Model-View

Custom models:

Read-Only Access

• flags()
• data()
• headerData()
• rowCount()
• columnCount() (This function is already implemented in QAbstractListModel

Editable Models

• flags() return flags which include Qt::ItemIsEditable
• setData()
• setHeaderData()

Resizable Models

• insertRows()
• removeRows()
• insertColumns()
• removeColumns()

Changes to the models

Perform this sequences if there is any changes to the models:

• Emit the layoutAboutToBeChanged() signal.
• Update internal data which represents the strucutre of the model.
• Update persistent indexes using changePersistentindexList().
• Emit the layoutChanged() signal.

Lazy population

Only call rowCount() when necessary by reimplementin hasChildren()