#!/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 #----------------------------------------------------------------------------- class _DummyMainloop(object): """A special manager to hijack GUI mainloops that is mostly a no-op. We are not using this class currently as it breaks GUI code that calls a mainloop function after the app has started to process pending events. """ def __init__(self, ml, ihm, gui_type): self.ml = ml self.ihm = ihm self.gui_type = gui_type def __call__(self, *args, **kw): if self.ihm.current_gui() == self.gui_type: pass else: self.ml(*args, **kw) #----------------------------------------------------------------------------- # Appstart and spin functions #----------------------------------------------------------------------------- def appstart_qt4(app): """Start the qt4 event loop in a way that plays with IPython. When a qt4 app is run interactively in IPython, the event loop should not be started. This function checks to see if IPython's qt4 integration is activated and if so, it passes. If not, it will call the :meth:`exec_` method of the main qt4 app. This function should be used by users who want their qt4 scripts to work both at the command line and in IPython. These users should put the following logic at the bottom on their script, after they create a :class:`QApplication` instance (called ``app`` here):: try: from IPython.lib.inputhook import appstart_qt4 appstart_qt4(app) except ImportError: app.exec_() """ from PyQt4 import QtCore, QtGui assert isinstance(app, QtCore.QCoreApplication) if app is not None: if current_gui() == GUI_QT4: pass else: app.exec_() def appstart_wx(app): """Start the wx event loop in a way that plays with IPython. When a wx app is run interactively in IPython, the event loop should not be started. This function checks to see if IPython's wx integration is activated and if so, it passes. If not, it will call the :meth:`MainLoop` method of the main qt4 app. This function should be used by users who want their wx scripts to work both at the command line and in IPython. These users should put the following logic at the bottom on their script, after they create a :class:`App` instance (called ``app`` here):: try: from IPython.lib.inputhook import appstart_wx appstart_wx(app) except ImportError: app.MainLoop() """ import wx assert isinstance(app, wx.App) if app is not None: if current_gui() == GUI_WX: pass else: app.MainLoop() def appstart_tk(app): """Start the tk event loop in a way that plays with IPython. When a tk app is run interactively in IPython, the event loop should not be started. This function checks to see if IPython's tk integration is activated and if so, it passes. If not, it will call the :meth:`mainloop` method of the tk object passed to this method. This function should be used by users who want their tk scripts to work both at the command line and in IPython. These users should put the following logic at the bottom on their script, after they create a :class:`Tk` instance (called ``app`` here):: try: from IPython.lib.inputhook import appstart_tk appstart_tk(app) except ImportError: app.mainloop() """ if app is not None: if current_gui() == GUI_TK: pass else: app.mainloop() def appstart_gtk(): """Start the gtk event loop in a way that plays with IPython. When a gtk app is run interactively in IPython, the event loop should not be started. This function checks to see if IPython's gtk integration is activated and if so, it passes. If not, it will call :func:`gtk.main`. Unlike the other appstart implementations, this does not take an ``app`` argument. This function should be used by users who want their gtk scripts to work both at the command line and in IPython. These users should put the following logic at the bottom on their script:: try: from IPython.lib.inputhook import appstart_gtk appstart_gtk() except ImportError: gtk.main() """ import gtk if current_gui() == GUI_GTK: pass else: gtk.main() #----------------------------------------------------------------------------- # 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._spinner_dict = { GUI_QT4 : self._spin_qt4, GUI_WX : self._spin_wx, GUI_GTK : self._spin_gtk, GUI_TK : self._spin_tk} self._reset() def _reset(self): self._callback_pyfunctype = None self._callback = None self._installed = False self._current_gui = None def _hijack_wx(self): """Hijack the wx mainloop so a user calling it won't cause badness. We are not currently using this as it breaks GUI code that calls a mainloop at anytime but startup. """ import wx if hasattr(wx, '_core_'): core = getattr(wx, '_core_') elif hasattr(wx, '_core'): core = getattr(wx, '_core') else: raise AttributeError('Could not find wx core module') orig_mainloop = core.PyApp_MainLoop core.PyApp_MainLoop = _DummyMainloop return orig_mainloop def _hijack_qt4(self): """Hijack the qt4 mainloop so a user calling it won't cause badness. We are not currently using this as it breaks GUI code that calls a mainloop at anytime but startup. """ from PyQt4 import QtGui, QtCore orig_mainloop = QtGui.qApp.exec_ dumb_ml = _DummyMainloop(orig_mainloop, self, GUI_QT4) QtGui.qApp.exec_ = dumb_ml QtGui.QApplication.exec_ = dumb_ml QtCore.QCoreApplication.exec_ = dumb_ml return orig_mainloop def _hijack_gtk(self): """Hijack the gtk mainloop so a user calling it won't cause badness. We are not currently using this as it breaks GUI code that calls a mainloop at anytime but startup. """ import gtk orig_mainloop = gtk.main dumb_ml = _DummyMainloop(orig_mainloop, self, GUI_GTK) gtk.mainloop = dumb_ml gtk.main = dumb_ml return orig_mainloop def _hijack_tk(self): """Hijack the tk mainloop so a user calling it won't cause badness. We are not currently using this as it breaks GUI code that calls a mainloop at anytime but startup. """ import Tkinter orig_mainloop = gtk.main dumb_ml = _DummyMainloop(orig_mainloop, self, GUI_TK) Tkinter.Misc.mainloop = dumb_ml Tkinter.mainloop = dumb_ml def _spin_qt4(self): """Process all pending events in the qt4 event loop. This is for internal IPython use only and user code should not call this. Instead, they should issue the raw GUI calls themselves. """ from PyQt4 import QtCore, QtGui app = QtCore.QCoreApplication.instance() if app is not None: QtCore.QCoreApplication.processEvents(QtCore.QEventLoop.AllEvents) def _spin_wx(self): """Process all pending events in the wx event loop. This is for internal IPython use only and user code should not call this. Instead, they should issue the raw GUI calls themselves. """ import wx app = wx.GetApp() if app is not None and wx.Thread_IsMain(): evtloop = wx.EventLoop() ea = wx.EventLoopActivator(evtloop) while evtloop.Pending(): evtloop.Dispatch() app.ProcessIdle() del ea def _spin_gtk(self): """Process all pending events in the gtk event loop. This is for internal IPython use only and user code should not call this. Instead, they should issue the raw GUI calls themselves. """ import gtk gtk.gdk.threads_enter() while gtk.events_pending(): gtk.main_iteration(False) gtk.gdk.flush() gtk.gdk.threads_leave() def _spin_tk(self): """Process all pending events in the tk event loop. This is for internal IPython use only and user code should not call this. Instead, they should issue the raw GUI calls themselves. """ app = self._apps.get(GUI_TK) if app is not None: app.update() def spin(self): """Process pending events in the current gui. This method is just provided for IPython to use internally if needed for things like testing. Third party projects should not call this method, but instead should call the underlying GUI toolkit methods that we are calling. """ spinner = self._spinner_dict.get(self._current_gui, lambda: None) spinner() 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=False): """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 if app: import wx app = wx.GetApp() if app is None: app = wx.App(redirect=False, clearSigInt=False) self._apps[GUI_WX] = app return app def disable_wx(self): """Disable event loop integration with wxPython. This merely sets PyOS_InputHook to NULL. """ self.clear_inputhook() def enable_qt4(self, app=False): """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 if app: from PyQt4 import QtGui app = QtCore.QCoreApplication.instance() if app is None: app = QtGui.QApplication(sys.argv) self._apps[GUI_QT4] = app return app def disable_qt4(self): """Disable event loop integration with PyQt4. This merely sets PyOS_InputHook to NULL. """ 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 spin = inputhook_manager.spin # Convenience function to switch amongst them def enable_gui(gui=None, app=True): """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(app)