## AtkUtil AtkUtil — A set of ATK utility functions for event and toolkit support. |

## Synopsis

    struct              AtkUtil;
    enum                AtkCoordType;
    guint               atk_add_focus_tracker               (AtkEventListener focus_tracker);
    void                atk_remove_focus_tracker            (guint tracker_id);
    void                atk_focus_tracker_init              (AtkEventListenerInit init);
    void                atk_focus_tracker_notify            (AtkObject *object);
    void                (*AtkEventListener)                 (AtkObject *obj);
    void                (*AtkEventListenerInit)             (void);
    guint               atk_add_global_event_listener       (GSignalEmissionHook listener,
                                                             const gchar *event_type);
    void                atk_remove_global_event_listener    (guint listener_id);
    struct              AtkKeyEventStruct;
    enum                AtkKeyEventType;
    gint                (*AtkKeySnoopFunc)                  (AtkKeyEventStruct *event,
                                                             gpointer func_data);
    guint               atk_add_key_event_listener          (AtkKeySnoopFunc listener,
                                                             gpointer data);
    void                atk_remove_key_event_listener       (guint listener_id);
    AtkObject *         atk_get_root                        (void);
    AtkObject *         atk_get_focus_object                (void);
    const gchar *       atk_get_toolkit_name                (void);
    const gchar *       atk_get_toolkit_version             (void);
    const gchar *       atk_get_version                     (void);
    #define             ATK_DEFINE_TYPE                     (TN,
                                                             t_n,
                                                             T_P)
    #define             ATK_DEFINE_TYPE_EXTENDED            (TN,
                                                             t_n,
                                                             T_P,
                                                             _f_,
                                                             _C_)
    #define             ATK_DEFINE_TYPE_WITH_CODE           (TN,
                                                             t_n,
                                                             T_P,
                                                             _C_)
    #define             ATK_DEFINE_ABSTRACT_TYPE            (TN,
                                                             t_n,
                                                             T_P)
    #define             ATK_DEFINE_ABSTRACT_TYPE_WITH_CODE  (TN,
                                                             t_n,
                                                             T_P,
                                                             _C_)

## Object Hierarchy

      GObject
       +----AtkUtil

## Description

A set of ATK utility functions which are used to support event registration of various types, and obtaining the 'root' accessible of a process and information about the current ATK implementation and toolkit version.

## Details

### struct AtkUtil

    struct AtkUtil;

The AtkUtil struct does not contain any fields.

### enum AtkCoordType

    typedef enum {
      ATK_XY_SCREEN,
      ATK_XY_WINDOW
    } AtkCoordType;

Specifies how xy coordinates are to be interpreted. Used by functions such as `atk_component_get_position()` and `atk_text_get_character_extents()`

`ATK_XY_SCREEN` | specifies xy coordinates relative to the screen
`ATK_XY_WINDOW` | specifies xy coordinates relative to the widget's top-level window

### atk_add_focus_tracker ()

    guint               atk_add_focus_tracker               (AtkEventListener focus_tracker);

Adds the specified function to the list of functions to be called when an object receives focus.

`focus_tracker` : | Function to be added to the list of functions to be called when an object receives focus.
Returns : | added focus tracker id, or 0 on failure.

### atk_remove_focus_tracker ()

    void                atk_remove_focus_tracker            (guint tracker_id);

Removes the specified focus tracker from the list of functions to be called when any object receives focus.

`tracker_id` : | the id of the focus tracker to remove

### atk_focus_tracker_init ()

    void                atk_focus_tracker_init              (AtkEventListenerInit init);

Specifies the function to be called for focus tracker initialization. This function should be called by an implementation of the ATK interface if any specific work needs to be done to enable focus tracking.

`init` : | Function to be called for focus tracker initialization

### atk_focus_tracker_notify ()

    void                atk_focus_tracker_notify            (AtkObject *object);

Cause the focus tracker functions which have been specified to be executed for the object.

`object` : | an AtkObject

### AtkEventListener ()

    void                (*AtkEventListener)                 (AtkObject *obj);

A function which is called when an object emits a matching event, as used in atk_add_focus_tracker. Currently the only events for which object-specific handlers are supported are events of type "focus:". Most clients of ATK will prefer to attach signal handlers for the various ATK signals instead.

see atk_add_focus_tracker.

`obj` : | An AtkObject instance for whom the callback will be called when the specified event (e.g. 'focus:') takes place.

### AtkEventListenerInit ()

    void                (*AtkEventListenerInit)             (void);

An AtkEventListenerInit function is a special function that is called in order to initialize the per-object event registration system used by AtkEventListener, if any preparation is required.

see atk_focus_tracker_init.

