glibmm 2.56.0

Public Member Functions | Static Public Member Functions | Protected Member Functions | Related Functions | List of all members
Gio::ActionGroup Class Reference

ActionGroup - a group of actions. More...

`#include <giomm/actiongroup.h>`

Inheritance diagram for Gio::ActionGroup:
[legend]

## Public Member Functions
| ActionGroup (ActionGroup&& src) noexcept
ActionGroup& | operator= (ActionGroup&& src) noexcept
| ~ActionGroup () noexcept override
GActionGroup* | gobj ()
| Provides access to the underlying C GObject. More...
const GActionGroup* | gobj () const
| Provides access to the underlying C GObject. More...
bool | has_action (const Glib::ustring& action_name) const
| Checks if the named action exists within action_group. More...
std::vector< Glib::ustring > | list_actions () const
| Lists the actions contained within action_group. More...
bool | query_action (const Glib::ustring& action_name, bool& enabled, Glib::VariantType& parameter_type, Glib::VariantBase& state_hint, Glib::VariantType& state_type, Glib::VariantBase& state)
| Queries all aspects of the named action within an action_group. More...
bool | query_action (const Glib::ustring& action_name, bool& enabled, Glib::VariantType& parameter_type, Glib::VariantBase& state_hint, Glib::VariantType& state_type)
| A query_action() convenience overload. More...
bool | query_action (const Glib::ustring& action_name, bool& enabled, Glib::VariantType& parameter_type, Glib::VariantBase& state_hint, Glib::VariantBase& state)
| A query_action() convenience overload. More...
bool | query_action (const Glib::ustring& action_name, bool& enabled, Glib::VariantType& parameter_type, Glib::VariantBase& state_hint)
| A query_action() convenience overload. More...
bool | query_action (const Glib::ustring& action_name, bool& enabled, Glib::VariantBase& state_hint, Glib::VariantType& state_type, Glib::VariantBase& state)
| A query_action() convenience overload. More...
bool | query_action (const Glib::ustring& action_name, bool& enabled, Glib::VariantBase& state_hint, Glib::VariantType& state_type)
| A query_action() convenience overload. More...
bool | query_action (const Glib::ustring& action_name, bool& enabled, Glib::VariantBase& state_hint, Glib::VariantBase& state)
| A query_action() convenience overload. More...
bool | query_action (const Glib::ustring& action_name, bool& enabled, Glib::VariantBase& state_hint)
| A query_action() convenience overload. More...
bool | get_action_enabled (const Glib::ustring& action_name) const
| Checks if the named action within action_group is currently enabled. More...
Glib::VariantType | get_action_parameter_type (const Glib::ustring& action_name) const
| Queries the type of the parameter that must be given when activating the named action within action_group. More...
Glib::VariantType | get_action_state_type (const Glib::ustring& action_name) const
| Queries the type of the state of the named action within action_group. More...
Glib::VariantContainerBase | get_action_state_hint (const Glib::ustring& action_name) const
| Requests a hint about the valid range of values for the state of the named action within action_group. More...
template<typename T_Value >
void | get_action_state_hint (const Glib::ustring& action_name, T_Value& value) const
| Requests a hint about the valid range of values for the state of the named action within the action group. More...
Glib::VariantContainerBase | get_action_state_hint_variant (const Glib::ustring& action_name) const
| Requests a hint about the valid range of values for the state of the named action within action_group. More...
Glib::VariantBase | get_action_state (const Glib::ustring& action_name) const
| Queries the current state of the named action within action_group. More...
template<typename T_Value >
void | get_action_state (const Glib::ustring& action_name, T_Value& value) const
| Queries the current state of the named action within the action group. More...
Glib::VariantBase | get_action_state_variant (const Glib::ustring& action_name) const
| Queries the current state of the named action within action_group. More...
void | change_action_state (const Glib::ustring& action_name, const Glib::VariantBase& value)
| Request for the state of the named action within action_group to be changed to value. More...
void | activate_action (const Glib::ustring& action_name, const Glib::VariantBase& parameter)
| Activate the named action within action_group. More...
void | activate_action (const Glib::ustring& action_name)
| A activate_action() convenience overload. More...
void | action_added (const Glib::ustring& action_name)
| Emits the ActionGroup::signal_action_added() signal on action_group. More...
void | action_removed (const Glib::ustring& action_name)
| Emits the ActionGroup::signal_action_removed() signal on action_group. More...
void | action_enabled_changed (const Glib::ustring& action_name, bool enabled)
| Emits the ActionGroup::signal_action_enabled_changed() signal on action_group. More...
