/*

 * Copyright © 2010 Codethink Limited

 *

 * SPDX-License-Identifier: LGPL-2.1-or-later

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General

 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.

 *

 * Authors: Ryan Lortie <desrt@desrt.ca>

 */

#include "config.h"

#include "gactiongroup.h"

#include "gaction.h"

#include "glibintl.h"

#include "gmarshal-internal.h"

/**

 * GActionGroup:

 *

 * `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 `GMenuModel` 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 `GVariant` 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 #GVariant. 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 equivalent set() call.

 *

 * 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].

 */

/**

 * GActionGroupInterface:

 * @has_action: the virtual function pointer for g_action_group_has_action()

 * @list_actions: the virtual function pointer for g_action_group_list_actions()

 * @get_action_parameter_type: the virtual function pointer for g_action_group_get_action_parameter_type()

 * @get_action_state_type: the virtual function pointer for g_action_group_get_action_state_type()

 * @get_action_state_hint: the virtual function pointer for g_action_group_get_action_state_hint()

 * @get_action_enabled: the virtual function pointer for g_action_group_get_action_enabled()

 * @get_action_state: the virtual function pointer for g_action_group_get_action_state()

 * @change_action_state: the virtual function pointer for g_action_group_change_action_state()

 * @activate_action: the virtual function pointer for g_action_group_activate_action()

 * @action_added: the class closure for the #GActionGroup::action-added signal

 * @action_removed: the class closure for the #GActionGroup::action-removed signal

 * @action_enabled_changed: the class closure for the #GActionGroup::action-enabled-changed signal

 * @action_state_changed: the class closure for the #GActionGroup::action-enabled-changed signal

 * @query_action: the virtual function pointer for g_action_group_query_action()

 *

 * The virtual function table for #GActionGroup.

 *

 * Since: 2.28

 **/

G_DEFINE_INTERFACE (GActionGroup, g_action_group, G_TYPE_OBJECT)

enum

{

  SIGNAL_ACTION_ADDED,

  SIGNAL_ACTION_REMOVED,

  SIGNAL_ACTION_ENABLED_CHANGED,

  SIGNAL_ACTION_STATE_CHANGED,

  NR_SIGNALS

};

static guint g_action_group_signals[NR_SIGNALS];

static gboolean

g_action_group_real_has_action (GActionGroup *action_group,

                                const gchar  *action_name)

{

  return g_action_group_query_action (action_group, action_name, NULL, NULL, NULL, NULL, NULL);

}

static gboolean

g_action_group_real_get_action_enabled (GActionGroup *action_group,

                                        const gchar  *action_name)

{

  gboolean enabled;

  if (!g_action_group_query_action (action_group, action_name, &enabled, NULL, NULL, NULL, NULL))

    return FALSE;

  return enabled;

}

static const GVariantType *

g_action_group_real_get_action_parameter_type (GActionGroup *action_group,

                                               const gchar  *action_name)

{

  const GVariantType *type;

  if (!g_action_group_query_action (action_group, action_name, NULL, &type, NULL, NULL, NULL))

    return NULL;

  return type;

}

static const GVariantType *

g_action_group_real_get_action_state_type (GActionGroup *action_group,

                                           const gchar  *action_name)

{

  const GVariantType *type;

  if (!g_action_group_query_action (action_group, action_name, NULL, NULL, &type, NULL, NULL))

    return NULL;

  return type;

}

static GVariant *

g_action_group_real_get_action_state_hint (GActionGroup *action_group,

                                           const gchar  *action_name)

{

  GVariant *hint;

  if (!g_action_group_query_action (action_group, action_name, NULL, NULL, NULL, &hint, NULL))

    return NULL;

  return hint;

}

static GVariant *

g_action_group_real_get_action_state (GActionGroup *action_group,

                                      const gchar  *action_name)

{

  GVariant *state;

  if (!g_action_group_query_action (action_group, action_name, NULL, NULL, NULL, NULL, &state))

    return NULL;

  return state;

}

static gboolean

g_action_group_real_query_action (GActionGroup        *action_group,

                                  const gchar         *action_name,

                                  gboolean            *enabled,

                                  const GVariantType **parameter_type,

                                  const GVariantType **state_type,

                                  GVariant           **state_hint,

                                  GVariant           **state)

{

  GActionGroupInterface *iface = G_ACTION_GROUP_GET_IFACE (action_group);

  /* we expect implementations to override this method, but we also

   * allow for implementations that existed before this method was

   * introduced to override the individual accessors instead.

