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                    if (startItems.count() > 0 && endItems.count() > 0 &&
                        startItems.first()->type() == GraphicsRectItem::Type &&
                        endItems.first()->type() == GraphicsRectItem::Type &&
                        startItems.first() != endItems.first()) {
                        //qDebug() << "in Arrow IF";
                        GraphicsRectItem *startItem =
                            qgraphicsitem_cast<GraphicsRectItem *>(startItems.first());
                        GraphicsRectItem *endItem =
                            qgraphicsitem_cast<GraphicsRectItem *>(endItems.first());
                        Arrow *arrow = new Arrow(startItem, endItem);
                        arrow->setColor(myLineColor);
                        startItem->addArrow(arrow);
                        endItem->addArrow(arrow);
                        arrow->setZValue(-1000.0);
                        addItem(arrow);                      // Add the arrow to the scene
                        arrow->updatePosition();
                    }

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#ifndef ARROW_H
#define ARROW_H

#include <QObject>
#include <QGraphicsLineItem>
#include "graphicsrectitem.h"

class QGraphicsLineItem;
class GraphicsRectItem;

class Arrow : public QObject, public QGraphicsLineItem {
    Q_OBJECT

public:
    enum { Type = UserType + 4 };

    Arrow(GraphicsRectItem *startItem, GraphicsRectItem *endItem,
          QGraphicsItem *parent = 0, QGraphicsScene *scene = 0);
    Arrow(QGraphicsItem *parent = 0, QGraphicsScene *scene = 0);
    void setObjects(GraphicsRectItem *startItem, GraphicsRectItem *endItem);
    int type() const { return Type; }
    QRectF boundingRect() const;
    QPainterPath shape() const;
    void setColor(const QColor &color) { myColor = color; }
    GraphicsRectItem *startItem() const { return myStartItem; }
    GraphicsRectItem *endItem() const { return myEndItem; }

public slots:
    void updatePosition();

protected:
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option,
               QWidget *widget = 0);
    void hoverEnterEvent(QGraphicsSceneHoverEvent * event);
    void hoverLeaveEvent(QGraphicsSceneHoverEvent * event);

private:
    GraphicsRectItem *myStartItem;
    GraphicsRectItem *myEndItem;
    QColor myColor;
    QPolygonF arrowHead;

signals:
	void insertConnections(qint32 start_item_id, qint32 start_schema_id, qreal start_pos_x,
                           qreal start_pos_y, qreal start_pos_z, qint32 end_item_id,
                           qint32 end_schema_id, qreal end_pos_x, qreal end_pos_y,
                           qreal end_pos_z);
    void updateConnections(qint32 start_item_id, qint32 start_schema_id, qreal start_pos_x,
                           qreal start_pos_y, qreal start_pos_z, qint32 end_item_id,
                           qint32 end_schema_id, qreal end_pos_x, qreal end_pos_y,
                           qreal end_pos_z);
};

#endif

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#include <QtGui>

#include "arrow.h"
#include <math.h>

const qreal Pi = 3.14;

Arrow::Arrow(GraphicsRectItem *startItem, GraphicsRectItem *endItem,
         QGraphicsItem *parent, QGraphicsScene *scene)
    : QGraphicsLineItem(parent, scene) {
    myStartItem = startItem;
    myEndItem = endItem;
    setFlag(QGraphicsItem::ItemIsSelectable, true);
    myColor = Qt::black;
    setPen(QPen(myColor, 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
    setAcceptHoverEvents(true);

