QGroupingProxyModel Class Reference

The QGroupingProxyModel class implements a grouping proxy model. More...

#include <qgroupingproxymodel.h>

Inheritance diagram for QGroupingProxyModel:

Public Member Functions
	QGroupingProxyModel (QObject *parent=0)
	~QGroupingProxyModel ()
void	addGroup (const QString &text, const QVariant &value=QVariant())
void	addGroup (const QIcon &icon, const QString &text, const QVariant &value=QVariant())
int	columnCount (const QModelIndex &parent=QModelIndex()) const
QVariant	data (const QModelIndex &proxyIndex, int role) const
Qt::ItemFlags	flags (const QModelIndex &index) const
bool	groupsSpanned () const
QVariant	headerData (int section, Qt::Orientation orientation, int role) const
QModelIndex	index (int row, int column, const QModelIndex &parent=QModelIndex()) const
int	findText (const QString &text) const
QModelIndex	mapFromSource (const QModelIndex &sourceIndex) const
QModelIndex	mapToSource (const QModelIndex &proxyIndex) const
int	modelColumn () const
QModelIndex	parent (const QModelIndex &child) const
bool	removeGroup (int index)
bool	restoreGroups (const QByteArray &data)
int	rowCount (const QModelIndex &parent=QModelIndex()) const
QByteArray	saveGroups () const
bool	setData (const QModelIndex &index, const QVariant &value, int role)
void	setGroupSectionHeader (const QString &header)
void	setGroupsSpanned (bool on)
void	setModelColumn (int column)
virtual void	setSourceModel (QAbstractItemModel *sourceModel)
void	setUngroupedItemTitle (const QString &title)
void	setUngroupedItemTitle (const QString &title, const QIcon &icon)
virtual QSize	span (const QModelIndex &index) const

Properties
bool	groupsSpanned
int	modelColumn

Detailed Description

The QGroupingProxyModel class implements a grouping proxy model.

The QGroupingProxyModel can be used for grouping items. A tree structure is created to arrange the source items as defined by the group definitions.

Let's assume that we want to group the items provided by a custom model. The code to set up the model and the view, without grouping, would look like this:

QTreeView* treeView = new QTreeView;
QStandardItemModel* model = new QStandardItemModel(this);
treeView->setModel(model);

To add grouping support to mDataModel, we need to create a QGroupingProxyModel, call setSourceModel() with the mDataModel as argument, and install the QGroupingProxyModel on the view:

QTreeView* treeView = new QTreeView;
QStandardItemModel* model = new QStandardItemModel(this);
QGroupingProxyModel* proxy = new QGroupingProxyModel(this);
proxy->setSourceModel(model);
treeiew->setModel(proxy);

At this point no grouping is applied and the source model items are displayed in the tree view as children of the group "Ungrouped".

Grouping

To enable grouping it is required to call setModelColumn() to determine the source model colum the proxy shall operate on.

proxy->setModelColumn(2);

Once the model column is set, groups can be added by calling addGroup().

QTreeView* treeView = new QTreeView;
QStandardItemModel* model = new QStandardItemModel(this);
QGroupingProxyModel* proxy = new QGroupingProxyModel(this);

proxy->setModelColumn(2);
proxy->addGroup(QIcon(":/icons/folder"), "Qt's Tools", "Qt's tools");

proxy->setSourceModel(mItemModel);
treeView->setModel(mGroupingProxy);

A second group 'Qt's Tools' is added to the tree listing all source items matching the value 'Qt's tools' in the selected model column.

Note

The addGroup() call use different values for displaying the group title and matching.

Sorting

Sorting can be achieved by cascading proxy models. The first proxy will group the model items and the second sorts them.

QTreeView* treeView = new QTreeView;
QStandardItemModel* model = new QStandardItemModel(this);
QGroupingProxyModel* goupingProxy = new QGroupingProxyModel(this);

goupingProxy->setModelColumn(2);
goupingProxy->addGroup(QIcon(":/icons/folder"), "Qt's Tools", "Qt's tools");

proxy->setSourceModel(model);

QSortFilterProxyModel* sortFilterProxy = new QSortFilterProxyModel(this);
sortFilterProxy->setSourceModel(goupingProxy);

treeView->setModel(sortFilterProxy);

Save and Restore Groups

Group definitions can be saved and restored calling saveGroups() or restoreGroups().

Constructor & Destructor Documentation

QGroupingProxyModel::QGroupingProxyModel ( QObject *  parent = 0 )

explicit

Constructs a QGroupingProxyModel with the given parent.

