- Qt 5.5
- Qt Widgets
- Boxes
- qtbox.cpp Example File
- Qt 5.5.1 Reference Documentation

# qtbox.cpp Example File

graphicsview/boxes/qtbox.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the demonstration applications of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:LGPL21$
    ** Commercial License Usage
    ** Licensees holding valid commercial Qt licenses may use this file in
    ** accordance with the commercial license agreement provided with the
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    **
    ** GNU Lesser General Public License Usage
    ** Alternatively, this file may be used under the terms of the GNU Lesser
    ** General Public License version 2.1 or version 3 as published by the Free
    ** Software Foundation and appearing in the file LICENSE.LGPLv21 and
    ** LICENSE.LGPLv3 included in the packaging of this file. Please review the
    ** following information to ensure the GNU Lesser General Public License
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    ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
    **
    ** As a special exception, The Qt Company gives you certain additional
    ** rights. These rights are described in The Qt Company LGPL Exception
    ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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    ** $QT_END_LICENSE$
    **
    ****************************************************************************/

    #include "qtbox.h"

    const qreal ROTATE_SPEED_X = 30.0 / 1000.0;
    const qreal ROTATE_SPEED_Y = 20.0 / 1000.0;
    const qreal ROTATE_SPEED_Z = 40.0 / 1000.0;
    const int MAX_ITEM_SIZE = 512;
    const int MIN_ITEM_SIZE = 16;

    //============================================================================//
    //                                  ItemBase                                  //
    //============================================================================//

    ItemBase::ItemBase(int size, int x, int y) : m_size(size), m_isResizing(false)
    {
        setFlag(QGraphicsItem::ItemIsMovable, true);
        setFlag(QGraphicsItem::ItemIsSelectable, true);
        setFlag(QGraphicsItem::ItemIsFocusable, true);
        setAcceptHoverEvents(true);
        setPos(x, y);
        m_startTime = QTime::currentTime();
    }

    ItemBase::~ItemBase()
    {
    }

    QRectF ItemBase::boundingRect() const
    {
        return QRectF(-m_size / 2, -m_size / 2, m_size, m_size);
    }

    void ItemBase::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *)
    {
        if (option->state & QStyle::State_Selected) {
            painter->setRenderHint(QPainter::Antialiasing, true);
            if (option->state & QStyle::State_HasFocus)
                painter->setPen(Qt::yellow);
            else
                painter->setPen(Qt::white);
            painter->drawRect(boundingRect());

            painter->drawLine(m_size / 2 - 9, m_size / 2, m_size / 2, m_size / 2 - 9);
            painter->drawLine(m_size / 2 - 6, m_size / 2, m_size / 2, m_size / 2 - 6);
            painter->drawLine(m_size / 2 - 3, m_size / 2, m_size / 2, m_size / 2 - 3);

            painter->setRenderHint(QPainter::Antialiasing, false);
        }
    }

    void ItemBase::contextMenuEvent(QGraphicsSceneContextMenuEvent *event)
    {
        if (!isSelected() && scene()) {
            scene()->clearSelection();
            setSelected(true);
        }

        QMenu menu;
        QAction *delAction = menu.addAction("Delete");
        QAction *newAction = menu.addAction("New");
        QAction *growAction = menu.addAction("Grow");
        QAction *shrinkAction = menu.addAction("Shrink");

        QAction *selectedAction = menu.exec(event->screenPos());

        if (selectedAction == delAction)
            deleteSelectedItems(scene());
        else if (selectedAction == newAction)
            duplicateSelectedItems(scene());
        else if (selectedAction == growAction)
            growSelectedItems(scene());
        else if (selectedAction == shrinkAction)
            shrinkSelectedItems(scene());
    }

    void ItemBase::duplicateSelectedItems(QGraphicsScene *scene)
    {
        if (!scene)
            return;

        QList<QGraphicsItem *> selected;
        selected = scene->selectedItems();

        foreach (QGraphicsItem *item, selected) {
            ItemBase *itemBase = qgraphicsitem_cast<ItemBase *>(item);
            if (itemBase)
                scene->addItem(itemBase->createNew(itemBase->m_size, itemBase->pos().x() + itemBase->m_size, itemBase->pos().y()));
        }
    }

    void ItemBase::deleteSelectedItems(QGraphicsScene *scene)
    {
        if (!scene)
            return;

