- Qt 5.5
- Qt Widgets
- Embedded Dialogs
- customproxy.cpp Example File
- Qt 5.5.1 Reference Documentation

# customproxy.cpp Example File

graphicsview/embeddeddialogs/customproxy.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
    ** Software or, alternatively, in accordance with the terms contained in
    ** a written agreement between you and The Qt Company. For licensing terms
    ** and conditions see http://www.qt.io/terms-conditions. For further
    ** information use the contact form at http://www.qt.io/contact-us.
    **
    ** 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
    ** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
    ** 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.
    **
    ** $QT_END_LICENSE$
    **
    ****************************************************************************/

    #include "customproxy.h"

    #include <QStyleOptionGraphicsItem>
    #include <QPainter>
    #include <QGraphicsScene>

    CustomProxy::CustomProxy(QGraphicsItem *parent, Qt::WindowFlags wFlags)
        : QGraphicsProxyWidget(parent, wFlags), popupShown(false), currentPopup(0)
    {
        timeLine = new QTimeLine(250, this);
        connect(timeLine, SIGNAL(valueChanged(qreal)),
                this, SLOT(updateStep(qreal)));
        connect(timeLine, SIGNAL(stateChanged(QTimeLine::State)),
                this, SLOT(stateChanged(QTimeLine::State)));
    }

    QRectF CustomProxy::boundingRect() const
    {
        return QGraphicsProxyWidget::boundingRect().adjusted(0, 0, 10, 10);
    }

    void CustomProxy::paintWindowFrame(QPainter *painter, const QStyleOptionGraphicsItem *option,
                                       QWidget *widget)
    {
        const QColor color(0, 0, 0, 64);

        QRectF r = windowFrameRect();
        QRectF right(r.right(), r.top() + 10, 10, r.height() - 10);
        QRectF bottom(r.left() + 10, r.bottom(), r.width(), 10);
        bool intersectsRight = right.intersects(option->exposedRect);
        bool intersectsBottom = bottom.intersects(option->exposedRect);
        if (intersectsRight && intersectsBottom) {
            QPainterPath path;
            path.addRect(right);
            path.addRect(bottom);
            painter->setPen(Qt::NoPen);
            painter->setBrush(color);
            painter->drawPath(path);
        } else if (intersectsBottom) {
            painter->fillRect(bottom, color);
        } else if (intersectsRight) {
            painter->fillRect(right, color);
        }

        QGraphicsProxyWidget::paintWindowFrame(painter, option, widget);
    }

    void CustomProxy::hoverEnterEvent(QGraphicsSceneHoverEvent *event)
    {
        QGraphicsProxyWidget::hoverEnterEvent(event);
        scene()->setActiveWindow(this);
        if (timeLine->currentValue() != 1)
            zoomIn();
    }

    void CustomProxy::hoverLeaveEvent(QGraphicsSceneHoverEvent *event)
    {
        QGraphicsProxyWidget::hoverLeaveEvent(event);
        if (!popupShown
                && (timeLine->direction() != QTimeLine::Backward || timeLine->currentValue() != 0)) {
            zoomOut();
        }
    }

    bool CustomProxy::sceneEventFilter(QGraphicsItem *watched, QEvent *event)
    {
        if (watched->isWindow()
                && (event->type() == QEvent::UngrabMouse || event->type() == QEvent::GrabMouse)) {
            popupShown = watched->isVisible();
            if (!popupShown && !isUnderMouse())
                zoomOut();
        }
        return QGraphicsProxyWidget::sceneEventFilter(watched, event);
    }

    QVariant CustomProxy::itemChange(GraphicsItemChange change, const QVariant &value)
    {
        if (change == ItemChildAddedChange || change == ItemChildRemovedChange) {
            if (change == ItemChildAddedChange) {
                currentPopup = qvariant_cast<QGraphicsItem *>(value);
                currentPopup->setCacheMode(ItemCoordinateCache);
                if (scene())
                    currentPopup->installSceneEventFilter(this);
            } else if (scene()) {
                currentPopup->removeSceneEventFilter(this);
                currentPopup = 0;
            }
        } else if (currentPopup && change == ItemSceneHasChanged) {
            currentPopup->installSceneEventFilter(this);
        }
        return QGraphicsProxyWidget::itemChange(change, value);
    }

    void CustomProxy::updateStep(qreal step)
    {
        QRectF r = boundingRect();
        setTransform(QTransform()
                     .translate(r.width() / 2, r.height() / 2)
                     .rotate(step * 30, Qt::XAxis)
                     .rotate(step * 10, Qt::YAxis)
                     .rotate(step * 5, Qt::ZAxis)
                     .scale(1 + 1.5 * step, 1 + 1.5 * step)
                     .translate(-r.width() / 2, -r.height() / 2));
    }

    void CustomProxy::stateChanged(QTimeLine::State state)
    {
        if (state == QTimeLine::Running) {
            if (timeLine->direction() == QTimeLine::Forward)
                setCacheMode(ItemCoordinateCache);
        } else if (state == QTimeLine::NotRunning) {
            if (timeLine->direction() == QTimeLine::Backward)
                setCacheMode(DeviceCoordinateCache);
        }
    }

    void CustomProxy::zoomIn()
    {
        if (timeLine->direction() != QTimeLine::Forward)
            timeLine->setDirection(QTimeLine::Forward);
        if (timeLine->state() == QTimeLine::NotRunning)
            timeLine->start();
    }

    void CustomProxy::zoomOut()
    {
        if (timeLine->direction() != QTimeLine::Backward)
            timeLine->setDirection(QTimeLine::Backward);
        if (timeLine->state() == QTimeLine::NotRunning)
            timeLine->start();
    }