   *

   * detect the case that neither has happened and report it.

   */

  if G_UNLIKELY (iface->has_action == g_action_group_real_has_action ||

                 iface->get_action_enabled == g_action_group_real_get_action_enabled ||

                 iface->get_action_parameter_type == g_action_group_real_get_action_parameter_type ||

                 iface->get_action_state_type == g_action_group_real_get_action_state_type ||

                 iface->get_action_state_hint == g_action_group_real_get_action_state_hint ||

                 iface->get_action_state == g_action_group_real_get_action_state)

    {

      g_critical ("Class '%s' implements GActionGroup interface without overriding "

                  "query_action() method -- bailing out to avoid infinite recursion.",

                  G_OBJECT_TYPE_NAME (action_group));

      return FALSE;

    }

  if (!(* iface->has_action) (action_group, action_name))

    return FALSE;

  if (enabled != NULL)

    *enabled = (* iface->get_action_enabled) (action_group, action_name);

  if (parameter_type != NULL)

    *parameter_type = (* iface->get_action_parameter_type) (action_group, action_name);

  if (state_type != NULL)

    *state_type = (* iface->get_action_state_type) (action_group, action_name);

  if (state_hint != NULL)

    *state_hint = (* iface->get_action_state_hint) (action_group, action_name);

  if (state != NULL)

    *state = (* iface->get_action_state) (action_group, action_name);

  return TRUE;

}

static void

g_action_group_default_init (GActionGroupInterface *iface)

{

  iface->has_action = g_action_group_real_has_action;

  iface->get_action_enabled = g_action_group_real_get_action_enabled;

  iface->get_action_parameter_type = g_action_group_real_get_action_parameter_type;

  iface->get_action_state_type = g_action_group_real_get_action_state_type;

  iface->get_action_state_hint = g_action_group_real_get_action_state_hint;

  iface->get_action_state = g_action_group_real_get_action_state;

  iface->query_action = g_action_group_real_query_action;

  /**

   * GActionGroup::action-added:

   * @action_group: the #GActionGroup that changed

   * @action_name: the name of the action in @action_group

   *

   * 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: 2.28

   **/

  g_action_group_signals[SIGNAL_ACTION_ADDED] =

    g_signal_new (I_("action-added"),

                  G_TYPE_ACTION_GROUP,

                  G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED,

                  G_STRUCT_OFFSET (GActionGroupInterface, action_added),

                  NULL, NULL,

                  NULL,

                  G_TYPE_NONE, 1,

                  G_TYPE_STRING);

  /**

   * GActionGroup::action-removed:

   * @action_group: the #GActionGroup that changed

   * @action_name: the name of the action in @action_group

   *

   * 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: 2.28

   **/

  g_action_group_signals[SIGNAL_ACTION_REMOVED] =

    g_signal_new (I_("action-removed"),

                  G_TYPE_ACTION_GROUP,

                  G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED,

                  G_STRUCT_OFFSET (GActionGroupInterface, action_removed),

                  NULL, NULL,

                  NULL,

                  G_TYPE_NONE, 1,

                  G_TYPE_STRING);

  /**

   * GActionGroup::action-enabled-changed:

   * @action_group: the #GActionGroup that changed

   * @action_name: the name of the action in @action_group

   * @enabled: whether the action is enabled or not

   *

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

   *

   * Since: 2.28

   **/

  g_action_group_signals[SIGNAL_ACTION_ENABLED_CHANGED] =

    g_signal_new (I_("action-enabled-changed"),

                  G_TYPE_ACTION_GROUP,

                  G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED,

                  G_STRUCT_OFFSET (GActionGroupInterface,

                                   action_enabled_changed),

                  NULL, NULL,

                  _g_cclosure_marshal_VOID__STRING_BOOLEAN,

                  G_TYPE_NONE, 2,

                  G_TYPE_STRING,

                  G_TYPE_BOOLEAN);

  g_signal_set_va_marshaller (g_action_group_signals[SIGNAL_ACTION_ENABLED_CHANGED],

