-
-# frontend detectors
-def qtAvailable():
- try:
- import PyQt4
- return True
- except ImportError:
- return False
-
-def zenityAvailable():
- try:
- from dsl import processOutputIt
- processOutputIt("zenity", "--version")
- return True
- except Exception:
- return False
-
-# 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()
-
-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'
+import collections
+
+from qt_frontend import QtFrontend
+from cli_frontend import CLIFrontend
+from zenity_frontend import ZenityFrontend
+
+
+# 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")