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#ifndef SPECTROGRAPH_H
52#define SPECTROGRAPH_H
53
54#include "frequencyspectrum.h"
55
56#include <QWidget>
57
58/**
59 * Widget which displays a spectrograph showing the frequency spectrum
60 * of the window of audio samples most recently analyzed by the Engine.
61 */
62class Spectrograph : public QWidget
63{
64 Q_OBJECT
65
66public:
67 explicit Spectrograph(QWidget *parent = 0);
68 ~Spectrograph();
69
70 void setParams(int numBars, qreal lowFreq, qreal highFreq);
71
72 // QObject
73 void timerEvent(QTimerEvent *event) override;
74
75 // QWidget
76 void paintEvent(QPaintEvent *event) override;
77 void mousePressEvent(QMouseEvent *event) override;
78
79signals:
80 void infoMessage(const QString &message, int intervalMs);
81
82public slots:
83 void reset();
84 void spectrumChanged(const FrequencySpectrum &spectrum);
85
86private:
87 int barIndex(qreal frequency) const;
88 QPair<qreal, qreal> barRange(int barIndex) const;
89 void updateBars();
90
91 void selectBar(int index);
92
93private:
94 struct Bar {
95 Bar() : value(0.0), clipped(false) { }
96 qreal value;
97 bool clipped;
98 };
99
100 QVector<Bar> m_bars;
101 int m_barSelected;
102 int m_timerId;
103 qreal m_lowFreq;
104 qreal m_highFreq;
105 FrequencySpectrum m_spectrum;
106};
107
108#endif // SPECTROGRAPH_H
109

source code of qtmultimedia/examples/multimedia/spectrum/app/spectrograph.h