void | action_state_changed (const Glib::ustring& action_name, const Glib::VariantBase& state)
| Emits the ActionGroup::signal_action_state_changed() signal on action_group. More...
Glib::SignalProxy< void, const Glib::ustring&> | signal_action_added ()
Glib::SignalProxyDetailedAnyType< void, const Glib::ustring&> | signal_action_added (const Glib::ustring& action_name)
Glib::SignalProxy< void, const Glib::ustring&, bool > | signal_action_enabled_changed ()
Glib::SignalProxyDetailedAnyType< void, const Glib::ustring&, bool > | signal_action_enabled_changed (const Glib::ustring& action_name)
Glib::SignalProxy< void, const Glib::ustring&> | signal_action_removed ()
Glib::SignalProxyDetailedAnyType< void, const Glib::ustring&> | signal_action_removed (const Glib::ustring& action_name)
Glib::SignalProxy< void, const Glib::ustring&, const Glib::VariantBase&> | signal_action_state_changed ()
Glib::SignalProxyDetailedAnyType< void, const Glib::ustring&, const Glib::VariantBase&> | signal_action_state_changed (const Glib::ustring& action_name)
virtual bool | has_action_vfunc (const Glib::ustring& name) const
virtual std::vector< Glib::ustring > | list_actions_vfunc () const
virtual bool | get_action_enabled_vfunc (const Glib::ustring& name) const
virtual Glib::VariantType | get_action_parameter_type_vfunc (const Glib::ustring& name) const
virtual Glib::VariantType | get_action_state_type_vfunc (const Glib::ustring& name) const
virtual Glib::VariantBase | get_action_state_hint_vfunc (const Glib::ustring& name) const
virtual Glib::VariantBase | get_action_state_vfunc (const Glib::ustring& name) const
virtual void | change_action_state_vfunc (const Glib::ustring& name, const Glib::VariantBase& value)
virtual void | activate_action_vfunc (const Glib::ustring& name, const Glib::VariantBase& parameter)
Public Member Functions inherited from Glib::Interface
| Interface ()
| A Default constructor. More...
| Interface (Interface&& src) noexcept
Interface& | operator= (Interface&& src) noexcept
| Interface (const Glib::Interface_Class& interface_class)
| Called by constructors of derived classes. More...
| Interface (GObject* castitem)
| Called by constructors of derived classes. More...
| ~Interface () noexcept override
| Interface (const Interface&)=delete
Interface& | operator= (const Interface&)=delete
GObject* | gobj ()
const GObject* | gobj () const
Public Member Functions inherited from Glib::ObjectBase
| ObjectBase (const ObjectBase&)=delete
ObjectBase& | operator= (const ObjectBase&)=delete
void | set_property_value (const Glib::ustring& property_name, const Glib::ValueBase& value)
| You probably want to use a specific property_*() accessor method instead. More...
void | get_property_value (const Glib::ustring& property_name, Glib::ValueBase& value) const
| You probably want to use a specific property_*() accessor method instead. More...
template<class PropertyType >
void | set_property (const Glib::ustring& property_name, const PropertyType& value)
| You probably want to use a specific property_*() accessor method instead. More...
template<class PropertyType >
void | get_property (const Glib::ustring& property_name, PropertyType& value) const
| You probably want to use a specific property_*() accessor method instead. More...
void | connect_property_changed (const Glib::ustring& property_name, const sigc::slot< void >& slot)
| You can use the signal_changed() signal of the property proxy instead. More...
void | connect_property_changed (const Glib::ustring& property_name, sigc::slot< void >&& slot)
| You can use the signal_changed() signal of the property proxy instead. More...
sigc::connection | connect_property_changed_with_return (const Glib::ustring& property_name, const sigc::slot< void >& slot)
| You can use the signal_changed() signal of the property proxy instead. More...
sigc::connection | connect_property_changed_with_return (const Glib::ustring& property_name, sigc::slot< void >&& slot)
| You can use the signal_changed() signal of the property proxy instead. More...
void | freeze_notify ()
| Increases the freeze count on object. More...
void | thaw_notify ()
| Reverts the effect of a previous call to freeze_notify(). More...
virtual void | reference () const
| Increment the reference count for this object. More...
virtual void | unreference () const
| Decrement the reference count for this object. More...
GObject* | gobj ()
| Provides access to the underlying C GObject. More...
const GObject* | gobj () const
| Provides access to the underlying C GObject. More...
GObject* | gobj_copy () const
| Give a ref-ed copy to someone. Use for direct struct access. More...
Public Member Functions inherited from sigc::trackable
| trackable () noexcept
| trackable (const trackable &src) noexcept
| trackable (trackable &&src)
| ~trackable ()
void | add_destroy_notify_callback (void *data, func_destroy_notify func) const
void | notify_callbacks ()
trackable & | operator= (const trackable &src)
trackable & | operator= (trackable &&src)
void | remove_destroy_notify_callback (void *data) const

