Qt Reference Documentation

# progressbar.cpp Example File

demos/spectrum/app/progressbar.cpp

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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();
     }