make it work properly with python 3
[lilass.git] / dsl.py
diff --git a/dsl.py b/dsl.py
index d5802764c5e8c6167d05c000b5816fdb7606d8b5..7dc86654ec88bb6066cf073050bf5d68104192e0 100755 (executable)
--- a/dsl.py
+++ b/dsl.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 # DSL - easy Display Setup for Laptops
 # Copyright (C) 2012 Ralf Jung <post@ralfj.de>
 #
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
-# along with this program (gpl.txt); if not, write to the Free Software
+# along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 
-import os, re, subprocess
-from selector_window import PositionSelection
-import gui
+import argparse, sys, os, re, subprocess
+from gui import getFrontend
+frontend = getFrontend("cli") # the fallback, until we got a proper frontend. This is guaranteed to be available.
 
 # for auto-config: common names of internal connectors
 commonInternalConnectorNames = ['LVDS', 'LVDS0', 'LVDS1', 'LVDS-0', 'LVDS-1']
 
+# this is as close as one can get to an enum in Python
+class RelativeScreenPosition:
+       LEFT          = 0
+       RIGHT         = 1
+       EXTERNAL_ONLY = 2
+
+# storing what's necessary for screen setup
+class ScreenSetup:
+       def __init__(self, relPosition, intResolution, extResolution, extIsPrimary = False):
+               '''relPosition must be one of the RelativeScreenPosition members, the resolutions must be (width, height) pairs'''
+               self.relPosition = relPosition
+               self.intResolution = intResolution # value doesn't matter if the internal screen is disabled
+               self.extResolution = extResolution
+               self.extIsPrimary = extIsPrimary or self.relPosition == RelativeScreenPosition.EXTERNAL_ONLY # external is always primary if it is the only one
+       
+       def getInternalArgs(self):
+               if self.relPosition == RelativeScreenPosition.EXTERNAL_ONLY:
+                       return ["--off"]
+               args = ["--mode", res2xrandr(self.intResolution)] # set internal screen to desired resolution
+               if not self.extIsPrimary:
+                       args.append('--primary')
+               return args
+       
+       def getExternalArgs(self, intName):
+               args = ["--mode", res2xrandr(self.extResolution)] # set external screen to desired resolution
+               if self.extIsPrimary:
+                       args.append('--primary')
+               if self.relPosition == RelativeScreenPosition.LEFT:
+                       args += ['--left-of', intName]
+               elif self.relPosition == RelativeScreenPosition.RIGHT:
+                       args += ['--right-of', intName]
+               return args
+
 # Load a section-less config file: maps parameter names to space-separated lists of strings (with shell quotation)
-def loadConfigFile(file):
+def loadConfigFile(filename):
        import shlex
        result = {}
-       if not os.path.exists(file):
+       if not os.path.exists(filename):
                return result # no config file
        # read config file
        linenr = 0
-       with open(file) as file:
-               for line in file:
+       with open(filename) as f:
+               for line in f:
                        linenr += 1
                        line = line.strip()
                        if not len(line) or line.startswith("#"): continue # skip empty and comment lines
@@ -42,17 +75,31 @@ def loadConfigFile(file):
                                curKey = line[:pos].strip()
                                result[curKey] = shlex.split(line[pos+1:]) # shlex.split also strips
                        except Exception:
-                               raise Exception("Invalid config, line %d: Error parsing line (quoting issue?)." % linenr)
+                               raise Exception("Invalid config, line %d: Error parsing line (may be a quoting issue)." % linenr)
        # add some convencience get functions
        return result
 