        QList<QGraphicsItem *> selected;
        selected = scene->selectedItems();

        foreach (QGraphicsItem *item, selected) {
            ItemBase *itemBase = qgraphicsitem_cast<ItemBase *>(item);
            if (itemBase)
                delete itemBase;
        }
    }

    void ItemBase::growSelectedItems(QGraphicsScene *scene)
    {
        if (!scene)
            return;

        QList<QGraphicsItem *> selected;
        selected = scene->selectedItems();

        foreach (QGraphicsItem *item, selected) {
            ItemBase *itemBase = qgraphicsitem_cast<ItemBase *>(item);
            if (itemBase) {
                itemBase->prepareGeometryChange();
                itemBase->m_size *= 2;
                if (itemBase->m_size > MAX_ITEM_SIZE)
                    itemBase->m_size = MAX_ITEM_SIZE;
            }
        }
    }

    void ItemBase::shrinkSelectedItems(QGraphicsScene *scene)
    {
        if (!scene)
            return;

        QList<QGraphicsItem *> selected;
        selected = scene->selectedItems();

        foreach (QGraphicsItem *item, selected) {
            ItemBase *itemBase = qgraphicsitem_cast<ItemBase *>(item);
            if (itemBase) {
                itemBase->prepareGeometryChange();
                itemBase->m_size /= 2;
                if (itemBase->m_size < MIN_ITEM_SIZE)
                    itemBase->m_size = MIN_ITEM_SIZE;
            }
        }
    }

    void ItemBase::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
    {
        if (m_isResizing) {
            int dx = int(2.0 * event->pos().x());
            int dy = int(2.0 * event->pos().y());
            prepareGeometryChange();
            m_size = (dx > dy ? dx : dy);
            if (m_size < MIN_ITEM_SIZE)
                m_size = MIN_ITEM_SIZE;
            else if (m_size > MAX_ITEM_SIZE)
                m_size = MAX_ITEM_SIZE;
        } else {
            QGraphicsItem::mouseMoveEvent(event);
        }
    }

    void ItemBase::hoverMoveEvent(QGraphicsSceneHoverEvent *event)
    {
        if (m_isResizing || (isInResizeArea(event->pos()) && isSelected()))
            setCursor(Qt::SizeFDiagCursor);
        else
            setCursor(Qt::ArrowCursor);
        QGraphicsItem::hoverMoveEvent(event);
    }

    void ItemBase::mousePressEvent(QGraphicsSceneMouseEvent *event)
    {
        static qreal z = 0.0;
        setZValue(z += 1.0);
        if (event->button() == Qt::LeftButton && isInResizeArea(event->pos())) {
            m_isResizing = true;
        } else {
            QGraphicsItem::mousePressEvent(event);
        }
    }

    void ItemBase::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
    {
        if (event->button() == Qt::LeftButton && m_isResizing) {
            m_isResizing = false;
        } else {
            QGraphicsItem::mouseReleaseEvent(event);
        }
    }

    void ItemBase::keyPressEvent(QKeyEvent *event)
    {
        switch (event->key()) {
        case Qt::Key_Delete:
            deleteSelectedItems(scene());
            break;
        case Qt::Key_Insert:
            duplicateSelectedItems(scene());
            break;
        case Qt::Key_Plus:
            growSelectedItems(scene());
            break;
        case Qt::Key_Minus:
            shrinkSelectedItems(scene());
            break;
        default:
            QGraphicsItem::keyPressEvent(event);
            break;
        }
    }

    void ItemBase::wheelEvent(QGraphicsSceneWheelEvent *event)
    {
        prepareGeometryChange();
        m_size = int(m_size * qExp(-event->delta() / 600.0));
        if (m_size > MAX_ITEM_SIZE)
            m_size = MAX_ITEM_SIZE;
        else if (m_size < MIN_ITEM_SIZE)
            m_size = MIN_ITEM_SIZE;
    }

    int ItemBase::type() const
    {
        return Type;
    }

    bool ItemBase::isInResizeArea(const QPointF &pos)
    {
        return (-pos.y() < pos.x() - m_size + 9);
    }

    //============================================================================//
    //                                    QtBox                                   //
    //============================================================================//