    // Insert Connection Location
    qint32 start_item_id = 0;
    qint32 start_schema_id = 0;
    qreal start_pos_x = 0;
    qreal start_pos_y = 0;
    qreal start_pos_z = 0;

    qint32 end_item_id = 0;
    qint32 end_schema_id = 0;
    qreal end_pos_x = 0;
    qreal end_pos_y = 0;
    qreal end_pos_z = 0;

    if(myEndItem->whichSide() == GraphicsRectItem::RightSide && myStartItem->whichSide() == GraphicsRectItem::LeftSide) {
        start_item_id = myEndItem->objectID();
        start_schema_id = 1;
        start_pos_x = myEndItem->rect().x() + myEndItem->rect().width() + myEndItem->parentItem()->pos().x();
        start_pos_y = myEndItem->rect().y() + (myEndItem->rect().height()/2) + myEndItem->parentItem()->pos().y();
        start_pos_z = myEndItem->zValue();

        end_item_id = myStartItem->objectID();
        end_schema_id = 1;
        end_pos_x = myStartItem->rect().x() + myStartItem->parentItem()->pos().x();
        end_pos_y = myStartItem->rect().y() + (myStartItem->rect().height()/2) + myStartItem->parentItem()->pos().y();
        end_pos_z = myStartItem->zValue();

        emit insertConnections(start_item_id,       // start_item_id
                               start_schema_id,     // start_schema_id
                               start_pos_x,         // start_pos_x
                               start_pos_y,         // start_pos_y
                               start_pos_z,         // start_pos_z
                               end_item_id,         // end_item_id
                               end_schema_id,       // end_schema_id
                               end_pos_x,           // end_pos_x
                               end_pos_y,           // end_pos_y
                               end_pos_z);          // end_pos_z
    }
    else {
        start_item_id = myStartItem->objectID();
        start_schema_id = 1;
        start_pos_x = myStartItem->rect().x() + myStartItem->rect().width() + myStartItem->parentItem()->pos().x();
        start_pos_y = myStartItem->rect().y() + (myStartItem->rect().height()/2) + myStartItem->parentItem()->pos().y();
        start_pos_z = myStartItem->zValue();

        end_item_id = myEndItem->objectID();
        end_schema_id = 1;
        end_pos_x = myEndItem->rect().x() + myEndItem->parentItem()->pos().x();
        end_pos_y = myEndItem->rect().y() + (myEndItem->rect().height()/2) + myEndItem->parentItem()->pos().y();
        end_pos_z = myEndItem->zValue();

        emit insertConnections(start_item_id,       // start_item_id
                               start_schema_id,     // start_schema_id
                               start_pos_x,         // start_pos_x
                               start_pos_y,         // start_pos_y
                               start_pos_z,         // start_pos_z
                               end_item_id,         // end_item_id
                               end_schema_id,       // end_schema_id
                               end_pos_x,           // end_pos_x
                               end_pos_y,           // end_pos_y
                               end_pos_z);          // end_pos_z
    }
}

Arrow::Arrow(QGraphicsItem *parent, QGraphicsScene *scene) : QGraphicsLineItem(parent, scene) {
    setFlag(QGraphicsItem::ItemIsSelectable, true);
    myColor = Qt::black;
    setPen(QPen(myColor, 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
    setAcceptHoverEvents(true);
}

void Arrow::setObjects(GraphicsRectItem *startItem, GraphicsRectItem *endItem) {
    myStartItem = startItem;
    myEndItem = endItem;

    // Insert Connection Location
    qint32 start_item_id = 0;
    qint32 start_schema_id = 0;
    qreal start_pos_x = 0;
    qreal start_pos_y = 0;
    qreal start_pos_z = 0;

    qint32 end_item_id = 0;
    qint32 end_schema_id = 0;
    qreal end_pos_x = 0;
    qreal end_pos_y = 0;
    qreal end_pos_z = 0;

    if(myEndItem->whichSide() == GraphicsRectItem::RightSide && myStartItem->whichSide() == GraphicsRectItem::LeftSide) {
        start_item_id = myEndItem->objectID();
        start_schema_id = 1;
        start_pos_x = myEndItem->rect().x() + myEndItem->rect().width() + myEndItem->parentItem()->pos().x();
        start_pos_y = myEndItem->rect().y() + (myEndItem->rect().height()/2) + myEndItem->parentItem()->pos().y();
        start_pos_z = myEndItem->zValue();