## Static Public Member Functions
static void | add_interface (GType gtype_implementer)
static GType | get_type ()
| Get the GType for this class, for use with the underlying GObject type system. More...

## Protected Member Functions
| ActionGroup ()
| You should derive from this class to use it. More...
virtual void | on_action_added (const Glib::ustring& action_name)
| This is a default handler for the signal signal_action_added(). More...
virtual void | on_action_enabled_changed (const Glib::ustring& action_name, bool enabled)
| This is a default handler for the signal signal_action_enabled_changed(). More...
virtual void | on_action_removed (const Glib::ustring& action_name)
| This is a default handler for the signal signal_action_removed(). More...
virtual void | on_action_state_changed (const Glib::ustring& action_name, const Glib::VariantBase& value)
| This is a default handler for the signal signal_action_state_changed(). More...
Protected Member Functions inherited from Glib::ObjectBase
| ObjectBase ()
| This default constructor is called implicitly from the constructor of user-derived classes, even if, for instance, Gtk::Button calls a different ObjectBase constructor. More...
| ObjectBase (const char* custom_type_name)
| A derived constructor always overrides this choice. More...
| ObjectBase (const std::type_info& custom_type_info)
| This constructor is a special feature to allow creation of derived types on the fly, without having to use g_object_new() manually. More...
| ObjectBase (ObjectBase&& src) noexcept
ObjectBase& | operator= (ObjectBase&& src) noexcept
virtual | ~ObjectBase () noexcept=0
void | initialize (GObject* castitem)
void | initialize_move (GObject* castitem, Glib::ObjectBase* previous_wrapper)

## Related Functions
(Note that these are not member functions.)
Glib::RefPtr< Gio::ActionGroup > | wrap (GActionGroup* object, bool take_copy=false)
| A Glib::wrap() method for this object. More...

## Additional Inherited Members
Public Types inherited from sigc::trackable
typedef internal::func_destroy_notify | func_destroy_notify

## Detailed Description

ActionGroup - a group of actions.

ActionGroup represents a group of actions.

Each action in the group has a unique name (which is a string). All method calls, except list_actions() take the name of an action as an argument.

The GActionGroup API is meant to be the 'public' API to the action group. The calls here are exactly the interaction that 'external forces' (eg: UI, incoming D-Bus messages, etc.) are supposed to have with actions. 'Internal' APIs (ie: ones meant only to be accessed by the action group implementation) are found on subclasses. This is why you will find – for example – get_action_enabled() but not an equivalent `set()` call.

Signals are emitted on the action group in response to state changes on individual actions.

## Constructor & Destructor Documentation

## ◆ ActionGroup() [1/2]

Gio::ActionGroup::ActionGroup | ( |  | ) |
| protected

You should derive from this class to use it.

## ◆ ActionGroup() [2/2]

Gio::ActionGroup::ActionGroup | ( | ActionGroup&& | src | ) |
| noexcept

## ◆ ~ActionGroup()

Gio::ActionGroup::~ActionGroup | ( |  | ) |
| override noexcept

## Member Function Documentation

## ◆ action_added()

void Gio::ActionGroup::action_added | ( | const Glib::ustring& | action_name | ) |

Emits the ActionGroup::signal_action_added() signal on action_group.

