A class for grouping radio buttons logically together. More...

#include <Wt/WButtonGroup.h>

Inheritance diagram for Wt::WButtonGroup:

Public Member Functions
	WButtonGroup ()
	Creates a new empty button group. More...

void	addButton (WRadioButton *button, int id=-1)
	Adds a radio button to the group. More...

void	removeButton (WRadioButton *button)
	Removes a radio button from the group. More...

WRadioButton *	button (int id) const
	Returns the button for the given id. More...

int	id (WRadioButton *button) const
	Returns the id for the given button. More...

virtual const std::string	id () const override
	Returns the (unique) identifier for this object. More...

std::vector< WRadioButton * >	buttons () const
	Returns the buttons in this group.

int	count () const
	Returns the number of radiobuttons in this group.

int	checkedId () const
	Returns the id of the checked button. More...

void	setCheckedButton (WRadioButton *button)
	Sets the currently checked radiobutton. More...

WRadioButton *	checkedButton () const
	Returns the checked radiobutton. More...

void	setSelectedButtonIndex (int idx)
	Sets the currently checked radiobutton. More...

int	selectedButtonIndex () const
	Returns the index of the checked radiobutton. More...

Signal< WRadioButton * > &	checkedChanged ()
	Signal emitted when a button was checked. More...

Public Member Functions inherited from Wt::WObject
void	addChild (std::unique_ptr< WObject > child)
	Add a child WObject whose lifetime is determined by this WObject.

template<typename Child >
Child *	addChild (std::unique_ptr< Child > child)
	Add a child WObject, returning a raw pointer. More...

std::unique_ptr< WObject >	removeChild (WObject *child)
	Remove a child WObject, so its lifetime is no longer determined by this WObject.

template<typename Child >
std::unique_ptr< Child >	removeChild (Child *child)
	Remove a child WObject, so its lifetime is no longer determined by this WObject. More...

virtual void	setObjectName (const std::string &name)
	Sets an object name. More...

virtual std::string	objectName () const
	Returns the object name. More...

void	resetLearnedSlots ()
	Resets learned stateless slot implementations. More...

template<class T >
void	resetLearnedSlot (void(T::*method)())
	Resets a learned stateless slot implementation. More...

template<class T >
WStatelessSlot *	implementStateless (void(T::*method)())
	Declares a slot to be stateless and learn client-side behaviour on first invocation. More...

template<class T >
WStatelessSlot *	implementStateless (void(T::method)(), void(T::undoMethod)())
	Declares a slot to be stateless and learn client-side behaviour in advance. More...

void	isNotStateless ()
	Marks the current function as not stateless. More...

template<class T >
WStatelessSlot *	implementJavaScript (void(T::*method)(), const std::string &jsCode)
	Provides a JavaScript implementation for a method. More...

Public Member Functions inherited from Wt::Core::observable
	observable () noexcept
	Default constructor.

virtual	~observable ()
	Destructor. More...

template<typename... Args, typename C >
auto	bindSafe (void(C::*method)(Args...)) noexcept
	Protects a method call against object destruction. More...

template<typename... Args, typename C >
auto	bindSafe (void(C::*method)(Args...) const) const noexcept
	Protects a const method call against object destruction. More...

template<typename Function >
auto	bindSafe (const Function &function) noexcept
	Protects a function against object destruction. More...

Additional Inherited Members
Public Types inherited from Wt::WObject
typedef void(WObject::*	Method) ()
	Typedef for a WObject method without arguments.

Protected Member Functions inherited from Wt::WObject
virtual WStatelessSlot *	getStateless (Method method)
	On-demand stateless slot implementation. More...

Detailed Description

A class for grouping radio buttons logically together.

A button group manages a set of radio buttons, making them exclusive of each other.

It is not a widget, but instead provides only a logical grouping. Radio buttons are aware of the group in which they have been added, see WRadioButton::group(). When a button is deleted, it is automatically removed its button group.

It allows you to associate id's with each button, which you may use to identify a particular button. The special value of -1 is reserved to indicate no button.

