X-Git-Url: https://git.ralfj.de/lilass.git/blobdiff_plain/a9394222c323143c0fea03848a3f1daf79017a00..aaa0b27561726d84cc7c3fcfd16302c87dc628d7:/gui.py

diff --git a/gui.py b/gui.py
index 6dabe0f..560cb01 100644
--- a/gui.py
+++ b/gui.py
@@ -29,42 +29,81 @@ def setup(internalResolutions, externalResolutions):
 	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
-
-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)
+# Qt frontend
+class QtFrontend:
+	def __init__(self):
+		from PyQt4 import QtGui
+		self.app = QtGui.QApplication(sys.argv)
+		print("Qt loaded")
 	
-	def error(message):
+	def error(self, message):
+		from PyQt4 import QtGui
 		QtGui.QMessageBox.critical(None, 'Fatal error', message)
 	
-	def setup(internalResolutions, externalResolutions):
+	def setup(self, internalResolutions, externalResolutions):
+		from qt_dialogue import PositionSelection
 		return PositionSelection(internalResolutions, externalResolutions).run()
-
-elif zenityAvailable():
-	import subprocess
-	from zenity_dialogue import run as setup # this provides the setup function
 	
+	@staticmethod
+	def isAvailable():
+		try:
+			import PyQt4
+			return True
+		except ImportError:
+			return False
+
+
+# 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):
+		from zenity_dialogue import run
+		run(internalResolutions, externalResolutions)
+	
+	@staticmethod
+	def isAvailable():
+		try:
+			from dsl import processOutputIt
+			processOutputIt("zenity", "--version")
+			return True
+		except Exception:
+			return False
+
+
+# CLI frontend
+class CLIFrontend:
+	def error(self, message):
+		print(message, file=sys.stderr)
+	
+	def setup(self, internalResolutions, externalResolutions):
+		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
 
-else:
-	print >> sys.stderr, 'No GUI frontend available, please make sure PyQt4 or Zenity is installed'
+# 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 list(frontends.values()):
+		if frontend.isAvailable():
+			return frontend() # call constructor
+	raise Exception("No frontend is available - this should not happen")