    QtBox::QtBox(int size, int x, int y) : ItemBase(size, x, y), m_texture(0)
    {
        for (int i = 0; i < 8; ++i) {
            m_vertices[i].setX(i & 1 ? 0.5f : -0.5f);
            m_vertices[i].setY(i & 2 ? 0.5f : -0.5f);
            m_vertices[i].setZ(i & 4 ? 0.5f : -0.5f);
        }
        for (int i = 0; i < 4; ++i) {
            m_texCoords[i].setX(i & 1 ? 1.0f : 0.0f);
            m_texCoords[i].setY(i & 2 ? 1.0f : 0.0f);
        }
        m_normals[0] = QVector3D(-1.0f, 0.0f, 0.0f);
        m_normals[1] = QVector3D(1.0f, 0.0f, 0.0f);
        m_normals[2] = QVector3D(0.0f, -1.0f, 0.0f);
        m_normals[3] = QVector3D(0.0f, 1.0f, 0.0f);
        m_normals[4] = QVector3D(0.0f, 0.0f, -1.0f);
        m_normals[5] = QVector3D(0.0f, 0.0f, 1.0f);
    }

    QtBox::~QtBox()
    {
        if (m_texture)
            delete m_texture;
    }

    ItemBase *QtBox::createNew(int size, int x, int y)
    {
        return new QtBox(size, x, y);
    }

    void QtBox::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
    {
        QRectF rect = boundingRect().translated(pos());
        float width = float(painter->device()->width());
        float height = float(painter->device()->height());

        float left = 2.0f * float(rect.left()) / width - 1.0f;
        float right = 2.0f * float(rect.right()) / width - 1.0f;
        float top = 1.0f - 2.0f * float(rect.top()) / height;
        float bottom = 1.0f - 2.0f * float(rect.bottom()) / height;
        float moveToRectMatrix[] = {
            0.5f * (right - left), 0.0f, 0.0f, 0.0f,
            0.0f, 0.5f * (bottom - top), 0.0f, 0.0f,
            0.0f, 0.0f, 1.0f, 0.0f,
            0.5f * (right + left), 0.5f * (bottom + top), 0.0f, 1.0f
        };

        painter->beginNativePainting();

        glMatrixMode(GL_PROJECTION);
        glPushMatrix();
        glLoadMatrixf(moveToRectMatrix);
        qgluPerspective(60.0, 1.0, 0.01, 10.0);

        glMatrixMode(GL_MODELVIEW);
        glPushMatrix();
        glLoadIdentity();

        //glEnable(GL_DEPTH_TEST);
        glEnable(GL_CULL_FACE);
        glEnable(GL_LIGHTING);
        glEnable(GL_COLOR_MATERIAL);
        glEnable(GL_NORMALIZE);

        if(m_texture == 0)
            m_texture = new GLTexture2D(":/res/boxes/qt-logo.jpg", 64, 64);
        m_texture->bind();
        glEnable(GL_TEXTURE_2D);

        glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
        float lightColour[] = {1.0f, 1.0f, 1.0f, 1.0f};
        float lightDir[] = {0.0f, 0.0f, 1.0f, 0.0f};
        glLightfv(GL_LIGHT0, GL_DIFFUSE, lightColour);
        glLightfv(GL_LIGHT0, GL_POSITION, lightDir);
        glEnable(GL_LIGHT0);

        glTranslatef(0.0f, 0.0f, -1.5f);
        glRotatef(ROTATE_SPEED_X * m_startTime.msecsTo(QTime::currentTime()), 1.0f, 0.0f, 0.0f);
        glRotatef(ROTATE_SPEED_Y * m_startTime.msecsTo(QTime::currentTime()), 0.0f, 1.0f, 0.0f);
        glRotatef(ROTATE_SPEED_Z * m_startTime.msecsTo(QTime::currentTime()), 0.0f, 0.0f, 1.0f);
        int dt = m_startTime.msecsTo(QTime::currentTime());
        if (dt < 500)
            glScalef(dt / 500.0f, dt / 500.0f, dt / 500.0f);

        for (int dir = 0; dir < 3; ++dir) {
            glColor4f(1.0f, 1.0f, 1.0f, 1.0);

            glBegin(GL_TRIANGLE_STRIP);
            glNormal3fv(reinterpret_cast<float *>(&m_normals[2 * dir + 0]));
            for (int i = 0; i < 2; ++i) {
                for (int j = 0; j < 2; ++j) {
                    glTexCoord2fv(reinterpret_cast<float *>(&m_texCoords[(j << 1) | i]));
                    glVertex3fv(reinterpret_cast<float *>(&m_vertices[(i << ((dir + 2) % 3)) | (j << ((dir + 1) % 3))]));
                }
            }
            glEnd();

            glBegin(GL_TRIANGLE_STRIP);
            glNormal3fv(reinterpret_cast<float *>(&m_normals[2 * dir + 1]));
            for (int i = 0; i < 2; ++i) {
                for (int j = 0; j < 2; ++j) {
                    glTexCoord2fv(reinterpret_cast<float *>(&m_texCoords[(j << 1) | i]));
                    glVertex3fv(reinterpret_cast<float *>(&m_vertices[(1 << dir) | (i << ((dir + 1) % 3)) | (j << ((dir + 2) % 3))]));
                }
            }
            glEnd();
        }
        m_texture->unbind();

