Qt 5.6 | Qt Widgets | Embedded Dialogs | customproxy.cpp Example File

Qt 5.6.2 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();
      }