This function should only be called by ActionGroup implementations.

Since glibmm 2.28:

Parameters

  action_name | The name of an action in the group.

## ◆ action_enabled_changed()

void Gio::ActionGroup::action_enabled_changed | ( | const Glib::ustring& | action_name,
|  | bool | enabled
| ) |  |

Emits the ActionGroup::signal_action_enabled_changed() signal on action_group.

This function should only be called by ActionGroup implementations.

Since glibmm 2.28:

Parameters

  action_name | The name of an action in the group.
  enabled | Whether or not the action is now enabled.

## ◆ action_removed()

void Gio::ActionGroup::action_removed | ( | const Glib::ustring& | action_name | ) |

Emits the ActionGroup::signal_action_removed() signal on action_group.

This function should only be called by ActionGroup implementations.

Since glibmm 2.28:

Parameters

  action_name | The name of an action in the group.

## ◆ action_state_changed()

void Gio::ActionGroup::action_state_changed | ( | const Glib::ustring& | action_name,
|  | const Glib::VariantBase& | state
| ) |  |

Emits the ActionGroup::signal_action_state_changed() signal on action_group.

This function should only be called by ActionGroup implementations.

Since glibmm 2.28:

Parameters

  action_name | The name of an action in the group.
  state | The new state of the named action.

## ◆ activate_action() [1/2]

void Gio::ActionGroup::activate_action | ( | const Glib::ustring& | action_name,
|  | const Glib::VariantBase& | parameter
| ) |  |

Activate the named action within action_group.

If the action is expecting a parameter, then the correct type of parameter must be given as parameter. If the action is expecting no parameters then parameter must be `nullptr`. See g_action_group_get_action_parameter_type().

Since glibmm 2.28:

Parameters

  action_name | The name of the action to activate.
  parameter | Parameters to the activation.

## ◆ activate_action() [2/2]

void Gio::ActionGroup::activate_action | ( | const Glib::ustring& | action_name | ) |

A activate_action() convenience overload.

## ◆ activate_action_vfunc()

virtual void Gio::ActionGroup::activate_action_vfunc | ( | const Glib::ustring& | name,
|  | const Glib::VariantBase& | parameter
| ) |  |
| virtual

## ◆ add_interface()

static void Gio::ActionGroup::add_interface | ( | GType | gtype_implementer | ) |
| static

## ◆ change_action_state()

void Gio::ActionGroup::change_action_state | ( | const Glib::ustring& | action_name,
|  | const Glib::VariantBase& | value
| ) |  |

Request for the state of the named action within action_group to be changed to value.

The action must be stateful and value must be of the correct type. See g_action_group_get_action_state_type().

This call merely requests a change. The action may refuse to change its state or may change its state to something other than value. See g_action_group_get_action_state_hint().

If the value GVariant is floating, it is consumed.

Since glibmm 2.28:

Parameters

  action_name | The name of the action to request the change on.
  value | The new state.

## ◆ change_action_state_vfunc()

virtual void Gio::ActionGroup::change_action_state_vfunc | ( | const Glib::ustring& | name,
|  | const Glib::VariantBase& | value
| ) |  |
| virtual

## ◆ get_action_enabled()

bool Gio::ActionGroup::get_action_enabled | ( | const Glib::ustring& | action_name | ) | const

Checks if the named action within action_group is currently enabled.

An action must be enabled in order to be activated or in order to have its state changed from outside callers.

Since glibmm 2.28:

Parameters

  action_name | The name of the action to query.

Returns
  Whether or not the action is currently enabled.

## ◆ get_action_enabled_vfunc()

virtual bool Gio::ActionGroup::get_action_enabled_vfunc | ( | const Glib::ustring& | name | ) | const
| virtual

## ◆ get_action_parameter_type()

Glib::VariantType Gio::ActionGroup::get_action_parameter_type | ( | const Glib::ustring& | action_name | ) | const

Queries the type of the parameter that must be given when activating the named action within action_group.

When activating the action using g_action_group_activate_action(), the Variant given to that function must be of the type returned by this function.

In the case that this function returns `nullptr`, you must not give any Variant, but `nullptr` instead.

