layoutscene.cpp

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//=============================================================================================================
//=============================================================================================================
// INCLUDES
//=============================================================================================================
 
#include "layoutscene.h"
 
//=============================================================================================================
// QT INCLUDES
//=============================================================================================================
 
#include <QGraphicsView>
#include <QGraphicsSceneMouseEvent>
#include <QGestureEvent>
#include <QScrollBar>
#include <QDebug>
 
//=============================================================================================================
// USED NAMESPACES
//=============================================================================================================
 
using namespace DISPLIB;
 
//=============================================================================================================
// DEFINE MEMBER METHODS
//=============================================================================================================
 
LayoutScene::LayoutScene(QGraphicsView* view,
                         QObject* parent)
: QGraphicsScene(parent)
, m_qvView(view)
, m_bDragMode(false)
//, m_bExtendedSelectionMode(false)
{
    m_qvView->grabGesture(Qt::PanGesture);
    m_qvView->grabGesture(Qt::PinchGesture);
 
    //Install event filter to overcome QGrabGesture and QScrollBar problem
    m_qvView->installEventFilter(this);
}
 
//=============================================================================================================
 
void LayoutScene::wheelEvent(QGraphicsSceneWheelEvent* event) {
    m_qvView->setTransformationAnchor(QGraphicsView::AnchorViewCenter);
 
    // Scale the view / do the zoom
    double scaleFactor = 1.15;
    if(event->delta() > 0) {
        // Zoom in
        m_qvView->scale(scaleFactor, scaleFactor);
    } else {
        // Zooming out
        m_qvView->scale(1.0 / scaleFactor, 1.0 / scaleFactor);
    }
}
 
//=============================================================================================================
 
void LayoutScene::mouseDoubleClickEvent(QGraphicsSceneMouseEvent* mouseEvent)
{
    if(mouseEvent->button() == Qt::LeftButton)
        m_qvView->fitInView(this->itemsBoundingRect(), Qt::KeepAspectRatio);
 
    QGraphicsScene::mouseDoubleClickEvent(mouseEvent);
}
 
//=============================================================================================================
 
void LayoutScene::mousePressEvent(QGraphicsSceneMouseEvent *mouseEvent)
{
    switch(mouseEvent->button()) {
    case Qt::LeftButton:
        m_qvView->setDragMode(QGraphicsView::RubberBandDrag);
 
//        //If a normal left lick occurs without holding down CTRL -> Delete all selected items
//        if(!m_bExtendedSelectionMode)
//            m_selectedItems.clear();
 
        break;
 
    case Qt::RightButton:
        m_bDragMode = true;
        m_qvView->setDragMode(QGraphicsView::NoDrag);
        m_mousePressPosition = mouseEvent->screenPos();
 
        //return so that no selection event is called
        return;
    }
 
    QGraphicsScene::mousePressEvent(mouseEvent);
}
 
//=============================================================================================================
 
void LayoutScene::mouseMoveEvent(QGraphicsSceneMouseEvent *mouseEvent)
{
    if(m_bDragMode) {
        int diffX = mouseEvent->screenPos().x() - m_mousePressPosition.x();
        int diffY = mouseEvent->screenPos().y() - m_mousePressPosition.y();
 
        m_mousePressPosition = mouseEvent->screenPos();
 
        m_qvView->verticalScrollBar()->setValue(m_qvView->verticalScrollBar()->value() - diffY);
        m_qvView->horizontalScrollBar()->setValue(m_qvView->horizontalScrollBar()->value() - diffX);
    }
 
    QGraphicsScene::mouseMoveEvent(mouseEvent);
}
 
//=============================================================================================================
 
void LayoutScene::mouseReleaseEvent(QGraphicsSceneMouseEvent *mouseEvent)
{
//    if(m_bExtendedSelectionMode) {
//        qDebug()<<"Extended Selection";
//        //List of selected items during last rubberband action
//        QList<QGraphicsItem *> currentSelectedItemsList = this->selectedItems();
 
