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

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

 void ProgressBar::bufferDurationChanged(qint64 bufferSize)
 {
     m_bufferDuration = 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_bufferDuration);
     m_recordPosition = recordPosition;
     repaint();
 }

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

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