atk/atkobject.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 #ifndef __ATK_OBJECT_H__
  21 #define __ATK_OBJECT_H__
  22
  23 #ifdef __cplusplus
  24 extern "C" {
  25 #endif /* __cplusplus */
  26
  27 #include <glib-object.h>
  28
  29 /*
  30  * AtkObject represents the minimum information all accessible objects
  31  * return. This information includes accessible name, accessible
  32  * description, role and state of the object, as well information about
  33  * its parent and children. It is also possible to obtain more specific
  34  * accessibility information about a component if it supports one or more
  35  * of the following interfaces:
  36  */
  37 typedef enum
  38 {
  39   ATK_CHILD_ADDED,
  40   ATK_CHILD_REMOVED,
  41   ATK_CHILD_CHANGED
  42 } AtkChildChangeType;
  43
  44 typedef enum
  45 {
  46   ATK_ROLE_INVALID,
  47   /* Object is used to alert the user about something */
  48   ATK_ROLE_ALERT,
  49   /* Object that can be drawn into and is sued to trap events */
  50   ATK_ROLE_CANVAS,
  51   /*
  52    * A choice that can be checked or unchecked and provides a separate
  53    * indicator for the current state.
  54    */
  55   ATK_ROLE_CHECK_BOX,
  56   /* A specialized dialog that lets the user choose a color. */
  57   ATK_ROLE_COLOR_CHOOSER,
  58   /* The header for a column of data */
  59   ATK_ROLE_COLUMN_HEADER,
  60   /* A list of choices the user can select from */
  61   ATK_ROLE_COMBO_BOX,
  62   /* An inconifed internal frame within a DESKTOP_PANE */
  63   ATK_ROLE_DESKTOP_ICON,
  64   /*
  65    * A pane that supports internal frames and iconified versions of those
  66    * internal frames.
  67    */
  68   ATK_ROLE_DESKTOP_FRAME,
  69   /* A top level window with title bar and a border */
  70   ATK_ROLE_DIALOG,
  71   /*
  72    * A pane that allows the user to navigate through and select the contents
  73    * of a directory
  74    */
  75   ATK_ROLE_DIRECTORY_PANE,
  76   /*
  77    * A specialized dialog that displays the files in the directory and lets
  78    * the user select a file, browse a different directory, or specify a
  79    * filename.
  80    */
  81   ATK_ROLE_FILE_CHOOSER,
  82   /*
  83    * A object that fills up space in a user interface
  84    */
  85   ATK_ROLE_FILLER,
  86   /* XXX Don't know sure about this. */
  87   ATK_ROLE_FOCUS_TRAVERSABLE,
  88   /* A top level window with a title bar, border, menubar, etc. */
  89   ATK_ROLE_FRAME,
  90   /* A pane that is guaranteed to be painted on top of all panes beneath it */
  91   ATK_ROLE_GLASS_PANE,
  92   /*
  93    * A document container for HTML, whose children
  94    * represent the document content.
  95    */
  96   ATK_ROLE_HTML_CONTAINER,
  97   /* A small fixed size picture, typically used to decorate components */
  98   ATK_ROLE_ICON,
  99   /* A frame-like object that is clipped by a desktop pane. */
 100   ATK_ROLE_INTERNAL_FRAME,
 101   /* An object used to present an icon or short string in an interface */
 102   ATK_ROLE_LABEL,
 103   /*
 104    * A specialized pane that allows its children to be drawn in layers,
 105    * providing a form of stacking order.
 106    */
 107   ATK_ROLE_LAYERED_PANE,
 108   /*
 109    * An object that presents a list of objects to the user and allows the
 110    * user to select one or more of them.
 111    */
 112   ATK_ROLE_LIST,
 113    /* An object that represents an element of a list. */
 114   ATK_ROLE_LIST_ITEM,
 115   /*
 116    * An object usually found inside a menu bar that contains a list of
 117    * actions the user can choose from.
