#include <kviewstatesaver.h>

Inheritance diagram for KViewStateSaver:

Public Member Functions
	KViewStateSaver (QObject *parent=0)

	~KViewStateSaver ()

QString	currentIndexKey () const

QStringList	expansionKeys () const

void	restoreCurrentItem (const QString &indexString)

void	restoreExpanded (const QStringList &indexStrings)

void	restoreScrollState (int verticalScoll, int horizontalScroll)

void	restoreSelection (const QStringList &indexStrings)

void	restoreState (const KConfigGroup &configGroup)

void	saveState (KConfigGroup &configGroup)

QPair< int, int >	scrollState () const

QStringList	selectionKeys () const

QItemSelectionModel *	selectionModel () const

void	setSelectionModel (QItemSelectionModel *selectionModel)

void	setView (QAbstractItemView *view)

QAbstractItemView *	view () const

Public Member Functions inherited from QObject
	QObject (QObject *parent)

	QObject (QObject parent, const char name)

virtual	~QObject ()

bool	blockSignals (bool block)

QObject *	child (const char objName, const char inheritsClass, bool recursiveSearch) const

const QObjectList &	children () const

const char *	className () const

bool	connect (const QObject sender, const char signal, const char *method, Qt::ConnectionType type) const

void	deleteLater ()

void	destroyed (QObject *obj)

bool	disconnect (const QObject receiver, const char method)

bool	disconnect (const char signal, const QObject receiver, const char *method)

void	dumpObjectInfo ()

void	dumpObjectTree ()

QList< QByteArray >	dynamicPropertyNames () const

virtual bool	event (QEvent *e)

virtual bool	eventFilter (QObject watched, QEvent event)

T	findChild (const QString &name) const

QList< T >	findChildren (const QRegExp &regExp) const

QList< T >	findChildren (const QString &name) const

bool	inherits (const char *className) const

void	insertChild (QObject *object)

void	installEventFilter (QObject *filterObj)

bool	isA (const char *className) const

bool	isWidgetType () const

void	killTimer (int id)

virtual const QMetaObject *	metaObject () const

void	moveToThread (QThread *targetThread)

const char *	name () const

const char *	name (const char *defaultName) const

QString	objectName () const

QObject *	parent () const

QVariant	property (const char *name) const

void	removeChild (QObject *object)

void	removeEventFilter (QObject *obj)

void	setName (const char *name)

void	setObjectName (const QString &name)

void	setParent (QObject *parent)

bool	setProperty (const char *name, const QVariant &value)

bool	signalsBlocked () const

int	startTimer (int interval)

QThread *	thread () const

Protected Member Functions
virtual QModelIndex	indexFromConfigString (const QAbstractItemModel *model, const QString &key) const =0

virtual QString	indexToConfigString (const QModelIndex &index) const =0

Protected Member Functions inherited from QObject
bool	checkConnectArgs (const char signal, const QObject object, const char *method)

virtual void	childEvent (QChildEvent *event)

virtual void	connectNotify (const char *signal)

virtual void	customEvent (QEvent *event)

virtual void	disconnectNotify (const char *signal)

int	receivers (const char *signal) const

QObject *	sender () const

int	senderSignalIndex () const

virtual void	timerEvent (QTimerEvent *event)

Additional Inherited Members
Static Public Member Functions inherited from QObject
bool	connect (const QObject sender, const char signal, const QObject receiver, const char method, Qt::ConnectionType type)

bool	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type)

bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char method)

bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method)

QString	tr (const char sourceText, const char disambiguation, int n)

QString	trUtf8 (const char sourceText, const char disambiguation, int n)

Static Protected Member Functions inherited from QObject
QByteArray	normalizeSignalSlot (const char *signalSlot)

Properties inherited from QObject
	objectName

Detailed Description

Object for saving and restoring state in QTreeViews and QItemSelectionModels.

Implement the indexFromConfigString and indexToConfigString methods to handle the model in the view whose state is being saved. These implementations can be quite trivial:

QModelIndex DynamicTreeStateSaver::indexFromConfigString(const QAbstractItemModel* model, const QString& key) const
{
  QModelIndexList list = model->match(model->index(0, 0), DynamicTreeModel::DynamicTreeModelId, key.toInt(), 1, Qt::MatchRecursive);
  if (list.isEmpty())
    return QModelIndex();
  return list.first();
}
QString DynamicTreeStateSaver::indexToConfigString(const QModelIndex& index) const
{
  return index.data(DynamicTreeModel::DynamicTreeModelId).toString();
}

It is possible to restore the state of a QTreeView (that is, the expanded state and selected state of all indexes as well as the horizontal and vertical scroll state) by using setTreeView.

If there is no tree view state to restore (for example if using QML), the selection state of a QItemSelectionModel can be saved or restored instead.

The state of any QAbstractScrollArea can also be saved and restored.

A KViewStateSaver should be created on the stack when saving and on the heap when restoring. The model may be populated dynamically between several event loops, so it may not be immediate for the indexes that should be selected to be in the model. The saver should not be persisted as a member. The saver will destroy itself when it has completed the restoration specified in the config group, or a small amount of time has elapsed.

