text: #ifndef FLOWEREXTENSION_H
  #define FLOWEREXTENSION_H
  
  #include "flower.h"
  
  class FlowerExtension : public QObject
  {
    Q_OBJECT
  
    Q_PROPERTY(QColor complementaryColor
               READ complementaryColor
               WRITE setComplementaryColor
               NOTIFY complementaryColorChanged)        // [1]
  
  public:
    explicit FlowerExtension(QObject *parent = nullptr);
  
    QColor complementaryColor() const;
  
  signals:
    void complementaryColorChanged(QColor complementaryColor);
  
  public slots:
    void setComplementaryColor(QColor complementaryColor);
  
  private:
    Flower *m_flower;                                   // [2]
    QColor m_complementaryColor;
  };
  
  #endif // FLOWEREXTENSION_H
  