1/****************************************************************************
2**
3** Copyright (C) 2017 The Qt Company Ltd.
4** Contact: https://www.qt.io/licensing/
5**
6** This file is part of the examples 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#include "graph.h"
52
53#include "noisynode.h"
54#include "gridnode.h"
55#include "linenode.h"
56
57Graph::Graph()
58 : m_samplesChanged(false)
59 , m_geometryChanged(false)
60{
61 setFlag(flag: ItemHasContents, enabled: true);
62}
63
64
65void Graph::appendSample(qreal value)
66{
67 m_samples << value;
68 m_samplesChanged = true;
69 update();
70}
71
72
73void Graph::removeFirstSample()
74{
75 m_samples.removeFirst();
76 m_samplesChanged = true;
77 update();
78}
79
80void Graph::geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry)
81{
82 m_geometryChanged = true;
83 update();
84 QQuickItem::geometryChanged(newGeometry, oldGeometry);
85}
86
87
88class GraphNode : public QSGNode
89{
90public:
91 NoisyNode *background;
92 GridNode *grid;
93 LineNode *line;
94 LineNode *shadow;
95};
96
97
98QSGNode *Graph::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
99{
100 GraphNode *n= static_cast<GraphNode *>(oldNode);
101
102 QRectF rect = boundingRect();
103
104 if (rect.isEmpty()) {
105 delete n;
106 return nullptr;
107 }
108
109 if (!n) {
110 n = new GraphNode();
111
112 n->background = new NoisyNode(window());
113 n->grid = new GridNode();
114 n->line = new LineNode(10, 0.5, QColor("steelblue"));
115 n->shadow = new LineNode(20, 0.2f, QColor::fromRgbF(r: 0.2, g: 0.2, b: 0.2, a: 0.4));
116
117 n->appendChildNode(node: n->background);
118 n->appendChildNode(node: n->grid);
119 n->appendChildNode(node: n->shadow);
120 n->appendChildNode(node: n->line);
121 }
122
123 if (m_geometryChanged) {
124 n->background->setRect(rect);
125 n->grid->setRect(rect);
126 }
127
128 if (m_geometryChanged || m_samplesChanged) {
129 n->line->updateGeometry(bounds: rect, samples: m_samples);
130 // We don't need to calculate the geometry twice, so just steal it from the other one...
131 n->shadow->setGeometry(n->line->geometry());
132 }
133
134 m_geometryChanged = false;
135 m_samplesChanged = false;
136
137 return n;
138}
139

source code of qtdeclarative/examples/quick/scenegraph/graph/graph.cpp