The parameter type of a particular action will never change but it is possible for an action to be removed and for a new action to be added with the same name but a different parameter type.

Since glibmm 2.28:

Parameters

  action_name | The name of the action to query.

Returns
  The parameter type.

## ◆ get_action_parameter_type_vfunc()

virtual Glib::VariantType Gio::ActionGroup::get_action_parameter_type_vfunc | ( | const Glib::ustring& | name | ) | const
| virtual

## ◆ get_action_state() [1/2]

Glib::VariantBase Gio::ActionGroup::get_action_state | ( | const Glib::ustring& | action_name | ) | const

Queries the current state of the named action within action_group.

If the action is not stateful then `nullptr` will be returned. If the action is stateful then the type of the return value is the type given by g_action_group_get_action_state_type().

The return value (if non-`nullptr`) should be freed with Glib::variant_unref() when it is no longer required.

Since glibmm 2.28:

Deprecated:
  Use the get_action_state() method that takes an output parameter instead.

Parameters

  action_name | The name of the action to query.

Returns
  The current state of the action.

## ◆ get_action_state() [2/2]

template <typename T_Value >

void Gio::ActionGroup::get_action_state | ( | const Glib::ustring& | action_name,
|  | T_Value & | value
| ) |  | const

Queries the current state of the named action within the action group.

If the action is not stateful then a null Variant will be returned. If the action is stateful then the type of the return value is the type given by get_action_state_type().

Parameters

  action_name | The name of the action to query.
  value | This will be set to the current state of the action.

## ◆ get_action_state_hint() [1/2]

Glib::VariantContainerBase Gio::ActionGroup::get_action_state_hint | ( | const Glib::ustring& | action_name | ) | const

Requests a hint about the valid range of values for the state of the named action within action_group.

If `nullptr` is returned it either means that the action is not stateful or that there is no hint about the valid range of values for the state of the action.

If a Variant array is returned then each item in the array is a possible value for the state. If a Variant pair (ie: two-tuple) is returned then the tuple specifies the inclusive lower and upper bound of valid values for the state.

In any case, the information is merely a hint. It may be possible to have a state value outside of the hinted range and setting a value within the range may fail.

The return value (if non-`nullptr`) should be freed with Glib::variant_unref() when it is no longer required.

Since glibmm 2.28:

Deprecated:
  Use the get_action_state() method that takes an output parameter instead.

Parameters

  action_name | The name of the action to query.

Returns
  The state range hint.

## ◆ get_action_state_hint() [2/2]

template <typename T_Value >

void Gio::ActionGroup::get_action_state_hint | ( | const Glib::ustring& | action_name,
|  | T_Value & | value
| ) |  | const

Requests a hint about the valid range of values for the state of the named action within the action group.

If a null Variant is returned it either means that the action is not stateful or that there is no hint about the valid range of values for the state of the action.

If a ariant array is returned then each item in the array is a possible value for the state. If Variant pair (ie: two-tuple) is returned then the tuple specifies the inclusive lower and upper bound of valid values for the state.

In any case, the information is merely a hint. It may be possible to have a state value outside of the hinted range and setting a value within the range may fail.

Parameters

  action_name | The name of the action to query.
  value | This will be set to the state range hint.

## ◆ get_action_state_hint_variant()

Glib::VariantContainerBase Gio::ActionGroup::get_action_state_hint_variant | ( | const Glib::ustring& | action_name | ) | const

Requests a hint about the valid range of values for the state of the named action within action_group.

If `nullptr` is returned it either means that the action is not stateful or that there is no hint about the valid range of values for the state of the action.

If a Variant array is returned then each item in the array is a possible value for the state. If a Variant pair (ie: two-tuple) is returned then the tuple specifies the inclusive lower and upper bound of valid values for the state.

In any case, the information is merely a hint. It may be possible to have a state value outside of the hinted range and setting a value within the range may fail.

The return value (if non-`nullptr`) should be freed with Glib::variant_unref() when it is no longer required.

Since glibmm 2.28:

Parameters

  action_name | The name of the action to query.

Returns
  The state range hint.