Usage example:

enum class Vote { Republican = 1, Democrat = 2, NoVote = 10 };
 
// use a group box as widget container for 3 radio buttons, with a title
auto container = std::make_unique<Wt::WGroupBox>("USA elections vote");
 
// use a button group to logically group the 3 options
auto group = std::make_shared<Wt::WButtonGroup>();
 
Wt::WRadioButton *button;
button = container->addWidget(
           std::make_unique<Wt::WRadioButton>(
             "I voted Republican"));
container->addWidget(std::make_unique<Wt::WBreak>());
group->addButton(button, Vote::Republican);
 
button = container->addWidget(
           std::make_unique<Wt::WRadioButton>(
             "I voted Democrat"));
container->addWidget(std::make_unique<Wt::WBreak>());
group->addButton(button, Vote::Democrat);
 
button = container->addWidget(
           std::make_unique<Wt::WRadioButton>(
             "I didn't vote"));
container->addWidget(std::make_unique<Wt::WBreak>());
group->addButton(button, Vote::NoVote);
 
group->setCheckedButton(group->button(Vote::NoVote));

See also: WRadioButton

Constructor & Destructor Documentation

◆ WButtonGroup()

Wt::WButtonGroup::WButtonGroup ( )

Creates a new empty button group.

Note: The WRadioButtons associated with this WButtonGroup keep a shared_ptr to this WButtonGroup. Therefore, you should store a WButtonGroup in a shared_ptr (e.g. construct it with make_shared) before adding any radio buttons to it.

Member Function Documentation

◆ addButton()

void Wt::WButtonGroup::addButton	(	WRadioButton *	button,
		int	id = `-1`
	)

Adds a radio button to the group.

You can assign an id to the button. If id is -1, then a unique id will be generated.

Note: WButtonGroup should be owned by a shared_ptr before addButton is called on it!

See also: removeButton(WRadioButton *)

◆ button()

WRadioButton * Wt::WButtonGroup::button ( int id ) const

Returns the button for the given id.

Returns nullptr if no button exists for the given id.

See also: id(), addButton()

◆ checkedButton()

WRadioButton * Wt::WButtonGroup::checkedButton ( ) const

Returns the checked radiobutton.

If there is no radiobutton currently checked this function returns nullptr.

See also: setCheckedButton(), selectedButtonIndex()

◆ checkedChanged()

Signal< WRadioButton * > & Wt::WButtonGroup::checkedChanged ( )

Signal emitted when a button was checked.

The argument passed is the new checkedButton().

◆ checkedId()

int Wt::WButtonGroup::checkedId ( ) const

Returns the id of the checked button.

Returns the id of the currently checked button, or -1 if no button is currently checked.

◆ id() [1/2]

virtual const std::string Wt::WButtonGroup::id ( ) const

overridevirtual

Returns the (unique) identifier for this object.

For a WWidget, this corresponds to the id of the DOM element that represents the widget. This is not entirely unique, since a composite widget shares the same id as its implementation.

By default, the id is auto-generated, unless a custom id is set for a widget using WWidget::setId().

See also: WWidget::jsRef()

Reimplemented from Wt::WObject.

◆ id() [2/2]

int Wt::WButtonGroup::id ( WRadioButton * button ) const

Returns the id for the given button.

See also: button(), addButton()

◆ removeButton()

void Wt::WButtonGroup::removeButton ( WRadioButton * button )

Removes a radio button from the group.

See also: addButton(WRadioButton *, int)

◆ selectedButtonIndex()

int Wt::WButtonGroup::selectedButtonIndex ( ) const

Returns the index of the checked radiobutton.

The index reflects the order in which the buttons have been added to the button group. Use checkedId() if you want to know the id of the button that is currently checked. If there is no radiobutton selected this function returns -1.

See also: checkedId()

◆ setCheckedButton()

void Wt::WButtonGroup::setCheckedButton ( WRadioButton * button )

Sets the currently checked radiobutton.

The button button of this group is checked. A value of 0 will uncheck all radiobuttons.

Initially, no button is checked.

See also: checkedId()

◆ setSelectedButtonIndex()

void Wt::WButtonGroup::setSelectedButtonIndex ( int idx )