X-Git-Url: https://git.ralfj.de/lilass.git/blobdiff_plain/a9394222c323143c0fea03848a3f1daf79017a00..6fd92bb21b1a743d0a794141277a7aea857d3c50:/gui.py

diff --git a/gui.py b/gui.py
index 6dabe0f..d586442 100644
--- a/gui.py
+++ b/gui.py
@@ -1,5 +1,5 @@
 # DSL - easy Display Setup for Laptops
-# Copyright (C) 2012 Ralf Jung <post@ralfj.de>
+# Copyright (C) 2012-2015 Ralf Jung <post@ralfj.de>
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -22,49 +22,117 @@ import sys
 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
+from question_frontend import QuestionFrontend
+from screen import processOutputIt
 
-def zenityAvailable():
-	try:
-		from dsl import processOutputIt
-		processOutputIt("zenity", "--version")
-		return True
-	except Exception:
-		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, situation):
+        from qt_dialogue import PositionSelection
+        return PositionSelection(situation).run()
+    
+    @staticmethod
+    def isAvailable():
+        try:
+            import PyQt4
+            return True
+        except ImportError:
+            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])
+# Zenity frontend
+class ZenityFrontend(QuestionFrontend):
+    def error(self, message):
+        '''Displays a fatal error to the user'''
+        subprocess.check_call(["zenity", "--error", "--text="+message])
+    def userChoose (self, title, choices, returns, fallback):
+        assert len(choices) == len(returns)
+        args = ["zenity", "--list", "--text="+title, "--column="]+choices
+        switch = dict (list(zip (choices,returns)))
+        try:
+            for line in processOutputIt(*args):
+                return switch.get(line.strip(), fallback)
+        except Exception:
+            # on user cancel, the return code of zenity is nonzero
+            return fallback
+        # if the output was empty
+        return fallback
+    def isAvailable():
+        try:
+            processOutputIt("zenity", "--version")
+            return True
+        except FileNotFoundError:
+            return False
+        except PermissionError:
+            return False
 
-else:
-	print >> sys.stderr, 'No GUI frontend available, please make sure PyQt4 or Zenity is installed'
+# CLI frontend
+class CLIFrontend(QuestionFrontend):
+    def error(self, message):
+        print(message, file=sys.stderr)
+
+    def userChoose (self, title, choices, returns, fallback):
+        while True:
+            # print question
+            print(title)
+            for i in range(len(choices)):
+                print("%d. %s"%(i,choices[i]))
+            print("Enter 'c' to cancel.")
+            # handle input
+            answer = input("> ")
+            if answer == "c":
+                return None
+            #else
+            try:
+                answerint = int(answer)
+                if answerint >= 0 and answerint < len(choices):
+                    return returns[answerint]
+            except ValueError:
+                pass
+            # if we are here something invalid was entered
+            print("INVALID ANSWER: '%s'" % answer)
+
+    @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
+            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")