旋转QQuickItem中的鼠标事件处理

#ifndef ROTATABLEITEM_H
#define ROTATABLEITEM_H

#include <QQuickItem>

class RotatableItem : public QQuickItem
{
    Q_OBJECT
    Q_PROPERTY(qreal rotationAngle READ rotationAngle WRITE setRotationAngle NOTIFY rotationAngleChanged)

public:
    explicit RotatableItem(QQuickItem *parent = nullptr);

    qreal rotationAngle() const;
    void setRotationAngle(qreal angle);

protected:
    void mousePressEvent(QMouseEvent *event) override;
    void mouseMoveEvent(QMouseEvent *event) override;
    void mouseReleaseEvent(QMouseEvent *event) override;
    void paint(QPainter *painter) override;

signals:
    void rotationAngleChanged();

private:
    qreal m_rotationAngle;
};

#endif // ROTATABLEITEM_H

#include "RotatableItem.h"
#include <QPainter>

RotatableItem::RotatableItem(QQuickItem *parent)
    : QQuickItem(parent), m_rotationAngle(0)
{
    setAcceptedMouseButtons(Qt::LeftButton);
}

qreal RotatableItem::rotationAngle() const
{
    return m_rotationAngle;
}

void RotatableItem::setRotationAngle(qreal angle)
{
    if (qFuzzyCompare(m_rotationAngle, angle))
        return;

    m_rotationAngle = angle;
    emit rotationAngleChanged();

    update();
}

void RotatableItem::mousePressEvent(QMouseEvent *event)
{
    // 处理鼠标按下事件
    // ...
}

void RotatableItem::mouseMoveEvent(QMouseEvent *event)
{
    // 处理鼠标移动事件
    // ...
}

void RotatableItem::mouseReleaseEvent(QMouseEvent *event)
{
    // 处理鼠标释放事件
    // ...
}

void RotatableItem::paint(QPainter *painter)
{
    painter->save();

    // 设置旋转角度
    painter->rotate(m_rotationAngle);

    // 绘制旋转后的内容
    // ...

    painter->restore();
}

import QtQuick 2.0

RotatableItem {
    width: 200
    height: 200
    rotationAngle: 45

    // 其他属性和事件处理
    // ...
}