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QButtonGroup Class

The QButtonGroup class provides a container to organize groups of button widgets. More...

Header: #include <QButtonGroup>
CMake: find_package(Qt6 REQUIRED COMPONENTS Widgets)
target_link_libraries(mytarget PRIVATE Qt6::Widgets)
qmake: QT += widgets
Inherits: QObject

Properties

Public Functions

QButtonGroup(QObject *parent = nullptr)
virtual ~QButtonGroup()
void addButton(QAbstractButton *button, int id = -1)
QAbstractButton *button(int id) const
QList<QAbstractButton *> buttons() const
QAbstractButton *checkedButton() const
int checkedId() const
bool exclusive() const
int id(QAbstractButton *button) const
void removeButton(QAbstractButton *button)
void setExclusive(bool)
void setId(QAbstractButton *button, int id)

Signals

void buttonClicked(QAbstractButton *button)
void buttonPressed(QAbstractButton *button)
void buttonReleased(QAbstractButton *button)
void buttonToggled(QAbstractButton *button, bool checked)
void idClicked(int id)
void idPressed(int id)
void idReleased(int id)
void idToggled(int id, bool checked)

Detailed Description

QButtonGroup provides an abstract container into which button widgets can be placed. It does not provide a visual representation of this container (see QGroupBox for a container widget), but instead manages the states of each of the buttons in the group.

An exclusive button group switches off all checkable (toggle) buttons except the one that has been clicked. By default, a button group is exclusive. The buttons in a button group are usually checkable QPushButtons, QCheckBoxes (normally for non-exclusive button groups), or QRadioButtons. If you create an exclusive button group, you should ensure that one of the buttons in the group is initially checked; otherwise, the group will initially be in a state where no buttons are checked.

A button can be added to the group with addButton() and removed with removeButton(). If the group is exclusive, the currently checked button is available with checkedButton(). If a button is clicked, the buttonClicked() signal is emitted; for a checkable button in an exclusive group this means that the button has been checked. The list of buttons in the group is returned by buttons().

In addition, QButtonGroup can map between integers and buttons. You can assign an integer id to a button with setId(), and retrieve it with id(). The id of the currently checked button is available with checkedId(), and there is a signal idClicked() that emits the id of the button. The id -1 is reserved by QButtonGroup to mean "no such button". The purpose of the mapping mechanism is to simplify the representation of enum values in a user interface.

See also QGroupBox, QPushButton, QCheckBox, and QRadioButton.

Property Documentation

exclusive : bool

This property holds whether the button group is exclusive

If this property is true, then only one button in the group can be checked at any given time. The user can click on any button to check it, and that button will replace the existing one as the checked button in the group.

In an exclusive group, the user cannot uncheck the currently checked button by clicking on it; instead, another button in the group must be clicked to set the new checked button for that group.

By default, this property is true.

Access functions:

bool exclusive() const
void setExclusive(bool)

Member Function Documentation

[explicit] QButtonGroup::QButtonGroup(QObject *parent = nullptr)

Constructs a new, empty button group with the given parent.

See also addButton() and setExclusive().

[virtual noexcept] QButtonGroup::~QButtonGroup()

Destroys the button group.

void QButtonGroup::addButton(QAbstractButton *button, int id = -1)

Adds the given button to the button group. If id is -1, an id will be assigned to the button. Automatically assigned ids are guaranteed to be negative, starting with -2. If you are assigning your own ids, use positive values to avoid conflicts.

See also removeButton() and buttons().

QAbstractButton *QButtonGroup::button(int id) const

Returns the button with the specified id, or nullptr if no such button exists.

[signal] void QButtonGroup::buttonClicked(QAbstractButton *button)

This signal is emitted when the given button is clicked. A button is clicked when it is first pressed and then released, when its shortcut key is typed, or when QAbstractButton::click() or QAbstractButton::animateClick() is programmatically called.

See also checkedButton() and QAbstractButton::clicked().

[signal] void QButtonGroup::buttonPressed(QAbstractButton *button)

This signal is emitted when the given button is pressed down.

See also QAbstractButton::pressed().

[signal] void QButtonGroup::buttonReleased(QAbstractButton *button)

This signal is emitted when the given button is released.

See also QAbstractButton::released().

[signal] void QButtonGroup::buttonToggled(QAbstractButton *button, bool checked)

This signal is emitted when the given button is toggled. checked is true if the button is checked, or false if the button is unchecked.

See also QAbstractButton::toggled().

QList<QAbstractButton *> QButtonGroup::buttons() const

Returns the button group's list of buttons. This may be empty.

See also addButton() and removeButton().

QAbstractButton *QButtonGroup::checkedButton() const

Returns the button group's checked button, or nullptr if no buttons are checked.

See also buttonClicked().

int QButtonGroup::checkedId() const

Returns the id of the checkedButton(), or -1 if no button is checked.

See also setId().

int QButtonGroup::id(QAbstractButton *button) const

Returns the id for the specified button, or -1 if no such button exists.

See also setId().

[signal] void QButtonGroup::idClicked(int id)

This signal is emitted when a button with the given id is clicked.

See also checkedButton() and QAbstractButton::clicked().

[signal] void QButtonGroup::idPressed(int id)

This signal is emitted when a button with the given id is pressed down.

See also QAbstractButton::pressed().

[signal] void QButtonGroup::idReleased(int id)

This signal is emitted when a button with the given id is released.

See also QAbstractButton::released().

[signal] void QButtonGroup::idToggled(int id, bool checked)

This signal is emitted when a button with the given id is toggled. checked is true if the button is checked, or false if the button is unchecked.

See also QAbstractButton::toggled().

void QButtonGroup::removeButton(QAbstractButton *button)

Removes the given button from the button group.

See also addButton() and buttons().

void QButtonGroup::setId(QAbstractButton *button, int id)

Sets the id for the specified button. Note that id cannot be -1.

See also id().

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