QTabWidget Class

The QTabWidget class provides a stack of tabbed widgets. More...

Header:	#include <QTabWidget>
qmake:	QT += widgets
Inherits:	QWidget

• List of all members, including inherited members

Public Types

enum	TabPosition { North, South, West, East }
enum	TabShape { Rounded, Triangular }

Properties

count : const int currentIndex : int documentMode : bool elideMode : Qt::TextElideMode iconSize : QSize movable : bool

tabBarAutoHide : bool tabPosition : TabPosition tabShape : TabShape tabsClosable : bool usesScrollButtons : bool

Public Functions

	QTabWidget(QWidget *parent = nullptr)
virtual	~QTabWidget()
int	addTab(QWidget *page, const QString &label)
int	addTab(QWidget *page, const QIcon &icon, const QString &label)
void	clear()
QWidget *	cornerWidget(Qt::Corner corner = Qt::TopRightCorner) const
int	count() const
int	currentIndex() const
QWidget *	currentWidget() const
bool	documentMode() const
Qt::TextElideMode	elideMode() const
QSize	iconSize() const
int	indexOf(QWidget *w) const
int	insertTab(int index, QWidget *page, const QString &label)
int	insertTab(int index, QWidget *page, const QIcon &icon, const QString &label)
bool	isMovable() const
bool	isTabEnabled(int index) const
void	removeTab(int index)
void	setCornerWidget(QWidget *widget, Qt::Corner corner = Qt::TopRightCorner)
void	setDocumentMode(bool set)
void	setElideMode(Qt::TextElideMode)
void	setIconSize(const QSize &size)
void	setMovable(bool movable)
void	setTabBarAutoHide(bool enabled)
void	setTabEnabled(int index, bool enable)
void	setTabIcon(int index, const QIcon &icon)
void	setTabPosition(QTabWidget::TabPosition)
void	setTabShape(QTabWidget::TabShape s)
void	setTabText(int index, const QString &label)
void	setTabToolTip(int index, const QString &tip)
void	setTabWhatsThis(int index, const QString &text)
void	setTabsClosable(bool closeable)
void	setUsesScrollButtons(bool useButtons)
QTabBar *	tabBar() const
bool	tabBarAutoHide() const
QIcon	tabIcon(int index) const
QTabWidget::TabPosition	tabPosition() const
QTabWidget::TabShape	tabShape() const
QString	tabText(int index) const
QString	tabToolTip(int index) const
QString	tabWhatsThis(int index) const
bool	tabsClosable() const
bool	usesScrollButtons() const
QWidget *	widget(int index) const

Reimplemented Public Functions

virtual bool	hasHeightForWidth() const override
virtual int	heightForWidth(int width) const override
virtual QSize	minimumSizeHint() const override
virtual QSize	sizeHint() const override

Public Slots

void	setCurrentIndex(int index)
void	setCurrentWidget(QWidget *widget)

Signals

void	currentChanged(int index)
void	tabBarClicked(int index)
void	tabBarDoubleClicked(int index)
void	tabCloseRequested(int index)

Protected Functions

void	initStyleOption(QStyleOptionTabWidgetFrame *option) const
void	setTabBar(QTabBar *tb)
virtual void	tabInserted(int index)
virtual void	tabRemoved(int index)

Reimplemented Protected Functions

virtual void	changeEvent(QEvent *ev) override
virtual bool	event(QEvent *ev) override
virtual void	keyPressEvent(QKeyEvent *e) override
virtual void	paintEvent(QPaintEvent *event) override
virtual void	resizeEvent(QResizeEvent *e) override
virtual void	showEvent(QShowEvent *) override

Detailed Description

A tab widget provides a tab bar (see QTabBar) and a "page area" that is used to display pages related to each tab. By default, the tab bar is shown above the page area, but different configurations are available (see TabPosition). Each tab is associated with a different widget (called a page). Only the current page is shown in the page area; all the other pages are hidden. The user can show a different page by clicking on its tab or by pressing its Alt+letter shortcut if it has one.