        end_item_id = myStartItem->objectID();
        end_schema_id = 1;
        end_pos_x = myStartItem->rect().x() + myStartItem->parentItem()->pos().x();
        end_pos_y = myStartItem->rect().y() + (myStartItem->rect().height()/2) + myStartItem->parentItem()->pos().y();
        end_pos_z = myStartItem->zValue();

        emit insertConnections(start_item_id,       // start_item_id
                               start_schema_id,     // start_schema_id
                               start_pos_x,         // start_pos_x
                               start_pos_y,         // start_pos_y
                               start_pos_z,         // start_pos_z
                               end_item_id,         // end_item_id
                               end_schema_id,       // end_schema_id
                               end_pos_x,           // end_pos_x
                               end_pos_y,           // end_pos_y
                               end_pos_z);          // end_pos_z
    }
    else {
        start_item_id = myStartItem->objectID();
        start_schema_id = 1;
        start_pos_x = myStartItem->rect().x() + myStartItem->rect().width() + myStartItem->parentItem()->pos().x();
        start_pos_y = myStartItem->rect().y() + (myStartItem->rect().height()/2) + myStartItem->parentItem()->pos().y();
        start_pos_z = myStartItem->zValue();

        end_item_id = myEndItem->objectID();
        end_schema_id = 1;
        end_pos_x = myEndItem->rect().x() + myEndItem->parentItem()->pos().x();
        end_pos_y = myEndItem->rect().y() + (myEndItem->rect().height()/2) + myEndItem->parentItem()->pos().y();
        end_pos_z = myEndItem->zValue();

        emit insertConnections(start_item_id,       // start_item_id
                               start_schema_id,     // start_schema_id
                               start_pos_x,         // start_pos_x
                               start_pos_y,         // start_pos_y
                               start_pos_z,         // start_pos_z
                               end_item_id,         // end_item_id
                               end_schema_id,       // end_schema_id
                               end_pos_x,           // end_pos_x
                               end_pos_y,           // end_pos_y
                               end_pos_z);          // end_pos_z
    }
}

QRectF Arrow::boundingRect() const {
    qreal extra = (pen().width() + 20) / 2.0;

    return QRectF(line().p1(), QSizeF(line().p2().x() - line().p1().x(),
                                      line().p2().y() - line().p1().y()))
        .normalized()
        .adjusted(-extra, -extra, extra, extra);
}

QPainterPath Arrow::shape() const {
    QPainterPath path = QGraphicsLineItem::shape();
    path.addPolygon(arrowHead);
    return path;
}

void Arrow::updatePosition() {
    QLineF line(mapFromItem(myStartItem, 0, 0), mapFromItem(myEndItem, 0, 0));
    setLine(line);

    // Update Connection Location
    qint32 start_item_id = 0;
    qint32 start_schema_id = 0;
    qreal start_pos_x = 0;
    qreal start_pos_y = 0;
    qreal start_pos_z = 0;

    qint32 end_item_id = 0;
    qint32 end_schema_id = 0;
    qreal end_pos_x = 0;
    qreal end_pos_y = 0;
    qreal end_pos_z = 0;

    if(myEndItem->whichSide() == GraphicsRectItem::RightSide && myStartItem->whichSide() == GraphicsRectItem::LeftSide) {
        start_item_id = myEndItem->objectID();
        start_schema_id = 1;
        start_pos_x = myEndItem->rect().x() + myEndItem->rect().width() + myEndItem->parentItem()->pos().x();
        start_pos_y = myEndItem->rect().y() + (myEndItem->rect().height()/2) + myEndItem->parentItem()->pos().y();
        start_pos_z = myEndItem->zValue();