+# helper function: execute a process, return output as iterator, throw exception if there was an error
+# you *must* iterate to the end if you use this!
+def processOutputGen(*args):
+       with subprocess.Popen(args, stdout=subprocess.PIPE) as p:
+               for line in p.stdout:
+                       yield line.decode("utf-8")
+       if p.returncode != 0:
+               raise Exception("Error executing "+str(args))
+def processOutputIt(*args):
+       return list(processOutputGen(*args)) # list() iterates over the generator
+
+# Run xrandr and return a dict of output names mapped to lists of available resolutions, each being a (width, height) pair.
+# An empty list indicates that the connector is disabled.
 def getXrandrInformation():
-       p = subprocess.Popen(["xrandr", "-q"], stdout=subprocess.PIPE)
        connectors = {} # map of connector names to a list of resolutions
        connector = None # current connector
-       for line in p.stdout:
-               # ignore screens
-               if line.startswith("Screen"):
+       for line in processOutputGen("xrandr", "-q"):
+               # screen?
+               m = re.search(r'^Screen [0-9]+: ', line)
+               if m is not None: # ignore this line
+                       connector = None
                        continue
                # new connector?
                m = re.search(r'^([\w\-]+) (dis)?connected ', line)
@@ -66,14 +113,19 @@ def getXrandrInformation():
                if m is not None:
                        assert connector is not None
                        connectors[connector].append((int(m.groups()[0]), int(m.groups()[1])))
-       p.communicate()
-       if p.returncode != 0: raise Exception("Querying xrandr for data failed.")
+                       continue
+               # unknown line
+               # not fatal as my xrandr shows strange stuff when a display is enabled, but not connected
+               #raise Exception("Unknown line in xrandr output:\n"+line)
+               print("Warning: Unknown xrandr line %s" % line)
        return connectors
 
+# convert a (width, height) pair into a string accepted by xrandr as argument for --mode
 def res2xrandr(res):
        (w, h) = res
        return str(w)+'x'+str(h)
 
+# convert a (width, height) pair into a string to be displayed to the user
 def res2user(res):
        (w, h) = res
        # get ratio
@@ -86,87 +138,101 @@ def res2user(res):
                strRatio = '16:%d' % ratio
        return '%dx%d (%s)' %(w, h, strRatio)
 
+# return the first available connector from those listed in tryConnectors, skipping disabled connectors
 def findAvailableConnector(tryConnectors, allConnectors):
        for connector in tryConnectors:
                if connector in allConnectors and allConnectors[connector]: # if the connector exists and is active (i.e. there is a resolution)
                        return connector
        return None
 
-# the main function
-def main():
-       # load connectors and options
-       connectors = getXrandrInformation()
+# Return a (internalConnector, externalConnectors) pair: The name of the internal connector, and a list of external connectors.
+# Use the config file at ~/.dsl.conf and fall back to auto-detection
+def classifyConnectors(allConnectors):
        config = loadConfigFile(os.getenv('HOME') + '/.dsl.conf')
        # find internal connector
        if 'internalConnector' in config:
                if len(config['internalConnector']) != 1:
                        raise Exception("You must specify exactly one internal connector.")
                internalConnector = config['internalConnector'][0]
-               if not internalConnector in connectors:
+               if not internalConnector in allConnectors:
                        raise Exception("Connector %s does not exist, there is an error in your config file." % internalConnector)
        else:
                # auto-config
-               internalConnector = findAvailableConnector(commonInternalConnectorNames, connectors)
+               internalConnector = findAvailableConnector(commonInternalConnectorNames, allConnectors)
                if internalConnector is None:
                        raise Exception("Could not automatically find internal connector, please use ~/.dsl.conf to specify it manually.")
        # all the rest is external then, obviously - unless the user wants to do that manually
        if 'externalConnectors' in config:
                externalConnectors = config['externalConnectors']
                for connector in externalConnectors:
-                       if not connector in connectors:
-                               raise Exception("Connector %s does not exist, there is an error in your config file." % internalConnector)
+                       if not connector in allConnectors:
+                               raise Exception("Connector %s does not exist, there is an error in your config file." % connector)
+                       if connector == internalConnector:
+                               raise Exception("%s is both internal and external, that doesn't make sense." % connector)
        else:
-               externalConnectors = connectors.keys()
+               externalConnectors = list(allConnectors.keys())
                externalConnectors.remove(internalConnector)
        if not externalConnectors:
                raise Exception("No external connector found - either your config is wrong, or your machine has only one connector.")
-
-       # default: screen off
-       args = {} # maps connector names to xrand arguments
-       for c in externalConnectors+[internalConnector]:
-               args[c] = ["--off"]
-
-       # Check what to do
-       usedExternalConnector = findAvailableConnector(externalConnectors, connectors) # *the* external connector which is actually used
-       if usedExternalConnector is not None: # there's an external screen connected, we need to ask what to do
-               internalResolutions = connectors[internalConnector]
-               externalResolutions = connectors[usedExternalConnector]
-               extPosition = PositionSelection(usedExternalConnector, map(res2user, internalResolutions), map(res2user, externalResolutions))
-               extPosition.exec_()
-               if not extPosition.result(): sys.exit(1) # the user canceled
-               extResolution = res2xrandr(externalResolutions[extPosition.extResolutions.currentIndex()])
-               intResolution = res2xrandr(internalResolutions[extPosition.intResolutions.currentIndex()])
-               # build command-line
-               args[usedExternalConnector] = ["--mode", extResolution] # set external screen to desired resolution
-               if extPosition.extOnly.isChecked():
-                       args[usedExternalConnector] += ["--primary"]
-               else:
-                       # there are two screens
-                       args[internalConnector] = ["--mode", intResolution] # set internal screen to desired resolution
-                       # set position
-                       if extPosition.posLeft.isChecked():
-                               args[usedExternalConnector] += ["--left-of", internalConnector]
-                       else:
-                               args[usedExternalConnector] += ["--right-of", internalConnector]
-                       # set primary screen
-                       if extPosition.primExt.isChecked():
-                               args[usedExternalConnector] += ["--primary"]
-                       else:
-                               args[internalConnector] += ["--primary"]
-       else:
-               # use first resolution
-               args[internalConnector] = ["--mode", res2xrandr(connectors[internalConnector][0]), "--primary"]
-       # and do it
-       call = ["xrandr"]
-       for name in args:
-               call += ["--output", name] + args[name]
-       print "Call that will be made:",call
-       subprocess.check_call(call)
+       # done!
+       return (internalConnector, externalConnectors)
 
