/**************************************************************************** ** ** 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 LEVELMETER_H #define LEVELMETER_H #include #include /** * Widget which displays a vertical audio level meter, indicating the * RMS and peak levels of the window of audio samples most recently analysed * by the Engine. */ class LevelMeter : public QWidget { Q_OBJECT public: LevelMeter(QWidget *parent = 0); ~LevelMeter(); void paintEvent(QPaintEvent *event); public slots: void reset(); void levelChanged(qreal rmsLevel, qreal peakLevel, int numSamples); private slots: void redrawTimerExpired(); private: /** * Height of RMS level bar. * Range 0.0 - 1.0. */ qreal m_rmsLevel; /** * Most recent peak level. * Range 0.0 - 1.0. */ qreal m_peakLevel; /** * Height of peak level bar. * This is calculated by decaying m_peakLevel depending on the * elapsed time since m_peakLevelChanged, and the value of m_decayRate. */ qreal m_decayedPeakLevel; /** * Time at which m_peakLevel was last changed. */ QTime m_peakLevelChanged; /** * Rate at which peak level bar decays. * Expressed in level units / millisecond. */ qreal m_peakDecayRate; /** * High watermark of peak level. * Range 0.0 - 1.0. */ qreal m_peakHoldLevel; /** * Time at which m_peakHoldLevel was last changed. */ QTime m_peakHoldLevelChanged; QTimer *m_redrawTimer; QColor m_rmsColor; QColor m_peakColor; }; #endif // LEVELMETER_H