- Qt 5.5
- Qt Core
- Queued Custom Type Example
- renderthread.cpp Example File
- Qt 5.5.1 Reference Documentation

# renderthread.cpp Example File

threads/queuedcustomtype/renderthread.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** 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 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 "renderthread.h"

    RenderThread::RenderThread(QObject *parent)
        : QThread(parent)
    {
        m_abort = false;
    }

    RenderThread::~RenderThread()
    {
        mutex.lock();
        m_abort = true;
        mutex.unlock();

        wait();
    }

    void RenderThread::processImage(const QImage &image)
    {
        if (image.isNull())
            return;

        m_image = image;
        m_abort = false;
        start();
    }

    void RenderThread::run()
    {
        int size = qMax(m_image.width()/20, m_image.height()/20);
        for (int s = size; s > 0; --s) {
            for (int c = 0; c < 400; ++c) {
                int x1 = qMax(0, (qrand() % m_image.width()) - s/2);
                int x2 = qMin(x1 + s/2 + 1, m_image.width());
                int y1 = qMax(0, (qrand() % m_image.height()) - s/2);
                int y2 = qMin(y1 + s/2 + 1, m_image.height());
                int n = 0;
                int red = 0;
                int green = 0;
                int blue = 0;
                for (int i = y1; i < y2; ++i) {
                    for (int j = x1; j < x2; ++j) {
                        QRgb pixel = m_image.pixel(j, i);
                        red += qRed(pixel);
                        green += qGreen(pixel);
                        blue += qBlue(pixel);
                        n += 1;
                    }
                }
                Block block(QRect(x1, y1, x2 - x1 + 1, y2 - y1 + 1),
                            QColor(red/n, green/n, blue/n));
                emit sendBlock(block);
                if (m_abort)
                    return;
                msleep(10);
            }
        }
    }

    void RenderThread::stopProcess()
    {
        mutex.lock();
        m_abort = true;
        mutex.unlock();
    }