 118    */
 119   ATK_ROLE_MENU,
 120   /*
 121    * An object usually drawn at the top of the primary dialog box of an
 122    * application that contains a list of menus the user can choose from.
 123    */
 124   ATK_ROLE_MENU_BAR,
 125   /*
 126    * An object usually contained in a menu that presents an action the
 127    * user can choose.
 128    */
 129   ATK_ROLE_MENU_ITEM,
 130   /* A specialized pane whose primary use is inside a DIALOG */
 131   ATK_ROLE_OPTION_PANE,
 132   /* An object that is a child of a page tab list */
 133   ATK_ROLE_PAGE_TAB,
 134   /*
 135    * An object that presents a series of panels (or page tabs), one at a time,
 136    * through some mechanism provided by the object.
 137    */
 138   ATK_ROLE_PAGE_TAB_LIST,
 139   /* A generic container that is often used to group objects. */
 140   ATK_ROLE_PANEL,
 141   /*
 142    * A text object uses for passwords, or other places where the text
 143    * content is not shown visibly to the user.
 144    */
 145   ATK_ROLE_PASSWORD_TEXT,
 146   /*
 147    * A temporary window that is usually used to offer the user a list of
 148    * choices, and then hides when the user selects one of those choices.
 149    */
 150   ATK_ROLE_POPUP_MENU,
 151   /* An object used to indicate how much of a task has been completed. */
 152   ATK_ROLE_PROGRESS_BAR,
 153   /*
 154    * An object the user can manipulate to tell the application to do
 155    * something.
 156    */
 157   ATK_ROLE_PUSH_BUTTON,
 158   /*
 159    * A specialized check box that will cause other radio buttons in the
 160    * same group to become uncghecked when this one is checked.
 161    */
 162   ATK_ROLE_RADIO_BUTTON,
 163   /*
 164    * A specialized pane that has a glass pane and a layered pane as its
 165    * children.
 166    */
 167   ATK_ROLE_ROOT_PANE,
 168   /* The header for a row of data */
 169   ATK_ROLE_ROW_HEADER,
 170   /*
 171    * An object usually used to allow a user to incrementally view a large
 172    * amount of data.
 173    */
 174   ATK_ROLE_SCROLL_BAR,
 175   /*
 176    * An object that allows a user to incrementally view a large amount
 177    * of information.
 178    */
 179   ATK_ROLE_SCROLL_PANE,
 180   /*
 181    * An object usually contained in a menu to provide a visible and
 182    * logical separation of the contents in a menu.
 183    */
 184   ATK_ROLE_SEPARATOR,
 185   /* An object that allows the user to select from a bounded range */
 186   ATK_ROLE_SLIDER,
 187   /* A specialized panel that presents two other panels at the same time. */
 188   ATK_ROLE_SPLIT_PANE,
 189   /* An object used to rpesent information in terms of rows and columns. */
 190   ATK_ROLE_TABLE,
 191   ATK_ROLE_TABLE_CELL,
 192   ATK_ROLE_TABLE_COLUMN_HEADER,
 193   ATK_ROLE_TABLE_ROW_HEADER,
 194   /* An object that presents text to the user */
 195   ATK_ROLE_TEXT,
 196   /*
 197    * A specialized push button that can be checked or unchecked, but does
 198    * not procide a separate indicator for the current state.
 199    */
 200   ATK_ROLE_TOGGLE_BUTTON,
 201   /*
 202    * A bar or palette usually composed of push buttons or toggle buttons
 203    */
 204   ATK_ROLE_TOOL_BAR,
 205   /*
 206    * An object that provides information about another object
 207    */
 208   ATK_ROLE_TOOL_TIP,
 209   /* An object used to repsent hierarchical information to the user. */
 210   ATK_ROLE_TREE,
 211   /*
 212    * The object contains some Accessible information, but its role is
 213    * not known.
