allow to select frontend via command-line; add a GUI-less frontend for scripted actions

[lilass.git] / dsl.py

diff --git a/dsl.py b/dsl.py
index 890ea70e8cdc5b24520ea3cf30fe1b1b0fa56f06..b4f77bf413391f2bf4b7e01d835c80b76b695299 100755 (executable)
--- a/dsl.py
+++ b/dsl.py
@@ -17,7 +17,8 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 
 import argparse, sys, os, re, subprocess
-import gui
+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']
@@ -78,13 +79,24 @@ def loadConfigFile(file):
        # 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):
+       p = subprocess.Popen(args, stdout=subprocess.PIPE)
+       for line in p.stdout:
+               yield line
+       p.wait() # wait for process to exit (it closed stdout, so it can't block anymore)
+       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:
+       for line in processOutputGen("xrandr", "-q"):
                # screen?
                m = re.search(r'^Screen [0-9]+: ', line)
                if m is not None: # ignore this line
@@ -107,10 +119,6 @@ def getXrandrInformation():
                # 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
-       # be sure to always proprly finish up with the xrandr
-       p.communicate()
-       # if everything succeededso far, check return code
-       if p.returncode != 0: raise Exception("Querying xrandr for data failed.")
        return connectors
 
 # convert a (width, height) pair into a string accepted by xrandr as argument for --mode
@@ -175,11 +183,17 @@ if __name__ == "__main__":
        try:
                # 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)
@@ -205,7 +219,7 @@ if __name__ == "__main__":
                                setup = ScreenSetup(relPosition, connectors[internalConnector][0], connectors[usedExternalConnector][0]) # use default resolutions
                        else:
                                # use GUI
-                               setup = gui.setup(connectors[internalConnector], connectors[usedExternalConnector])
+                               setup = frontend.setup(connectors[internalConnector], connectors[usedExternalConnector])
                        if setup is None: sys.exit(1) # the user canceled
                        # apply it
                        connectorArgs[internalConnector] = setup.getInternalArgs()
@@ -221,5 +235,5 @@ if __name__ == "__main__":
                print "Call that will be made:",call
                subprocess.check_call(call)
        except Exception as e:
-               gui.error(str(e))
+               frontend.error(str(e))
                raise