--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/demos/spectrum/app/waveform.h Fri Jun 11 14:24:45 2010 +0300
@@ -0,0 +1,198 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** 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 Nokia Corporation and its Subsidiary(-ies) 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 <QWidget>
+#include <QtMultimedia/QAudioFormat>
+#include <QPixmap>
+#include <QScopedPointer>
+
+class QByteArray;
+
+/**
+ * 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:
+ Waveform(const QByteArray &buffer, QWidget *parent = 0);
+ ~Waveform();
+
+ // QWidget
+ void paintEvent(QPaintEvent *event);
+ void resizeEvent(QResizeEvent *event);
+
+ void initialize(const QAudioFormat &format, qint64 audioBufferSize, qint64 windowDurationUs);
+ void reset();
+
+ void setAutoUpdatePosition(bool enabled);
+
+public slots:
+ void dataLengthChanged(qint64 length);
+ void positionChanged(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:
+ const QByteArray& m_buffer;
+ qint64 m_dataLength;
+ qint64 m_position;
+ 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