Package org.gnome.gio

Interface ActionGroup

All Superinterfaces:

Proxy

All Known Subinterfaces:

RemoteActionGroup

All Known Implementing Classes:

ActionGroup.ActionGroupImpl, Application, Application, Application, ApplicationWindow, ApplicationWindow, DBusActionGroup, RemoteActionGroup.RemoteActionGroupImpl, SimpleActionGroup

@Generated("io.github.jwharm.JavaGI")
public interface ActionGroup
extends Proxy

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 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 activateAction(java.lang.String, org.gnome.glib.Variant). Activating an action may require a GLib.Variant parameter. The required type of the parameter can be inquired with getActionParameterType(java.lang.String). Actions may be disabled, see getActionEnabled(java.lang.String). Activating a disabled action has no effect.

Actions may optionally have a state in the form of a GLib.Variant. The current state of an action can be inquired with getActionState(java.lang.String). Activating a stateful action may change its state, but it is also possible to set the state by calling changeActionState(java.lang.String, org.gnome.glib.Variant).

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 listActions() 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 – getActionEnabled(java.lang.String) but not an equivalent set_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 listActions() and queryAction(java.lang.String, io.github.jwharm.javagi.base.Out<java.lang.Boolean>, io.github.jwharm.javagi.base.Out<org.gnome.glib.VariantType>, io.github.jwharm.javagi.base.Out<org.gnome.glib.VariantType>, io.github.jwharm.javagi.base.Out<org.gnome.glib.Variant>, io.github.jwharm.javagi.base.Out<org.gnome.glib.Variant>). The other virtual functions should not be implemented — their ‘wrappers’ are actually implemented with calls to queryAction(java.lang.String, io.github.jwharm.javagi.base.Out<java.lang.Boolean>, io.github.jwharm.javagi.base.Out<org.gnome.glib.VariantType>, io.github.jwharm.javagi.base.Out<org.gnome.glib.VariantType>, io.github.jwharm.javagi.base.Out<org.gnome.glib.Variant>, io.github.jwharm.javagi.base.Out<org.gnome.glib.Variant>).

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	ActionGroup.ActionAddedCallback	Functional interface declaration of the ActionAddedCallback callback.
static interface	ActionGroup.ActionEnabledChangedCallback	Functional interface declaration of the ActionEnabledChangedCallback callback.
static class	ActionGroup.ActionGroupImpl	The ActionGroupImpl type represents a native instance of the ActionGroup interface.
static class	ActionGroup.ActionGroupInterface	The virtual function table for Gio.ActionGroup.
static interface	ActionGroup.ActionRemovedCallback	Functional interface declaration of the ActionRemovedCallback callback.
static interface	ActionGroup.ActionStateChangedCallback	Functional interface declaration of the ActionStateChangedCallback callback.

Method Summary

Modifier and Type	Method	Description
default void	actionAdded(String actionName)	Emits the Gio.ActionGroup::action-added signal on this ActionGroup.
default void	actionEnabledChanged(String actionName, boolean enabled)	Emits the Gio.ActionGroup::action-enabled-changed signal on this ActionGroup.
default void	actionRemoved(String actionName)	Emits the Gio.ActionGroup::action-removed signal on this ActionGroup.
default void	actionStateChanged(String actionName, Variant state)	Emits the Gio.ActionGroup::action-state-changed signal on this ActionGroup.
default void	activateAction(String actionName, @Nullable Variant parameter)	Activate the named action within this ActionGroup.
default void	changeActionState(String actionName, Variant value)	Request for the state of the named action within this ActionGroup to be changed to value.
default void	emitActionAdded(@Nullable String detail, String actionName)	Emits the "action-added" signal.
default void	emitActionEnabledChanged(@Nullable String detail, String actionName, boolean enabled)	Emits the "action-enabled-changed" signal.
default void	emitActionRemoved(@Nullable String detail, String actionName)	Emits the "action-removed" signal.
default void	emitActionStateChanged(@Nullable String detail, String actionName, Variant value)	Emits the "action-state-changed" signal.
default boolean	getActionEnabled(String actionName)	Checks if the named action within this ActionGroup is currently enabled.
default VariantType	getActionParameterType(String actionName)	Queries the type of the parameter that must be given when activating the named action within this ActionGroup.
default Variant	getActionState(String actionName)	Queries the current state of the named action within this ActionGroup.
default Variant	getActionStateHint(String actionName)	Requests a hint about the valid range of values for the state of the named action within this ActionGroup.
default VariantType	getActionStateType(String actionName)	Queries the type of the state of the named action within this ActionGroup.
static Type	getType()	Get the GType of the ActionGroup class
default boolean	hasAction(String actionName)	Checks if the named action exists within this ActionGroup.
default String[]	listActions()	Lists the actions contained within this ActionGroup.
default SignalConnection<ActionGroup.ActionAddedCallback>	onActionAdded(@Nullable String detail, ActionGroup.ActionAddedCallback handler)	Signals that a new action was just added to the group.
default SignalConnection<ActionGroup.ActionEnabledChangedCallback>	onActionEnabledChanged(@Nullable String detail, ActionGroup.ActionEnabledChangedCallback handler)	Signals that the enabled status of the named action has changed.
default SignalConnection<ActionGroup.ActionRemovedCallback>	onActionRemoved(@Nullable String detail, ActionGroup.ActionRemovedCallback handler)	Signals that an action is just about to be removed from the group.
default SignalConnection<ActionGroup.ActionStateChangedCallback>	onActionStateChanged(@Nullable String detail, ActionGroup.ActionStateChangedCallback handler)	Signals that the state of the named action has changed.
default boolean	queryAction(String actionName, Out<Boolean> enabled, @Nullable Out<VariantType> parameterType, @Nullable Out<VariantType> stateType, @Nullable Out<Variant> stateHint, @Nullable Out<Variant> state)	Queries all aspects of the named action within an this ActionGroup.

