atk/atkutil.h

   1 /* ATK -  Accessibility Toolkit
   2  * Copyright 2001 Sun Microsystems Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Library General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 #if defined(ATK_DISABLE_SINGLE_INCLUDES) && !defined (__ATK_H_INSIDE__) && !defined (ATK_COMPILATION)
  21 #error "Only <atk/atk.h> can be included directly."
  22 #endif
  23
  24 #ifndef __ATK_UTIL_H__
  25 #define __ATK_UTIL_H__
  26
  27 #include <atk/atkobject.h>
  28
  29 G_BEGIN_DECLS
  30
  31 #define ATK_TYPE_UTIL                   (atk_util_get_type ())
  32 #define ATK_IS_UTIL(obj)                G_TYPE_CHECK_INSTANCE_TYPE ((obj), ATK_TYPE_UTIL)
  33 #define ATK_UTIL(obj)                   G_TYPE_CHECK_INSTANCE_CAST ((obj), ATK_TYPE_UTIL, AtkUtil)
  34 #define ATK_UTIL_CLASS(klass)                   (G_TYPE_CHECK_CLASS_CAST ((klass), ATK_TYPE_UTIL, AtkUtilClass))
  35 #define ATK_IS_UTIL_CLASS(klass)                (G_TYPE_CHECK_CLASS_TYPE ((klass), ATK_TYPE_UTIL))
  36 #define ATK_UTIL_GET_CLASS(obj)                 (G_TYPE_INSTANCE_GET_CLASS ((obj), ATK_TYPE_UTIL, AtkUtilClass))
  37
  38
  39 #ifndef _TYPEDEF_ATK_UTIL_
  40 #define _TYPEDEF_ATK_UTIL_
  41 typedef struct _AtkUtil      AtkUtil;
  42 typedef struct _AtkUtilClass AtkUtilClass;
  43 typedef struct _AtkKeyEventStruct AtkKeyEventStruct;
  44 #endif
  45
  46 /**
  47  * AtkEventListener:
  48  * @obj: An #AtkObject instance for whom the callback will be called when
  49  * the specified event (e.g. 'focus:') takes place.
  50  *
  51  * A function which is called when an object emits a matching event,
  52  * as used in #atk_add_focus_tracker.
  53  * Currently the only events for which object-specific handlers are
  54  * supported are events of type "focus:".  Most clients of ATK will prefer to
  55  * attach signal handlers for the various ATK signals instead.
  56  *
  57  * see atk_add_focus_tracker.
  58  **/
  59 typedef void  (*AtkEventListener) (AtkObject* obj);
  60 /**
  61  * AtkEventListenerInit:
  62  *
  63  * An #AtkEventListenerInit function is a special function that is
  64  * called in order to initialize the per-object event registration system
  65  * used by #AtkEventListener, if any preparation is required.
  66  *
  67  * see atk_focus_tracker_init.
  68  **/
  69 typedef void  (*AtkEventListenerInit) (void);
  70 /**
  71  * AtkKeySnoopFunc:
  72  * @event: an AtkKeyEventStruct containing information about the key event for which
  73  * notification is being given.
  74  * @user_data: a block of data which will be passed to the event listener, on notification.
  75  *
  76  * An #AtkKeySnoopFunc is a type of callback which is called whenever a key event occurs,
  77  * if registered via atk_add_key_event_listener.  It allows for pre-emptive
  78  * interception of key events via the return code as described below.
  79  *
  80  * Returns: TRUE (nonzero) if the event emission should be stopped and the event
  81  * discarded without being passed to the normal GUI recipient; FALSE (zero) if the
  82  * event dispatch to the client application should proceed as normal.
  83  *
  84  * see atk_add_key_event_listener.