                              G_TYPE_FROM_INTERFACE (iface),

                              _g_cclosure_marshal_VOID__STRING_BOOLEANv);

  /**

   * GActionGroup::action-state-changed:

   * @action_group: the #GActionGroup that changed

   * @action_name: the name of the action in @action_group

   * @value: the new value of the state

   *

   * Signals that the state of the named action has changed.

   *

   * Since: 2.28

   **/

  g_action_group_signals[SIGNAL_ACTION_STATE_CHANGED] =

    g_signal_new (I_("action-state-changed"),

                  G_TYPE_ACTION_GROUP,

                  G_SIGNAL_RUN_LAST |

                  G_SIGNAL_DETAILED |

                  G_SIGNAL_MUST_COLLECT,

                  G_STRUCT_OFFSET (GActionGroupInterface,

                                   action_state_changed),

                  NULL, NULL,

                  _g_cclosure_marshal_VOID__STRING_VARIANT,

                  G_TYPE_NONE, 2,

                  G_TYPE_STRING,

                  G_TYPE_VARIANT);

  g_signal_set_va_marshaller (g_action_group_signals[SIGNAL_ACTION_STATE_CHANGED],

                              G_TYPE_FROM_INTERFACE (iface),

                              _g_cclosure_marshal_VOID__STRING_VARIANTv);

}

/**

 * g_action_group_list_actions:

 * @action_group: a #GActionGroup

 *

 * Lists the actions contained within @action_group.

 *

 * The caller is responsible for freeing the list with g_strfreev() when

 * it is no longer required.

 *

 * Returns: (transfer full): a %NULL-terminated array of the names of the

 * actions in the group

 *

 * Since: 2.28

 **/

gchar **

g_action_group_list_actions (GActionGroup *action_group)

{

  g_return_val_if_fail (G_IS_ACTION_GROUP (action_group), NULL);

  return G_ACTION_GROUP_GET_IFACE (action_group)

    ->list_actions (action_group);

}

/**

 * g_action_group_has_action:

 * @action_group: a #GActionGroup

 * @action_name: the name of the action to check for

 *

 * Checks if the named action exists within @action_group.

 *

 * Returns: whether the named action exists

 *

 * Since: 2.28

 **/

gboolean

g_action_group_has_action (GActionGroup *action_group,

                           const gchar  *action_name)

{

  g_return_val_if_fail (G_IS_ACTION_GROUP (action_group), FALSE);

  return G_ACTION_GROUP_GET_IFACE (action_group)

    ->has_action (action_group, action_name);

}

/**

 * g_action_group_get_action_parameter_type:

 * @action_group: a #GActionGroup

 * @action_name: the name of the action to query

 *

 * 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 #GVariant 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

 * #GVariant, 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.

 *

 * Returns: (nullable): the parameter type

 *

 * Since: 2.28

 **/

const GVariantType *

g_action_group_get_action_parameter_type (GActionGroup *action_group,

                                          const gchar  *action_name)

{

  g_return_val_if_fail (G_IS_ACTION_GROUP (action_group), NULL);

  return G_ACTION_GROUP_GET_IFACE (action_group)

    ->get_action_parameter_type (action_group, action_name);

}

/**

 * g_action_group_get_action_state_type:

 * @action_group: a #GActionGroup

 * @action_name: the name of the action to query

 *

 * Queries the type of the state of the named action within

 * @action_group.

 *

 * If the action is stateful then this function returns the

 * #GVariantType of the state.  All calls to

 * g_action_group_change_action_state() must give a #GVariant of this

 * type and g_action_group_get_action_state() will return a #GVariant

 * of the same type.

 *

 * If the action is not stateful then this function will return %NULL.

 * In that case, g_action_group_get_action_state() will return %NULL

 * 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.