Methods inherited from interface io.github.jwharm.javagi.base.Proxy

handle

Method Details

getType

static Type getType()

Get the GType of the ActionGroup class

Returns:

the GType

actionAdded

default void actionAdded(String actionName)

Emits the Gio.ActionGroup::action-added signal on this ActionGroup.

This function should only be called by Gio.ActionGroup implementations.

Parameters:

actionName - the name of an action in the group

actionEnabledChanged

default void actionEnabledChanged(String actionName,
 boolean enabled)

Emits the Gio.ActionGroup::action-enabled-changed signal on this ActionGroup.

This function should only be called by Gio.ActionGroup implementations.

Parameters:

actionName - the name of an action in the group

enabled - whether the action is now enabled

actionRemoved

default void actionRemoved(String actionName)

Emits the Gio.ActionGroup::action-removed signal on this ActionGroup.

This function should only be called by Gio.ActionGroup implementations.

Parameters:

actionName - the name of an action in the group

actionStateChanged

default void actionStateChanged(String actionName,
 Variant state)

Emits the Gio.ActionGroup::action-state-changed signal on this ActionGroup.

This function should only be called by Gio.ActionGroup implementations.

Parameters:

actionName - the name of an action in the group

state - the new state of the named action

activateAction

default void activateAction(String actionName,
 @Nullable
 @Nullable Variant parameter)

Activate the named action within this ActionGroup.

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 getActionParameterType(java.lang.String).

If the 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, DBusConnection.flush(org.gnome.gio.Cancellable, org.gnome.gio.AsyncReadyCallback) 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 DBusConnection.flush(org.gnome.gio.Cancellable, org.gnome.gio.AsyncReadyCallback) is called before exit(). Without g_dbus_connection_flush(), the ‘quit’ action may fail to be activated on the primary instance.

// call ‘quit’ action on primary instance
 g_action_group_activate_action (G_ACTION_GROUP (app), "quit", NULL);

 // make sure the action is activated now
 g_dbus_connection_flush (…);

 g_debug ("Application has been terminated. Exiting.");

 exit (0);
 

Parameters:

actionName - the name of the action to activate

parameter - parameters to the activation

changeActionState

default void changeActionState(String actionName,
 Variant value)

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

The action must be stateful and value must be of the correct type. See getActionStateType(java.lang.String).

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 getActionStateHint(java.lang.String).

If the value GVariant is floating, it is consumed.

Parameters:

actionName - the name of the action to request the change on

value - the new state

getActionEnabled

default boolean getActionEnabled(String actionName)

Checks if the named action within this ActionGroup is currently enabled.

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

Parameters:

actionName - the name of the action to query

Returns:

whether the action is currently enabled

getActionParameterType

default VariantType getActionParameterType(String actionName)

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

When activating the action using activateAction(java.lang.String, org.gnome.glib.Variant), the 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 GLib.Variant, but NULL 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.

Parameters:

actionName - the name of the action to query

Returns:

the parameter type

getActionState

default Variant getActionState(String actionName)

Queries the current state of the named action within this ActionGroup.

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 getActionStateType(java.lang.String).

The return value (if non-NULL) should be freed with Variant.unref() when it is no longer required.

Parameters:

actionName - the name of the action to query

Returns:

the current state of the action

getActionStateHint

default Variant getActionStateHint(String actionName)

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

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 GLib.Variant array is returned then each item in the array is a possible value for the state. If a 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 Variant.unref() when it is no longer required.