        end_item_id = myStartItem->objectID();
        end_schema_id = 1;
        end_pos_x = myStartItem->rect().x() + myStartItem->parentItem()->pos().x();
        end_pos_y = myStartItem->rect().y() + (myStartItem->rect().height()/2) + myStartItem->parentItem()->pos().y();
        end_pos_z = myStartItem->zValue();

        emit updateConnections(start_item_id,       // start_item_id
                               start_schema_id,     // start_schema_id
                               start_pos_x,         // start_pos_x
                               start_pos_y,         // start_pos_y
                               start_pos_z,         // start_pos_z
                               end_item_id,         // end_item_id
                               end_schema_id,       // end_schema_id
                               end_pos_x,           // end_pos_x
                               end_pos_y,           // end_pos_y
                               end_pos_z);          // end_pos_z
    }
    else {
        start_item_id = myStartItem->objectID();
        start_schema_id = 1;
        start_pos_x = myStartItem->rect().x() + myStartItem->rect().width() + myStartItem->parentItem()->pos().x();
        start_pos_y = myStartItem->rect().y() + (myStartItem->rect().height()/2) + myStartItem->parentItem()->pos().y();
        start_pos_z = myStartItem->zValue();

        end_item_id = myEndItem->objectID();
        end_schema_id = 1;
        end_pos_x = myEndItem->rect().x() + myEndItem->parentItem()->pos().x();
        end_pos_y = myEndItem->rect().y() + (myEndItem->rect().height()/2) + myEndItem->parentItem()->pos().y();
        end_pos_z = myEndItem->zValue();

        emit updateConnections(start_item_id,       // start_item_id
                               start_schema_id,     // start_schema_id
                               start_pos_x,         // start_pos_x
                               start_pos_y,         // start_pos_y
                               start_pos_z,         // start_pos_z
                               end_item_id,         // end_item_id
                               end_schema_id,       // end_schema_id
                               end_pos_x,           // end_pos_x
                               end_pos_y,           // end_pos_y
                               end_pos_z);          // end_pos_z
    }
}

void Arrow::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *) {
    if (myStartItem->collidesWithItem(myEndItem)) {
        qDebug() << "!!!!!!!!!!!!!!!!(myStartItem->collidesWithItem(myEndItem))";
        return;
    }

     QPen myPen = pen();
     myPen.setColor(myColor);
     painter->setPen(myPen);
     painter->setBrush(myColor);

     QLineF centerLine(myStartItem->pos(), myEndItem->pos());
     QPolygonF endPolygon = QPolygonF(myEndItem->rect());//myEndItem->polygon();
     QPointF p1 = endPolygon.first() + myEndItem->pos();
     QPointF p2;
     QPointF intersectPoint;
     QLineF polyLine;
     for (int i = 0; i < endPolygon.count(); ++i) {
         p2 = endPolygon.at(i) + myEndItem->pos();
         polyLine = QLineF(p1, p2);
         QLineF::IntersectType intersectType = polyLine.intersect(centerLine, &intersectPoint);
         if (intersectType == QLineF::BoundedIntersection)
             break;
             p1 = p2;
     }

    if(myEndItem->whichSide() == GraphicsRectItem::RightSide && myStartItem->whichSide() == GraphicsRectItem::LeftSide) {
        setLine(QLineF(myEndItem->rect().x() + myEndItem->rect().width() + myEndItem->parentItem()->pos().x() + 10,
                   myEndItem->rect().y() + (myEndItem->rect().height()/2) + myEndItem->parentItem()->pos().y(),
                   myStartItem->rect().x() + myStartItem->parentItem()->pos().x() - 10,
                   myStartItem->rect().y() + (myStartItem->rect().height()/2) + myStartItem->parentItem()->pos().y()));

