## GActionMap

GActionMap — Interface for action containers

## Functions

GAction * | g_action_map_lookup_action ()
void | g_action_map_add_action_entries ()
void | g_action_map_add_action ()
void | g_action_map_remove_action ()

## Types and Values

| GActionMap
struct | GActionMapInterface
struct | GActionEntry

## Object Hierarchy

        GInterface
        ╰── GActionMap

## Prerequisites

GActionMap requires GObject.

## Known Implementations

GActionMap is implemented by GApplication and GSimpleActionGroup.

## Includes

    #include <gio/gio.h>

## Description

The GActionMap interface is implemented by GActionGroup implementations that operate by containing a number of named GAction instances, such as GSimpleActionGroup.

One useful application of this interface is to map the names of actions from various action groups to unique, prefixed names (e.g. by prepending "app." or "win."). This is the motivation for the 'Map' part of the interface name.

## Functions

### g_action_map_lookup_action ()

    GAction *
    g_action_map_lookup_action (GActionMap *action_map,
                                const gchar *action_name);

Looks up the action with the name `action_name` in `action_map` .

If no such action exists, returns `NULL`.

#### Parameters

action_map | a GActionMap |
action_name | the name of an action |

#### Returns

a GAction, or `NULL`.

[transfer none]

Since: 2.32

### g_action_map_add_action_entries ()

    void
    g_action_map_add_action_entries (GActionMap *action_map,
                                     const GActionEntry *entries,
                                     gint n_entries,
                                     gpointer user_data);

A convenience function for creating multiple GSimpleAction instances and adding them to a GActionMap.

Each action is constructed as per one GActionEntry.

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    static void
    activate_quit (GSimpleAction *simple,
                   GVariant      *parameter,
                   gpointer       user_data)
    {
      exit (0);
    }

    static void
    activate_print_string (GSimpleAction *simple,
                           GVariant      *parameter,
                           gpointer       user_data)
    {
      g_print ("%s\n", g_variant_get_string (parameter, NULL));
    }

    static GActionGroup *
    create_action_group (void)
    {
      const GActionEntry entries[] = {
        { "quit",         activate_quit              },
        { "print-string", activate_print_string, "s" }
      };
      GSimpleActionGroup *group;

      group = g_simple_action_group_new ();
      g_action_map_add_action_entries (G_ACTION_MAP (group), entries, G_N_ELEMENTS (entries), NULL);

      return G_ACTION_GROUP (group);
    }

#### Parameters

action_map | a GActionMap |
entries | a pointer to the first item in an array of GActionEntry structs. | [array length=n_entries][element-type GActionEntry]
n_entries | the length of `entries` , or -1 if `entries` is `NULL`-terminated |
user_data | the user data for signal connections |

Since: 2.32

### g_action_map_add_action ()

    void
    g_action_map_add_action (GActionMap *action_map,
                             GAction *action);

Adds an action to the `action_map` .

If the action map already contains an action with the same name as `action` then the old action is dropped from the action map.

The action map takes its own reference on `action` .

#### Parameters

action_map | a GActionMap |
action | a GAction |

Since: 2.32

### g_action_map_remove_action ()

    void
    g_action_map_remove_action (GActionMap *action_map,
                                const gchar *action_name);

Removes the named action from the action map.

If no action of this name is in the map then nothing happens.

#### Parameters

action_map | a GActionMap |
action_name | the name of the action |

Since: 2.32

## Types and Values

### GActionMap

    typedef struct _GActionMap GActionMap;

GActionMap is an opaque data structure and can only be accessed using the following functions.

### struct GActionMapInterface

    struct GActionMapInterface {
      GTypeInterface g_iface;

      GAction * (* lookup_action) (GActionMap  *action_map,
                                   const gchar *action_name);
      void      (* add_action)    (GActionMap  *action_map,
                                   GAction     *action);
      void      (* remove_action) (GActionMap  *action_map,
                                   const gchar *action_name);
    };

The virtual function table for GActionMap.

#### Members

`lookup_action` () | the virtual function pointer for `g_action_map_lookup_action()` |
`add_action` () | the virtual function pointer for `g_action_map_add_action()` |
`remove_action` () | the virtual function pointer for `g_action_map_remove_action()` |

Since: 2.32

### struct GActionEntry

    struct GActionEntry {
      const gchar *name;

      void (* activate) (GSimpleAction *action,
                         GVariant      *parameter,
                         gpointer       user_data);

      const gchar *parameter_type;

      const gchar *state;

      void (* change_state) (GSimpleAction *action,
                             GVariant      *value,
                             gpointer       user_data);
    };

This struct defines a single action. It is for use with `g_action_map_add_action_entries()`.

The order of the items in the structure are intended to reflect frequency of use. It is permissible to use an incomplete initialiser in order to leave some of the later values as `NULL`. All values after `name` are optional. Additional optional fields may be added in the future.

See `g_action_map_add_action_entries()` for an example.

#### Members

const gchar *`name`; | the name of the action |
`activate` () | the callback to connect to the "activate" signal of the action. Since GLib 2.40, this can be `NULL` for stateful actions, in which case the default handler is used. For boolean-stated actions with no parameter, this is a toggle. For other state types (and parameter type equal to the state type) this will be a function that just calls `change_state` (which you should provide). |
const gchar *`parameter_type`; | the type of the parameter that must be passed to the activate function for this action, given as a single GVariant type string (or `NULL` for no parameter) |
const gchar *`state`; | the initial state for this action, given in GVariant text format. The state is parsed with no extra type information, so type tags must be added to the string if they are necessary. Stateless actions should give `NULL` here. |
`change_state` () | the callback to connect to the "change-state" signal of the action. All stateful actions should provide a handler here; stateless actions should not. |