QGroupingProxyModel::~QGroupingProxyModel

(

)

Destroys the QGroupingProxyModel object.

Member Function Documentation

void QGroupingProxyModel::addGroup	(	const QString &	text,
		const QVariant &	value = QVariant()
	)

Creates a new group named text matching the specified value. This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

void QGroupingProxyModel::addGroup	(	const QIcon &	icon,
		const QString &	text,
		const QVariant &	value = QVariant()
	)

Creates a new group named text, with an icon and matching the specified value. This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

int QGroupingProxyModel::columnCount

(

const QModelIndex &

parent = QModelIndex()

)

const

Returns the number of columns for the children of the given parent.

See also

rowCount()

QVariant QGroupingProxyModel::data	(	const QModelIndex &	proxyIndex,
		int	role
	)		const

QAbstractItemModel::data()

Qt::ItemFlags QGroupingProxyModel::flags

(

const QModelIndex &

index

)

const

QAbstractItemModel::data()

QVariant QGroupingProxyModel::headerData	(	int	section,
		Qt::Orientation	orientation,
		int	role
	)		const

QAbstractItemModel::data()

QModelIndex QGroupingProxyModel::index	(	int	row,
		int	column,
		const QModelIndex &	parent = QModelIndex()
	)		const

QAbstractItemModel::data()

QModelIndex QGroupingProxyModel::mapFromSource

(

const QModelIndex &

sourceIndex

)

const

Returns the model index in the proxy model that corresponds to the sourceIndex from the source model.

See also

mapToSource()

QModelIndex QGroupingProxyModel::mapToSource

(

const QModelIndex &

proxyIndex

)

const

Returns the model index in the source model that corresponds to the proxyIndex in the proxy model.

See also

mapToSource()

int QGroupingProxyModel::modelColumn

(

)

const

Returns the source model column used for grouping items.

See also

setModelColumn()

QModelIndex QGroupingProxyModel::parent

(

const QModelIndex &

child

)

const

Returns the parent of the model item with the given index. If the item has no parent, an invalid QModelIndex is returned.

bool QGroupingProxyModel::removeGroup

(

int

index

)

Removes the group specified by the given index.

bool QGroupingProxyModel::restoreGroups

(

const QByteArray &

data

)

Restores the group definitions. Returns true if the groups are restored; otherwise returns false. Typically this is used in conjunction with QSettings to restore the group definitions from a past session. Here is an example:

QSettings settings;
groupingProxyModel->restoreGroups(settings.value("groups").toByteArray());

A failure to restore the group definitions may result from either invalid or out-of-date data in the supplied byte array.

int QGroupingProxyModel::rowCount

(

const QModelIndex &

parent = QModelIndex()

)

const

Returns the number of rows under the given parent. When the parent is valid it means that rowCount is returning the number of children of parent.

See also

columnCount()

QByteArray QGroupingProxyModel::saveGroups

(

)

const

Saves the proxy's group definitions. Typically this is used in conjunction with QSettings to remember the groups for a future session. A version number is stored as part of the data. Here is an example:

QSettings settings;
settings.setValue("groups", groupingProxyModel->saveGroups());

See also

restoreGroups()

bool QGroupingProxyModel::setData	(	const QModelIndex &	index,
		const QVariant &	value,
		int	role
	)

Sets the role data for the item at index to value.

void QGroupingProxyModel::setGroupsSpanned

(

bool

on

)

If on is true, the groups are spanned over all columns.

See also

span()

void QGroupingProxyModel::setModelColumn

(

int

column

)

Sets the source model column that is used for grouping items.

See also

modelColumn()

void QGroupingProxyModel::setSourceModel ( QAbstractItemModel *  sourceModel )

virtual

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

QSize QGroupingProxyModel::span ( const QModelIndex &  index ) const

virtual

Returns the row and column span of the item represented by index. If groupsSpanned is enabled QSize(columnCount(), 1) is returned for all root indexes.

Property Documentation

bool QGroupingProxyModel::groupsSpanned

readwrite

Returns true if the groups are spanned over all columns. Otherwise false.

See also

span()

int QGroupingProxyModel::modelColumn

readwrite

This property holds the column in the source model that is used for grouping items.

By default, this property contains 0, indicating that the first column in the source model will be used.

See also

modelColumn() setModelColumn()

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

• D:/Entwicklung/qaiv/qaivlib/qgroupingproxymodel.h
• D:/Entwicklung/qaiv/qaivlib/qgroupingproxymodel.cpp