 *

 * Returns: (nullable): the state type, if the action is stateful

 *

 * Since: 2.28

 **/

const GVariantType *

g_action_group_get_action_state_type (GActionGroup *action_group,

                                      const gchar  *action_name)

{

  g_return_val_if_fail (G_IS_ACTION_GROUP (action_group), NULL);

  return G_ACTION_GROUP_GET_IFACE (action_group)

    ->get_action_state_type (action_group, action_name);

}

/**

 * g_action_group_get_action_state_hint:

 * @action_group: a #GActionGroup

 * @action_name: the name of the action to query

 *

 * 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 #GVariant array is returned then each item in the array is a

 * possible value for the state.  If a #GVariant 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

 * g_variant_unref() when it is no longer required.

 *

 * Returns: (nullable) (transfer full): the state range hint

 *

 * Since: 2.28

 **/

GVariant *

g_action_group_get_action_state_hint (GActionGroup *action_group,

                                      const gchar  *action_name)

{

  g_return_val_if_fail (G_IS_ACTION_GROUP (action_group), NULL);

  return G_ACTION_GROUP_GET_IFACE (action_group)

    ->get_action_state_hint (action_group, action_name);

}

/**

 * g_action_group_get_action_enabled:

 * @action_group: a #GActionGroup

 * @action_name: the name of the action to query

 *

 * 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.

 *

 * Returns: whether or not the action is currently enabled

 *

 * Since: 2.28

 **/

gboolean

g_action_group_get_action_enabled (GActionGroup *action_group,

                                   const gchar  *action_name)

{

  g_return_val_if_fail (G_IS_ACTION_GROUP (action_group), FALSE);

  return G_ACTION_GROUP_GET_IFACE (action_group)

    ->get_action_enabled (action_group, action_name);

}

/**

 * g_action_group_get_action_state:

 * @action_group: a #GActionGroup

 * @action_name: the name of the action to query

 *

 * 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 g_action_group_get_action_state_type().

 *

 * The return value (if non-%NULL) should be freed with

 * g_variant_unref() when it is no longer required.

 *

 * Returns: (nullable) (transfer full): the current state of the action

 *

 * Since: 2.28

 **/

GVariant *

g_action_group_get_action_state (GActionGroup *action_group,

                                 const gchar  *action_name)

{

  g_return_val_if_fail (G_IS_ACTION_GROUP (action_group), NULL);

  return G_ACTION_GROUP_GET_IFACE (action_group)

    ->get_action_state (action_group, action_name);

}

/**

 * g_action_group_change_action_state:

 * @action_group: a #GActionGroup

 * @action_name: the name of the action to request the change on

 * @value: 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 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: 2.28

 **/

void

g_action_group_change_action_state (GActionGroup *action_group,

                                    const gchar  *action_name,

                                    GVariant     *value)

{

  g_return_if_fail (G_IS_ACTION_GROUP (action_group));

  g_return_if_fail (action_name != NULL);

  g_return_if_fail (value != NULL);

  G_ACTION_GROUP_GET_IFACE (action_group)

    ->change_action_state (action_group, action_name, value);

}

/**

 * g_action_group_activate_action:

 * @action_group: a #GActionGroup

 * @action_name: the name of the action to activate

 * @parameter: (nullable): 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

 * g_action_group_get_action_parameter_type().

 *

 * If the #GActionGroup 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,

 * g_dbus_connection_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 g_dbus_connection_flush() is called

 * before `exit()`. Without g_dbus_connection_flush(), the "quit" action

 * may fail to be activated on the primary instance.

 *

 * |[<!-- language="C" -->

 * // 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);

 * ]|

 *

 * Since: 2.28

 **/

void

g_action_group_activate_action (GActionGroup *action_group,

                                const gchar  *action_name,

                                GVariant     *parameter)

{

  g_return_if_fail (G_IS_ACTION_GROUP (action_group));

  g_return_if_fail (action_name != NULL);

  G_ACTION_GROUP_GET_IFACE (action_group)

    ->activate_action (action_group, action_name, parameter);

}

/**

 * g_action_group_action_added:

 * @action_group: a #GActionGroup

 * @action_name: the name of an action in the group

 *

 * Emits the #GActionGroup::action-added signal on @action_group.

