tr compatible with all Qt APIs

src/tr.py

@@ -1,7 +1,6 @@
 """
-Translating text
+Slim layer providing environment agnostic _translate()
 """
-import os
 
 try:
     import state
@@ -9,51 +8,33 @@ except ImportError:
     from . import state
 
 
-class translateClass:
+def _tr_dummy(context, text, disambiguation=None, n=None):
-    """
-    This is used so that the translateText function can be used
-    when we are in daemon mode and not using any QT functions.
-    """
-    # pylint: disable=old-style-class,too-few-public-methods
-    def __init__(self, context, text):
-        self.context = context
-        self.text = text
-
-    def arg(self, _):
-        """Replace argument placeholders"""
-        if '%' in self.text:
-            # This doesn't actually do anything with the arguments
-            # because we don't have a UI in which to display this information anyway.
-            return translateClass(self.context, self.text.replace('%', '', 1))
-        return self.text
-
-
-def _translate(context, text, disambiguation=None, encoding=None, n=None):
     # pylint: disable=unused-argument
-    return translateText(context, text, n)
-
-
-def translateText(context, text, n=None):
-    """Translate text in context"""
-    try:
-        enableGUI = state.enableGUI
-    except AttributeError:  # inside the plugin
-        enableGUI = True
-    if enableGUI:
-        try:
-            from PyQt4 import QtCore, QtGui
-        except Exception as err:
-            print('PyBitmessage requires PyQt unless you want to run it as a daemon'
-                  ' and interact with it using the API.'
-                  ' You can download PyQt from http://www.riverbankcomputing.com/software/pyqt/download'
-                  ' or by searching Google for \'PyQt Download\'.'
-                  ' If you want to run in daemon mode, see https://bitmessage.org/wiki/Daemon')
-            print('Error message:', err)
-            os._exit(0)  # pylint: disable=protected-access
-        if n is None:
-            return QtGui.QApplication.translate(context, text)
-        return QtGui.QApplication.translate(context, text, None, QtCore.QCoreApplication.CodecForTr, n)
-    else:
-        if '%' in text:
-            return translateClass(context, text.replace('%', '', 1))
     return text
+
+
+if state.enableGUI and not state.curses:
+    try:
+        from fallback import PyQt5  # noqa:F401
+        from PyQt5 import QtWidgets, QtCore
+    except ImportError:
+        _translate = _tr_dummy
+    else:
+        try:
+            from PyQt5 import API
+        except ImportError:
+            API = 'pyqt5'
+        if API == 'pyqt5':
+            _translate = QtWidgets.QApplication.translate
+        else:
+            def _translate(context, text, disambiguation=None, n=None):
+                return (
+                    QtWidgets.QApplication.translate(
+                        context, text, disambiguation)
+                    if n is None else
+                    QtWidgets.QApplication.translate(
+                        context, text, disambiguation,
+                        QtCore.QCoreApplication.CodecForTr, n)
+                )
+else:
+    _translate = _tr_dummy