181 lines
6.6 KiB
Python
181 lines
6.6 KiB
Python
|
# -*- coding: utf-8 -*-
|
||
|
|
"""
|
||
|
|
Qt4's inputhook support function
|
||
|
|
|
||
|
|
Author: Christian Boos
|
||
|
|
"""
|
||
|
|
|
||
|
|
#-----------------------------------------------------------------------------
|
||
|
|
# Copyright (C) 2011 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 os
|
||
|
|
import signal
|
||
|
|
import threading
|
||
|
|
|
||
|
|
from IPython.core.interactiveshell import InteractiveShell
|
||
|
|
from IPython.external.qt_for_kernel import QtCore, QtGui
|
||
|
|
from IPython.lib.inputhook import allow_CTRL_C, ignore_CTRL_C, stdin_ready
|
||
|
|
|
||
|
|
#-----------------------------------------------------------------------------
|
||
|
|
# Module Globals
|
||
|
|
#-----------------------------------------------------------------------------
|
||
|
|
|
||
|
|
got_kbdint = False
|
||
|
|
sigint_timer = None
|
||
|
|
|
||
|
|
#-----------------------------------------------------------------------------
|
||
|
|
# Code
|
||
|
|
#-----------------------------------------------------------------------------
|
||
|
|
|
||
|
|
def create_inputhook_qt4(mgr, app=None):
|
||
|
|
"""Create an input hook for running the Qt4 application event loop.
|
||
|
|
|
||
|
|
Parameters
|
||
|
|
----------
|
||
|
|
mgr : an InputHookManager
|
||
|
|
|
||
|
|
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.
|
||
|
|
|
||
|
|
Returns
|
||
|
|
-------
|
||
|
|
A pair consisting of a Qt Application (either the one given or the
|
||
|
|
one found or created) and a inputhook.
|
||
|
|
|
||
|
|
Notes
|
||
|
|
-----
|
||
|
|
We use a custom input hook instead of PyQt4's default one, as it
|
||
|
|
interacts better with the readline packages (issue #481).
|
||
|
|
|
||
|
|
The inputhook function works in tandem with a 'pre_prompt_hook'
|
||
|
|
which automatically restores the hook as an inputhook in case the
|
||
|
|
latter has been temporarily disabled after having intercepted a
|
||
|
|
KeyboardInterrupt.
|
||
|
|
"""
|
||
|
|
|
||
|
|
if app is None:
|
||
|
|
app = QtCore.QCoreApplication.instance()
|
||
|
|
if app is None:
|
||
|
|
app = QtGui.QApplication([" "])
|
||
|
|
|
||
|
|
# Re-use previously created inputhook if any
|
||
|
|
ip = InteractiveShell.instance()
|
||
|
|
if hasattr(ip, '_inputhook_qt4'):
|
||
|
|
return app, ip._inputhook_qt4
|
||
|
|
|
||
|
|
# Otherwise create the inputhook_qt4/preprompthook_qt4 pair of
|
||
|
|
# hooks (they both share the got_kbdint flag)
|
||
|
|
|
||
|
|
def inputhook_qt4():
|
||
|
|
"""PyOS_InputHook python hook for Qt4.
|
||
|
|
|
||
|
|
Process pending Qt events and if there's no pending keyboard
|
||
|
|
input, spend a short slice of time (50ms) running the Qt event
|
||
|
|
loop.
|
||
|
|
|
||
|
|
As a Python ctypes callback can't raise an exception, we catch
|
||
|
|
the KeyboardInterrupt and temporarily deactivate the hook,
|
||
|
|
which will let a *second* CTRL+C be processed normally and go
|
||
|
|
back to a clean prompt line.
|
||
|
|
"""
|
||
|
|
try:
|
||
|
|
allow_CTRL_C()
|
||
|
|
app = QtCore.QCoreApplication.instance()
|
||
|
|
if not app: # shouldn't happen, but safer if it happens anyway...