 *

 * This function should only be called by #GActionGroup implementations.

 *

 * Since: 2.28

 **/

void

g_action_group_action_added (GActionGroup *action_group,

                             const gchar  *action_name)

{

  g_return_if_fail (G_IS_ACTION_GROUP (action_group));

  g_return_if_fail (action_name != NULL);

  g_signal_emit (action_group,

                 g_action_group_signals[SIGNAL_ACTION_ADDED],

                 g_quark_try_string (action_name),

                 action_name);

}

/**

 * g_action_group_action_removed:

 * @action_group: a #GActionGroup

 * @action_name: the name of an action in the group

 *

 * Emits the #GActionGroup::action-removed signal on @action_group.

 *

 * This function should only be called by #GActionGroup implementations.

 *

 * Since: 2.28

 **/

void

g_action_group_action_removed (GActionGroup *action_group,

                               const gchar  *action_name)

{

  g_return_if_fail (G_IS_ACTION_GROUP (action_group));

  g_return_if_fail (action_name != NULL);

  g_signal_emit (action_group,

                 g_action_group_signals[SIGNAL_ACTION_REMOVED],

                 g_quark_try_string (action_name),

                 action_name);

}

/**

 * g_action_group_action_enabled_changed:

 * @action_group: a #GActionGroup

 * @action_name: the name of an action in the group

 * @enabled: whether or not the action is now enabled

 *

 * Emits the #GActionGroup::action-enabled-changed signal on @action_group.

 *

 * This function should only be called by #GActionGroup implementations.

 *

 * Since: 2.28

 **/

void

g_action_group_action_enabled_changed (GActionGroup *action_group,

                                       const gchar  *action_name,

                                       gboolean      enabled)

{

  g_return_if_fail (G_IS_ACTION_GROUP (action_group));

  g_return_if_fail (action_name != NULL);

  enabled = !!enabled;

  g_signal_emit (action_group,

                 g_action_group_signals[SIGNAL_ACTION_ENABLED_CHANGED],

                 g_quark_try_string (action_name),

                 action_name,

                 enabled);

}

/**

 * g_action_group_action_state_changed:

 * @action_group: a #GActionGroup

 * @action_name: the name of an action in the group

 * @state: the new state of the named action

 *

 * Emits the #GActionGroup::action-state-changed signal on @action_group.

 *

 * This function should only be called by #GActionGroup implementations.

 *

 * Since: 2.28

 **/

void

g_action_group_action_state_changed (GActionGroup *action_group,

                                     const gchar  *action_name,

                                     GVariant     *state)

{

  g_return_if_fail (G_IS_ACTION_GROUP (action_group));

  g_return_if_fail (action_name != NULL);

  g_signal_emit (action_group,

                 g_action_group_signals[SIGNAL_ACTION_STATE_CHANGED],

                 g_quark_try_string (action_name),

                 action_name,

                 state);

}

/**

 * g_action_group_query_action:

 * @action_group: a #GActionGroup

 * @action_name: the name of an action in the group

 * @enabled: (out): if the action is presently enabled

 * @parameter_type: (out) (transfer none) (optional): the parameter type, or %NULL if none needed

 * @state_type: (out) (transfer none) (optional): the state type, or %NULL if stateless

 * @state_hint: (out) (optional): the state hint, or %NULL if none

 * @state: (out) (optional): the current state, or %NULL if stateless

 *

 * 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

 * #GActionGroup 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.

 *

 * Returns: %TRUE if the action exists, else %FALSE

 *

 * Since: 2.32

 **/

gboolean

g_action_group_query_action (GActionGroup        *action_group,

                             const gchar         *action_name,

                             gboolean            *enabled,

                             const GVariantType **parameter_type,

                             const GVariantType **state_type,

                             GVariant           **state_hint,

                             GVariant           **state)

{

  return G_ACTION_GROUP_GET_IFACE (action_group)

    ->query_action (action_group, action_name, enabled, parameter_type, state_type, state_hint, state);

}