 # if we run top-level
 if __name__ == "__main__":
        try:
-               main()
+               # parse command-line arguments
+               parser = argparse.ArgumentParser(description='easy Display Setup for Laptops')
+               parser.add_argument("-f, --frontend",
+                                                       dest="frontend",
+                                                       help="The frontend to be used for user interaction")
+               parser.add_argument("-r, --relative-position",
+                                                       dest="rel_position", choices=('left', 'right', 'external-only'),
+                                                       help="Position of external screen relative to internal one")
+               cmdArgs = parser.parse_args()
+               
+               # load frontend
+               frontend = getFrontend(cmdArgs.frontend)
+               
+               # load connectors and classify them
+               connectors = getXrandrInformation()
+               (internalConnector, externalConnectors) = classifyConnectors(connectors)
+               
+               # default: screen off
+               connectorArgs = {} # maps connector names to xrand arguments
+               for c in externalConnectors+[internalConnector]:
+                       connectorArgs[c] = ["--off"]
+               
+               # check whether we got an external screen or not
+               # Check what to do
+               usedExternalConnector = findAvailableConnector(externalConnectors, connectors) # *the* external connector which is actually used
+               if usedExternalConnector is not None:
+                       # there's an external screen connected, we need to get a setup
+                       if cmdArgs.rel_position is not None:
+                               # use command-line arguments (can we do this relPosition stuff more elegant?)
+                               if cmdArgs.rel_position == 'left':
+                                       relPosition = RelativeScreenPosition.LEFT
+                               elif cmdArgs.rel_position == 'right':
+                                       relPosition = RelativeScreenPosition.RIGHT
+                               else:
+                                       relPosition = RelativeScreenPosition.EXTERNAL_ONLY
+                               setup = ScreenSetup(relPosition, connectors[internalConnector][0], connectors[usedExternalConnector][0]) # use default resolutions
+                       else:
+                               # use GUI
+                               setup = frontend.setup(connectors[internalConnector], connectors[usedExternalConnector])
+                       if setup is None: sys.exit(1) # the user canceled
+                       # apply it
+                       connectorArgs[internalConnector] = setup.getInternalArgs()
+                       connectorArgs[usedExternalConnector] = setup.getExternalArgs(internalConnector)
+               else:
+                       # use first resolution of internal connector
+                       connectorArgs[internalConnector] = ["--mode", res2xrandr(connectors[internalConnector][0]), "--primary"]
+               
+               # and do it
+               call = ["xrandr"]
+               for name in connectorArgs:
+                       call += ["--output", name] + connectorArgs[name]
+               print("Call that will be made:",call)
+               subprocess.check_call(call)
        except Exception as e:
-               gui.error(str(e))
+               frontend.error(str(e))
                raise