renderer.cpp Example File

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    #include "renderer.hpp"

    #include <bb/cascades/AbsoluteLayoutProperties>

    using namespace ::bb::cascades;

    Renderer::Renderer(QObject *parent)
        : QObject(parent), m_active(false)
    {
        /**
         * We use only one RenderThread object in this example, so only one
         * image can be transformed at a time.
         */
        m_thread = new RenderThread();

        // Connect the signals of the render thread against our own slots.
        connect(m_thread, SIGNAL(finished()), this, SLOT(threadFinished()));
        connect(m_thread, SIGNAL(sendBlock(Block)), this, SLOT(addBlock(Block)));
    }

    void Renderer::setCanvas(bb::cascades::Container *container)
    {
        m_container = container;
    }

    void Renderer::loadImage(const QString &name)
    {
        // Remove all blocks (from a previous transformation) from the canvas container
        m_container->removeAll();

        // Load the image from the file system and scale it down to 300x300 pixels
        QImage image;
        image.load(QString::fromLatin1("app/native/assets/images/%1").arg(name));
        image = image.scaled(300, 300);

        // Start the transformation of the image
        m_thread->processImage(image);

        // Adapt the 'active' property to the new state
        m_active = true;
        emit activeChanged();
    }

    void Renderer::stop()
    {
        // Trigger the abortion of the worker thread
        m_thread->stopProcess();
    }

    void Renderer::addBlock(const Block &block)
    {
        /**
         * We represent each block by a 'pixel' Container object with the same
         * geometry and color as the block.
         * The pixel containers are placed on the canvas container.
         */
        Container *pixel = new Container(m_container);
        pixel->setBackground(block.color());
        pixel->setPreferredWidth(block.rect().width());
        pixel->setPreferredHeight(block.rect().height());

        AbsoluteLayoutProperties *properties = new AbsoluteLayoutProperties;
        properties->setPositionX(block.rect().x());
        properties->setPositionY(block.rect().y());
        pixel->setLayoutProperties(properties);
    }

    void Renderer::threadFinished()
    {
        // Reset the 'active' property whenever the worker thread has finished.
        m_active = false;
        emit activeChanged();
    }

    bool Renderer::active() const
    {
        return m_active;
    }