The normal way to use QTabWidget is to do the following:

1. Create a QTabWidget.
2. Create a QWidget for each of the pages in the tab dialog, but do not specify parent widgets for them.
3. Insert child widgets into the page widget, using layouts to position them as normal.
4. Call addTab() or insertTab() to put the page widgets into the tab widget, giving each tab a suitable label with an optional keyboard shortcut.

The position of the tabs is defined by tabPosition, their shape by tabShape.

The signal currentChanged() is emitted when the user selects a page.

The current page index is available as currentIndex(), the current page widget with currentWidget(). You can retrieve a pointer to a page widget with a given index using widget(), and can find the index position of a widget with indexOf(). Use setCurrentWidget() or setCurrentIndex() to show a particular page.

You can change a tab's text and icon using setTabText() or setTabIcon(). A tab and its associated page can be removed with removeTab().

Each tab is either enabled or disabled at any given time (see setTabEnabled()). If a tab is enabled, the tab text is drawn normally and the user can select that tab. If it is disabled, the tab is drawn in a different way and the user cannot select that tab. Note that even if a tab is disabled, the page can still be visible, for example if all of the tabs happen to be disabled.

Tab widgets can be a very good way to split up a complex dialog. An alternative is to use a QStackedWidget for which you provide some means of navigating between pages, for example, a QToolBar or a QListWidget.

Most of the functionality in QTabWidget is provided by a QTabBar (at the top, providing the tabs) and a QStackedWidget (most of the area, organizing the individual pages).

See also QTabBar, QStackedWidget, QToolBox, and Tab Dialog Example.

Member Type Documentation

enum QTabWidget::TabPosition

This enum type defines where QTabWidget draws the tab row:

Constant	Value	Description
QTabWidget::North	0	The tabs are drawn above the pages.
QTabWidget::South	1	The tabs are drawn below the pages.
QTabWidget::West	2	The tabs are drawn to the left of the pages.
QTabWidget::East	3	The tabs are drawn to the right of the pages.

enum QTabWidget::TabShape

This enum type defines the shape of the tabs:

Constant	Value	Description
QTabWidget::Rounded	0	The tabs are drawn with a rounded look. This is the default shape.
QTabWidget::Triangular	1	The tabs are drawn with a triangular look.

Member Function Documentation

QTabWidget::QTabWidget(QWidget *parent = nullptr)

Constructs a tabbed widget with parent parent.

[signal] void QTabWidget::currentChanged(int index)

This signal is emitted whenever the current page index changes. The parameter is the new current page index position, or -1 if there isn't a new one (for example, if there are no widgets in the QTabWidget)

Note: Notifier signal for property currentIndex.

See also currentWidget() and currentIndex.

[slot] void QTabWidget::setCurrentWidget(QWidget *widget)

Makes widget the current widget. The widget used must be a page in this tab widget.

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

[signal] void QTabWidget::tabBarClicked(int index)

This signal is emitted when user clicks on a tab at an index.

index refers to the tab clicked, or -1 if no tab is under the cursor.

This function was introduced in Qt 5.2.

[signal] void QTabWidget::tabBarDoubleClicked(int index)

This signal is emitted when the user double clicks on a tab at an index.

index is the index of a clicked tab, or -1 if no tab is under the cursor.

This function was introduced in Qt 5.2.

[signal] void QTabWidget::tabCloseRequested(int index)

This signal is emitted when the close button on a tab is clicked. The index is the index that should be removed.

This function was introduced in Qt 4.5.

See also setTabsClosable().

[virtual] QTabWidget::~QTabWidget()

Destroys the tabbed widget.

int QTabWidget::addTab(QWidget *page, const QString &label)

Adds a tab with the given page and label to the tab widget, and returns the index of the tab in the tab bar. Ownership of page is passed on to the QTabWidget.

If the tab's label contains an ampersand, the letter following the ampersand is used as a shortcut for the tab, e.g. if the label is "Bro&wse" then Alt+W becomes a shortcut which will move the focus to this tab.

