Gio.ActionGroup¶
- Implementations:
Methods¶
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Virtual Methods¶
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Properties¶
None
Signals¶
Name |
Short Description |
---|---|
Signals that a new action was just added to the group. |
|
Signals that the enabled status of the named action has changed. |
|
Signals that an action is just about to be removed from the group. |
|
Signals that the state of the named action has changed. |
Fields¶
None
Class Details¶
- class Gio.ActionGroup¶
- Bases:
- Structure:
GActionGroup
represents a group of actions.Actions can be used to expose functionality in a structured way, either from one part of a program to another, or to the outside world. Action groups are often used together with a [type`Gio`.MenuModel] that provides additional representation data for displaying the actions to the user, e.g. in a menu.
The main way to interact with the actions in a
GActionGroup
is to activate them with [method`Gio`.ActionGroup.activate_action]. Activating an action may require a [type`GLib`.Variant] parameter. The required type of the parameter can be inquired with [method`Gio`.ActionGroup.get_action_parameter_type]. Actions may be disabled, see [method`Gio`.ActionGroup.get_action_enabled]. Activating a disabled action has no effect.Actions may optionally have a state in the form of a [type`GLib`.Variant]. The current state of an action can be inquired with [method`Gio`.ActionGroup.get_action_state]. Activating a stateful action may change its state, but it is also possible to set the state by calling [method`Gio`.ActionGroup.change_action_state].
As typical example, consider a text editing application which has an option to change the current font to ‘bold’. A good way to represent this would be a stateful action, with a boolean state. Activating the action would toggle the state.
Each action in the group has a unique name (which is a string). All method calls, except [method`Gio`.ActionGroup.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 – [method`Gio`.ActionGroup.get_action_enabled] but not an equivalentset_action_enabled()
method.Signals are emitted on the action group in response to state changes on individual actions.
Implementations of
GActionGroup
should provide implementations for the virtual functions [method`Gio`.ActionGroup.list_actions] and [method`Gio`.ActionGroup.query_action]. The other virtual functions should not be implemented — their ‘wrappers’ are actually implemented with calls to [method`Gio`.ActionGroup.query_action].- action_added(action_name)[source]¶
- Parameters:
action_name (
str
) – the name of an action in the group
Emits the [signal`Gio`.ActionGroup::action-added] signal on self.
This function should only be called by [type`Gio`.ActionGroup] implementations.
New in version 2.28.
- action_enabled_changed(action_name, enabled)[source]¶
- Parameters:
Emits the [signal`Gio`.ActionGroup::action-enabled-changed] signal on self.
This function should only be called by [type`Gio`.ActionGroup] implementations.
New in version 2.28.
- action_removed(action_name)[source]¶
- Parameters:
action_name (
str
) – the name of an action in the group
Emits the [signal`Gio`.ActionGroup::action-removed] signal on self.
This function should only be called by [type`Gio`.ActionGroup] implementations.
New in version 2.28.
- action_state_changed(action_name, state)[source]¶
- Parameters:
action_name (
str
) – the name of an action in the groupstate (
GLib.Variant
) – the new state of the named action
Emits the [signal`Gio`.ActionGroup::action-state-changed] signal on self.
This function should only be called by [type`Gio`.ActionGroup] implementations.
New in version 2.28.
- activate_action(action_name, parameter)[source]¶
- Parameters:
action_name (
str
) – the name of the action to activateparameter (
GLib.Variant
orNone
) – parameters to the activation
Activate the named action within self.
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
NULL
. See [method`Gio`.ActionGroup.get_action_parameter_type].If the [type`Gio`.ActionGroup] implementation supports asynchronous remote activation over D-Bus, this call may return before the relevant D-Bus traffic has been sent, or any replies have been received. In order to block on such asynchronous activation calls, [method`Gio`.DBusConnection.flush] should be called prior to the code, which depends on the result of the action activation. Without flushing the D-Bus connection, there is no guarantee that the action would have been activated.
The following code which runs in a remote app instance, shows an example of a ‘quit’ action being activated on the primary app instance over D-Bus. Here [method`Gio`.DBusConnection.flush] is called before
exit()
. Withoutg_dbus_connection_flush()
, the ‘quit’ action may fail to be activated on the primary instance.```c // call ‘quit’ action on primary instance
Gio.ActionGroup.activate_action
(G_ACTION_GROUP (app), “quit”,None
);// make sure the action is activated now
Gio.DBusConnection.flush
(…);g_debug (“Application has been terminated. Exiting.”);
exit (0); ```
New in version 2.28.
