Qt 5.9 | Qt Multimedia | Spectrum Example | progressbar.cpp Example File

Qt 5.9.4 Reference Documentation

# progressbar.cpp Example File

multimedia/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();
      }