Qt 5.11 | Qt Multimedia | Spectrum Example | progressbar.cpp Example File

Qt 5.11.3 Reference Documentation

# progressbar.cpp Example File

multimedia/spectrum/app/progressbar.cpp

      /****************************************************************************
      **
      ** Copyright (C) 2017 The Qt Company Ltd.
      ** Contact: https://www.qt.io/licensing/
      **
      ** This file is part of the examples of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:BSD$
      ** Commercial License Usage
      ** Licensees holding valid commercial Qt licenses may use this file in
      ** accordance with the commercial license agreement provided with the
      ** Software or, alternatively, in accordance with the terms contained in
      ** a written agreement between you and The Qt Company. For licensing terms
      ** and conditions see https://www.qt.io/terms-conditions. For further
      ** information use the contact form at https://www.qt.io/contact-us.
      **
      ** BSD License Usage
      ** Alternatively, you may use this file under the terms of the BSD license
      ** as follows:
      **
      ** "Redistribution and use in source and binary forms, with or without
      ** modification, are permitted provided that the following conditions are
      ** met:
      **   * Redistributions of source code must retain the above copyright
      **     notice, this list of conditions and the following disclaimer.
      **   * Redistributions in binary form must reproduce the above copyright
      **     notice, this list of conditions and the following disclaimer in
      **     the documentation and/or other materials provided with the
      **     distribution.
      **   * Neither the name of The Qt Company Ltd nor the names of its
      **     contributors may be used to endorse or promote products derived
      **     from this software without specific prior written permission.
      **
      **
      ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
      ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
      ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
      ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
      ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
      **
      ** $QT_END_LICENSE$
      **
      ****************************************************************************/

      #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();
      }