progressbar.cpp Example File

 /****************************************************************************
 **
 ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** 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 Nokia Corporation and its Subsidiary(-ies) 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();
 }