- Qt 5.5
- Qt Multimedia
- Spectrum Example
- progressbar.cpp Example File
- Qt 5.5.1 Reference Documentation

# progressbar.cpp Example File

spectrum/app/progressbar.cpp

    /****************************************************************************
    **
    ** 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:
    **
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    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
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    #include "progressbar.h"
    #include "spectrum.h"
    #include <QPainter>

    ProgressBar::ProgressBar(QWidget *parent)
        :   QWidget(parent)
        ,   m_bufferLength(0)
        ,   m_recordPosition(0)
        ,   m_playPosition(0)
        ,   m_windowPosition(0)
        ,   m_windowLength(0)
    {
        setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
        setMinimumHeight(30);
    #ifdef SUPERIMPOSE_PROGRESS_ON_WAVEFORM
        setAutoFillBackground(false);
    #endif
    }

    ProgressBar::~ProgressBar()
    {

    }

    void ProgressBar::reset()
    {
        m_bufferLength = 0;
        m_recordPosition = 0;
        m_playPosition = 0;
        m_windowPosition = 0;
        m_windowLength = 0;
        update();
    }

    void ProgressBar::paintEvent(QPaintEvent * /*event*/)
    {
        QPainter painter(this);

        QColor bufferColor(0, 0, 255);
        QColor windowColor(0, 255, 0);

    #ifdef SUPERIMPOSE_PROGRESS_ON_WAVEFORM
        bufferColor.setAlphaF(0.5);
        windowColor.setAlphaF(0.5);
    #else
        painter.fillRect(rect(), Qt::black);
    #endif

        if (m_bufferLength) {
            QRect bar = rect();
            const qreal play = qreal(m_playPosition) / m_bufferLength;
            bar.setLeft(rect().left() + play * rect().width());
            const qreal record = qreal(m_recordPosition) / m_bufferLength;
            bar.setRight(rect().left() + record * rect().width());
            painter.fillRect(bar, bufferColor);

            QRect window = rect();
            const qreal windowLeft = qreal(m_windowPosition) / m_bufferLength;
            window.setLeft(rect().left() + windowLeft * rect().width());
            const qreal windowWidth = qreal(m_windowLength) / m_bufferLength;
            window.setWidth(windowWidth * rect().width());
            painter.fillRect(window, windowColor);
        }
    }

    void ProgressBar::bufferLengthChanged(qint64 bufferSize)
    {
        m_bufferLength = bufferSize;
        m_recordPosition = 0;
        m_playPosition = 0;
        m_windowPosition = 0;
        m_windowLength = 0;
        repaint();
    }

    void ProgressBar::recordPositionChanged(qint64 recordPosition)
    {
        Q_ASSERT(recordPosition >= 0);
        Q_ASSERT(recordPosition <= m_bufferLength);
        m_recordPosition = recordPosition;
        repaint();
    }

    void ProgressBar::playPositionChanged(qint64 playPosition)
    {
        Q_ASSERT(playPosition >= 0);
        Q_ASSERT(playPosition <= m_bufferLength);
        m_playPosition = playPosition;
        repaint();
    }

    void ProgressBar::windowChanged(qint64 position, qint64 length)
    {
        Q_ASSERT(position >= 0);
        Q_ASSERT(position <= m_bufferLength);
        Q_ASSERT(position + length <= m_bufferLength);
        m_windowPosition = position;
        m_windowLength = length;
        repaint();
    }