Qt 4.8: customproxy.cpp Example File (demos/embeddeddialogs/customproxy.cpp)

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# customproxy.cpp Example File

demos/embeddeddialogs/customproxy.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
     ** Contact: http://www.qt-project.org/legal
     **
     ** This file is part of the demonstration applications of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:LGPL$
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     ** 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 as published by the Free Software
     ** Foundation and appearing in the file LICENSE.LGPL included in the
     ** packaging of this file.  Please review the following information to
     ** ensure the GNU Lesser General Public License version 2.1 requirements
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     ** rights.  These rights are described in the Digia Qt LGPL Exception
     ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
     **
     ** GNU General Public License Usage
     ** Alternatively, this file may be used under the terms of the GNU
     ** General Public License version 3.0 as published by the Free Software
     ** Foundation and appearing in the file LICENSE.GPL included in the
     ** packaging of this file.  Please review the following information to
     ** ensure the GNU General Public License version 3.0 requirements will be
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     ****************************************************************************/

     #include "customproxy.h"

     #include <QtGui>

     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();
     }