|
||
|
|
return 0
|
||
|
|
app.processEvents(QtCore.QEventLoop.AllEvents, 300)
|
||
|
|
if not stdin_ready():
|
||
|
|
# Generally a program would run QCoreApplication::exec()
|
||
|
|
# from main() to enter and process the Qt event loop until
|
||
|
|
# quit() or exit() is called and the program terminates.
|
||
|
|
#
|
||
|
|
# For our input hook integration, we need to repeatedly
|
||
|
|
# enter and process the Qt event loop for only a short
|
||
|
|
# amount of time (say 50ms) to ensure that Python stays
|
||
|
|
# responsive to other user inputs.
|
||
|
|
#
|
||
|
|
# A naive approach would be to repeatedly call
|
||
|
|
# QCoreApplication::exec(), using a timer to quit after a
|
||
|
|
# short amount of time. Unfortunately, QCoreApplication
|
||
|
|
# emits an aboutToQuit signal before stopping, which has
|
||
|
|
# the undesirable effect of closing all modal windows.
|
||
|
|
#
|
||
|
|
# To work around this problem, we instead create a
|
||
|
|
# QEventLoop and call QEventLoop::exec(). Other than
|
||
|
|
# setting some state variables which do not seem to be
|
||
|
|
# used anywhere, the only thing QCoreApplication adds is
|
||
|
|
# the aboutToQuit signal which is precisely what we are
|
||
|
|
# trying to avoid.
|
||
|
|
timer = QtCore.QTimer()
|
||
|
|
event_loop = QtCore.QEventLoop()
|
||
|
|
timer.timeout.connect(event_loop.quit)
|
||
|
|
while not stdin_ready():
|
||
|
|
timer.start(50)
|
||
|
|
event_loop.exec_()
|
||
|
|
timer.stop()
|
||
|
|
except KeyboardInterrupt:
|
||
|
|
global got_kbdint, sigint_timer
|
||
|
|
|
||
|
|
ignore_CTRL_C()
|
||
|
|
got_kbdint = True
|
||
|
|
mgr.clear_inputhook()
|
||
|
|
|
||
|
|
# This generates a second SIGINT so the user doesn't have to
|
||
|
|
# press CTRL+C twice to get a clean prompt.
|
||
|
|
#
|
||
|
|
# Since we can't catch the resulting KeyboardInterrupt here
|
||
|
|
# (because this is a ctypes callback), we use a timer to
|
||
|
|
# generate the SIGINT after we leave this callback.
|
||
|
|
#
|
||
|
|
# Unfortunately this doesn't work on Windows (SIGINT kills
|
||
|
|
# Python and CTRL_C_EVENT doesn't work).
|
||
|
|
if(os.name == 'posix'):
|
||
|
|
pid = os.getpid()
|
||
|
|
if(not sigint_timer):
|
||
|
|
sigint_timer = threading.Timer(.01, os.kill,
|
||
|
|
args=[pid, signal.SIGINT] )
|
||
|
|
sigint_timer.start()
|
||
|
|
else:
|
||
|
|
print("\nKeyboardInterrupt - Ctrl-C again for new prompt")
|
||
|
|
|
||
|
|
|
||
|
|
except: # NO exceptions are allowed to escape from a ctypes callback
|
||
|
|
ignore_CTRL_C()
|
||
|
|
from traceback import print_exc
|
||
|
|
print_exc()
|
||
|
|
print("Got exception from inputhook_qt4, unregistering.")
|
||
|
|
mgr.clear_inputhook()
|
||
|
|
finally:
|
||
|
|
allow_CTRL_C()
|
||
|
|
return 0
|
||
|
|
|
||
|
|
def preprompthook_qt4(ishell):
|
||
|
|
"""'pre_prompt_hook' used to restore the Qt4 input hook
|
||
|
|
|
||
|
|
(in case the latter was temporarily deactivated after a
|
||
|
|
CTRL+C)
|
||
|
|
"""
|
||
|
|
global got_kbdint, sigint_timer
|
||
|
|
|
||
|
|
if(sigint_timer):
|
||
|
|
sigint_timer.cancel()
|
||
|
|
sigint_timer = None
|
||
|
|
|
||
|
|
if got_kbdint:
|
||
|
|
mgr.set_inputhook(inputhook_qt4)
|
||
|
|
got_kbdint = False
|
||
|
|
|
||
|
|
ip._inputhook_qt4 = inputhook_qt4
|
||
|
|
ip.set_hook('pre_prompt_hook', preprompthook_qt4)
|
||
|
|
|
||
|
|
return app, inputhook_qt4
|