        QGraphicsLineItem *left_l = new QGraphicsLineItem(this);
        left_l->setPen(QPen(myColor, 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
        left_l->setLine(myStartItem->rect().x() + myStartItem->parentItem()->pos().x(),
                        myStartItem->rect().y() + (myStartItem->rect().height()/2) + myStartItem->parentItem()->pos().y(),
                        myStartItem->rect().x() + myStartItem->parentItem()->pos().x() - 10,
                        myStartItem->rect().y() + (myStartItem->rect().height()/2) + myStartItem->parentItem()->pos().y());
        left_l->setParentItem(this);


        QGraphicsLineItem *left_r = new QGraphicsLineItem(this);
        left_r->setPen(QPen(myColor, 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
        left_r->setLine(myEndItem->rect().x() + myEndItem->rect().width() + myEndItem->parentItem()->pos().x(),
                        myEndItem->rect().y() + (myEndItem->rect().height()/2) + myEndItem->parentItem()->pos().y(),
                        myEndItem->rect().x() + myEndItem->rect().width() + myEndItem->parentItem()->pos().x() + 10,
                        myEndItem->rect().y() + (myEndItem->rect().height()/2) + myEndItem->parentItem()->pos().y());
        left_r->setParentItem(this);
    }
    else {
        setLine(QLineF(myEndItem->rect().x() + myEndItem->parentItem()->pos().x() - 10,
                       myEndItem->rect().y() + (myEndItem->rect().height()/2) + myEndItem->parentItem()->pos().y(),
                       myStartItem->rect().x() + myStartItem->rect().width() + myStartItem->parentItem()->pos().x() + 10,
                       myStartItem->rect().y() + (myStartItem->rect().height()/2) + myStartItem->parentItem()->pos().y()));

        QGraphicsLineItem *left_l = new QGraphicsLineItem(this);
        left_l->setPen(QPen(myColor, 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
        left_l->setLine(myEndItem->rect().x() + myEndItem->parentItem()->pos().x(),
                        myEndItem->rect().y() + (myEndItem->rect().height()/2) + myEndItem->parentItem()->pos().y(),
                        myEndItem->rect().x() + myEndItem->parentItem()->pos().x() - 10,
                        myEndItem->rect().y() + (myEndItem->rect().height()/2) + myEndItem->parentItem()->pos().y());
        left_l->setParentItem(this);


        QGraphicsLineItem *left_r = new QGraphicsLineItem(this);
        left_r->setPen(QPen(myColor, 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
        left_r->setLine(myStartItem->rect().x() + myStartItem->rect().width() + myStartItem->parentItem()->pos().x(),
                        myStartItem->rect().y() + (myStartItem->rect().height()/2) + myStartItem->parentItem()->pos().y(),
                        myStartItem->rect().x() + myStartItem->rect().width() + myStartItem->parentItem()->pos().x() + 10,
                        myStartItem->rect().y() + (myStartItem->rect().height()/2) + myStartItem->parentItem()->pos().y());
        left_r->setParentItem(this);
    }

     double angle = ::acos(line().dx() / line().length());
     if (line().dy() >= 0)
         angle = (Pi * 2) - angle;

         painter->drawLine(line());
         if (isSelected()) {
             painter->setPen(QPen(myColor, 1, Qt::DashLine));
             QLineF myLine = line();
             myLine.translate(0, 4.0);
             painter->drawLine(myLine);
             myLine.translate(0,-8.0);
             painter->drawLine(myLine);
         }
    setAcceptHoverEvents(true);
}


void Arrow::hoverEnterEvent(QGraphicsSceneHoverEvent * event) {
    QGraphicsLineItem::hoverEnterEvent(event);
    qDebug() << "void Arrow::hoverEnterEvent(QGraphicsSceneHoverEvent * event)";
    this->setPen(QPen(QColor( 204, 0, 255, 76)));
    this->update();
}

void Arrow::hoverLeaveEvent(QGraphicsSceneHoverEvent * event) {
    qDebug() << "void Arrow::hoverLeaveEvent(QGraphicsSceneHoverEvent * event)";
    this->setPen(QPen(myColor));
    this->update();
}