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added shutdown notification handling to ipythonqt
added shutdown notification handling to ipythonqt

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inputhook.py
324 lines | 10.5 KiB | text/x-python | PythonLexer
#!/usr/bin/env python
# coding: utf-8
"""
Inputhook management for GUI event loop integration.
"""
#-----------------------------------------------------------------------------
# Copyright (C) 2008-2009 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
#-----------------------------------------------------------------------------
import ctypes
import sys
#-----------------------------------------------------------------------------
# Constants
#-----------------------------------------------------------------------------
# Constants for identifying the GUI toolkits.
GUI_WX = 'wx'
GUI_QT = 'qt'
GUI_QT4 = 'qt4'
GUI_GTK = 'gtk'
GUI_TK = 'tk'
#-----------------------------------------------------------------------------
# Utility classes
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Main InputHookManager class
#-----------------------------------------------------------------------------
class InputHookManager(object):
"""Manage PyOS_InputHook for different GUI toolkits.
This class installs various hooks under ``PyOSInputHook`` to handle
GUI event loop integration.
"""
def __init__(self):
self.PYFUNC = ctypes.PYFUNCTYPE(ctypes.c_int)
self._apps = {}
self._reset()
def _reset(self):
self._callback_pyfunctype = None
self._callback = None
self._installed = False
self._current_gui = None
def get_pyos_inputhook(self):
"""Return the current PyOS_InputHook as a ctypes.c_void_p."""
return ctypes.c_void_p.in_dll(ctypes.pythonapi,"PyOS_InputHook")
def get_pyos_inputhook_as_func(self):
"""Return the current PyOS_InputHook as a ctypes.PYFUNCYPE."""
return self.PYFUNC.in_dll(ctypes.pythonapi,"PyOS_InputHook")
def set_inputhook(self, callback):
"""Set PyOS_InputHook to callback and return the previous one."""
self._callback = callback
self._callback_pyfunctype = self.PYFUNC(callback)
pyos_inputhook_ptr = self.get_pyos_inputhook()
original = self.get_pyos_inputhook_as_func()
pyos_inputhook_ptr.value = \
ctypes.cast(self._callback_pyfunctype, ctypes.c_void_p).value
self._installed = True
return original
def clear_inputhook(self, app=None):
"""Set PyOS_InputHook to NULL and return the previous one.
Parameters
----------
app : optional, ignored
This parameter is allowed only so that clear_inputhook() can be
called with a similar interface as all the ``enable_*`` methods. But
the actual value of the parameter is ignored. This uniform interface
makes it easier to have user-level entry points in the main IPython
app like :meth:`enable_gui`."""
pyos_inputhook_ptr = self.get_pyos_inputhook()
original = self.get_pyos_inputhook_as_func()
pyos_inputhook_ptr.value = ctypes.c_void_p(None).value
self._reset()
return original
def clear_app_refs(self, gui=None):
"""Clear IPython's internal reference to an application instance.
Whenever we create an app for a user on qt4 or wx, we hold a
reference to the app. This is needed because in some cases bad things
can happen if a user doesn't hold a reference themselves. This
method is provided to clear the references we are holding.
Parameters
----------
gui : None or str
If None, clear all app references. If ('wx', 'qt4') clear
the app for that toolkit. References are not held for gtk or tk
as those toolkits don't have the notion of an app.
"""
if gui is None:
self._apps = {}
elif self._apps.has_key(gui):
del self._apps[gui]
def enable_wx(self):
"""Enable event loop integration with wxPython.
Parameters
----------
app : bool
Create a running application object or not.
Notes
-----
This methods sets the ``PyOS_InputHook`` for wxPython, which allows
the wxPython to integrate with terminal based applications like
IPython.
If ``app`` is True, we create an :class:`wx.App` as follows::
import wx
app = wx.App(redirect=False, clearSigInt=False)
Both options this constructor are important for things to work
properly in an interactive context.
But, we first check to see if an application has already been
created. If so, we simply return that instance.
"""
from IPython.lib.inputhookwx import inputhook_wx
self.set_inputhook(inputhook_wx)
self._current_gui = GUI_WX
import wx
app = wx.GetApp()
if app is None:
app = wx.App(redirect=False, clearSigInt=False)
app._in_event_loop = True
self._apps[GUI_WX] = app
return app
def disable_wx(self):
"""Disable event loop integration with wxPython.
This merely sets PyOS_InputHook to NULL.
"""
if self._apps.has_key(GUI_WX):
self._apps[GUI_WX]._in_event_loop = False
self.clear_inputhook()
def enable_qt4(self):
"""Enable event loop integration with PyQt4.