## ◆ get_action_state_hint_vfunc()

virtual Glib::VariantBase Gio::ActionGroup::get_action_state_hint_vfunc | ( | const Glib::ustring& | name | ) | const
| virtual

## ◆ get_action_state_type()

Glib::VariantType Gio::ActionGroup::get_action_state_type | ( | const Glib::ustring& | action_name | ) | const

Queries the type of the state of the named action within action_group.

If the action is stateful then this function returns the VariantType of the state. All calls to g_action_group_change_action_state() must give a Variant of this type and g_action_group_get_action_state() will return a Variant of the same type.

If the action is not stateful then this function will return `nullptr`. In that case, g_action_group_get_action_state() will return `nullptr` and you must not call g_action_group_change_action_state().

The state type of a particular action will never change but it is possible for an action to be removed and for a new action to be added with the same name but a different state type.

Since glibmm 2.28:

Parameters

  action_name | The name of the action to query.

Returns
  The state type, if the action is stateful.

## ◆ get_action_state_type_vfunc()

virtual Glib::VariantType Gio::ActionGroup::get_action_state_type_vfunc | ( | const Glib::ustring& | name | ) | const
| virtual

## ◆ get_action_state_variant()

Glib::VariantBase Gio::ActionGroup::get_action_state_variant | ( | const Glib::ustring& | action_name | ) | const

Queries the current state of the named action within action_group.

If the action is not stateful then `nullptr` will be returned. If the action is stateful then the type of the return value is the type given by g_action_group_get_action_state_type().

The return value (if non-`nullptr`) should be freed with Glib::variant_unref() when it is no longer required.

Since glibmm 2.28:

Parameters

  action_name | The name of the action to query.

Returns
  The current state of the action.

## ◆ get_action_state_vfunc()

virtual Glib::VariantBase Gio::ActionGroup::get_action_state_vfunc | ( | const Glib::ustring& | name | ) | const
| virtual

## ◆ get_type()

static GType Gio::ActionGroup::get_type | ( |  | ) |
| static

Get the GType for this class, for use with the underlying GObject type system.

## ◆ gobj() [1/2]

GActionGroup* Gio::ActionGroup::gobj | ( |  | ) |
| inline

Provides access to the underlying C GObject.

## ◆ gobj() [2/2]

const GActionGroup* Gio::ActionGroup::gobj | ( |  | ) | const
| inline

Provides access to the underlying C GObject.

## ◆ has_action()

bool Gio::ActionGroup::has_action | ( | const Glib::ustring& | action_name | ) | const

Checks if the named action exists within action_group.

Since glibmm 2.28:

Parameters

  action_name | The name of the action to check for.

Returns
  Whether the named action exists.

## ◆ has_action_vfunc()

virtual bool Gio::ActionGroup::has_action_vfunc | ( | const Glib::ustring& | name | ) | const
| virtual

## ◆ list_actions()

std::vector<Glib::ustring> Gio::ActionGroup::list_actions | ( |  | ) | const

Lists the actions contained within action_group.

Since glibmm 2.28:

Returns
  A `nullptr`-terminated array of the names of the actions in the group.

## ◆ list_actions_vfunc()

virtual std::vector<Glib::ustring> Gio::ActionGroup::list_actions_vfunc | ( |  | ) | const
| virtual

## ◆ on_action_added()

virtual void Gio::ActionGroup::on_action_added | ( | const Glib::ustring& | action_name | ) |
| protected virtual

This is a default handler for the signal signal_action_added().

## ◆ on_action_enabled_changed()

virtual void Gio::ActionGroup::on_action_enabled_changed | ( | const Glib::ustring& | action_name,
|  | bool | enabled
| ) |  |
| protected virtual

This is a default handler for the signal signal_action_enabled_changed().

## ◆ on_action_removed()

virtual void Gio::ActionGroup::on_action_removed | ( | const Glib::ustring& | action_name | ) |
| protected virtual

This is a default handler for the signal signal_action_removed().

## ◆ on_action_state_changed()

virtual void Gio::ActionGroup::on_action_state_changed | ( | const Glib::ustring& | action_name,
|  | const Glib::VariantBase& | value
| ) |  |
| protected virtual

This is a default handler for the signal signal_action_state_changed().

