guisupport.py
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PythonLexer
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r2892 | # 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 | ||||
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r4872 | support in the terminal by setting PyOS_InputHook to a function that | ||
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r2892 | 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. | ||||
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r4872 | 2. In the two process IPython kernel/frontend, the GUI event loop is run in | ||
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r2892 | 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. | ||||
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r2900 | * If you want GUI support and no one else has created an application or | ||
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r4872 | started the event loop you *must* do this. We don't want projects to | ||
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r2900 | attempt to defer these things to someone else if they themselves need it. | ||
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r2892 | |||
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. | ||||
""" | ||||
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r23138 | # Copyright (c) IPython Development Team. | ||
# Distributed under the terms of the Modified BSD License. | ||||
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r2892 | |||
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r23138 | from IPython.core.getipython import get_ipython | ||
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r2892 | |||
#----------------------------------------------------------------------------- | ||||
# 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: | ||||
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r7859 | if 'redirect' not in kwargs: | ||
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r2943 | kwargs['redirect'] = False | ||
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r2892 | app = wx.PySimpleApp(*args, **kwargs) | ||
return app | ||||
def is_event_loop_running_wx(app=None): | ||||
"""Is the wx event loop running.""" | ||||
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r23138 | # 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 | ||||
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r2892 | 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.""" | ||||
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r4149 | from IPython.external.qt_for_kernel import QtGui | ||
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r2892 | app = QtGui.QApplication.instance() | ||
if app is None: | ||||
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r2942 | if not args: | ||
args = ([''],) | ||||
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r2892 | app = QtGui.QApplication(*args, **kwargs) | ||
return app | ||||
def is_event_loop_running_qt4(app=None): | ||||
"""Is the qt4 event loop running.""" | ||||
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r23138 | # 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 | ||||
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r2892 | if app is None: | ||
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r2942 | app = get_app_qt4(['']) | ||
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r2892 | 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: | ||||
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r2942 | app = get_app_qt4(['']) | ||
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r2892 | if not is_event_loop_running_qt4(app): | ||
app._in_event_loop = True | ||||
app.exec_() | ||||
app._in_event_loop = False | ||||
else: | ||||
app._in_event_loop = True | ||||
#----------------------------------------------------------------------------- | ||||
# Tk | ||||
#----------------------------------------------------------------------------- | ||||
#----------------------------------------------------------------------------- | ||||
# gtk | ||||
#----------------------------------------------------------------------------- | ||||