//        //Generate list of all selected items (dont add duplicates)
//        for(int i = 0; i<currentSelectedItemsList.size(); i++) {
//            if(!m_selectedItems.contains(currentSelectedItemsList.at(i))) {
//                //Duplicate not found - new item was selected since the last extended selection
//                qDebug()<<"add item to m_selectedItems";
//                m_selectedItems << currentSelectedItemsList.at(i);
//            }
//            else {
//                qDebug()<<"delete item from m_selectedItems";
//                //Duplicate found - already selected item was selected again since the last extended selection
//                m_selectedItems.removeAll(currentSelectedItemsList.at(i));
//                currentSelectedItemsList.at(i)->setSelected(false);
//            }
//        }
 
//        for(int i = 0; i<m_selectedItems.size(); i++)
//            m_selectedItems.at(i)->setSelected(true);
 
//        qDebug()<<m_selectedItems.size();
//    }
 
    if(m_bDragMode) {
        m_bDragMode = false;
        this->update();
    }
 
    QGraphicsScene::mouseReleaseEvent(mouseEvent);
}
 
//=============================================================================================================
 
void LayoutScene::keyPressEvent(QKeyEvent *keyEvent)
{
//    if(keyEvent->key() == Qt::Key_Control)
//        m_bExtendedSelectionMode = true;
 
    QGraphicsScene::keyPressEvent(keyEvent);
}
 
//=============================================================================================================
 
void LayoutScene::keyReleaseEvent(QKeyEvent *keyEvent)
{
//    if(keyEvent->key() == Qt::Key_Control)
//        m_bExtendedSelectionMode = false;
 
    QGraphicsScene::keyReleaseEvent(keyEvent);
}
 
//=============================================================================================================
 
bool LayoutScene::event(QEvent *event)
{
    if (event->type() == QEvent::Gesture) {
        QGestureEvent* gestureEventCast = static_cast<QGestureEvent*>(event);
 
//        QList<QGesture *> gestureList = gestureEventCast->gestures();
//        for(int i = 0; i<gestureList.size(); i++)
//            qDebug()<<gestureList.at(i)->gestureType();
//        qDebug()<<"-----------------------";
 
        return gestureEvent(static_cast<QGestureEvent*>(gestureEventCast));
    }
 
    return QGraphicsScene::event(event);
}
 
//=============================================================================================================
 
bool LayoutScene::gestureEvent(QGestureEvent *event)
{
    //Pan event
    if (QGesture *pan = event->gesture(Qt::PanGesture))
        panTriggered(static_cast<QPanGesture *>(pan));
 
    //Pinch event
    if (QGesture *pinch = event->gesture(Qt::PinchGesture))
        pinchTriggered(static_cast<QPinchGesture *>(pinch));
 
    return true;
}
 
//=============================================================================================================
 
void LayoutScene::panTriggered(QPanGesture *gesture)
{
    QPointF delta = gesture->delta();
 
    m_qvView->verticalScrollBar()->setValue(m_qvView->verticalScrollBar()->value() + delta.y());
    m_qvView->horizontalScrollBar()->setValue(m_qvView->horizontalScrollBar()->value() + delta.x());
}
 
//=============================================================================================================
 
void LayoutScene::pinchTriggered(QPinchGesture *gesture)
{
    m_qvView->setTransformationAnchor(QGraphicsView::NoAnchor);
    m_qvView->scale(gesture->scaleFactor(), gesture->scaleFactor());
}
 
//=============================================================================================================
 
bool LayoutScene::eventFilter(QObject *object, QEvent *event)
{
    if (object == m_qvView && event->type() == QEvent::Gesture) {
        QGestureEvent* gestureEventCast = static_cast<QGestureEvent*>(event);
 
        return gestureEvent(static_cast<QGestureEvent*>(gestureEventCast));
    }
 
    return false;
}