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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
|
/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of The Qt Company Ltd nor the names of its
** contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef WAVEFORM_H
#define WAVEFORM_H
#include <QAudioFormat>
#include <QPixmap>
#include <QScopedPointer>
#include <QWidget>
/**
* Widget which displays a section of the audio waveform.
*
* The waveform is rendered on a set of QPixmaps which form a group of tiles
* whose extent covers the widget. As the audio position is updated, these
* tiles are scrolled from left to right; when the left-most tile scrolls
* outside the widget, it is moved to the right end of the tile array and
* painted with the next section of the waveform.
*/
class Waveform : public QWidget
{
Q_OBJECT
public:
explicit Waveform(QWidget *parent = 0);
~Waveform();
// QWidget
void paintEvent(QPaintEvent *event) override;
void resizeEvent(QResizeEvent *event) override;
void initialize(const QAudioFormat &format, qint64 audioBufferSize, qint64 windowDurationUs);
void reset();
void setAutoUpdatePosition(bool enabled);
public slots:
void bufferChanged(qint64 position, qint64 length, const QByteArray &buffer);
void audioPositionChanged(qint64 position);
private:
static const int NullIndex = -1;
void deletePixmaps();
/*
* (Re)create all pixmaps, repaint and update the display.
* Triggers an update();
*/
void createPixmaps(const QSize &newSize);
/*
* Update window position.
* Triggers an update().
*/
void setWindowPosition(qint64 position);
/*
* Base position of tile
*/
qint64 tilePosition(int index) const;
/*
* Structure which identifies a point within a given
* tile.
*/
struct TilePoint
{
TilePoint(int idx = 0, qint64 pos = 0, qint64 pix = 0)
: index(idx), positionOffset(pos), pixelOffset(pix)
{ }
// Index of tile
int index;
// Number of bytes from start of tile
qint64 positionOffset;
// Number of pixels from left of corresponding pixmap
int pixelOffset;
};
/*
* Convert position in m_buffer into a tile index and an offset in pixels
* into the corresponding pixmap.
*
* \param position Offset into m_buffer, in bytes
* If position is outside the tile array, index is NullIndex and
* offset is zero.
*/
TilePoint tilePoint(qint64 position) const;
/*
* Convert offset in bytes into a tile into an offset in pixels
* within that tile.
*/
int tilePixelOffset(qint64 positionOffset) const;
/*
* Convert offset in bytes into the window into an offset in pixels
* within the widget rect().
*/
int windowPixelOffset(qint64 positionOffset) const;
/*
* Paint all tiles which can be painted.
* \return true iff update() was called
*/
bool paintTiles();
/*
* Paint the specified tile
*
* \pre Sufficient data is available to completely paint the tile, i.e.
* m_dataLength is greater than the upper bound of the tile.
*/
void paintTile(int index);
/*
* Move the first n tiles to the end of the array, and mark them as not
* painted.
*/
void shuffleTiles(int n);
/*
* Reset tile array
*/
void resetTiles(qint64 newStartPos);
private:
qint64 m_bufferPosition;
qint64 m_bufferLength;
QByteArray m_buffer;
qint64 m_audioPosition;
QAudioFormat m_format;
bool m_active;
QSize m_pixmapSize;
QVector<QPixmap*> m_pixmaps;
struct Tile {
// Pointer into parent m_pixmaps array
QPixmap* pixmap;
// Flag indicating whether this tile has been painted
bool painted;
};
QVector<Tile> m_tiles;
// Length of audio data in bytes depicted by each tile
qint64 m_tileLength;
// Position in bytes of the first tile, relative to m_buffer
qint64 m_tileArrayStart;
qint64 m_windowPosition;
qint64 m_windowLength;
};
#endif // WAVEFORM_H
|
