/****************************************************************************+
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**+
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** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).+
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** All rights reserved.+
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** Contact: Nokia Corporation (qt-info@nokia.com)+
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**+
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** This file is part of the examples of the Qt Toolkit.+
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**+
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** $QT_BEGIN_LICENSE:BSD$+
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** You may use this file under the terms of the BSD license as follows:+
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**+
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** "Redistribution and use in source and binary forms, with or without+
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** modification, are permitted provided that the following conditions are+
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** met:+
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**   * Redistributions of source code must retain the above copyright+
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**     notice, this list of conditions and the following disclaimer.+
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**   * Redistributions in binary form must reproduce the above copyright+
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**     notice, this list of conditions and the following disclaimer in+
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**     the documentation and/or other materials provided with the+
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**     distribution.+
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**   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor+
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**     the names of its contributors may be used to endorse or promote+
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**     products derived from this software without specific prior written+
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**     permission.+
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** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS+
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** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT+
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****************************************************************************/+
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+
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#ifndef LEVELMETER_H+
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#define LEVELMETER_H+
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+
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#include <QTime>+
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#include <QWidget>+
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+
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/**+
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 * Widget which displays a vertical audio level meter, indicating the+
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 * RMS and peak levels of the window of audio samples most recently analysed+
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 * by the Engine.+
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 */+
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class LevelMeter : public QWidget {+
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    Q_OBJECT+
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public:+
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    LevelMeter(QWidget *parent = 0);+
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    ~LevelMeter();+
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+
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    void paintEvent(QPaintEvent *event);+
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+
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public slots:+
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    void reset();+
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    void levelChanged(qreal rmsLevel, qreal peakLevel, int numSamples);+
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+
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private slots:+
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    void redrawTimerExpired();+
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+
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private:+
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    /**+
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     * Height of RMS level bar.+
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     * Range 0.0 - 1.0.+
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     */+
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    qreal m_rmsLevel;+
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+
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    /**+
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     * Most recent peak level.+
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     * Range 0.0 - 1.0.+
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     */+
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    qreal m_peakLevel;+
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+
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    /**+
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     * Height of peak level bar.+
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     * This is calculated by decaying m_peakLevel depending on the+
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     * elapsed time since m_peakLevelChanged, and the value of m_decayRate.+
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     */+
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    qreal m_decayedPeakLevel;+
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+
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    /**+
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     * Time at which m_peakLevel was last changed.+
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     */+
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    QTime m_peakLevelChanged;+
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+
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    /**+
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     * Rate at which peak level bar decays.+
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     * Expressed in level units / millisecond.+
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     */+
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    qreal m_peakDecayRate;+
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+
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    /**+
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     * High watermark of peak level.+
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     * Range 0.0 - 1.0.+
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     */+
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    qreal m_peakHoldLevel;+
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+
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    /**+
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     * Time at which m_peakHoldLevel was last changed.+
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     */+
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    QTime m_peakHoldLevelChanged;+
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+
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    QTimer *m_redrawTimer;+
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+
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    QColor m_rmsColor;+
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    QColor m_peakColor;+
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+
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};+
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+
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#endif // LEVELMETER_H+
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