 214    */
 215   ATK_ROLE_UNKNOWN,
 216   /* An object usually used in a scroll pane. */
 217   ATK_ROLE_VIEWPORT,
 218   /* A top level window with no title or border */
 219   ATK_ROLE_WINDOW,
 220   /* not a valid role, used for finding end of enumeration. */
 221   ATK_ROLE_LAST_DEFINED
 222 } AtkRole;
 223
 224 AtkRole                  atk_role_register        (const gchar *name);
 225
 226 typedef enum
 227 {
 228   ATK_STATE_INVALID,
 229   /* Indicates a window is currently the active window */
 230   ATK_STATE_ACTIVE,
 231   /* Indicates that the object is armed */
 232   ATK_STATE_ARMED,
 233   /* Indicates the current object is busy */
 234   ATK_STATE_BUSY,
 235   /* Indicates this object is currently checked */
 236   ATK_STATE_CHECKED,
 237   /* Indicates this object is collapsed */
 238   ATK_STATE_COLLAPSED,
 239   /* Indicates the user can change the contents of this object */
 240   ATK_STATE_DEFUNCT,
 241   /* Indicates this object may have been removed by the application */
 242   ATK_STATE_EDITABLE,
 243   /* Indicates this object allows progressive disclosure of its children */
 244   ATK_STATE_EXPANDABLE,
 245   /* Indicates this object is expandable */
 246   ATK_STATE_EXPANDED,
 247   /*
 248    * Indicates this object can accept keyboard focus, which means all
 249    * events resulting from typing on the keyboard will normally be passed
 250    * to it when it has focus
 251    */
 252   ATK_STATE_FOCUSABLE,
 253   /* Indicates this object currently has the keyboard focus */
 254   ATK_STATE_FOCUSED,
 255   /* Indicates the orientation of thsi object is horizontal */
 256   ATK_STATE_HORIZONTAL,
 257   /* Indicates this object is minimized and is represented only by an icon */
 258   ATK_STATE_ICONIFIED,
 259   /*
 260    * Indicates something must be done with this object before the user can
 261    * interact with an object in a different window.
 262    */
 263   ATK_STATE_MODAL,
 264   /* Indicates this (text) object can contain multiple lines of text */
 265   ATK_STATE_MULTI_LINE,
 266   /*
 267    * Indicates this object allows more than one of its children to be
 268    * selected at the same time
 269    */
 270   ATK_STATE_MULTISELECTABLE,
 271   /* Indicates this object paints every pixel within its rectangular region. */
 272   ATK_STATE_OPAQUE,
 273   /* Indicates this object is currently pressed */
 274   ATK_STATE_PRESSED,
 275   /* Indicates the size of this object is not fixed */
 276   ATK_STATE_RESIZABLE,
 277   /*
 278    * Indicates this object is the child of an object that allows its
 279    * children to be selected and that this child is one of those children
 280    * that can be selected.
 281    */
 282   ATK_STATE_SELECTABLE,
 283   /*
 284    * Indicates this object is the child of an object that allows its
 285    * children to be selected and that this child is one of those children
 286    * that has been selected.
