Logo Search packages:      
Sourcecode: qt4-x11 version File versions

QModelIndex Class Reference

List of all members.


Detailed Description

The QModelIndex class is used to locate data in a data model.

This class is used as an index into item models derived from QAbstractItemModel. The index is used by item views, delegates, and selection models to locate an item in the model.

New QModelIndex objects are created by the model using the QAbstractItemModel::createIndex() function. An invalid model index can be constructed with the QModelIndex constructor. Invalid indexes are often used as parent indexes when referring to top-level items in a model.

Model indexes refer to items in models, and contain all the information required to specify their locations in those models. Each index is located in a given row and column, and may have a parent index; use row(), column(), and parent() to obtain this information. Each top-level item in a model is represented by a model index that does not have a parent index - in this case, parent() will return an invalid model index, equivalent to an index constructed with the zero argument form of the QModelIndex() constructor.

To obtain a model index that refers to an existing item in a model, call QAbstractItemModel::index() with the required row and column values, and the model index of the parent. When referring to top-level items in a model, supply QModelIndex() as the parent index.

The model() function returns the model that the index references as a QAbstractItemModel. The child() function is used to examine the items held beneath the index in the model. The sibling() function allows you to traverse items in the model on the same level as the index.

Note:
Model indexes should be used immediately and then discarded. You should not rely on indexes to remain valid after calling model functions that change the structure of the model or delete items. If you need to keep a model index over time use a QPersistentModelIndex.
See also:
Model/View Programming QPersistentModelIndex QAbstractItemModel

Definition at line 59 of file qabstractitemmodel.h.


Public Member Functions

QModelIndex child (int row, int column) const
int column () const
QVariant data (int role=Qt::DisplayRole) const
Qt::ItemFlags flags () const
qint64 internalId () const
void * internalPointer () const
bool isValid () const
const QAbstractItemModelmodel () const
bool operator!= (const QModelIndex &other) const
bool operator< (const QModelIndex &other) const
bool operator== (const QModelIndex &other) const
QModelIndex parent () const
 QModelIndex (const QModelIndex &other)
 QModelIndex ()
int row () const
QModelIndex sibling (int row, int column) const
 ~QModelIndex ()

Private Member Functions

 QModelIndex (int row, int column, void *ptr, const QAbstractItemModel *model)

Private Attributes

int c
const QAbstractItemModelm
void * p
int r

Friends

class QAbstractItemModel
class QProxyModel

Related Functions

(Note that these are not member functions.)

 QModelIndexList

The documentation for this class was generated from the following files:

Generated by  Doxygen 1.6.0   Back to index