Note: If you call addTab() after show(), the layout system will try to adjust to the changes in its widgets hierarchy and may cause flicker. To prevent this, you can set the QWidget::updatesEnabled property to false prior to changes; remember to set the property to true when the changes are done, making the widget receive paint events again.

See also insertTab().

int QTabWidget::addTab(QWidget *page, const QIcon &icon, const QString &label)

This is an overloaded function.

Adds a tab with the given page, icon, and label to the tab widget, and returns the index of the tab in the tab bar. Ownership of page is passed on to the QTabWidget.

This function is the same as addTab(), but with an additional icon.

[override virtual protected] void QTabWidget::changeEvent(QEvent *ev)

Reimplements: QWidget::changeEvent(QEvent *event).

void QTabWidget::clear()

Removes all the pages, but does not delete them. Calling this function is equivalent to calling removeTab() until the tab widget is empty.

QWidget *QTabWidget::cornerWidget(Qt::Corner corner = Qt::TopRightCorner) const

Returns the widget shown in the corner of the tab widget or nullptr.

See also setCornerWidget().

QWidget *QTabWidget::currentWidget() const

Returns a pointer to the page currently being displayed by the tab dialog. The tab dialog does its best to make sure that this value is never 0 (but if you try hard enough, it can be).

See also currentIndex() and setCurrentWidget().

[override virtual protected] bool QTabWidget::event(QEvent *ev)

Reimplements: QWidget::event(QEvent *event).

[override virtual] bool QTabWidget::hasHeightForWidth() const

Reimplements: QWidget::hasHeightForWidth() const.

[override virtual] int QTabWidget::heightForWidth(int width) const

Reimplements: QWidget::heightForWidth(int w) const.

int QTabWidget::indexOf(QWidget *w) const

Returns the index position of the page occupied by the widget w, or -1 if the widget cannot be found.

[protected] void QTabWidget::initStyleOption(QStyleOptionTabWidgetFrame *option) const

Initialize option with the values from this QTabWidget. This method is useful for subclasses when they need a QStyleOptionTabWidgetFrame, but don't want to fill in all the information themselves.

See also QStyleOption::initFrom() and QTabBar::initStyleOption().

int QTabWidget::insertTab(int index, QWidget *page, const QString &label)

Inserts a tab with the given label and page into the tab widget at the specified index, and returns the index of the inserted tab in the tab bar. Ownership of page is passed on to the QTabWidget.

The label is displayed in the tab and may vary in appearance depending on the configuration of the tab widget.

If the tab's label contains an ampersand, the letter following the ampersand is used as a shortcut for the tab, e.g. if the label is "Bro&wse" then Alt+W becomes a shortcut which will move the focus to this tab.

If index is out of range, the tab is simply appended. Otherwise it is inserted at the specified position.

If the QTabWidget was empty before this function is called, the new page becomes the current page. Inserting a new tab at an index less than or equal to the current index will increment the current index, but keep the current page.

Note: If you call insertTab() after show(), the layout system will try to adjust to the changes in its widgets hierarchy and may cause flicker. To prevent this, you can set the QWidget::updatesEnabled property to false prior to changes; remember to set the property to true when the changes are done, making the widget receive paint events again.

See also addTab().

int QTabWidget::insertTab(int index, QWidget *page, const QIcon &icon, const QString &label)

This is an overloaded function.

Inserts a tab with the given label, page, and icon into the tab widget at the specified index, and returns the index of the inserted tab in the tab bar. Ownership of page is passed on to the QTabWidget.

This function is the same as insertTab(), but with an additional icon.

bool QTabWidget::isTabEnabled(int index) const

Returns true if the page at position index is enabled; otherwise returns false.

See also setTabEnabled() and QWidget::isEnabled().

[override virtual protected] void QTabWidget::keyPressEvent(QKeyEvent *e)

Reimplements: QWidget::keyPressEvent(QKeyEvent *event).

[override virtual] QSize QTabWidget::minimumSizeHint() const

Reimplements an access function for property: QWidget::minimumSizeHint.

Returns a suitable minimum size for the tab widget.