  85  **/
  86 typedef gint  (*AtkKeySnoopFunc)  (AtkKeyEventStruct *event,
  87                                    gpointer user_data);
  88
  89 /**
  90  * AtkKeyEventStruct:
  91  * @type: An AtkKeyEventType, generally one of ATK_KEY_EVENT_PRESS or ATK_KEY_EVENT_RELEASE
  92  * @state: A bitmask representing the state of the modifier keys immediately after the event takes place.
  93  * The meaning of the bits is currently defined to match the bitmask used by GDK in
  94  * GdkEventType.state, see
  95  * http://developer.gnome.org/doc/API/2.0/gdk/gdk-Event-Structures.html#GdkEventKey
  96  * @keyval: A guint representing a keysym value corresponding to those used by GDK and X11: see
  97  * /usr/X11/include/keysymdef.h.
  98  * @length: The length of member #string.
  99  * @string: A string containing one of the following: either a string approximating the text that would
 100  * result from this keypress, if the key is a control or graphic character, or a symbolic name for this keypress.
 101  * Alphanumeric and printable keys will have the symbolic key name in this string member, for instance "A". "0",
 102  * "semicolon", "aacute".  Keypad keys have the prefix "KP".
 103  * @keycode: The raw hardware code that generated the key event.  This field is raraly useful.
 104  * @timestamp: A timestamp in milliseconds indicating when the event occurred.
 105  * These timestamps are relative to a starting point which should be considered arbitrary,
 106  * and only used to compare the dispatch times of events to one another.
 107  *
 108  * Encapsulates information about a key event.
 109  **/
 110 struct _AtkKeyEventStruct {
 111   gint type;
 112   guint state;
 113   guint keyval;
 114   gint length;
 115   gchar *string;
 116   guint16 keycode;
 117   guint32 timestamp;
 118 };
 119
 120 /**
 121  *AtkKeyEventType:
 122  *@ATK_KEY_EVENT_PRESS: specifies a key press event
 123  *@ATK_KEY_EVENT_RELEASE: specifies a key release event
 124  *@ATK_KEY_EVENT_LAST_DEFINED: Not a valid value; specifies end of enumeration
 125  *
 126  *Specifies the type of a keyboard evemt.
 127  **/
 128 typedef enum
 129 {
 130   ATK_KEY_EVENT_PRESS,
 131   ATK_KEY_EVENT_RELEASE,
 132   ATK_KEY_EVENT_LAST_DEFINED
 133 } AtkKeyEventType;
 134
 135 struct _AtkUtil
 136 {
 137   GObject parent;
 138 };
 139
 140 struct _AtkUtilClass
 141 {
 142    GObjectClass parent;
 143    guint        (* add_global_event_listener)    (GSignalEmissionHook listener,
 144                                                   const gchar        *event_type);
 145    void         (* remove_global_event_listener) (guint               listener_id);
 146    guint        (* add_key_event_listener)       (AtkKeySnoopFunc     listener,
 147                                                   gpointer data);
 148    void         (* remove_key_event_listener)    (guint               listener_id);
 149    AtkObject*   (* get_root)                     (void);
 150    const gchar* (* get_toolkit_name)             (void);
 151    const gchar* (* get_toolkit_version)          (void);
 152 };
 153 GType atk_util_get_type (void);
 154
 155 /**
 156  *AtkCoordType:
 157  *@ATK_XY_SCREEN: specifies xy coordinates relative to the screen
 158  *@ATK_XY_WINDOW: specifies xy coordinates relative to the widget's
 159  * top-level window
 160  *
 161  *Specifies how xy coordinates are to be interpreted. Used by functions such
 162  *as atk_component_get_position() and atk_text_get_character_extents()
 163  **/
 164 typedef enum {
 165   ATK_XY_SCREEN,
 166   ATK_XY_WINDOW
 167 }AtkCoordType;
 168
 169 G_DEPRECATED