## ◆ operator=()

ActionGroup& Gio::ActionGroup::operator= | ( | ActionGroup&& | src | ) |
| noexcept

## ◆ query_action() [1/8]

bool Gio::ActionGroup::query_action | ( | const Glib::ustring& | action_name,
|  | bool & | enabled,
|  | Glib::VariantType& | parameter_type,
|  | Glib::VariantBase& | state_hint,
|  | Glib::VariantType& | state_type,
|  | Glib::VariantBase& | state
| ) |  |

Queries all aspects of the named action within an action_group.

This function acquires the information available from g_action_group_has_action(), g_action_group_get_action_enabled(), g_action_group_get_action_parameter_type(), g_action_group_get_action_state_type(), g_action_group_get_action_state_hint() and g_action_group_get_action_state() with a single function call.

This provides two main benefits.

The first is the improvement in efficiency that comes with not having to perform repeated lookups of the action in order to discover different things about it. The second is that implementing ActionGroup can now be done by only overriding this one virtual function.

The interface provides a default implementation of this function that calls the individual functions, as required, to fetch the information. The interface also provides default implementations of those functions that call this function. All implementations, therefore, must override either this function or all of the others.

If the action exists, `true` is returned and any of the requested fields (as indicated by having a non-`nullptr` reference passed in) are filled. If the action doesn't exist, `false` is returned and the fields may or may not have been modified.

Since glibmm 2.32:

Parameters

  action_name | The name of an action in the group.
  enabled | If the action is presently enabled.
  parameter_type | The parameter type, or `nullptr` if none needed.
  state_type | The state type, or `nullptr` if stateless.
  state_hint | The state hint, or `nullptr` if none.
  state | The current state, or `nullptr` if stateless.

Returns
  `true` if the action exists, else `false`.

## ◆ query_action() [2/8]

bool Gio::ActionGroup::query_action | ( | const Glib::ustring& | action_name,
|  | bool & | enabled,
|  | Glib::VariantType& | parameter_type,
|  | Glib::VariantBase& | state_hint,
|  | Glib::VariantType& | state_type
| ) |  |

A query_action() convenience overload.

## ◆ query_action() [3/8]

bool Gio::ActionGroup::query_action | ( | const Glib::ustring& | action_name,
|  | bool & | enabled,
|  | Glib::VariantType& | parameter_type,
|  | Glib::VariantBase& | state_hint,
|  | Glib::VariantBase& | state
| ) |  |

A query_action() convenience overload.

## ◆ query_action() [4/8]

bool Gio::ActionGroup::query_action | ( | const Glib::ustring& | action_name,
|  | bool & | enabled,
|  | Glib::VariantType& | parameter_type,
|  | Glib::VariantBase& | state_hint
| ) |  |

A query_action() convenience overload.

## ◆ query_action() [5/8]

bool Gio::ActionGroup::query_action | ( | const Glib::ustring& | action_name,
|  | bool & | enabled,
|  | Glib::VariantBase& | state_hint,
|  | Glib::VariantType& | state_type,
|  | Glib::VariantBase& | state
| ) |  |

A query_action() convenience overload.

## ◆ query_action() [6/8]

bool Gio::ActionGroup::query_action | ( | const Glib::ustring& | action_name,
|  | bool & | enabled,
|  | Glib::VariantBase& | state_hint,
|  | Glib::VariantType& | state_type
| ) |  |

A query_action() convenience overload.

## ◆ query_action() [7/8]

bool Gio::ActionGroup::query_action | ( | const Glib::ustring& | action_name,
|  | bool & | enabled,
|  | Glib::VariantBase& | state_hint,
|  | Glib::VariantBase& | state
| ) |  |

A query_action() convenience overload.

## ◆ query_action() [8/8]

bool Gio::ActionGroup::query_action | ( | const Glib::ustring& | action_name,
|  | bool & | enabled,
|  | Glib::VariantBase& | state_hint
| ) |  |

A query_action() convenience overload.

## ◆ signal_action_added() [1/2]

Glib::SignalProxy< void,const Glib::ustring& > Gio::ActionGroup::signal_action_added | ( |  | ) |

Slot Prototype:
  `void on_my_action_added(const Glib::ustring& action_name)`

Flags: Run Last

Signals that a new action was just added to the group. This signal is emitted after the action has been added and is now visible.

Since glibmm 2.28:

Parameters

  action_name | The name of the action in action_group.

