- Qt 5.5
- Qt Widgets
- Application Chooser Example
- main.cpp Example File
- Qt 5.5.1 Reference Documentation

# main.cpp Example File

animation/appchooser/main.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the QtCore module 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."
    **
    ** $QT_END_LICENSE$
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    ****************************************************************************/

    #include <QtCore>
    #include <QtWidgets>

    class Pixmap : public QGraphicsWidget
    {
        Q_OBJECT

    public:
        Pixmap(const QPixmap &pix, QGraphicsItem *parent = 0)
            : QGraphicsWidget(parent), orig(pix), p(pix)
        {
        }

        void paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *) Q_DECL_OVERRIDE
        {
            painter->drawPixmap(QPointF(), p);
        }

        virtual void mousePressEvent(QGraphicsSceneMouseEvent * ) Q_DECL_OVERRIDE
        {
            emit clicked();
        }

        virtual void setGeometry(const QRectF &rect) Q_DECL_OVERRIDE
        {
            QGraphicsWidget::setGeometry(rect);

            if (rect.size().width() > orig.size().width())
                p = orig.scaled(rect.size().toSize());
            else
                p = orig;
        }

    Q_SIGNALS:
        void clicked();

    private:
        QPixmap orig;
        QPixmap p;
    };

    class GraphicsView : public QGraphicsView
    {
        Q_OBJECT
    public:
        GraphicsView(QGraphicsScene *scene, QWidget *parent = 0) : QGraphicsView(scene, parent)
        {
        }

        virtual void resizeEvent(QResizeEvent *) Q_DECL_OVERRIDE
        {
            fitInView(sceneRect(), Qt::KeepAspectRatio);
        }
    };

    void createStates(const QObjectList &objects,
                      const QRect &selectedRect, QState *parent)
    {
        for (int i = 0; i < objects.size(); ++i) {
            QState *state = new QState(parent);
            state->assignProperty(objects.at(i), "geometry", selectedRect);
            parent->addTransition(objects.at(i), SIGNAL(clicked()), state);
        }
    }

    void createAnimations(const QObjectList &objects, QStateMachine *machine)
    {
        for (int i=0; i<objects.size(); ++i)
            machine->addDefaultAnimation(new QPropertyAnimation(objects.at(i), "geometry"));
    }

    int main(int argc, char **argv)
    {
        Q_INIT_RESOURCE(appchooser);

        QApplication app(argc, argv);

        Pixmap *p1 = new Pixmap(QPixmap(":/digikam.png"));
        Pixmap *p2 = new Pixmap(QPixmap(":/akregator.png"));
        Pixmap *p3 = new Pixmap(QPixmap(":/accessories-dictionary.png"));
        Pixmap *p4 = new Pixmap(QPixmap(":/k3b.png"));

        p1->setObjectName("p1");
        p2->setObjectName("p2");
        p3->setObjectName("p3");
        p4->setObjectName("p4");

        p1->setGeometry(QRectF(  0.0,   0.0, 64.0, 64.0));
        p2->setGeometry(QRectF(236.0,   0.0, 64.0, 64.0));
        p3->setGeometry(QRectF(236.0, 236.0, 64.0, 64.0));
        p4->setGeometry(QRectF(  0.0, 236.0, 64.0, 64.0));

        QGraphicsScene scene(0, 0, 300, 300);
        scene.setBackgroundBrush(Qt::white);
        scene.addItem(p1);
        scene.addItem(p2);
        scene.addItem(p3);
        scene.addItem(p4);

        GraphicsView window(&scene);
        window.setFrameStyle(0);
        window.setAlignment(Qt::AlignLeft | Qt::AlignTop);
        window.setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
        window.setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

        QStateMachine machine;
        machine.setGlobalRestorePolicy(QState::RestoreProperties);

        QState *group = new QState(&machine);
        group->setObjectName("group");

        QRect selectedRect(86, 86, 128, 128);

        QState *idleState = new QState(group);
        group->setInitialState(idleState);

        QObjectList objects;
        objects << p1 << p2 << p3 << p4;
        createStates(objects, selectedRect, group);
        createAnimations(objects, &machine);

        machine.setInitialState(group);
        machine.start();

        window.resize(300, 300);
        window.show();

        return app.exec();
    }

    #include "main.moc"