 287    */
 288   ATK_STATE_SELECTED,
 289   /* Indicates this object is sensitive */
 290   ATK_STATE_SENSITIVE,
 291   /*
 292    * Indicates this object, the object's parent, the object's parent's
 293    * parent, and so on, are all visible
 294    */
 295   ATK_STATE_SHOWING,
 296   /* Indicates this (text) object can contain only a single line of text */
 297   ATK_STATE_SINGLE_LINE,
 298   /* Indicates this object is transient */
 299   ATK_STATE_TRANSIENT,
 300   /* Indicates the orientation of this object is vertical */
 301   ATK_STATE_VERTICAL,
 302   /* Indicates this object is visible */
 303   ATK_STATE_VISIBLE,
 304   ATK_STATE_LAST_DEFINED
 305 } AtkStateType;
 306
 307 AtkStateType               atk_state_type_register      (const gchar *name);
 308
 309
 310 #define ATK_TYPE_OBJECT                           (atk_object_get_type ())
 311 #define ATK_OBJECT(obj)                           (G_TYPE_CHECK_INSTANCE_CAST ((obj), ATK_TYPE_OBJECT, AtkObject))
 312 #define ATK_OBJECT_CLASS(klass)                   (G_TYPE_CHECK_CLASS_CAST ((klass), ATK_TYPE_OBJECT, AtkObjectClass))
 313 #define ATK_IS_OBJECT(obj)                        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), ATK_TYPE_OBJECT))
 314 #define ATK_IS_OBJECT_CLASS(klass)                (G_TYPE_CHECK_CLASS_TYPE ((klass), ATK_TYPE_OBJECT))
 315 #define ATK_OBJECT_GET_CLASS(obj)                 (G_TYPE_INSTANCE_GET_CLASS ((obj), ATK_TYPE_OBJECT, AtkObjectClass))
 316
 317 #define ATK_TYPE_IMPLEMENTOR                      (atk_implementor_get_type ())
 318 #define ATK_IS_IMPLEMENTOR(obj)                   G_TYPE_CHECK_INSTANCE_TYPE ((obj), ATK_TYPE_IMPLEMENTOR)
 319 #define ATK_IMPLEMENTOR(obj)                      G_TYPE_CHECK_INSTANCE_CAST ((obj), ATK_TYPE_IMPLEMENTOR, AtkImplementor)
 320 #define ATK_IMPLEMENTOR_GET_IFACE(obj)            (G_TYPE_INSTANCE_GET_INTERFACE ((obj), ATK_TYPE_IMPLEMENTOR, AtkImplementorIface))
 321
 322
 323 typedef struct _AtkImplementor            AtkImplementor; /* dummy typedef */
 324 typedef struct _AtkImplementorIface       AtkImplementorIface;
 325
 326
 327 typedef struct _AtkObject                 AtkObject;
 328 typedef struct _AtkObjectClass            AtkObjectClass;
 329 typedef struct _AtkRelationSet            AtkRelationSet;
 330 typedef struct _AtkStateSet               AtkStateSet;
 331
 332 typedef guint64                           AtkState;
 333 typedef guint64                           AtkStateMask;
 334
 335
 336 struct _AtkPropertyValues
 337 {
 338   gchar  *property_name;
 339   GValue old_value;
 340   GValue new_value;
 341 };
 342
 343 typedef struct _AtkPropertyValues        AtkPropertyValues;
 344
 345 /*
 346  * For most properties the old_value field of AtkPropertyValues will
 347  * not contain a valid value.
 348  *
 349  * Currently, the only property for which old_value is used is
 350  * accessible-state; for instance if there is a focus state the
 351  * property change handler will be called for the object which lost the focus
 352  * with the old_value containing an AtkState value corresponding to focused
 353  * and the property change handler will be called for the object which
 354  * received the focus with the new_value containing an AtkState value
 355  * corresponding to focused.
 356  */
 357 typedef void (*AtkPropertyChangeHandler) (AtkObject*, AtkPropertyValues*);
 358
 359
 360 struct _AtkObject
 361 {
 362   GObject parent;
 363
 364   gchar *description;
 365   gchar *name;
 366   AtkObject *accessible_parent;
 367   AtkRole role;
 368   AtkRelationSet *relation_set;
 369 };
 370
 371 struct _AtkObjectClass
 372 {
 373   GObjectClass parent;
 374
 375   /*
 376    * Gets the accessible name of the object
 377    */
 378   G_CONST_RETURN gchar*    (* get_name)            (AtkObject                *accessible);
 379   /*
 380    * Gets the accessible description of the object
 381    */
 382   G_CONST_RETURN gchar*    (* get_description)     (AtkObject                *accessible);
 383   /*
 384    * Gets the accessible parent of the object
 385    */
 386   AtkObject*               (*get_parent)           (AtkObject                *accessible);
 387
 388   /*
 389    * Gets the number of accessible children of the object
 390    */
 391   gint                    (* get_n_children)       (AtkObject                *accessible);
 392   /*
 393    * Returns a reference to the specified accessible child of the object.
