Qt 4.0: QStackedWidget Class Reference

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# QStackedWidget Class Reference
[QtGui module]

The QStackedWidget class provides a stack of widgets where only one widget is visible at a time. More...

    #include <QStackedWidget>

Inherits QFrame.

- List of all members, including inherited members

### Properties

- count : const int
- currentIndex : int

- 6 properties inherited from QFrame
- 52 properties inherited from QWidget
- 1 property inherited from QObject

### Public Functions

- QStackedWidget ( QWidget * parent = 0 )
- ~QStackedWidget ()
- int addWidget ( QWidget * widget )
- int count () const
- int currentIndex () const
- QWidget * currentWidget () const
- int indexOf ( QWidget * widget ) const
- int insertWidget ( int index, QWidget * widget )
- void removeWidget ( QWidget * widget )
- QWidget * widget ( int index ) const

- 13 public functions inherited from QFrame
- 184 public functions inherited from QWidget
- 28 public functions inherited from QObject
- 10 public functions inherited from QPaintDevice

### Public Slots

- void setCurrentIndex ( int index )
- void setCurrentWidget ( QWidget * w )

- 17 public slots inherited from QWidget
- 1 public slot inherited from QObject

### Signals

- void currentChanged ( int index )
- void widgetRemoved ( int index )

- 1 signal inherited from QWidget
- 1 signal inherited from QObject

### Additional Inherited Members

- 2 static public members inherited from QFrame
- 4 static public members inherited from QWidget
- 4 static public members inherited from QObject
- 39 protected functions inherited from QWidget
- 7 protected functions inherited from QObject

## Detailed Description

The QStackedWidget class provides a stack of widgets where only one widget is visible at a time.

QStackedWidget can be used to create a user interface similar to the one provided by QTabWidget. It is a convenience layout widget built on top of QStackedLayout.

A QStackedWidget can be constructed and populated with a number of child widgets ("pages"), each of which can be created without a parent widget:

        QWidget *firstPageWidget = new QWidget;
        QWidget *secondPageWidget = new QWidget;
        QWidget *thirdPageWidget = new QWidget;
        ...

        QStackedWidget *stackedWidget = new QStackedWidget(this);
        stackedWidget->addWidget(firstPageWidget);
        stackedWidget->addWidget(secondPageWidget);
        stackedWidget->addWidget(thirdPageWidget);

When inserted, the widgets are added to an internal list. The indexOf() function returns the index of a widget in that list. The widget() function returns the widget at a given index position. The widget that is shown on screen is the currentWidget(). It can be changed using setCurrentWidget() or setCurrentIndex()

QStackedWidget provides no intrinsic means for the user to switch page. This is typically done through a QComboBox or a QListWidget that stores the titles of the QStackedWidget's pages. For example:

        QComboBox *pageComboBox = new QComboBox;
        pageComboBox->addItem(tr("Page 1"));
        pageComboBox->addItem(tr("Page 2"));
        pageComboBox->addItem(tr("Page 3"));
        connect(pageComboBox, SIGNAL(activated(int)),
                stackedWidget, SLOT(setCurrentIndex(int)));

See also QStackedLayout and QTabWidget.

## Property Documentation

### count : const int

This property holds the number of child widgets.

Access functions:

- int count () const

See also currentIndex() and widget().

### currentIndex : int

This property holds the index position of the widget that is visible.

The current index is -1 if there is no current widget.

Access functions:

- int currentIndex () const
- void setCurrentIndex ( int index )

See also currentWidget() and indexOf().

## Member Function Documentation

### QStackedWidget::QStackedWidget ( QWidget * parent = 0 )

Constructs a QStackedWidget with the given parent.

### QStackedWidget::~QStackedWidget ()

Destroys the object and frees any allocated resources.

### int QStackedWidget::addWidget ( QWidget * widget )

Adds widget to this QStackedWidget and returns the index position of widget.

If the QStackedWidget is empty before this function is called, widget becomes the current widget.

See also insertWidget(), removeWidget(), and currentWidget().

### void QStackedWidget::currentChanged ( int index ) `[signal]`

This signal is emitted when the current widget is changed. The parameter holds the index of the new current widget, or -1 if there isn't a new one (for example, if there are no widgets in the QStackedWidget).

See also widgetRemoved() and indexOf().

### QWidget * QStackedWidget::currentWidget () const

Returns the current widget, or 0 if there are no child widgets.

Equivalent to widget(currentIndex()).

See also currentIndex() and setCurrentWidget().

### int QStackedWidget::indexOf ( QWidget * widget ) const

Returns the index of widget, or -1 if widget is not a child of QStackedWidget.

See also currentIndex() and widget().

### int QStackedWidget::insertWidget ( int index, QWidget * widget )

Inserts widget at position index in this QStackedWidget. If index is out of range, the widget is appended. Returns the actual index of widget.

If the QStackedWidget was empty before this function is called, widget becomes the current widget.

See also addWidget(), removeWidget(), count(), and currentWidget().

### void QStackedWidget::removeWidget ( QWidget * widget )

Removes widget from the QStackedWidget's layout. The widget is not deleted.

See also addWidget(), insertWidget(), and currentWidget().

### void QStackedWidget::setCurrentWidget ( QWidget * w ) `[slot]`

Sets w to be the current widget. w must be contained in this stacked widget.

Equivalent to

        stackedWidget->setCurrentIndex(stackedWidget->indexOf(w));

See also currentWidget(), addWidget(), and setCurrentIndex().

### QWidget * QStackedWidget::widget ( int index ) const

Returns the widget at position index, or 0 if there is no such widget.

See also indexOf().

### void QStackedWidget::widgetRemoved ( int index ) `[signal]`

This signal is emitted when the widget at position index is removed.

See also currentChanged().