1 /****************************************************************************
2 **
3 ** Copyright (C) 2016 The Qt Company Ltd.
4 ** Contact: https://www.qt.io/licensing/
5 **
6 ** This file is part of the documentation of the Qt Toolkit.
7 **
8 ** $QT_BEGIN_LICENSE:BSD$
9 ** Commercial License Usage
10 ** Licensees holding valid commercial Qt licenses may use this file in
11 ** accordance with the commercial license agreement provided with the
12 ** Software or, alternatively, in accordance with the terms contained in
13 ** a written agreement between you and The Qt Company. For licensing terms
14 ** and conditions see https://www.qt.io/terms-conditions. For further
15 ** information use the contact form at https://www.qt.io/contact-us.
16 **
17 ** BSD License Usage
18 ** Alternatively, you may use this file under the terms of the BSD license
19 ** as follows:
20 **
21 ** "Redistribution and use in source and binary forms, with or without
22 ** modification, are permitted provided that the following conditions are
23 ** met:
24 ** * Redistributions of source code must retain the above copyright
25 ** notice, this list of conditions and the following disclaimer.
26 ** * Redistributions in binary form must reproduce the above copyright
27 ** notice, this list of conditions and the following disclaimer in
28 ** the documentation and/or other materials provided with the
29 ** distribution.
30 ** * Neither the name of The Qt Company Ltd nor the names of its
31 ** contributors may be used to endorse or promote products derived
32 ** from this software without specific prior written permission.
33 **
34 **
35 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
36 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
37 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
38 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
39 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
41 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
42 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
43 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
44 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
45 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
46 **
47 ** $QT_END_LICENSE$
48 **
49 ****************************************************************************/
50
51 //! [0]
paintLayout(QPainter * painter,QLayoutItem * item)52 static void paintLayout(QPainter *painter, QLayoutItem *item)
53 {
54 QLayout *layout = item->layout();
55 if (layout) {
56 for (int i = 0; i < layout->count(); ++i)
57 paintLayout(painter, layout->itemAt(i));
58 }
59 painter->drawRect(item->geometry());
60 }
61
paintEvent(QPaintEvent *)62 void MyWidget::paintEvent(QPaintEvent *)
63 {
64 QPainter painter(this);
65 if (layout())
66 paintLayout(&painter, layout());
67 }
68 //! [0]
69
70
71 //! [1]
72 QLayoutItem *child;
73 while ((child = layout->takeAt(0)) != nullptr) {
74 ...
75 delete child->widget(); // delete the widget
76 delete child; // delete the layout item
77 }
78 //! [1]
79