progressbar.cpp Example File

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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();
  }