 170 guint    atk_add_focus_tracker     (AtkEventListener      focus_tracker);
 171 G_DEPRECATED
 172 void     atk_remove_focus_tracker  (guint                tracker_id);
 173 G_DEPRECATED
 174 void     atk_focus_tracker_init    (AtkEventListenerInit  init);
 175 G_DEPRECATED
 176 void     atk_focus_tracker_notify  (AtkObject            *object);
 177 guint   atk_add_global_event_listener (GSignalEmissionHook listener,
 178                                        const gchar        *event_type);
 179 void    atk_remove_global_event_listener (guint listener_id);
 180 guint   atk_add_key_event_listener (AtkKeySnoopFunc listener, gpointer data);
 181 void    atk_remove_key_event_listener (guint listener_id);
 182
 183 AtkObject* atk_get_root(void);
 184 AtkObject* atk_get_focus_object (void);
 185
 186 const gchar *atk_get_toolkit_name (void);
 187 const gchar *atk_get_toolkit_version (void);
 188 const gchar *atk_get_version (void);
 189
 190 /* --- GType boilerplate --- */
 191 /* convenience macros for atk type implementations, which for a type GtkGadgetAccessible will:
 192  * - prototype: static void     gtk_gadget_accessible_class_init (GtkGadgetClass *klass);
 193  * - prototype: static void     gtk_gadget_accessible_init       (GtkGadget      *self);
 194  * - define:    static gpointer gtk_gadget_accessible_parent_class = NULL;
 195  *   gtk_gadget_accessible_parent_class is initialized prior to calling gtk_gadget_class_init()
 196  * - implement: GType           gtk_gadget_accessible_get_type (void) { ... }
 197  * - support custom code in gtk_gadget_accessible_get_type() after the type is registered.
 198  *
 199  * macro arguments: TypeName, type_name, TYPE_PARENT, CODE
 200  * example: ATK_DEFINE_TYPE_WITH_CODE (GtkGadgetAccessible, gtk_gadget_accessible, GTK_TYPE_GADGET,
 201  *                                     G_IMPLEMENT_INTERFACE (ATK_TYPE_TABLE, gtk_gadget_accessible_table_iface_init))
 202  */
 203
 204 /**
 205  * ATK_DEFINE_TYPE:
 206  * @TN: The name of the new type, in Camel case.
 207  * @t_n: The name of the new type, in lowercase, with words separated by '_'.
 208  * @T_P: The #GType of the parent type.
 209  *
 210  * A convenience macro for type ATK implementations, which declares a class
 211  * initialization function, an instance initialization function (see #GTypeInfo
 212  * for information about these) and a static variable named
 213  * @t_n _parent_class pointing to the parent class. Furthermore, it
 214  * defines a _get_type() function.
 215  *
 216  * Since: 1.22
 217  */
 218 #define ATK_DEFINE_TYPE(TN, t_n, T_P)                          ATK_DEFINE_TYPE_EXTENDED (TN, t_n, T_P, 0, {})
 219
 220 /**
 221  * ATK_DEFINE_TYPE_WITH_CODE:
 222  * @TN: The name of the new type, in Camel case.
 223  * @t_n: The name of the new type in lowercase, with words separated by '_'.
 224  * @T_P: The #GType of the parent type.
 225  * @_C_: Custom code that gets inserted in the _get_type() function.
 226  *
 227  * A convenience macro for ATK type implementations.
 228  * Similar to ATK_DEFINE_TYPE(), but allows you to insert custom code into the
 229  * _get_type() function, e.g. interface implementations via G_IMPLEMENT_INTERFACE().
 230  *
 231  * Since: 1.22
 232  */
 233 #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()
 234
 235 /**
 236  * ATK_DEFINE_ABSTRACT_TYPE:
 237  * @TN: The name of the new type, in Camel case.
 238  * @t_n: The name of the new type, in lowercase, with words separated by '_'.
 239  * @T_P: The #GType of the parent type.
 240  *
 241  * A convenience macro for ATK type implementations.
 242  * Similar to ATK_DEFINE_TYPE(), but defines an abstract type.
