This module implements two functions:
def error(message):
- This function displays the error message to the user in some appropriate fassion
+ This function displays the error message to the user in some appropriate fassion
def setup(internalResolutions, externalResolutions):
- Both arguments are lists of (width, height) tuples of resolutions. You can use dsl.res2user to obtain a user-readable representation of a resolution tuple.
- The user should be asked about his display setup preferences.
- The function returns None if the user cancelled, and an instance of dsl.ScreenSetup otherwise.
+ Both arguments are lists of (width, height) tuples of resolutions. You can use dsl.res2user to obtain a user-readable representation of a resolution tuple.
+ The user should be asked about his display setup preferences.
+ The function returns None if the user cancelled, and an instance of dsl.ScreenSetup otherwise.
'''
+import subprocess, collections
-# frontend detectors
-def qtAvailable():
- try:
- import PyQt4
- return True
- except ImportError:
- return False
+# Qt frontend
+class QtFrontend:
+ def __init__(self):
+ from PyQt4 import QtGui
+ self.app = QtGui.QApplication(sys.argv)
+ print("Qt loaded")
+
+ def error(self, message):
+ from PyQt4 import QtGui
+ QtGui.QMessageBox.critical(None, 'Fatal error', message)
+
+ def setup(self, internalResolutions, externalResolutions, commonRes):
+ from qt_dialogue import PositionSelection
+ return PositionSelection(internalResolutions, externalResolutions, commonRes).run()
+
+ @staticmethod
+ def isAvailable():
+ try:
+ import PyQt4
+ return True
+ except ImportError:
+ return False
-def zenityAvailable():
- return True # FIXME
-# actual frontends
-if qtAvailable():
- from PyQt4 import QtGui
- from qt_dialogue import PositionSelection
- app = QtGui.QApplication(sys.argv)
-
- def error(message):
- QtGui.QMessageBox.critical(None, 'Fatal error', message)
-
- def setup(internalResolutions, externalResolutions):
- return PositionSelection(internalResolutions, externalResolutions).run()
+# Zenity frontend
+class ZenityFrontend:
+ def error(message):
+ '''Displays a fatal error to the user'''
+ subprocess.check_call(["zenity", "--error", "--text="+message])
+
+ def setup(self, internalResolutions, externalResolutions, commonRes):
+ from zenity_dialogue import run
+ return run(internalResolutions, externalResolutions)
+
+ @staticmethod
+ def isAvailable():
+ try:
+ from dsl import processOutputIt
+ processOutputIt("zenity", "--version")
+ return True
+ except Exception:
+ return False
-elif zenityAvailable():
- import subprocess
- from zenity_dialogue import run as setup # this provides the setup function
-
- def error(message):
- '''Displays a fatal error to the user'''
- subprocess.check_call(["zenity", "--error", "--text="+message])
-else:
- print >> sys.stderr, 'No GUI frontend available, please make sure PyQt4 or Zenity is installed'
+# CLI frontend
+class CLIFrontend:
+ def error(self, message):
+ print(message, file=sys.stderr)
+
+ def setup(self, internalResolutions, externalResolutions, commonRes):
+ raise Exception("Choosing the setup interactively is not supported with the CLI frontend")
+
+ @staticmethod
+ def isAvailable():
+ return True
+
+# list of available frontends
+frontends = collections.OrderedDict()
+frontends["qt"] = QtFrontend
+frontends["zenity"] = ZenityFrontend
+frontends["cli"] = CLIFrontend
+
+# get a frontend
+def getFrontend(name = None):
+ # by name
+ if name is not None:
+ if name in frontends:
+ if frontends[name].isAvailable():
+ return frontends[name]() # call constructor
+ # frontend not found or not available
+ raise Exception("Frontend %s not found or not available" % name)
+ # auto-detect
+ for frontend in frontends.values():
+ if frontend.isAvailable():
+ return frontend() # call constructor
+ raise Exception("No frontend is available - this should not happen")