Add input hooks for GTK4.

IPython/lib/inputhookgtk4.py

@@ -0,0 +1,42 b''
+"""
+Enable Gtk4 to be used interactively by IPython.
+"""
+#-----------------------------------------------------------------------------
+# Copyright (c) 2021, the IPython Development Team.
+#
+# Distributed under the terms of the Modified BSD License.
+#
+# The full license is in the file COPYING.txt, distributed with this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+import sys
+
+from gi.repository import GLib
+
+#-----------------------------------------------------------------------------
+# Code
+#-----------------------------------------------------------------------------
+
+class _InputHook:
+    def __init__(self, context):
+        self._quit = False
+        GLib.io_add_watch(sys.stdin, GLib.PRIORITY_DEFAULT, GLib.IO_IN, self.quit)
+
+    def quit(self, *args, **kwargs):
+        self._quit = True
+        return False
+
+    def run(self):
+        context = GLib.MainContext.default()
+        while not self._quit:
+            context.iteration(True)
+
+
+def inputhook_gtk4():
+    hook = _InputHook()
+    hook.run()
+    return 0

IPython/terminal/pt_inputhooks/gtk4.py

@@ -0,0 +1,25 b''
+"""
+prompt_toolkit input hook for GTK 4.
+"""
+
+from gi.repository import GLib
+
+
+class _InputHook:
+    def __init__(self, context):
+        self._quit = False
+        GLib.io_add_watch(context.fileno(), GLib.PRIORITY_DEFAULT, GLib.IO_IN, self.quit)
+
+    def quit(self, *args, **kwargs):
+        self._quit = True
+        return False
+
+    def run(self):
+        context = GLib.MainContext.default()
+        while not self._quit:
+            context.iteration(True)
+
+
+def inputhook(context):
+    hook = _InputHook(context)
+    hook.run()

examples/IPython Kernel/gui/gui-gtk4.py

@@ -0,0 +1,36 b''
+#!/usr/bin/env python
+"""Simple Gtk example to manually test event loop integration.
+
+This is meant to run tests manually in ipython as:
+
+In [1]: %gui gtk4
+
+In [2]: %run gui-gtk4.py
+"""
+
+import gi
+gi.require_version('Gtk', '4.0')
+from gi.repository import Gtk, GLib  # noqa
+
+
+def hello_world(wigdet, data=None):
+    print("Hello World")
+
+
+def close_request_cb(widget, data=None):
+    global running
+    running = False
+
+
+running = True
+window = Gtk.Window()
+window.connect("close-request", close_request_cb)
+button = Gtk.Button(label="Hello World")
+button.connect("clicked", hello_world, None)
+
+window.set_child(button)
+window.show()
+
+context = GLib.MainContext.default()
+while running:
+    context.iteration(True)

IPython/core/magics/basic.py

@@ -493,6 +493,7 b' Currently the magic system has the following functions:""",'
             %gui qt5     # enable PyQt5 event loop integration
             %gui gtk     # enable PyGTK event loop integration
             %gui gtk3    # enable Gtk3 event loop integration
+            %gui gtk4    # enable Gtk4 event loop integration
             %gui tk      # enable Tk event loop integration
             %gui osx     # enable Cocoa event loop integration
                          # (requires %matplotlib 1.1)

IPython/core/magics/pylab.py

@@ -88,7 +88,7 b' class PylabMagics(Magics):'
         You can list the available backends using the -l/--list option::
 
            In [4]: %matplotlib --list
-           Available matplotlib backends: ['osx', 'qt4', 'qt5', 'gtk3', 'notebook', 'wx', 'qt', 'nbagg',
+           Available matplotlib backends: ['osx', 'qt4', 'qt5', 'gtk3', 'gtk4', 'notebook', 'wx', 'qt', 'nbagg',
            'gtk', 'tk', 'inline']
         """
         args = magic_arguments.parse_argstring(self.matplotlib, line)

IPython/core/pylabtools.py

@@ -16,6 +16,7 b' backends = {'
     "tk": "TkAgg",
     "gtk": "GTKAgg",
     "gtk3": "GTK3Agg",
+    "gtk4": "GTK4Agg",
     "wx": "WXAgg",
     "qt4": "Qt4Agg",
     "qt5": "Qt5Agg",
@@ -44,6 +45,7 b" backend2gui['Qt4Agg'] = 'qt'"
 # map to the same GUI support
 backend2gui['GTK'] = backend2gui['GTKCairo'] = 'gtk'
 backend2gui['GTK3Cairo'] = 'gtk3'
+backend2gui['GTK4Cairo'] = 'gtk4'
 backend2gui['WX'] = 'wx'
 backend2gui['CocoaAgg'] = 'osx'
 # And some backends that don't need GUI integration

IPython/terminal/pt_inputhooks/__init__.py

@@ -14,6 +14,7 b' backends = ['
     "gtk",
     "gtk2",
     "gtk3",
+    "gtk4",
     "tk",
     "wx",
     "pyglet",

docs/source/config/eventloops.rst

@@ -7,9 +7,9 b' loop, so you can use both a GUI and an interactive prompt together. IPython'
 supports a number of common GUI toolkits, but from IPython 3.0, it is possible
 to integrate other event loops without modifying IPython itself.
 
