inputhook: move inputhook_qt4 related code in own file

IPython/lib/inputhookqt4.py

@@ -0,0 +1,90 b''
+# -*- coding: utf-8 -*-
+"""
+Qt4's inputhook support function
+
+Author: Christian Boos
+"""
+
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2011  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+from IPython.core import ipapi
+from IPython.external.qt_for_kernel import QtCore, QtGui
+from IPython.lib.inputhook import stdin_ready
+
+#-----------------------------------------------------------------------------
+# Code
+#-----------------------------------------------------------------------------
+
+def create_inputhook_qt4(mgr, app=None):
+    """Create an input hook for running the Qt4 application event loop.
+
+    Parameters
+    ----------
+    mgr : an InputHookManager
+
+    app : Qt Application, optional.
+        Running application to use.  If not given, we probe Qt for an
+        existing application object, and create a new one if none is found.
+
+    Returns
+    -------
+    A pair consisting of a Qt Application (either the one given or the
+    one found or created) and a inputhook.
+
+    Notes
+    -----
+    The inputhook function works in tandem with a 'pre_prompt_hook'
+    which automatically restores the hook as an inputhook in case the
+    latter has been temporarily disabled after having intercepted a
+    KeyboardInterrupt.
+    """
+    if app is None:
+        app = QtCore.QCoreApplication.instance()
+        if app is None:
+            app = QtGui.QApplication([" "])
+
+    # Always use a custom input hook instead of PyQt4's default
+    # one, as it interacts better with readline packages (issue
+    # #481).
+
+    # Note that we can't let KeyboardInterrupt escape from that
+    # hook, as no exception can be raised from within a ctypes
+    # python callback. We need to make a compromise: a trapped
+    # KeyboardInterrupt will temporarily disable the input hook
+    # until we start over with a new prompt line with a second
+    # CTRL+C.
+
+    got_kbdint = [False]
+
+    def inputhook_qt4():
+        try:
+            app.processEvents(QtCore.QEventLoop.AllEvents, 300)
+            if not stdin_ready():
+                timer = QtCore.QTimer()
+                timer.timeout.connect(app.quit)
+                while not stdin_ready():
+                    timer.start(50)
+                    app.exec_()
+                    timer.stop()
+        except KeyboardInterrupt:
+            got_kbdint[0] = True
+            mgr.clear_inputhook()
+            print("\n(event loop interrupted - "
+                  "hit CTRL+C again to clear the prompt)")
+        return 0
+
+    def preprompthook_qt4(ishell):
+        if got_kbdint[0]:
+            mgr.set_inputhook(inputhook_qt4)
+    ipapi.get().set_hook('pre_prompt_hook', preprompthook_qt4)
+
+    return app, inputhook_qt4

IPython/lib/inputhook.py

@@ -204,49 +204,9 b' class InputHookManager(object):'
             from PyQt4 import QtCore
             app = QtGui.QApplication(sys.argv)
         """
-        from IPython.external.qt_for_kernel import QtCore, QtGui
-        from IPython.core import ipapi
-
-        if app is None:
-            app = QtCore.QCoreApplication.instance()
-        if app is None:
-            app = QtGui.QApplication([" "])
-
-        # Always use a custom input hook instead of PyQt4's default
-        # one, as it interacts better with readline packages (issue
-        # #481).
-
-        # Note that we can't let KeyboardInterrupt escape from that
-        # hook, as no exception can be raised from within a ctypes
-        # python callback. We need to make a compromise: a trapped
-        # KeyboardInterrupt will temporarily disable the input hook
-        # until we start over with a new prompt line with a second
-        # CTRL+C.
-
-        got_kbdint = [False]
-
-        def inputhook_qt4():
-            try:
-                app.processEvents(QtCore.QEventLoop.AllEvents, 300)
-                if not stdin_ready():
-                    timer = QtCore.QTimer()
-                    timer.timeout.connect(app.quit)
-                    while not stdin_ready():
-                        timer.start(50)
-                        app.exec_()
-                        timer.stop()
-            except KeyboardInterrupt:
-                got_kbdint[0] = True
-                self.clear_inputhook()
-                print("\n(event loop interrupted - "
-                      "hit CTRL+C again to clear the prompt)")
-            return 0
-        self.set_inputhook(inputhook_qt4)
-
-        def preprompthook_qt4(ishell):
-            if got_kbdint[0]:
+        from IPython.lib.inputhookqt4 import create_inputhook_qt4
+        app, inputhook_qt4 = create_inputhook_qt4(self, app)
                 self.set_inputhook(inputhook_qt4)
-        ipapi.get().set_hook('pre_prompt_hook', preprompthook_qt4)
 
         self._current_gui = GUI_QT4
         app._in_event_loop = True