JSBTDieBondH/View/die-bonder-ui/CameraMaterialGroupWnd/MaterialWindow/DraggableLine.h

#ifndef RULERLINEITEM_H
#define RULERLINEITEM_H

#include <QGraphicsLineItem >
#include <QObject>
#include <QPainter>

class HandleItem : public QObject, public QGraphicsEllipseItem
{
    Q_OBJECT
public:
    enum { Type = UserType + 2 };

    HandleItem(QGraphicsItem* parent = nullptr)
        : QGraphicsEllipseItem(-6, -6, 12, 12, parent) {
        setFlag(QGraphicsItem::ItemIsSelectable);
        setFlag(QGraphicsItem::ItemIsMovable);
        setFlag(QGraphicsItem::ItemSendsGeometryChanges);
        setBrush(Qt::cyan);
        setPen(Qt::NoPen);
    }

    int type() const override { return Type; }

protected:
    QVariant itemChange(GraphicsItemChange change, const QVariant& value) override {
        if (change == ItemPositionHasChanged) {
            emit positionChanged();
        }
        return QGraphicsEllipseItem::itemChange(change, value);
    }

signals:
    void positionChanged();
};


class RulerLineItem : public QObject, public QGraphicsLineItem
{
    Q_OBJECT
public:
    enum HandleType
    {
        NoHandle,
        StartHandle,
        EndHandle
    };

    enum { Type = UserType + 1 };
    explicit RulerLineItem(const QLineF& line, QGraphicsItem* parent = nullptr);
    int type() const override;
    void setRulerText(const QString& strText);

signals:
    //标尺端点更新，发送信号
    void updateHandlesSignal(QPointF sPos, QPointF ePos);


private slots:
    void updateLineFromHandles();

private:
    void initRuler();
    void createTextItem();
    void createHandles();
    void updateHandlePositions();
    void updateTextPosition();

    // 成员变量
    HandleType m_draggingHandle = NoHandle;
    QPointF m_dragOffset;
    QGraphicsTextItem* m_textItem = nullptr;
    HandleItem* m_startHandle = nullptr;
    HandleItem* m_endHandle = nullptr;
    QString m_strRulerText;
};

#endif // RULERLINEITEM_H