qtbox.cpp Example File

graphicsview/boxes/qtbox.cpp
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**
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** This file is part of the demonstration applications of the Qt Toolkit.
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#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);
}

© 2016 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.