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[lilass.git] / gui.py

diff --git a/gui.py b/gui.py
index 6dabe0f048df2f0e47bc8dfa363a785bcc3266f2..7db44b83e1fe9f9128d1c6554eea6eb968349e26 100644 (file)
--- a/gui.py
+++ b/gui.py
@@ -22,49 +22,88 @@ import sys
 This module implements two functions:
 
 def error(message):
 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):
 
 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):
+        from qt_dialogue import PositionSelection
+        return PositionSelection(internalResolutions, externalResolutions).run()
+    
+    @staticmethod
+    def isAvailable():
+        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()
+# 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

 
 

-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):
+        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")