### atk_add_global_event_listener ()

    guint               atk_add_global_event_listener       (GSignalEmissionHook listener,
                                                             const gchar *event_type);

Adds the specified function to the list of functions to be called when an ATK event of type event_type occurs.

The format of event_type is the following: "ATK:<atk_type>:<atk_event>

Where "ATK" works as the namespace, <atk_interface> is the name of the ATK type (interface or object) and <atk_event> is the name of the signal defined on that interface.

For example: ATK:AtkObject:state-change ATK:AtkText:text-selection-changed

Toolkit implementor note: Atk provides a default implementation for this virtual method, and that implementation should be enough for most of the cases. You should have a really good reason to reimplement this method.

`listener` : | the listener to notify
`event_type` : | the type of event for which notification is requested
Returns : | added event listener id, or 0 on failure.

### atk_remove_global_event_listener ()

    void                atk_remove_global_event_listener    (guint listener_id);

`listener_id` is the value returned by atk_add_global_event_listener when you registered that event listener.

Toolkit implementor note: Atk provides a default implementation for this virtual method, and that implementation should be enough for most of the cases. You should have a really good reason to reimplement this method.

Removes the specified event listener

`listener_id` : | the id of the event listener to remove

### struct AtkKeyEventStruct

    struct AtkKeyEventStruct {
      gint type;
      guint state;
      guint keyval;
      gint length;
      gchar *string;
      guint16 keycode;
      guint32 timestamp;
    };

Encapsulates information about a key event.

gint `type`; | An AtkKeyEventType, generally one of ATK_KEY_EVENT_PRESS or ATK_KEY_EVENT_RELEASE
guint `state`; | A bitmask representing the state of the modifier keys immediately after the event takes place. The meaning of the bits is currently defined to match the bitmask used by GDK in GdkEventType.state, see http://developer.gnome.org/doc/API/2.0/gdk/gdk-Event-Structures.htmlGdkEventKey
guint `keyval`; | A guint representing a keysym value corresponding to those used by GDK and X11: see /usr/X11/include/keysymdef.h.
gint `length`; | The length of member string.
gchar *`string`; | A string containing one of the following: either a string approximating the text that would result from this keypress, if the key is a control or graphic character, or a symbolic name for this keypress. Alphanumeric and printable keys will have the symbolic key name in this string member, for instance "A". "0", "semicolon", "aacute". Keypad keys have the prefix "KP".
guint16 `keycode`; | The raw hardware code that generated the key event. This field is raraly useful.
guint32 `timestamp`; | A timestamp in milliseconds indicating when the event occurred. These timestamps are relative to a starting point which should be considered arbitrary, and only used to compare the dispatch times of events to one another.

### enum AtkKeyEventType

    typedef enum {
      ATK_KEY_EVENT_PRESS,
      ATK_KEY_EVENT_RELEASE,
      ATK_KEY_EVENT_LAST_DEFINED
    } AtkKeyEventType;

Specifies the type of a keyboard evemt.

`ATK_KEY_EVENT_PRESS` | specifies a key press event
`ATK_KEY_EVENT_RELEASE` | specifies a key release event
`ATK_KEY_EVENT_LAST_DEFINED` | Not a valid value; specifies end of enumeration

### AtkKeySnoopFunc ()

    gint                (*AtkKeySnoopFunc)                  (AtkKeyEventStruct *event,
                                                             gpointer func_data);

An AtkKeySnoopFunc is a type of callback which is called whenever a key event occurs, if registered via atk_add_key_event_listener. It allows for pre-emptive interception of key events via the return code as described below.

`event` : | an AtkKeyEventStruct containing information about the key event for which notification is being given.
`func_data` : | a block of data which will be passed to the event listener, on notification.
Returns : | TRUE (nonzero) if the event emission should be stopped and the event discarded without being passed to the normal GUI recipient; FALSE (zero) if the event dispatch to the client application should proceed as normal. see atk_add_key_event_listener.

### atk_add_key_event_listener ()

    guint               atk_add_key_event_listener          (AtkKeySnoopFunc listener,
                                                             gpointer data);

Adds the specified function to the list of functions to be called when a key event occurs. The `data` element will be passed to the AtkKeySnoopFunc (`listener`) as the `func_data` param, on notification.

`listener` : | the listener to notify
`data` : | a gpointer that points to a block of data that should be sent to the registered listeners, along with the event notification, when it occurs.
Returns : | added event listener id, or 0 on failure.

### atk_remove_key_event_listener ()

    void                atk_remove_key_event_listener       (guint listener_id);

`listener_id` is the value returned by atk_add_key_event_listener when you registered that event listener.

Removes the specified event listener.