Parameters:

actionName - the name of the action to query

Returns:

the state range hint

getActionStateType

default VariantType getActionStateType(String actionName)

Queries the type of the state of the named action within this ActionGroup.

If the action is stateful then this function returns the GLib.VariantType of the state. All calls to changeActionState(java.lang.String, org.gnome.glib.Variant) must give a GLib.Variant of this type and getActionState(java.lang.String) will return a GLib.Variant of the same type.

If the action is not stateful then this function will return NULL. In that case, getActionState(java.lang.String) will return NULL and you must not call changeActionState(java.lang.String, org.gnome.glib.Variant).

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.

Parameters:

actionName - the name of the action to query

Returns:

the state type, if the action is stateful

hasAction

default boolean hasAction(String actionName)

Checks if the named action exists within this ActionGroup.

Parameters:

actionName - the name of the action to check for

Returns:

whether the named action exists

listActions

default String[] listActions()

Lists the actions contained within this ActionGroup.

The caller is responsible for freeing the list with GLib.strfreev(java.lang.foreign.MemorySegment) when it is no longer required.

Returns:

a NULL-terminated array of the names of the actions in the group

queryAction

default boolean queryAction(String actionName,
 Out<Boolean> enabled,
 @Nullable
 @Nullable Out<VariantType> parameterType,
 @Nullable
 @Nullable Out<VariantType> stateType,
 @Nullable
 @Nullable Out<Variant> stateHint,
 @Nullable
 @Nullable Out<Variant> state)

Queries all aspects of the named action within an this ActionGroup.

This function acquires the information available from hasAction(java.lang.String), getActionEnabled(java.lang.String), getActionParameterType(java.lang.String), getActionStateType(java.lang.String), getActionStateHint(java.lang.String) and getActionState(java.lang.String) 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 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.

Parameters:

actionName - the name of an action in the group

enabled - if the action is presently enabled

parameterType - the parameter type, or NULL if none needed

stateType - the state type, or NULL if stateless

stateHint - the state hint, or NULL if none

state - the current state, or NULL if stateless

Returns:

TRUE if the action exists, else FALSE

onActionAdded

default SignalConnection<ActionGroup.ActionAddedCallback> onActionAdded(@Nullable
 @Nullable String detail,
 ActionGroup.ActionAddedCallback handler)

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.

Parameters:

detail - the signal detail

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• ActionGroup.ActionAddedCallback.run(java.lang.String)

emitActionAdded

default void emitActionAdded(@Nullable
 @Nullable String detail,
 String actionName)

Emits the "action-added" signal. See onActionAdded(java.lang.String, org.gnome.gio.ActionGroup.ActionAddedCallback).

onActionEnabledChanged

default SignalConnection<ActionGroup.ActionEnabledChangedCallback> onActionEnabledChanged(@Nullable
 @Nullable String detail,
 ActionGroup.ActionEnabledChangedCallback handler)

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

Parameters:

detail - the signal detail

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• ActionGroup.ActionEnabledChangedCallback.run(java.lang.String, boolean)

emitActionEnabledChanged

default void emitActionEnabledChanged(@Nullable
 @Nullable String detail,
 String actionName,
 boolean enabled)

Emits the "action-enabled-changed" signal. See onActionEnabledChanged(java.lang.String, org.gnome.gio.ActionGroup.ActionEnabledChangedCallback).

onActionRemoved

default SignalConnection<ActionGroup.ActionRemovedCallback> onActionRemoved(@Nullable
 @Nullable String detail,
 ActionGroup.ActionRemovedCallback handler)

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.

Parameters:

detail - the signal detail

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• ActionGroup.ActionRemovedCallback.run(java.lang.String)

emitActionRemoved

default void emitActionRemoved(@Nullable
 @Nullable String detail,
 String actionName)

Emits the "action-removed" signal. See onActionRemoved(java.lang.String, org.gnome.gio.ActionGroup.ActionRemovedCallback).

onActionStateChanged

default SignalConnection<ActionGroup.ActionStateChangedCallback> onActionStateChanged(@Nullable
 @Nullable String detail,
 ActionGroup.ActionStateChangedCallback handler)

Signals that the state of the named action has changed.

Parameters:

detail - the signal detail

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• ActionGroup.ActionStateChangedCallback.run(java.lang.String, org.gnome.glib.Variant)

emitActionStateChanged

default void emitActionStateChanged(@Nullable
 @Nullable String detail,
 String actionName,
 Variant value)

Emits the "action-state-changed" signal. See onActionStateChanged(java.lang.String, org.gnome.gio.ActionGroup.ActionStateChangedCallback).