        //glDisable(GL_DEPTH_TEST);
        glDisable(GL_CULL_FACE);
        glDisable(GL_LIGHTING);
        glDisable(GL_COLOR_MATERIAL);
        glDisable(GL_TEXTURE_2D);
        glDisable(GL_LIGHT0);
        glDisable(GL_NORMALIZE);

        glPopMatrix();

        glMatrixMode(GL_PROJECTION);
        glPopMatrix();

        painter->endNativePainting();

        ItemBase::paint(painter, option, widget);
    }

    //============================================================================//
    //                                 CircleItem                                 //
    //============================================================================//

    CircleItem::CircleItem(int size, int x, int y) : ItemBase(size, x, y)
    {
         m_color = QColor::fromHsv(rand() % 360, 255, 255);
    }

    void CircleItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
    {
        int dt = m_startTime.msecsTo(QTime::currentTime());

        qreal r0 = 0.5 * m_size * (1.0 - qExp(-0.001 * ((dt + 3800) % 4000)));
        qreal r1 = 0.5 * m_size * (1.0 - qExp(-0.001 * ((dt + 0) % 4000)));
        qreal r2 = 0.5 * m_size * (1.0 - qExp(-0.001 * ((dt + 1800) % 4000)));
        qreal r3 = 0.5 * m_size * (1.0 - qExp(-0.001 * ((dt + 2000) % 4000)));

        if (r0 > r1)
            r0 = 0.0;
        if (r2 > r3)
            r2 = 0.0;

        QPainterPath path;
        path.moveTo(r1, 0.0);
        path.arcTo(-r1, -r1, 2 * r1, 2 * r1, 0.0, 360.0);
        path.lineTo(r0, 0.0);
        path.arcTo(-r0, -r0, 2 * r0, 2 * r0, 0.0, -360.0);
        path.closeSubpath();
        path.moveTo(r3, 0.0);
        path.arcTo(-r3, -r3, 2 * r3, 2 * r3, 0.0, 360.0);
        path.lineTo(r0, 0.0);
        path.arcTo(-r2, -r2, 2 * r2, 2 * r2, 0.0, -360.0);
        path.closeSubpath();
        painter->setRenderHint(QPainter::Antialiasing, true);
        painter->setBrush(QBrush(m_color));
        painter->setPen(Qt::NoPen);
        painter->drawPath(path);
        painter->setBrush(Qt::NoBrush);
        painter->setPen(Qt::SolidLine);
        painter->setRenderHint(QPainter::Antialiasing, false);

        ItemBase::paint(painter, option, widget);
    }

    ItemBase *CircleItem::createNew(int size, int x, int y)
    {
        return new CircleItem(size, x, y);
    }

    //============================================================================//
    //                                 SquareItem                                 //
    //============================================================================//

    SquareItem::SquareItem(int size, int x, int y) : ItemBase(size, x, y)
    {
        m_image = QPixmap(":/res/boxes/square.jpg");
    }

    void SquareItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
    {
        int dt = m_startTime.msecsTo(QTime::currentTime());
        QTransform oldTransform = painter->worldTransform();
        int dtMod = dt % 2000;
        qreal amp = 0.002 * (dtMod < 1000 ? dtMod : 2000 - dtMod) - 1.0;

        qreal scale = 0.6 + 0.2 * amp * amp;
        painter->setWorldTransform(QTransform().rotate(15.0 * amp).scale(scale, scale), true);

        painter->drawPixmap(-m_size / 2, -m_size / 2, m_size, m_size, m_image);

        painter->setWorldTransform(oldTransform, false);
        ItemBase::paint(painter, option, widget);
    }

    ItemBase *SquareItem::createNew(int size, int x, int y)
    {
        return new SquareItem(size, x, y);
    }