Problem with custom property binding (C++ extension)

Hi
I try to create a C++ extension for QML. I have one problem. I have an item (button) that can have set a custom gradient:

(I've pasted only important (in my opinion) code)

Code:

---

class Button : public QDeclarativeItem {
    Q_OBJECT
    Q_PROPERTY(Gradient* gradient READ gradient WRITE setGradient)
 
    public:
    Gradient* gradient() const;
    void setGradient(Gradient* gradient);
};

---

QML file:

Code:

---

Button {
        ExtendedGradient {
            ExtendedGradientStop { position: "0, 0"; color: "red"; }
            ExtendedGradientStop { position: "120, 120"; color: "blue"; }
        }

---

and ExtendedGradient / ExtendedGradientStop classes:

Code:

---

class Gradient : public QObject
{
    Q_OBJECT
 
    Q_PROPERTY(QDeclarativeListProperty<GradientStop> stops READ stops)
    Q_CLASSINFO("DefaultProperty", "stops")
 
public:
    Gradient(QObject *parent=0);
    virtual ~Gradient();
 
    QDeclarativeListProperty<GradientStop> stops();
    QGradient* gradient();
 
private:
    QList<GradientStop *> stops_;
    QGradient *gradient_;
 
    friend class GradientStop;
};
 
class GradientStop : public QObject
{
    Q_OBJECT
 
    // properties and set/get methods
};
 
QML_DECLARE_TYPE(Gradient)
QML_DECLARE_TYPE(GradientStop)

---

Problem is that: In qml file I set a ExtendedGradient, but setter for this property is never called. Instead of this, it is set the dynamic property which have a name 'gradient' (the Gradient* Button::gradient_ is always 0x0).
This property isValid, !isNull, has correct typeName, but I cannot convert it to Gradient* (using property("gradient").value<Gradient*>()) - I always get 0x0.

Why the setGradient setter is not called? Is this possible to force a call of this method? What I'm doing wrong?