• An insertRows() implementation must call beginInsertRows() before inserting new rows into the data structure, and it must call endInsertRows() immediately afterwards.
• A removeRows() implementation must call beginRemoveRows() before the rows are removed from the data structure, and it must call endRemoveRows() immediately afterwards.

See also Model Classes, Model Subclassing Reference, QAbstractItemView, QAbstractTableModel, and Item Views Puzzle Example.

Model Subclassing Reference

• Item data handling: All models need to implement functions to enable views and delegates to query the dimensions of the model, examine items, and retrieve data.
• Navigation and index creation: Hierarchical models need to provide functions that views can call to navigate the tree-like structures they expose, and obtain model indexes for items.
• Drag and drop support and MIME type handling: Models inherit functions that control the way that internal and external drag and drop operations are performed. These functions allow items of data to be described in terms of MIME types that other components and applications can understand.

QHash<int, QByteArray> QAbstractItemModel::roleNames() const         [virtual]    

C++에서 정의한 함수를 QML 에서 호출하기 위해서는 Q_INVOKABLE 을 사용한다.

헤더 enumcode.h

 Q_ENUMS (Bit)   //C 파일에서 사용시 필요없지만 qml 에서 사용하기 위해서는 필요하다.

public: 

Q_INVOKABLE Bit igetBit()       { return eData; }

     Q_INVOKABLE void isetBit(Bit data)      { eData = data; }

main.cpp 에 추가 
1. 
qmlRegisterType<EnumCode>("kw.project", 1, 0, "Qmlkw");  
//qml 에서 사용시 import kw.project 1.0 주로 enum 값을 사용할 때 쓰임


2. 
QQuickView view;
    view.rootContext()->setContextProperty("BitObject", test1);  
    // QML 에서 BitObject 라는 이름으로 test1 객체(인스턴스를 사용한다.)

    view.setSource(QUrl::fromLocalFile("qml/main_front.qml"));

BitObject.KW 1        // enum 에접근 불가   view.rootContext()->setContextProperty("BitObject", test1);
Qmlkw.KW1             // enum 에 접근 가능  import kw.project 1.0

참고 사이트

New in Qt 5.5: Q_ENUM and the C++ tricks behind it

http://www.hitmaroc.net/508680-4550-exposing-enums-qml.html

http://www.qtcentre.org/threads/51015-Q_ENUMS-and-Qt-Style-Sheet