Qt 4.3: QProxyModel Class Reference

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# QProxyModel Class Reference
[QtGui module]

The QProxyModel class provides support for processing data passed between another model and a view. More...

     #include <QProxyModel>

This class is obsolete. It is provided to keep old source code working. We strongly advise against using it in new code.

Inherits QAbstractItemModel.

- List of all members, including inherited members

### Public Functions

- QProxyModel ( QObject * parent = 0 )
- ~QProxyModel ()
- virtual int columnCount ( const QModelIndex & parent ) const
- virtual QVariant data ( const QModelIndex & index, int role ) const
- virtual bool dropMimeData ( const QMimeData * data, Qt::DropAction action, int row, int column, const QModelIndex & parent )
- virtual void fetchMore ( const QModelIndex & parent )
- virtual Qt::ItemFlags flags ( const QModelIndex & index ) const
- virtual bool hasChildren ( const QModelIndex & parent ) const
- virtual QVariant headerData ( int section, Qt::Orientation orientation, int role ) const
- virtual QModelIndex index ( int row, int column, const QModelIndex & parent ) const
- virtual bool insertColumns ( int column, int count, const QModelIndex & parent )
- virtual bool insertRows ( int row, int count, const QModelIndex & parent )
- virtual QModelIndexList match ( const QModelIndex & start, int role, const QVariant & value, int hits, Qt::MatchFlags flags ) const
- virtual QMimeData * mimeData ( const QModelIndexList & indexes ) const
- virtual QStringList mimeTypes () const
- QAbstractItemModel * model () const
- virtual QModelIndex parent ( const QModelIndex & child ) const
- virtual void revert ()
- virtual int rowCount ( const QModelIndex & parent ) const
- virtual bool setData ( const QModelIndex & index, const QVariant & value, int role )
- virtual bool setHeaderData ( int section, Qt::Orientation orientation, const QVariant & value, int role )
- virtual void setModel ( QAbstractItemModel * model )
- virtual void sort ( int column, Qt::SortOrder order )
- virtual QSize span ( const QModelIndex & index ) const
- virtual bool submit ()
- virtual Qt::DropActions supportedDropActions () const

- 34 public functions inherited from QAbstractItemModel
- 29 public functions inherited from QObject

### Additional Inherited Members

- 1 property inherited from QObject
- 2 public slots inherited from QAbstractItemModel
- 1 public slot inherited from QObject
- 14 signals inherited from QAbstractItemModel
- 1 signal inherited from QObject
- 5 static public members inherited from QObject
- 14 protected functions inherited from QAbstractItemModel
- 7 protected functions inherited from QObject

## Detailed Description

The QProxyModel class provides support for processing data passed between another model and a view.

If you want to do filtering and sorting, see QSortFilterProxyModel.

Proxy models provide a standard model interface that can be used to manipulate the data retrieved through an underlying model. They can be used to perform operations such as sorting and filtering on the data obtained without changing the contents of the model.

Just as with subclasses of QAbstractItemView, QProxyModel provides the setModel() function that is used to specify the model to be acted on by the proxy. Views can be connected to either the underlying model or the proxy model with QAbstractItemView::setModel().

Since views rely on the information provided in model indexes to identify items of data from models, and to position these items in some visual representation, proxy models must create their own model indexes instead of supplying model indexes from their underlying models.

See also Model/View Programming and QAbstractItemModel.

## Member Function Documentation

### QProxyModel::QProxyModel ( QObject * parent = 0 )

Constructs a proxy model with the given parent.

### QProxyModel::~QProxyModel ()

Destroys the proxy model.

### int QProxyModel::columnCount ( const QModelIndex & parent ) const `[virtual]`

Returns the number of columns for the given parent.

Reimplemented from QAbstractItemModel.

See also QAbstractItemModel::columnCount().

### QVariant QProxyModel::data ( const QModelIndex & index, int role ) const `[virtual]`

Returns the data stored in the item with the given index under the specified role.

Reimplemented from QAbstractItemModel.

See also setData().

### bool QProxyModel::dropMimeData ( const QMimeData * data, Qt::DropAction action, int row, int column, const QModelIndex & parent ) `[virtual]`

Returns true if the model accepts the data dropped onto an attached view for the specified action; otherwise returns false.

The parent, row, and column details can be used to control which MIME types are acceptable to different parts of a model when received via the drag and drop system.

Reimplemented from QAbstractItemModel.

### void QProxyModel::fetchMore ( const QModelIndex & parent ) `[virtual]`

Fetches more child items of the given parent. This function is used by views to tell the model that they can display more data than the model has provided.

Reimplemented from QAbstractItemModel.

See also QAbstractItemModel::fetchMore().

### Qt::ItemFlags QProxyModel::flags ( const QModelIndex & index ) const `[virtual]`

Returns the item flags for the given index.