- change_action_state(action_name, value)[source]¶
- Parameters:
action_name (
str
) – the name of the action to request the change onvalue (
GLib.Variant
) – the new state
Request for the state of the named action within self to be changed to value.
The action must be stateful and value must be of the correct type. See [method`Gio`.ActionGroup.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 [method`Gio`.ActionGroup.get_action_state_hint].
If the value
GLib.Variant
is floating, it is consumed.New in version 2.28.
- get_action_enabled(action_name)[source]¶
- Parameters:
action_name (
str
) – the name of the action to query- Returns:
whether the action is currently enabled
- Return type:
Checks if the named action within self is currently enabled.
An action must be enabled in order to be activated or in order to have its state changed from outside callers.
New in version 2.28.
- get_action_parameter_type(action_name)[source]¶
- Parameters:
action_name (
str
) – the name of the action to query- Returns:
the parameter type
- Return type:
Queries the type of the parameter that must be given when activating the named action within self.
When activating the action using [method`Gio`.ActionGroup.activate_action], the [type`GLib`.Variant] given to that function must be of the type returned by this function.
In the case that this function returns
NULL
, you must not give any [type`GLib`.Variant], butNULL
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.
New in version 2.28.
- get_action_state(action_name)[source]¶
- Parameters:
action_name (
str
) – the name of the action to query- Returns:
the current state of the action
- Return type:
GLib.Variant
orNone
Queries the current state of the named action within self.
If the action is not stateful then
NULL
will be returned. If the action is stateful then the type of the return value is the type given by [method`Gio`.ActionGroup.get_action_state_type].The return value (if non-
NULL
) should be freed with [method`GLib`.Variant.unref] when it is no longer required.New in version 2.28.
- get_action_state_hint(action_name)[source]¶
- Parameters:
action_name (
str
) – the name of the action to query- Returns:
the state range hint
- Return type:
GLib.Variant
orNone
Requests a hint about the valid range of values for the state of the named action within self.
If
NULL
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 [type`GLib`.Variant] array is returned then each item in the array is a possible value for the state. If a [type`GLib`.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-
NULL
) should be freed with [method`GLib`.Variant.unref] when it is no longer required.New in version 2.28.
- get_action_state_type(action_name)[source]¶
- Parameters:
action_name (
str
) – the name of the action to query- Returns:
the state type, if the action is stateful
- Return type:
Queries the type of the state of the named action within self.
If the action is stateful then this function returns the [type`GLib`.VariantType] of the state. All calls to [method`Gio`.ActionGroup.change_action_state] must give a [type`GLib`.Variant] of this type and [method`Gio`.ActionGroup.get_action_state] will return a [type`GLib`.Variant] of the same type.
If the action is not stateful then this function will return
NULL
. In that case, [method`Gio`.ActionGroup.get_action_state] will returnNULL
and you must not call [method`Gio`.ActionGroup.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.
New in version 2.28.
- has_action(action_name)[source]¶
- Parameters:
action_name (
str
) – the name of the action to check for- Returns:
whether the named action exists
- Return type:
Checks if the named action exists within self.
New in version 2.28.
- list_actions()[source]¶
- Returns:
a
NULL
-terminated array of the names of the actions in the group- Return type:
[
str
]
Lists the actions contained within self.
The caller is responsible for freeing the list with [func`GLib`.strfreev] when it is no longer required.
New in version 2.28.
- query_action(action_name)[source]¶
- Parameters:
action_name (
str
) – the name of an action in the group- Returns:
TRUE
if the action exists, elseFALSE
- enabled:
if the action is presently enabled
- parameter_type:
the parameter type, or
NULL
if none needed- state_type:
the state type, or
NULL
if stateless- state_hint:
the state hint, or
NULL
if none- state:
the current state, or
NULL
if stateless
- Return type:
(
bool
, enabled:bool
, parameter_type:GLib.VariantType
, state_type:GLib.VariantType
, state_hint:GLib.Variant
, state:GLib.Variant
)
Queries all aspects of the named action within an self.