`listener_id` : | the id of the event listener to remove

### atk_get_root ()

    AtkObject *         atk_get_root                        (void);

Gets the root accessible container for the current application.

Returns : | the root accessible container for the current application. [transfer none]

### atk_get_focus_object ()

    AtkObject *         atk_get_focus_object                (void);

Gets the currently focused object.

Returns : | the currently focused object for the current application. [transfer none]

Since 1.6

### atk_get_toolkit_name ()

    const gchar *       atk_get_toolkit_name                (void);

Gets name string for the GUI toolkit implementing ATK for this application.

Returns : | name string for the GUI toolkit implementing ATK for this application

### atk_get_toolkit_version ()

    const gchar *       atk_get_toolkit_version             (void);

Gets version string for the GUI toolkit implementing ATK for this application.

Returns : | version string for the GUI toolkit implementing ATK for this application

### atk_get_version ()

    const gchar *       atk_get_version                     (void);

Gets the current version for ATK.

Returns : | version string for ATK

Since 1.20

### ATK_DEFINE_TYPE()

    #define ATK_DEFINE_TYPE(TN, t_n, T_P)			       ATK_DEFINE_TYPE_EXTENDED (TN, t_n, T_P, 0, {})

A convenience macro for type ATK implementations, which declares a class initialization function, an instance initialization function (see GTypeInfo for information about these) and a static variable named `t_n` _parent_class pointing to the parent class. Furthermore, it defines a `_get_type()` function.

`TN` : | The name of the new type, in Camel case.
`t_n` : | The name of the new type, in lowercase, with words separated by '_'.
`T_P` : | The GType of the parent type.

Since 1.22

### ATK_DEFINE_TYPE_EXTENDED()

    #define ATK_DEFINE_TYPE_EXTENDED(TN, t_n, T_P, _f_, _C_)      _ATK_DEFINE_TYPE_EXTENDED_BEGIN (TN, t_n, T_P, _f_) {_C_;} _ATK_DEFINE_TYPE_EXTENDED_END()

The most general convenience macro for ATK type implementations, on which `ATK_DEFINE_TYPE()`, etc are based.

`TN` : | The name of the new type, in Camel case.
`t_n` : | The name of the new type, in lowercase, with words separated by '_'.
`T_P` : | The GType of the parent type.
`_f_` : | GTypeFlags to pass to `g_type_register_static()`
`_C_` : | Custom code that gets inserted in the `_get_type()` function.

Since 1.22

### ATK_DEFINE_TYPE_WITH_CODE()

    #define ATK_DEFINE_TYPE_WITH_CODE(TN, t_n, T_P, _C_)	      _ATK_DEFINE_TYPE_EXTENDED_BEGIN (TN, t_n, T_P, 0) {_C_;} _ATK_DEFINE_TYPE_EXTENDED_END()

A convenience macro for ATK type implementations. Similar to `ATK_DEFINE_TYPE()`, but allows you to insert custom code into the `_get_type()` function, e.g. interface implementations via `G_IMPLEMENT_INTERFACE()`.

`TN` : | The name of the new type, in Camel case.
`t_n` : | The name of the new type in lowercase, with words separated by '_'.
`T_P` : | The GType of the parent type.
`_C_` : | Custom code that gets inserted in the `_get_type()` function.

Since 1.22

### ATK_DEFINE_ABSTRACT_TYPE()

    #define ATK_DEFINE_ABSTRACT_TYPE(TN, t_n, T_P)		       ATK_DEFINE_TYPE_EXTENDED (TN, t_n, T_P, G_TYPE_FLAG_ABSTRACT, {})

A convenience macro for ATK type implementations. Similar to `ATK_DEFINE_TYPE()`, but defines an abstract type.

`TN` : | The name of the new type, in Camel case.
`t_n` : | The name of the new type, in lowercase, with words separated by '_'.
`T_P` : | The GType of the parent type.

Since 1.22

### ATK_DEFINE_ABSTRACT_TYPE_WITH_CODE()

    #define ATK_DEFINE_ABSTRACT_TYPE_WITH_CODE(TN, t_n, T_P, _C_) _ATK_DEFINE_TYPE_EXTENDED_BEGIN (TN, t_n, T_P, G_TYPE_FLAG_ABSTRACT) {_C_;} _ATK_DEFINE_TYPE_EXTENDED_END()

A convenience macro for ATK type implementations. Similar to `ATK_DEFINE_TYPE_WITH_CODE()`, but defines an abstract type.

`TN` : | The name of the new type, in Camel case.
`t_n` : | The name of the new type, in lowercase, with words separated by '_'.
`T_P` : | The GType of the parent type.
`_C_` : | Custom code that gets inserted in the `_get_type()` function.

Since 1.22