Parameters
----------
app : bool
Create a running application object or not.
Notes
-----
This methods sets the PyOS_InputHook for PyQt4, which allows
the PyQt4 to integrate with terminal based applications like
IPython.
If ``app`` is True, we create an :class:`QApplication` as follows::
from PyQt4 import QtCore
app = QtGui.QApplication(sys.argv)
But, we first check to see if an application has already been
created. If so, we simply return that instance.
"""
from PyQt4 import QtCore
# PyQt4 has had this since 4.3.1. In version 4.2, PyOS_InputHook
# was set when QtCore was imported, but if it ever got removed,
# you couldn't reset it. For earlier versions we can
# probably implement a ctypes version.
try:
QtCore.pyqtRestoreInputHook()
except AttributeError:
pass
self._current_gui = GUI_QT4
from PyQt4 import QtGui
app = QtCore.QCoreApplication.instance()
if app is None:
app = QtGui.QApplication([" "])
app._in_event_loop = True
self._apps[GUI_QT4] = app
return app
def disable_qt4(self):
"""Disable event loop integration with PyQt4.
This merely sets PyOS_InputHook to NULL.
"""
if self._apps.has_key(GUI_QT4):
self._apps[GUI_QT4]._in_event_loop = False
self.clear_inputhook()
def enable_gtk(self, app=False):
"""Enable event loop integration with PyGTK.
Parameters
----------
app : bool
Create a running application object or not. Because gtk does't
have an app class, this does nothing.
Notes
-----
This methods sets the PyOS_InputHook for PyGTK, which allows
the PyGTK to integrate with terminal based applications like
IPython.
"""
import gtk
try:
gtk.set_interactive(True)
self._current_gui = GUI_GTK
except AttributeError:
# For older versions of gtk, use our own ctypes version
from IPython.lib.inputhookgtk import inputhook_gtk
self.set_inputhook(inputhook_gtk)
self._current_gui = GUI_GTK
def disable_gtk(self):
"""Disable event loop integration with PyGTK.
This merely sets PyOS_InputHook to NULL.
"""
self.clear_inputhook()
def enable_tk(self, app=False):
"""Enable event loop integration with Tk.
Parameters
----------
app : bool
Create a running application object or not.
Notes
-----
Currently this is a no-op as creating a :class:`Tkinter.Tk` object
sets ``PyOS_InputHook``.
"""
self._current_gui = GUI_TK
if app:
import Tkinter
app = Tkinter.Tk()
app.withdraw()
self._apps[GUI_TK] = app
return app
def disable_tk(self):
"""Disable event loop integration with Tkinter.
This merely sets PyOS_InputHook to NULL.
"""
self.clear_inputhook()
def current_gui(self):
"""Return a string indicating the currently active GUI or None."""
return self._current_gui
inputhook_manager = InputHookManager()
enable_wx = inputhook_manager.enable_wx
disable_wx = inputhook_manager.disable_wx
enable_qt4 = inputhook_manager.enable_qt4
disable_qt4 = inputhook_manager.disable_qt4
enable_gtk = inputhook_manager.enable_gtk
disable_gtk = inputhook_manager.disable_gtk
enable_tk = inputhook_manager.enable_tk
disable_tk = inputhook_manager.disable_tk
clear_inputhook = inputhook_manager.clear_inputhook
set_inputhook = inputhook_manager.set_inputhook
current_gui = inputhook_manager.current_gui
clear_app_refs = inputhook_manager.clear_app_refs
# Convenience function to switch amongst them
def enable_gui(gui=None):
"""Switch amongst GUI input hooks by name.
This is just a utility wrapper around the methods of the InputHookManager
object.
Parameters
----------
gui : optional, string or None
If None, clears input hook, otherwise it must be one of the recognized
GUI names (see ``GUI_*`` constants in module).
app : optional, bool
If true, create an app object and return it.
Returns
-------
The output of the underlying gui switch routine, typically the actual
PyOS_InputHook wrapper object or the GUI toolkit app created, if there was
one.
"""
guis = {None: clear_inputhook,
GUI_TK: enable_tk,
GUI_GTK: enable_gtk,
GUI_WX: enable_wx,
GUI_QT: enable_qt4, # qt3 not supported
GUI_QT4: enable_qt4 }
try:
gui_hook = guis[gui]
except KeyError:
e="Invalid GUI request %r, valid ones are:%s" % (gui, guis.keys())
raise ValueError(e)
return gui_hook()