Reimplemented from QAbstractItemModel.

### bool QProxyModel::hasChildren ( const QModelIndex & parent ) const `[virtual]`

Returns true if the item corresponding to the parent index has child items; otherwise returns false.

Reimplemented from QAbstractItemModel.

See also QAbstractItemModel::hasChildren().

### QVariant QProxyModel::headerData ( int section, Qt::Orientation orientation, int role ) const `[virtual]`

Returns the data stored in the section of the header with specified orientation under the given role.

Reimplemented from QAbstractItemModel.

See also setHeaderData().

### QModelIndex QProxyModel::index ( int row, int column, const QModelIndex & parent ) const `[virtual]`

Returns the model index with the given row, column, and parent.

Reimplemented from QAbstractItemModel.

See also QAbstractItemModel::index().

### bool QProxyModel::insertColumns ( int column, int count, const QModelIndex & parent ) `[virtual]`

Inserts count columns into the model, creating new items as children of the given parent. The new columns are inserted before the column specified. If the parent item has no children, a single row is created to contain the required number of columns.

Returns true if the columns were successfully inserted; otherwise returns false.

Reimplemented from QAbstractItemModel.

See also QAbstractItemModel::insertColumns().

### bool QProxyModel::insertRows ( int row, int count, const QModelIndex & parent ) `[virtual]`

Inserts count rows into the model, creating new items as children of the given parent. The new rows are inserted before the row specified. If the parent item has no children, a single column is created to contain the required number of rows.

Returns true if the rows were successfully inserted; otherwise returns false.

Reimplemented from QAbstractItemModel.

See also QAbstractItemModel::insertRows().

### QModelIndexList QProxyModel::match ( const QModelIndex & start, int role, const QVariant & value, int hits, Qt::MatchFlags flags ) const `[virtual]`

Returns a list of model indexes that each contain the given value for the role specified. The search begins at the start index and is performed according to the specified flags. The search continues until the number of matching data items equals hits, the last row is reached, or the search reaches start again, depending on whether `MatchWrap` is specified in flags.

Reimplemented from QAbstractItemModel.

See also QAbstractItemModel::match().

### QMimeData * QProxyModel::mimeData ( const QModelIndexList & indexes ) const `[virtual]`

Returns MIME data for the specified indexes in the model.

Reimplemented from QAbstractItemModel.

### QStringList QProxyModel::mimeTypes () const `[virtual]`

Returns a list of MIME types that are supported by the model.

Reimplemented from QAbstractItemModel.

### QAbstractItemModel * QProxyModel::model () const

Returns the model that contains the data that is available through the proxy model.

See also setModel().

### QModelIndex QProxyModel::parent ( const QModelIndex & child ) const `[virtual]`

Returns the model index that corresponds to the parent of the given child index.

Reimplemented from QAbstractItemModel.

### void QProxyModel::revert () `[virtual]`

Reimplemented from QAbstractItemModel.

### int QProxyModel::rowCount ( const QModelIndex & parent ) const `[virtual]`

Returns the number of rows for the given parent.

Reimplemented from QAbstractItemModel.

See also QAbstractItemModel::rowCount().

### bool QProxyModel::setData ( const QModelIndex & index, const QVariant & value, int role ) `[virtual]`

Sets the role data for the item at index to value. Returns true if successful; otherwise returns false.

The base class implementation returns false. This function and data() must be reimplemented for editable models.

Reimplemented from QAbstractItemModel.

See also data(), itemData(), and QAbstractItemModel::setData().

### bool QProxyModel::setHeaderData ( int section, Qt::Orientation orientation, const QVariant & value, int role ) `[virtual]`

Sets the role data in the section of the header with the specified orientation to the value given.

Reimplemented from QAbstractItemModel.

See also headerData() and QAbstractItemModel::setHeaderData().

### void QProxyModel::setModel ( QAbstractItemModel * model ) `[virtual]`

Sets the given model to be processed by the proxy model.

See also model().

### void QProxyModel::sort ( int column, Qt::SortOrder order ) `[virtual]`

Sorts the child items in the specified column according to the sort order defined by order.

Reimplemented from QAbstractItemModel.

See also QAbstractItemModel::sort().

### QSize QProxyModel::span ( const QModelIndex & index ) const `[virtual]`

Returns the size of the item that corresponds to the specified index.

Reimplemented from QAbstractItemModel.

### bool QProxyModel::submit () `[virtual]`

Reimplemented from QAbstractItemModel.

### Qt::DropActions QProxyModel::supportedDropActions () const `[virtual]`

Returns the drop actions that are supported by the model; this is a combination of the individual actions defined in Qt::DropActions.

The selection of drop actions provided by the model will influence the behavior of the component that started the drag and drop operation.

Reimplemented from QAbstractItemModel.

See also Drag and Drop.