[override virtual protected] void QTabWidget::paintEvent(QPaintEvent *event)

Reimplements: QWidget::paintEvent(QPaintEvent *event).

Paints the tab widget's tab bar in response to the paint event.

void QTabWidget::removeTab(int index)

Removes the tab at position index from this stack of widgets. The page widget itself is not deleted.

See also addTab() and insertTab().

[override virtual protected] void QTabWidget::resizeEvent(QResizeEvent *e)

Reimplements: QWidget::resizeEvent(QResizeEvent *event).

void QTabWidget::setCornerWidget(QWidget *widget, Qt::Corner corner = Qt::TopRightCorner)

Sets the given widget to be shown in the specified corner of the tab widget. The geometry of the widget is determined based on the widget's sizeHint() and the style().

Only the horizontal element of the corner will be used.

Passing 0 shows no widget in the corner.

Any previously set corner widget is hidden.

All widgets set here will be deleted by the tab widget when it is destroyed unless you separately reparent the widget after setting some other corner widget (or nullptr).

Note: Corner widgets are designed for North and South tab positions; other orientations are known to not work properly.

See also cornerWidget() and setTabPosition().

[protected] void QTabWidget::setTabBar(QTabBar *tb)

Replaces the dialog's QTabBar heading with the tab bar tb. Note that this must be called before any tabs have been added, or the behavior is undefined.

See also tabBar().

void QTabWidget::setTabEnabled(int index, bool enable)

If enable is true, the page at position index is enabled; otherwise the page at position index is disabled. The page's tab is redrawn appropriately.

QTabWidget uses QWidget::setEnabled() internally, rather than keeping a separate flag.

Note that even a disabled tab/page may be visible. If the page is visible already, QTabWidget will not hide it; if all the pages are disabled, QTabWidget will show one of them.

See also isTabEnabled() and QWidget::setEnabled().

void QTabWidget::setTabIcon(int index, const QIcon &icon)

Sets the icon for the tab at position index.

See also tabIcon().

void QTabWidget::setTabText(int index, const QString &label)

Defines a new label for the page at position index's tab.

If the provided text contains an ampersand character ('&'), a shortcut is automatically created for it. The character that follows the '&' will be used as the shortcut key. Any previous shortcut will be overwritten, or cleared if no shortcut is defined by the text. See the QShortcut documentation for details (to display an actual ampersand, use '&&').

See also tabText().

void QTabWidget::setTabToolTip(int index, const QString &tip)

Sets the tab tool tip for the page at position index to tip.

See also tabToolTip().

void QTabWidget::setTabWhatsThis(int index, const QString &text)

Sets the What's This help text for the page at position index to text.

This function was introduced in Qt 4.1.

See also tabWhatsThis().

[override virtual protected] void QTabWidget::showEvent(QShowEvent *)

Reimplements: QWidget::showEvent(QShowEvent *event).

[override virtual] QSize QTabWidget::sizeHint() const

Reimplements an access function for property: QWidget::sizeHint.

QTabBar *QTabWidget::tabBar() const

Returns the current QTabBar.

See also setTabBar().

QIcon QTabWidget::tabIcon(int index) const

Returns the icon for the tab on the page at position index.

See also setTabIcon().

[virtual protected] void QTabWidget::tabInserted(int index)

This virtual handler is called after a new tab was added or inserted at position index.

See also tabRemoved().

[virtual protected] void QTabWidget::tabRemoved(int index)

This virtual handler is called after a tab was removed from position index.

See also tabInserted().

QString QTabWidget::tabText(int index) const

Returns the label text for the tab on the page at position index.

See also setTabText().

QString QTabWidget::tabToolTip(int index) const

Returns the tab tool tip for the page at position index or an empty string if no tool tip has been set.

See also setTabToolTip().

QString QTabWidget::tabWhatsThis(int index) const

Returns the What's This help text for the page at position index, or an empty string if no help text has been set.

This function was introduced in Qt 4.1.

See also setTabWhatsThis().

QWidget *QTabWidget::widget(int index) const

Returns the tab page at index position index or nullptr if the index is out of range.