-Supported event loops include ``qt4``, ``qt5``, ``gtk2``, ``gtk3``, ``wx``,
-``osx`` and ``tk``. Make sure the event loop you specify matches the GUI
-toolkit used by your own code.
+Supported event loops include ``qt4``, ``qt5``, ``gtk2``, ``gtk3``, ``gtk4``,
+``wx``, ``osx`` and ``tk``. Make sure the event loop you specify matches the
+GUI toolkit used by your own code.
 
 To make IPython GUI event loop integration occur automatically at every
 startup, set the ``c.InteractiveShellApp.gui`` configuration key in your

docs/source/interactive/reference.rst

@@ -44,7 +44,7 b' the command-line by passing the full class name and a corresponding value; type'
     <...snip...>
     --matplotlib=<CaselessStrEnum> (InteractiveShellApp.matplotlib)
         Default: None
-        Choices: ['auto', 'gtk', 'gtk3', 'inline', 'nbagg', 'notebook', 'osx', 'qt', 'qt4', 'qt5', 'tk', 'wx']
+        Choices: ['auto', 'gtk', 'gtk3', 'gtk4', 'inline', 'nbagg', 'notebook', 'osx', 'qt', 'qt4', 'qt5', 'tk', 'wx']
         Configure matplotlib for interactive use with the default matplotlib
         backend.
     <...snip...>
@@ -902,7 +902,8 b' For users, enabling GUI event loop integration is simple. You simple use the'
     %gui [GUINAME]
 
 With no arguments, ``%gui`` removes all GUI support.  Valid ``GUINAME``
-arguments include ``wx``, ``qt``, ``qt5``, ``gtk``, ``gtk3`` and ``tk``.
+arguments include ``wx``, ``qt``, ``qt5``, ``gtk``, ``gtk3`` ``gtk4``, and
+``tk``.
 
 Thus, to use wxPython interactively and create a running :class:`wx.App`
 object, do::

examples/IPython Kernel/Index.ipynb

@@ -150,6 +150,7 b''
        "&nbsp;&nbsp;<a href='gui/gui-glut.py' target='_blank'>gui-glut.py</a><br>\n",
        "&nbsp;&nbsp;<a href='gui/gui-gtk.py' target='_blank'>gui-gtk.py</a><br>\n",
        "&nbsp;&nbsp;<a href='gui/gui-gtk3.py' target='_blank'>gui-gtk3.py</a><br>\n",
+       "&nbsp;&nbsp;<a href='gui/gui-gtk4.py' target='_blank'>gui-gtk4.py</a><br>\n",
        "&nbsp;&nbsp;<a href='gui/gui-pyglet.py' target='_blank'>gui-pyglet.py</a><br>\n",
        "&nbsp;&nbsp;<a href='gui/gui-qt.py' target='_blank'>gui-qt.py</a><br>\n",
        "&nbsp;&nbsp;<a href='gui/gui-tk.py' target='_blank'>gui-tk.py</a><br>\n",
@@ -160,6 +161,7 b''
        "  gui-glut.py\n",
        "  gui-gtk.py\n",
        "  gui-gtk3.py\n",
+       "  gui-gtk4.py\n",
        "  gui-pyglet.py\n",
        "  gui-qt.py\n",
        "  gui-tk.py\n",

examples/IPython Kernel/Rich Output.ipynb

@@ -3180,6 +3180,7 b''
        "&nbsp;&nbsp;<a href='./gui/gui-glut.py' target='_blank'>gui-glut.py</a><br>\n",
        "&nbsp;&nbsp;<a href='./gui/gui-gtk.py' target='_blank'>gui-gtk.py</a><br>\n",
        "&nbsp;&nbsp;<a href='./gui/gui-gtk3.py' target='_blank'>gui-gtk3.py</a><br>\n",
+       "&nbsp;&nbsp;<a href='./gui/gui-gtk4.py' target='_blank'>gui-gtk4.py</a><br>\n",
        "&nbsp;&nbsp;<a href='./gui/gui-pyglet.py' target='_blank'>gui-pyglet.py</a><br>\n",
        "&nbsp;&nbsp;<a href='./gui/gui-qt.py' target='_blank'>gui-qt.py</a><br>\n",
        "&nbsp;&nbsp;<a href='./gui/gui-tk.py' target='_blank'>gui-tk.py</a><br>\n",
@@ -3230,6 +3231,7 b''
        "  gui-glut.py\n",
        "  gui-gtk.py\n",
        "  gui-gtk3.py\n",
+       "  gui-gtk4.py\n",
        "  gui-pyglet.py\n",
        "  gui-qt.py\n",
        "  gui-tk.py\n",