 243  *
 244  * Since: 1.22
 245  */
 246 #define ATK_DEFINE_ABSTRACT_TYPE(TN, t_n, T_P)                 ATK_DEFINE_TYPE_EXTENDED (TN, t_n, T_P, G_TYPE_FLAG_ABSTRACT, {})
 247
 248 /**
 249  * ATK_DEFINE_ABSTRACT_TYPE_WITH_CODE:
 250  * @TN: The name of the new type, in Camel case.
 251  * @t_n: The name of the new type, in lowercase, with words separated by '_'.
 252  * @T_P: The #GType of the parent type.
 253  * @_C_: Custom code that gets inserted in the _get_type() function.
 254  *
 255  * A convenience macro for ATK type implementations.
 256  * Similar to ATK_DEFINE_TYPE_WITH_CODE(), but defines an abstract type.
 257  *
 258  * Since: 1.22
 259  */
 260 #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()
 261
 262 /**
 263  * ATK_DEFINE_TYPE_EXTENDED:
 264  * @TN: The name of the new type, in Camel case.
 265  * @t_n: The name of the new type, in lowercase, with words separated by '_'.
 266  * @T_P: The #GType of the parent type.
 267  * @_f_: #GTypeFlags to pass to g_type_register_static()
 268  * @_C_: Custom code that gets inserted in the _get_type() function.
 269  *
 270  * The most general convenience macro for ATK type implementations, on which
 271  * ATK_DEFINE_TYPE(), etc are based.
 272  *
 273  * Since: 1.22
 274  */
 275 #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()
 276
 277 #define _ATK_DEFINE_TYPE_EXTENDED_BEGIN(TypeName, type_name, TYPE, flags) \
 278 \
 279 static void     type_name##_init              (TypeName        *self); \
 280 static void     type_name##_class_init        (TypeName##Class *klass); \
 281 static gpointer type_name##_parent_class = NULL; \
 282 static void     type_name##_class_intern_init (gpointer klass) \
 283 { \
 284   type_name##_parent_class = g_type_class_peek_parent (klass); \
 285   type_name##_class_init ((TypeName##Class*) klass); \
 286 } \
 287 \
 288 GType \
 289 type_name##_get_type (void) \
 290 { \
 291   static volatile gsize g_define_type_id__volatile = 0; \
 292   if (g_once_init_enter (&g_define_type_id__volatile))  \
 293     { \
 294       AtkObjectFactory *factory; \
 295       GType derived_type; \
 296       GTypeQuery query; \
 297       GType derived_atk_type; \
 298       GType g_define_type_id; \
 299 \
 300       /* Figure out the size of the class and instance we are deriving from */ \
 301       derived_type = g_type_parent (TYPE); \
 302       factory = atk_registry_get_factory (atk_get_default_registry (), \
 303                                           derived_type); \
 304       derived_atk_type = atk_object_factory_get_accessible_type (factory); \
 305       g_type_query (derived_atk_type, &query); \
 306 \
 307       g_define_type_id = \
 308         g_type_register_static_simple (derived_atk_type, \
 309                                        g_intern_static_string (#TypeName), \
 310                                        query.class_size, \
 311                                        (GClassInitFunc) type_name##_class_intern_init, \
 312                                        query.instance_size, \
 313                                        (GInstanceInitFunc) type_name##_init, \
 314                                        (GTypeFlags) flags); \
 315       { /* custom code follows */
 316 #define _ATK_DEFINE_TYPE_EXTENDED_END() \
 317         /* following custom code */     \
 318       }                                 \
 319       g_once_init_leave (&g_define_type_id__volatile, g_define_type_id); \
 320     }                                   \
 321   return g_define_type_id__volatile;    \
 322 } /* closes type_name##_get_type() */
 323
 324 G_END_DECLS
 325
 326 #endif /* __ATK_UTIL_H__ */