
 155                         # set position
 156                         if extPosition.posLeft.isChecked():
 157                                 args[usedExternalConnector] += ["--left-of", internalConnector]
 158                         else:
 159                                 args[usedExternalConnector] += ["--right-of", internalConnector]
 160                         # set primary screen
 161                         if extPosition.primExt.isChecked():
 162                                 args[usedExternalConnector] += ["--primary"]
 163                         else:
 164                                 args[internalConnector] += ["--primary"]
 165         else:
 166                 # use first resolution
 167                 args[internalConnector] = ["--mode", res2xrandr(connectors[internalConnector][0]), "--primary"]
 168         # and do it
 169         call = ["xrandr"]
 170         for name in args:
 171                 call += ["--output", name] + args[name]
 172         print "Call that will be made:",call
 173         subprocess.check_call(call)
 174
 175 # if we run top-level
 176 if __name__ == "__main__":
 177         try:
 178                 main()
 179         except Exception as e:
 180                 gui.error(str(e))
 181                 raise