+ 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 sys
+import collections
+
+from cli_frontend import CLIFrontend
+from zenity_frontend import ZenityFrontend
+
+# 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, situation):
+ from qt_dialogue import PositionSelection
+ return PositionSelection(situation).run()
+
+ @staticmethod
+ def isAvailable():
+ try:
+ import PyQt4
+ return True
+ except ImportError:
+ return False
+
+# 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
+ else:
+ raise Exception("Frontend %s not available" % name)
+ # frontend not found
+ raise Exception("Frontend %s not found" % 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")