## ◆ signal_action_added() [2/2]

Glib::SignalProxyDetailedAnyType< void,const Glib::ustring& > Gio::ActionGroup::signal_action_added | ( | const Glib::ustring& | action_name | ) |

Slot Prototype:
  `void on_my_action_added(const Glib::ustring& action_name)`

Flags: Run Last

Signals that a new action was just added to the group. This signal is emitted after the action has been added and is now visible.

Since glibmm 2.28:

Parameters

  action_name | The name of the action in action_group.

## ◆ signal_action_enabled_changed() [1/2]

Glib::SignalProxy< void,const Glib::ustring&,bool > Gio::ActionGroup::signal_action_enabled_changed | ( |  | ) |

Slot Prototype:
  `void on_my_action_enabled_changed(const Glib::ustring& action_name, bool enabled)`

Flags: Run Last

Signals that the enabled status of the named action has changed.

Since glibmm 2.28:

Parameters

  action_name | The name of the action in action_group.
  enabled | Whether the action is enabled or not.

## ◆ signal_action_enabled_changed() [2/2]

Glib::SignalProxyDetailedAnyType< void,const Glib::ustring&,bool > Gio::ActionGroup::signal_action_enabled_changed | ( | const Glib::ustring& | action_name | ) |

Slot Prototype:
  `void on_my_action_enabled_changed(const Glib::ustring& action_name, bool enabled)`

Flags: Run Last

Signals that the enabled status of the named action has changed.

Since glibmm 2.28:

Parameters

  action_name | The name of the action in action_group.
  enabled | Whether the action is enabled or not.

## ◆ signal_action_removed() [1/2]

Glib::SignalProxy< void,const Glib::ustring& > Gio::ActionGroup::signal_action_removed | ( |  | ) |

Slot Prototype:
  `void on_my_action_removed(const Glib::ustring& action_name)`

Flags: Run Last

Signals that an action is just about to be removed from the group. This signal is emitted before the action is removed, so the action is still visible and can be queried from the signal handler.

Since glibmm 2.28:

Parameters

  action_name | The name of the action in action_group.

## ◆ signal_action_removed() [2/2]

Glib::SignalProxyDetailedAnyType< void,const Glib::ustring& > Gio::ActionGroup::signal_action_removed | ( | const Glib::ustring& | action_name | ) |

Slot Prototype:
  `void on_my_action_removed(const Glib::ustring& action_name)`

Flags: Run Last

Signals that an action is just about to be removed from the group. This signal is emitted before the action is removed, so the action is still visible and can be queried from the signal handler.

Since glibmm 2.28:

Parameters

  action_name | The name of the action in action_group.

## ◆ signal_action_state_changed() [1/2]

Glib::SignalProxy< void,const Glib::ustring&,const Glib::VariantBase& > Gio::ActionGroup::signal_action_state_changed | ( |  | ) |

Slot Prototype:
  `void on_my_action_state_changed(const Glib::ustring& action_name, const Glib::VariantBase& value)`

Flags: Run Last, Must Collect

Signals that the state of the named action has changed.

Since glibmm 2.28:

Parameters

  action_name | The name of the action in action_group.
  value | The new value of the state.

## ◆ signal_action_state_changed() [2/2]

Glib::SignalProxyDetailedAnyType< void,const Glib::ustring&,const Glib::VariantBase& > Gio::ActionGroup::signal_action_state_changed | ( | const Glib::ustring& | action_name | ) |

Slot Prototype:
  `void on_my_action_state_changed(const Glib::ustring& action_name, const Glib::VariantBase& value)`

Flags: Run Last, Must Collect

Signals that the state of the named action has changed.

Since glibmm 2.28:

Parameters

  action_name | The name of the action in action_group.
  value | The new value of the state.

## Friends And Related Function Documentation

## ◆ wrap()

Glib::RefPtr< Gio::ActionGroup > wrap | ( | GActionGroup * | object,
|  | bool | take_copy = `false`
| ) |  |
| related

A Glib::wrap() method for this object.

Parameters

  object | The C instance.
  take_copy | False if the result should take ownership of the C instance. True if it should take a new copy or ref.

Returns
  A C++ instance that wraps this C instance.