Small fix to docstring and qt example.

IPython/lib/guisupport.py

@@ -1,147 +1,149 b''
 #!/usr/bin/env python
 # coding: utf-8
 """
 Support for creating GUI apps and starting event loops.
 
 IPython's GUI integration allows interative plotting and GUI usage in IPython
 session. IPython has two different types of GUI integration:
 
 1. The terminal based IPython supports GUI event loops through Python's
    PyOS_InputHook. PyOS_InputHook is a hook that Python calls periodically
    whenever raw_input is waiting for a user to type code. We implement GUI
    support in the terminal by setting PyOS_InputHook to a function that 
    iterates the event loop for a short while. It is important to note that
    in this situation, the real GUI event loop is NOT run in the normal
    manner, so you can't use the normal means to detect that it is running.
 2. In the two process IPython kernel/frontend, the GUI event loop is run in 
    the kernel. In this case, the event loop is run in the normal manner by
    calling the function or method of the GUI toolkit that starts the event
    loop.
 
 In addition to starting the GUI event loops in one of these two ways, IPython
 will *always* create an appropriate GUI application object when GUi
 integration is enabled.
 
 If you want your GUI apps to run in IPython you need to do two things:
 
 1. Test to see if there is already an existing main application object. If
    there is, you should use it. If there is not an existing application object
    you should create one.
 2. Test to see if the GUI event loop is running. If it is, you should not
    start it. If the event loop is not running you may start it.
 
 This module contains functions for each toolkit that perform these things
 in a consistent manner. Because of how PyOS_InputHook runs the event loop
 you cannot detect if the event loop is running using the traditional calls
 (such as ``wx.GetApp.IsMainLoopRunning()`` in wxPython). If PyOS_InputHook is
 set These methods will return a false negative. That is, they will say the
 event loop is not running, when is actually is. To work around this limitation
 we proposed the following informal protocol:
 
 * Whenever someone starts the event loop, they *must* set the ``_in_event_loop``
   attribute of the main application object to ``True``. This should be done
   regardless of how the event loop is actually run.
 * Whenever someone stops the event loop, they *must* set the ``_in_event_loop``
   attribute of the main application object to ``False``.
 * If you want to see if the event loop is running, you *must* use ``hasattr``
   to see if ``_in_event_loop`` attribute has been set. If it is set, you
   *must* use its value. If it has not been set, you can query the toolkit
   in the normal manner.
 * If you want GUI support and no one else has created an application or
   started the event loop you *must* do this. We don't want projects to 
   attempt to defer these things to someone else if they themselves need it.
 
 The functions below implement this logic for each GUI toolkit. If you need
 to create custom application subclasses, you will likely have to modify this
 code for your own purposes. This code can be copied into your own project
 so you don't have to depend on IPython.
 
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2010  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
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # wx
 #-----------------------------------------------------------------------------
 
 def get_app_wx(*args, **kwargs):
     """Create a new wx app or return an exiting one."""
     import wx
     app = wx.GetApp()
     if app is None:
         if not kwargs.has_key('redirect'):
             kwargs['redirect'] = False
         app = wx.PySimpleApp(*args, **kwargs)
     return app
 
 def is_event_loop_running_wx(app=None):
     """Is the wx event loop running."""
     if app is None:
         app = get_app_wx()
     if hasattr(app, '_in_event_loop'):
         return app._in_event_loop
     else:
         return app.IsMainLoopRunning()
 
 def start_event_loop_wx(app=None):
     """Start the wx event loop in a consistent manner."""
     if app is None:
         app = get_app_wx()
     if not is_event_loop_running_wx(app):
         app._in_event_loop = True
         app.MainLoop()
         app._in_event_loop = False
     else:
         app._in_event_loop = True
 
 #-----------------------------------------------------------------------------
 # qt4
 #-----------------------------------------------------------------------------
 
 def get_app_qt4(*args, **kwargs):
     """Create a new qt4 app or return an existing one."""
     from IPython.external.qt_for_kernel import QtGui
     app = QtGui.QApplication.instance()
     if app is None:
         if not args:
             args = ([''],)
         app = QtGui.QApplication(*args, **kwargs)
     return app
 
 def is_event_loop_running_qt4(app=None):
     """Is the qt4 event loop running."""
     if app is None:
         app = get_app_qt4([''])
     if hasattr(app, '_in_event_loop'):
         return app._in_event_loop
     else:
         # Does qt4 provide a other way to detect this?
         return False
 
 def start_event_loop_qt4(app=None):
     """Start the qt4 event loop in a consistent manner."""
     if app is None:
         app = get_app_qt4([''])
     if not is_event_loop_running_qt4(app):
+        from .inputhook import enable_qt4
+        #enable_qt4(app)
         app._in_event_loop = True
         app.exec_()
         app._in_event_loop = False
     else:
         app._in_event_loop = True
 