MyWidget::MyWidget(Qobject *parent)
  : QWidget(parent)
{
  ...
  m_view = new QTreeView(splitter);
  m_view->setModel(model);
  connect( model, SIGNAL(modelAboutToBeReset()), SLOT(saveState()) );
  connect( model, SIGNAL(modelReset()), SLOT(restoreState()) );
  connect( qApp, SIGNAL(aboutToQuit()), SLOT(saveState()) );
  restoreState();
}
void StateSaverWidget::saveState()
{
  ConcreteStateSaver saver;
  saver.setTreeView(m_view);
  KConfigGroup cfg( KGlobal::config(), "ExampleViewState" );
  saver.saveState( cfg );
  cfg.sync();
}
void StateSaverWidget::restoreState()
{
  // Will delete itself.
  ConcreteTreeStateSaver *saver = new ConcreteStateSaver();
  saver->setTreeView(m_view);
  KConfigGroup cfg( KGlobal::config(), "ExampleViewState" );
  saver->restoreState( cfg );
}

After creating a saver, the state can be saved using a KConfigGroup.

It is also possible to save and restore state directly by using the restoreSelection, restoreExpanded etc methods. Note that the implementation of these methods should return strings that the indexFromConfigString implementation can handle.

class DynamicTreeStateSaver : public KViewStateSaver
{
  Q_OBJECT
public:
  // ...
  void selectItems(const QList<qint64> &items)
  {
    QStringList itemStrings;
    foreach(qint64 item, items)
      itemStrings << QString::number(item);
    restoreSelection(itemStrings);
  }
  void expandItems(const QList<qint64> &items)
  {
    QStringList itemStrings;
    foreach(qint64 item, items)
      itemStrings << QString::number(item);
    restoreSelection(itemStrings);
  }
};

Note that a single instance of this class should be used with only one widget. That is don't do this:

saver->setTreeView(treeView1);
saver->setSelectionModel(treeView2->selectionModel());
saver->setScrollArea(treeView3);

To save the state of 3 different widgets, use three savers, even if they operate on the same root model.

saver1->setTreeView(treeView1);
saver2->setSelectionModel(treeView2->selectionModel());
saver3->setScrollArea(treeView3);

Note: The KViewStateSaver does not take ownership of any widgets set on it.

It is recommended to restore the state on application startup and after the model has been reset, and to save the state on application close and before the model has been reset.

See also: QAbstractItemModel::modelAboutToBeReset QAbstractItemModel::modelReset

Author: Stephen Kelly steph.nosp@m.en@k.nosp@m.dab.c.nosp@m.om

Since: 4.5

Definition at line 169 of file kviewstatesaver.h.

Constructor & Destructor Documentation

KViewStateSaver::KViewStateSaver ( QObject * parent = 0 )

explicit

Constructor.

Parameters

parent standard parent object, but ignored since this object will delete itself

Definition at line 120 of file kviewstatesaver.cpp.

KViewStateSaver::~KViewStateSaver ( )

Destructor.

Definition at line 127 of file kviewstatesaver.cpp.

Member Function Documentation

QString KViewStateSaver::currentIndexKey ( ) const

Returns a QString describing the current index in the selection model.

Definition at line 370 of file kviewstatesaver.cpp.

QStringList KViewStateSaver::expansionKeys ( ) const

Returns a QStringList representing the expanded indexes in the QTreeView.

Definition at line 378 of file kviewstatesaver.cpp.

virtual QModelIndex KViewStateSaver::indexFromConfigString	(	const QAbstractItemModel *	model,
		const QString &	key
	)		const

protectedpure virtual

Reimplement to return an index in the model described by the unique key key.

virtual QString KViewStateSaver::indexToConfigString ( const QModelIndex & index ) const

protectedpure virtual

Reimplement to return a unique string for the index.

void KViewStateSaver::restoreCurrentItem ( const QString & indexString )

Make the index described by indexString the currentIndex in the selectionModel.

Definition at line 273 of file kviewstatesaver.cpp.

void KViewStateSaver::restoreExpanded ( const QStringList & indexStrings )

Expand the indexes described by indexStrings in the QTreeView.

Definition at line 308 of file kviewstatesaver.cpp.

void KViewStateSaver::restoreScrollState	(	int	verticalScoll,
		int	horizontalScroll
	)

Restores the scroll state of the QAbstractScrollArea to the verticalScoll and horizontalScroll.

Definition at line 323 of file kviewstatesaver.cpp.

void KViewStateSaver::restoreSelection ( const QStringList & indexStrings )

Select the indexes described by indexStrings.

Definition at line 354 of file kviewstatesaver.cpp.

void KViewStateSaver::restoreState ( const KConfigGroup & configGroup )

Restores the state from the configGroup.

Definition at line 196 of file kviewstatesaver.cpp.

void KViewStateSaver::saveState ( KConfigGroup & configGroup )

Saves the state to the configGroup.

Definition at line 233 of file kviewstatesaver.cpp.

QPair< int, int > KViewStateSaver::scrollState ( ) const

Returns the vertical and horizontal scroll of the QAbstractScrollArea.

Definition at line 401 of file kviewstatesaver.cpp.

QStringList KViewStateSaver::selectionKeys ( ) const

Returns a QStringList describing the selection in the selectionModel.

Definition at line 387 of file kviewstatesaver.cpp.

QItemSelectionModel * KViewStateSaver::selectionModel ( ) const

The QItemSelectionModel whose state is persisted.

Definition at line 152 of file kviewstatesaver.cpp.

void KViewStateSaver::setSelectionModel ( QItemSelectionModel * selectionModel )

Sets the QItemSelectionModel whose state is persisted.

Definition at line 158 of file kviewstatesaver.cpp.

void KViewStateSaver::setView ( QAbstractItemView * view )

Sets the view whose state is persisted.

Definition at line 132 of file kviewstatesaver.cpp.

QAbstractItemView * KViewStateSaver::view ( ) const

The view whose state is persisted.

Definition at line 146 of file kviewstatesaver.cpp.

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

KDEUI

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

KDEUI

kdelibs API Reference

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