 394    * The accessible children are 0-based so the first accessible child is
 395    * at index 0, the second at index 1 and so on.
 396    */
 397   AtkObject*              (* ref_child)            (AtkObject                *accessible,
 398                                                     gint                      i);
 399   /*
 400    * Gets the 0-based index of this object in its parent; returns -1 if the
 401    * object does not have an accessible parent.
 402    */
 403   gint                    (* get_index_in_parent) (AtkObject                 *accessible);
 404   /*
 405    * Gets the RelationSet associated with the object
 406    */
 407   AtkRelationSet*         (* ref_relation_set)    (AtkObject                 *accessible);
 408   /*
 409    * Gets the role of the object
 410    */
 411   AtkRole                 (* get_role)            (AtkObject                 *accessible);
 412   /*
 413    * Gets the state set of the object
 414    */
 415   AtkStateSet*            (* ref_state_set)       (AtkObject                 *accessible);
 416   /*
 417    * Sets the accessible name of the object
 418    */
 419   void                    (* set_name)            (AtkObject                 *accessible,
 420                                                    const gchar               *name);
 421   /*
 422    * Sets the accessible description of the object
 423    */
 424   void                    (* set_description)     (AtkObject                 *accessible,
 425                                                    const gchar               *description);
 426   /*
 427    * Sets the accessible parent of the object
 428    */
 429   void                    (* set_parent)          (AtkObject                 *accessible,
 430                                                    AtkObject                 *parent);
 431   /*
 432    * Sets the accessible role of the object
 433    */
 434   void                    (* set_role)            (AtkObject                 *accessible,
 435                                                    AtkRole                   role);
 436   /*
 437    * Specifies a function to be called when a property changes value
 438    */
 439 guint                     (* connect_property_change_handler)    (AtkObject
 440                  *accessible,
 441                                                                   AtkPropertyChangeHandler       *handler);
 442   /*
 443    * Removes a property change handler which was specified using
 444    * connect_property_change_handler
 445    */
 446 void                      (* remove_property_change_handler)     (AtkObject
 447                 *accessible,
 448                                                                   guint
 449                 handler_id);
 450   /*
 451    * The signal handler which is executed when there is a change in the
 452    * children of the object
 453    */
 454   void                    (* children_changed)    (AtkObject                  *accessible,
 455                                                    AtkChildChangeType         change_type,
 456                                                    AtkObject                  *changed_child);
 457 };
 458 GType            atk_object_get_type   (void);
 459
 460 struct _AtkImplementorIface
 461 {
 462   GTypeInterface parent;
 463
 464   AtkObject*   (*ref_accessible) (AtkImplementor *implementor);
 465 };
 466 GType atk_implementor_get_type (void);
 467
 468 /*
 469  * This method uses the ref_accessible method in AtkImplementorIface,
 470  * if the object's class implements AtkImplementorIface.
 471  * Otherwise it returns %NULL.
 472  *
 473  * IMPORTANT:
 474  * Note also that because this method may return flyweight objects,
 475  * it increments the returned AtkObject's reference count.
 476  * Therefore it is the responsibility of the calling
 477  * program to unreference the object when no longer needed.
 478  * (c.f. gtk_widget_get_accessible() where this is not the case).
