From da5a98f891dfc1ae03c5dda449d83f8f8999dc2a 2016-10-03 15:51:45
From: Thomas Kluyver <thomas@kluyver.me.uk>
Date: 2016-10-03 15:51:45
Subject: [PATCH] Let IPython.lib.guisupport detect terminal-integrated event loops

Closes gh-9974

---

diff --git a/IPython/core/interactiveshell.py b/IPython/core/interactiveshell.py
index 0c6d8b4..ab77854 100644
--- a/IPython/core/interactiveshell.py
+++ b/IPython/core/interactiveshell.py
@@ -2891,6 +2891,8 @@ class InteractiveShell(SingletonConfigurable):
     # Things related to GUI support and pylab
     #-------------------------------------------------------------------------
 
+    active_eventloop = None
+
     def enable_gui(self, gui=None):
         raise NotImplementedError('Implement enable_gui in a subclass')
     
diff --git a/IPython/lib/guisupport.py b/IPython/lib/guisupport.py
index e2fc107..5e13d43 100644
--- a/IPython/lib/guisupport.py
+++ b/IPython/lib/guisupport.py
@@ -57,16 +57,10 @@ so you don't have to depend on IPython.
 
 """
 
-#-----------------------------------------------------------------------------
-#  Copyright (C) 2008-2011  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.
-#-----------------------------------------------------------------------------
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
 
-#-----------------------------------------------------------------------------
-# Imports
-#-----------------------------------------------------------------------------
+from IPython.core.getipython import get_ipython
 
 #-----------------------------------------------------------------------------
 # wx
@@ -84,6 +78,15 @@ def get_app_wx(*args, **kwargs):
 
 def is_event_loop_running_wx(app=None):
     """Is the wx event loop running."""
+    # New way: check attribute on shell instance
+    ip = get_ipython()
+    if ip is not None:
+        if ip.active_eventloop and ip.active_eventloop == 'wx':
+            return True
+        # Fall through to checking the application, because Wx has a native way
+        # to check if the event loop is running, unlike Qt.
+
+    # Old way: check Wx application
     if app is None:
         app = get_app_wx()
     if hasattr(app, '_in_event_loop'):
@@ -118,6 +121,12 @@ def get_app_qt4(*args, **kwargs):
 
 def is_event_loop_running_qt4(app=None):
     """Is the qt4 event loop running."""
+    # New way: check attribute on shell instance
+    ip = get_ipython()
+    if ip is not None:
+        return ip.active_eventloop and ip.active_eventloop.startswith('qt')
+
+    # Old way: check attribute on QApplication singleton
     if app is None:
         app = get_app_qt4([''])
     if hasattr(app, '_in_event_loop'):
diff --git a/IPython/terminal/interactiveshell.py b/IPython/terminal/interactiveshell.py
index 9db6745..0de3aaa 100644
--- a/IPython/terminal/interactiveshell.py
+++ b/IPython/terminal/interactiveshell.py
@@ -28,7 +28,7 @@ from pygments.token import Token
 
 from .debugger import TerminalPdb, Pdb
 from .magics import TerminalMagics
-from .pt_inputhooks import get_inputhook_func
+from .pt_inputhooks import get_inputhook_name_and_func
 from .prompts import Prompts, ClassicPrompts, RichPromptDisplayHook
 from .ptutils import IPythonPTCompleter, IPythonPTLexer
 from .shortcuts import register_ipython_shortcuts
@@ -458,11 +458,13 @@ class TerminalInteractiveShell(InteractiveShell):
         if self._inputhook is not None:
             self._inputhook(context)
 
+    active_eventloop = None
     def enable_gui(self, gui=None):
         if gui:
-            self._inputhook = get_inputhook_func(gui)
+            self.active_eventloop, self._inputhook =\
+                get_inputhook_name_and_func(gui)
         else:
-            self._inputhook = None
+            self.active_eventloop = self._inputhook = None
 
     # Run !system commands directly, not through pipes, so terminal programs
     # work correctly.
diff --git a/IPython/terminal/pt_inputhooks/__init__.py b/IPython/terminal/pt_inputhooks/__init__.py
index 0f37b13..3766973 100644
--- a/IPython/terminal/pt_inputhooks/__init__.py
+++ b/IPython/terminal/pt_inputhooks/__init__.py
@@ -30,19 +30,20 @@ class UnknownBackend(KeyError):
                 "Supported event loops are: {}").format(self.name,
                                     ', '.join(backends + sorted(registered)))
 
-def get_inputhook_func(gui):
+def get_inputhook_name_and_func(gui):
     if gui in registered:
-        return registered[gui]
+        return gui, registered[gui]
 
     if gui not in backends:
         raise UnknownBackend(gui)
 
     if gui in aliases:
-        return get_inputhook_func(aliases[gui])
+        return get_inputhook_name_and_func(aliases[gui])
 
+    gui_mod = gui
     if gui == 'qt5':
         os.environ['QT_API'] = 'pyqt5'
-        gui = 'qt'
+        gui_mod = 'qt'
 
-    mod = importlib.import_module('IPython.terminal.pt_inputhooks.'+gui)
-    return mod.inputhook
+    mod = importlib.import_module('IPython.terminal.pt_inputhooks.'+gui_mod)
+    return gui, mod.inputhook