editor/item.cpp

#include "item.h"
#include "connection.h"
#include <QPainter>
#include <QStyleOptionGraphicsItem>

Item::Item(const QString &type, QGraphicsItem *parent)
    : QGraphicsObject(parent), type_(type)
{
    if (type == "常开")        color_ = Qt::blue;
    else if (type == "常闭")   color_ = Qt::red;
    else if (type == "比较指令") color_ = Qt::green;
    else                       color_ = Qt::darkYellow;

    setFlags(QGraphicsItem::ItemIsMovable |
             QGraphicsItem::ItemIsSelectable |
             QGraphicsItem::ItemSendsGeometryChanges);
}

QRectF Item::boundingRect() const
{
    return QRectF(-5, -5, 90, 50);
}

void Item::paint(QPainter *painter,
                 const QStyleOptionGraphicsItem *,
                 QWidget *)
{
    QRectF r = boundingRect().adjusted(5, 5, -5, -5); // 图元主体
    painter->setBrush(color_.lighter(150));
    painter->setPen(QPen(color_, 2));
    painter->drawRoundedRect(r, 5, 5);

    // 画锚点
    painter->setBrush(Qt::darkGray);
    painter->setPen(Qt::NoPen);
    painter->drawEllipse(QPointF(r.left(), r.center().y()), 5, 5);   // 左锚点
    painter->drawEllipse(QPointF(r.right(), r.center().y()), 5, 5);  // 右锚点

    painter->setPen(Qt::black);
    painter->drawText(r, Qt::AlignCenter, type_);
}

QPointF Item::anchorPos(AnchorType anc) const
{
    QRectF r = boundingRect();
    switch (anc) {
    case Left:  return mapToScene(QPointF(r.left(), r.center().y()));
    case Right: return mapToScene(QPointF(r.right(), r.center().y()));
    }
    return QPointF();
}

void Item::addConnection(Connection* conn)
{
    if (!connections_.contains(conn))
        connections_.append(conn);
}

void Item::removeConnection(Connection* conn)
{
    connections_.removeAll(conn);
}

QList<Connection *> Item::connections()
{
    return connections_;
}

QVariant Item::itemChange(GraphicsItemChange change, const QVariant &value)
{
    if (change == QGraphicsItem::ItemPositionChange) {
        for (Connection* conn : connections_)
            conn->updatePosition();
    }
    return QGraphicsObject::itemChange(change, value);
}