This function acquires the information available from [method`Gio`.ActionGroup.has_action], [method`Gio`.ActionGroup.get_action_enabled], [method`Gio`.ActionGroup.get_action_parameter_type], [method`Gio`.ActionGroup.get_action_state_type], [method`Gio`.ActionGroup.get_action_state_hint] and [method`Gio`.ActionGroup.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 [type`Gio`.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-NULL
reference passed in) are filled. If the action doesn’t exist,FALSE
is returned and the fields may or may not have been modified.New in version 2.32.
- do_action_added(action_name) virtual¶
- Parameters:
action_name (
str
) – the name of an action in the group
Emits the [signal`Gio`.ActionGroup::action-added] signal on action_group.
This function should only be called by [type`Gio`.ActionGroup] implementations.
New in version 2.28.
- do_action_enabled_changed(action_name, enabled) virtual¶
- Parameters:
Emits the [signal`Gio`.ActionGroup::action-enabled-changed] signal on action_group.
This function should only be called by [type`Gio`.ActionGroup] implementations.
New in version 2.28.
- do_action_removed(action_name) virtual¶
- Parameters:
action_name (
str
) – the name of an action in the group
Emits the [signal`Gio`.ActionGroup::action-removed] signal on action_group.
This function should only be called by [type`Gio`.ActionGroup] implementations.
New in version 2.28.
- do_action_state_changed(action_name, state) virtual¶
- Parameters:
action_name (
str
) – the name of an action in the groupstate (
GLib.Variant
) – the new state of the named action
Emits the [signal`Gio`.ActionGroup::action-state-changed] signal on action_group.
This function should only be called by [type`Gio`.ActionGroup] implementations.
New in version 2.28.
- do_activate_action(action_name, parameter) virtual¶
- Parameters:
action_name (
str
) – the name of the action to activateparameter (
GLib.Variant
orNone
) – parameters to the activation
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
NULL
. See [method`Gio`.ActionGroup.get_action_parameter_type].If the [type`Gio`.ActionGroup] implementation supports asynchronous remote activation over D-Bus, this call may return before the relevant D-Bus traffic has been sent, or any replies have been received. In order to block on such asynchronous activation calls, [method`Gio`.DBusConnection.flush] should be called prior to the code, which depends on the result of the action activation. Without flushing the D-Bus connection, there is no guarantee that the action would have been activated.
The following code which runs in a remote app instance, shows an example of a ‘quit’ action being activated on the primary app instance over D-Bus. Here [method`Gio`.DBusConnection.flush] is called before
exit()
. Withoutg_dbus_connection_flush()
, the ‘quit’ action may fail to be activated on the primary instance.```c // call ‘quit’ action on primary instance
Gio.ActionGroup.activate_action
(G_ACTION_GROUP (app), “quit”,None
);// make sure the action is activated now
Gio.DBusConnection.flush
(…);g_debug (“Application has been terminated. Exiting.”);
exit (0); ```
New in version 2.28.
- do_change_action_state(action_name, value) virtual¶
- Parameters:
action_name (
str
) – the name of the action to request the change onvalue (
GLib.Variant
) – the new state
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 [method`Gio`.ActionGroup.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 [method`Gio`.ActionGroup.get_action_state_hint].
If the value
GLib.Variant
is floating, it is consumed.New in version 2.28.
- do_get_action_enabled(action_name) virtual¶
- Parameters:
action_name (
str
) – the name of the action to query- Returns:
whether the action is currently enabled
- Return type:
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.
New in version 2.28.
- do_get_action_parameter_type(action_name) virtual¶
- Parameters:
action_name (
str
) – the name of the action to query- Returns:
the parameter type
- Return type:
Queries the type of the parameter that must be given when activating the named action within action_group.
When activating the action using [method`Gio`.ActionGroup.activate_action], the [type`GLib`.Variant] given to that function must be of the type returned by this function.
In the case that this function returns
NULL
, you must not give any [type`GLib`.Variant], butNULL
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.
New in version 2.28.
- do_get_action_state(action_name) virtual¶
- Parameters:
action_name (
str
) – the name of the action to query- Returns:
the current state of the action
- Return type:
GLib.Variant
orNone
Queries the current state of the named action within action_group.
If the action is not stateful then
NULL
will be returned. If the action is stateful then the type of the return value is the type given by [method`Gio`.ActionGroup.get_action_state_type].The return value (if non-
NULL
) should be freed with [method`GLib`.Variant.unref] when it is no longer required.New in version 2.28.
