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#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 : publicQWidget
{
Q_OBJECT
public:
explicit Waveform(QWidget*parent =0);
~Waveform();
// QWidgetvoid paintEvent(QPaintEvent*event) override;
void resizeEvent(QResizeEvent*event) override;
void initialize(constQAudioFormat&format,qint64 audioBufferSize,qint64 windowDurationUs);
void reset();
void setAutoUpdatePosition(bool enabled);
publicslots:
void bufferChanged(qint64 position,qint64 length,constQByteArray&buffer);
void audioPositionChanged(qint64 position);
private:
staticconstint NullIndex =-1;
void deletePixmaps();
/*
* (Re)create all pixmaps, repaint and update the display.
* Triggers an update();
*/void createPixmaps(constQSize&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 tileint index;
// Number of bytes from start of tileqint64 positionOffset;
// Number of pixels from left of corresponding pixmapint 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 arrayQPixmap* pixmap;
// Flag indicating whether this tile has been painted
bool painted;
};
QVector<Tile> m_tiles;
// Length of audio data in bytes depicted by each tileqint64 m_tileLength;
// Position in bytes of the first tile, relative to m_bufferqint64 m_tileArrayStart;
qint64 m_windowPosition;
qint64 m_windowLength;
};
#endif // WAVEFORM_H