 479  */
 480 AtkObject*              atk_implementor_ref_accessible            (AtkImplementor *implementor);
 481
 482 /*
 483  * Properties directly supported by AtkObject
 484  */
 485
 486 G_CONST_RETURN gchar*   atk_object_get_name                       (AtkObject *accessible);
 487 G_CONST_RETURN gchar*   atk_object_get_description                (AtkObject *accessible);
 488 AtkObject*              atk_object_get_parent                     (AtkObject *accessible);
 489 gint                    atk_object_get_n_accessible_children      (AtkObject *accessible);
 490 AtkObject*              atk_object_ref_accessible_child           (AtkObject *accessible,
 491                                                                    gint        i);
 492 AtkRelationSet*         atk_object_ref_relation_set               (AtkObject *accessible);
 493 AtkRole                 atk_object_get_role                       (AtkObject *accessible);
 494 AtkStateSet*            atk_object_ref_state_set                  (AtkObject *accessible);
 495 gint                    atk_object_get_index_in_parent            (AtkObject *accessible);
 496 void                    atk_object_set_name                       (AtkObject *accessible,
 497                                                                    const gchar *name);
 498 void                    atk_object_set_description                (AtkObject *accessible,
 499                                                                    const gchar *description);
 500 void                    atk_object_set_parent                     (AtkObject *accessible,
 501                                                                    AtkObject *parent);
 502 void                    atk_object_set_role                       (AtkObject *accessible,
 503                                                                    AtkRole   role);
 504
 505
 506 /*
 507  * to install property change listener, one must
 508  * install signal handler for gobject "properties_changed" signal.
 509  * (for single notifications of multiple changes).
 510  * We could use the "notify" signal instead.
 511  *
 512  */
 513 guint                atk_object_connect_property_change_handler  (AtkObject                      *accessible,
 514                                                                   AtkPropertyChangeHandler       *handler);
 515 void                 atk_object_remove_property_change_handler  (AtkObject                      *accessible,
 516                                                                   guint                         handler_id);
 517
 518 /*
 519  * Note: the properties which are registered with the GType
 520  *   property registry, for type ATK_TYPE_OBJECT, are as follows:
 521  *
 522  *   "accessible-name"
 523  *   "accessible-description"
 524  *   "accessible-parent"
 525  *   "accessible-child"
 526  *   "accessible-role"
 527  *   "accessible-state"
 528  *
 529  * accessibility property change listeners should use the
 530  *   normal GObject property interfaces and "properties_changed"
 531  *   signal handler semantics to interpret the property change
 532  *   information relayed from AtkObject.
 533  *   (AtkObject instances will connect to the "properties_changed"
 534  *   signal in their host objects, and relay the signals when appropriate).
 535  */
 536
 537 /* For other signals, see related interfaces
 538  *
 539  *    AtkActionIface,
 540  *    AtkComponentIface,
 541  *    AtkHypertextIface,
 542  *    AtkImageIface,
 543  *    AtkSelectionIface,
 544  *    AtkTableIface,
 545  *    AtkTextIface,
 546  *    AtkValueIface.
 547  *
 548  *  The usage model for obtaining these interface instances is:
 549  *    ATK_<interfacename>_GET_IFACE(GObject *accessible),
 550  *    where accessible, though specified as a GObject, is
 551  *    the AtkObject instance being queried.
 552  *  More usually, the interface will be used via a cast to the
 553  *    interface's corresponding "type":
 554  *
 555  *    AtkText textImpl = ATK_TEXT(accessible);
 556  *    if (textImpl)
 557  *      {
 558  *        cpos = atk_text_get_caret_position(textImpl);
 559  *      }
 560  *
 561  *  If it's known in advance that accessible implements AtkTextIface,
 562  *    this is shortened to:
 563  *
 564  *    cpos = atk_text_get_caret_position (ATK_TEXT (accessible));
 565  */
 566
 567 G_CONST_RETURN gchar* atk_state_mask_get_name         (AtkStateMask    state);
 568 AtkStateMask          atk_state_mask_for_name         (const gchar     *name);
 569
 570 #ifdef __cplusplus
 571 }
 572 #endif /* __cplusplus */
 573
 574
 575 #endif /* __ATK_OBJECT_H__ */