- do_get_action_state_hint(action_name) virtual¶
- Parameters:
action_name (
str
) – the name of the action to query- Returns:
the state range hint
- Return type:
GLib.Variant
orNone
Requests a hint about the valid range of values for the state of the named action within action_group.
If
NULL
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 [type`GLib`.Variant] array is returned then each item in the array is a possible value for the state. If a [type`GLib`.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-
NULL
) should be freed with [method`GLib`.Variant.unref] when it is no longer required.New in version 2.28.
- do_get_action_state_type(action_name) virtual¶
- Parameters:
action_name (
str
) – the name of the action to query- Returns:
the state type, if the action is stateful
- Return type:
Queries the type of the state of the named action within action_group.
If the action is stateful then this function returns the [type`GLib`.VariantType] of the state. All calls to [method`Gio`.ActionGroup.change_action_state] must give a [type`GLib`.Variant] of this type and [method`Gio`.ActionGroup.get_action_state] will return a [type`GLib`.Variant] of the same type.
If the action is not stateful then this function will return
NULL
. In that case, [method`Gio`.ActionGroup.get_action_state] will returnNULL
and you must not call [method`Gio`.ActionGroup.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.
New in version 2.28.
- do_has_action(action_name) virtual¶
- Parameters:
action_name (
str
) – the name of the action to check for- Returns:
whether the named action exists
- Return type:
Checks if the named action exists within action_group.
New in version 2.28.
- do_list_actions() virtual¶
- Returns:
a
NULL
-terminated array of the names of the actions in the group- Return type:
[
str
]
Lists the actions contained within action_group.
The caller is responsible for freeing the list with [func`GLib`.strfreev] when it is no longer required.
New in version 2.28.
- do_query_action(action_name) virtual¶
- Parameters:
action_name (
str
) – the name of an action in the group- Returns:
TRUE
if the action exists, elseFALSE
- enabled:
if the action is presently enabled
- parameter_type:
the parameter type, or
NULL
if none needed- state_type:
the state type, or
NULL
if stateless- state_hint:
the state hint, or
NULL
if none- state:
the current state, or
NULL
if stateless
- Return type:
(
bool
, enabled:bool
, parameter_type:GLib.VariantType
, state_type:GLib.VariantType
, state_hint:GLib.Variant
, state:GLib.Variant
)
Queries all aspects of the named action within an action_group.
This function acquires the information available from [method`Gio`.ActionGroup.has_action], [method`Gio`.ActionGroup.get_action_enabled], [method`Gio`.ActionGroup.get_action_parameter_type], [method`Gio`.ActionGroup.get_action_state_type], [method`Gio`.ActionGroup.get_action_state_hint] and [method`Gio`.ActionGroup.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 [type`Gio`.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-NULL
reference passed in) are filled. If the action doesn’t exist,FALSE
is returned and the fields may or may not have been modified.New in version 2.32.
Signal Details¶
- Gio.ActionGroup.signals.action_added(action_group, action_name)¶
- Signal Name:
action-added
- Flags:
- Parameters:
action_group (
Gio.ActionGroup
) – The object which received the signalaction_name (
str
) – the name of the action in self
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.
New in version 2.28.
- Gio.ActionGroup.signals.action_enabled_changed(action_group, action_name, enabled)¶
- Signal Name:
action-enabled-changed
- Flags:
- Parameters:
action_group (
Gio.ActionGroup
) – The object which received the signalaction_name (
str
) – the name of the action in selfenabled (
bool
) – whether the action is enabled
Signals that the enabled status of the named action has changed.
New in version 2.28.
- Gio.ActionGroup.signals.action_removed(action_group, action_name)¶
- Signal Name:
action-removed
- Flags:
- Parameters:
action_group (
Gio.ActionGroup
) – The object which received the signalaction_name (
str
) – the name of the action in self
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.
New in version 2.28.
- Gio.ActionGroup.signals.action_state_changed(action_group, action_name, value)¶
- Signal Name:
action-state-changed
- Flags:
- Parameters:
action_group (
Gio.ActionGroup
) – The object which received the signalaction_name (
str
) – the name of the action in selfvalue (
GLib.Variant
) – the new value of the state
Signals that the state of the named action has changed.
New in version 2.28.