 #-----------------------------------------------------------------------------
 # Tk
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # gtk
 #-----------------------------------------------------------------------------

IPython/lib/inputhook.py

@@ -1,345 +1,345 b''
 #!/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
 import warnings
 
 #-----------------------------------------------------------------------------
 # Constants
 #-----------------------------------------------------------------------------
 
 # Constants for identifying the GUI toolkits.
 GUI_WX = 'wx'
 GUI_QT = 'qt'
 GUI_QT4 = 'qt4'
 GUI_GTK = 'gtk'
 GUI_TK = 'tk'
 GUI_OSX = 'osx'
 
 #-----------------------------------------------------------------------------
 # 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, app=None):
         """Enable event loop integration with wxPython.
 
         Parameters
         ----------
         app : WX Application, optional.
             Running application to use.  If not given, we probe WX for an
             existing application object, and create a new one if none is found.
 
         Notes
         -----
         This methods sets the ``PyOS_InputHook`` for wxPython, which allows
         the wxPython to integrate with terminal based applications like
         IPython.
 
         If ``app`` is not given we probe for an existing one, and return it if
         found.  If no existing app is found, we create an :class:`wx.App` as
         follows::
 
             import wx
             app = wx.App(redirect=False, clearSigInt=False)
         """
         from IPython.lib.inputhookwx import inputhook_wx
         self.set_inputhook(inputhook_wx)
         self._current_gui = GUI_WX
         import wx
         if app is None:
             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, app=None):
         """Enable event loop integration with PyQt4.
         
         Parameters
         ----------
         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.
 
         Notes
         -----
         This methods sets the PyOS_InputHook for PyQt4, which allows
         the PyQt4 to integrate with terminal based applications like
         IPython.
 
         If ``app`` is not given we probe for an existing one, and return it if
         found.  If no existing app is found, we create an :class:`QApplication`
         as follows::
 
             from PyQt4 import QtCore
             app = QtGui.QApplication(sys.argv)
         """
         from IPython.external.qt_for_kernel import QtCore, QtGui
 
         if 'pyreadline' in sys.modules:
             # see IPython GitHub Issue #281 for more info on this issue
             # Similar intermittent behavior has been reported on OSX,
             # but not consistently reproducible
             warnings.warn("""PyReadline's inputhook can conflict with Qt, causing delays
             in interactive input. If you do see this issue, we recommend using another GUI
             toolkit if you can, or disable readline with the configuration option
             'TerminalInteractiveShell.readline_use=False', specified in a config file or
             at the command-line""",
             RuntimeWarning)
         
         # 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
         if app is None:
             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=None):
         """Enable event loop integration with PyGTK.
 
         Parameters
         ----------
         app : ignored
            Ignored, it's only a placeholder to keep the call signature of all
            gui activation methods consistent, which simplifies the logic of
            supporting magics.
 
         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=None):
         """Enable event loop integration with Tk.
 
         Parameters
         ----------
         app : toplevel :class:`Tkinter.Tk` widget, 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.
+            Running toplevel widget to use.  If not given, we probe Tk for an
+            existing one, and create a new one if none is found.
 
         Notes
         -----
         If you have already created a :class:`Tkinter.Tk` object, the only
         thing done by this method is to register with the
         :class:`InputHookManager`, since creating that object automatically
         sets ``PyOS_InputHook``.
         """
         self._current_gui = GUI_TK
         if app is None:
             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, app=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, existing application object.
       For toolkits that have the concept of a global app, you can supply an
       existing one.  If not given, the toolkit will be probed for one, and if
       none is found, a new one will be created.  Note that GTK does not have
       this concept, and passing an app if `gui`=="GTK" will raise an error.
 
     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_OSX: lambda app=False: None,
             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(app)