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
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
|
# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD
# license included in LICENSE.txt and may be redistributed only under
# the conditions described in the aforementioned license. The license
# is also available online at http://www.enthought.com/licenses/BSD.txt
#
# Thanks for using Enthought open source!
""" Tools for testing. """
from contextlib import contextmanager
import os
import sys
from pyface.qt.QtCore import QTimer
from pyface.util.guisupport import get_app_qt4
@contextmanager
def event_loop():
""" Post and process the Qt events at the exit of the code block. """
app = get_app_qt4()
yield
app.sendPostedEvents()
app.processEvents()
@contextmanager
def delete_widget(widget, timeout=1.0):
""" Context manager that executes the event loop so that we can safely
delete a Qt widget.
"""
app = get_app_qt4()
timer = QTimer()
timer.setSingleShot(True)
timer.setInterval(round(timeout * 1000))
timer.timeout.connect(app.quit)
widget.destroyed.connect(app.quit)
yield
timer.start()
if hasattr(app, 'exec'):
app.exec()
else:
app.exec_()
if not timer.isActive():
# We exited the event loop on timeout.
msg = "Could not destroy widget before timeout: {!r}"
raise AssertionError(msg.format(widget))
@contextmanager
def _convert_none_to_null_handle(stream):
""" If 'stream' is None, provide a temporary handle to /dev/null. """
if stream is None:
out = open(os.devnull, "w")
try:
yield out
finally:
out.close()
else:
yield stream
@contextmanager
def silence_output(out=None, err=None):
""" Re-direct the stderr and stdout streams while in the block. """
with _convert_none_to_null_handle(out) as out:
with _convert_none_to_null_handle(err) as err:
_old_stderr = sys.stderr
_old_stderr.flush()
_old_stdout = sys.stdout
_old_stdout.flush()
try:
sys.stdout = out
sys.stderr = err
yield
finally:
sys.stdout = _old_stdout
sys.stderr = _old_stderr
def print_qt_widget_tree(widget, level=0):
""" Debugging helper to print out the Qt widget tree starting at a
particular `widget`.
Parameters
----------
widget : QObject
The root widget in the tree to print.
level : int
The current level in the tree. Used internally for displaying the
tree level.
"""
level = level + 4
if level == 0:
print()
print(" " * level, widget)
for child in widget.children():
print_qt_widget_tree(child, level=level)
if level == 0:
print()
def find_qt_widget(start, type_, test=None):
"""Recursively walks the Qt widget tree from Qt widget `start` until it
finds a widget of type `type_` (a QWidget subclass) that
satisfies the provided `test` method.
Parameters
----------
start : QWidget
The widget from which to start walking the tree
type_ : type
A subclass of QWidget to use for an initial type filter while
walking the tree
test : Callable
A filter function that takes one argument (the current widget being
evaluated) and returns either True or False to determine if the
widget matches the required criteria.
"""
if test is None:
test = lambda widget: True
if isinstance(start, type_):
if test(start):
return start
for child in start.children():
widget = find_qt_widget(child, type_, test=test)
if widget:
return widget
return None
|
