forked from ipython/ipython
/
inputhookqt4.py
122 lines (100 loc) · 4.16 KB
/
inputhookqt4.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
# -*- 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
#-----------------------------------------------------------------------------
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
#-----------------------------------------------------------------------------
# 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)
got_kbdint = [False]
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():
timer = QtCore.QTimer()
timer.timeout.connect(app.quit)
while not stdin_ready():
timer.start(50)
app.exec_()
timer.stop()
except KeyboardInterrupt:
ignore_CTRL_C()
got_kbdint[0] = True
print("\nKeyboardInterrupt - Ctrl-C again for new prompt")
mgr.clear_inputhook()
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)
"""
if got_kbdint[0]:
mgr.set_inputhook(inputhook_qt4)
got_kbdint[0] = False
ip._inputhook_qt4 = inputhook_qt4
ip.set_hook('pre_prompt_hook', preprompthook_qt4)
return app, inputhook_qt4