path: root/atk/atkobject.h

/* ATK -  Accessibility Toolkit
 * Copyright 2001 Sun Microsystems Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifndef __ATK_OBJECT_H__
#define __ATK_OBJECT_H__

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

#include <glib-object.h>
#include <atk/atkstate.h>

/*
 * AtkObject represents the minimum information all accessible objects
 * return. This information includes accessible name, accessible
 * description, role and state of the object, as well information about
 * its parent and children. It is also possible to obtain more specific
 * accessibility information about a component if it supports one or more
 * of the following interfaces:
 */


/**
 *AtkRole:
 *@ATK_ROLE_INVALID: Invalid role
 *@ATK_ROLE_ACCEL_LABEL: A label which represents an accelerator
 *@ATK_ROLE_ALERT: An object which is an alert to the user
 *@ATK_ROLE_ANIMATION: An object which is an animated image
 *@ATK_ROLE_ARROW: An arrow in one of the four cardinal directions
 *@ATK_ROLE_CALENDAR:  An object that displays a calendar and allows the user to select a date
 *@ATK_ROLE_CANVAS: An object that can be drawn into and is used to trap events
 *@ATK_ROLE_CHECK_BOX: A choice that can be checked or unchecked and provides a separate indicator for the current state
 *@ATK_ROLE_CHECK_MENU_ITEM: A menu item with a check box
 *@ATK_ROLE_COLOR_CHOOSER: A specialized dialog that lets the user choose a color
 *@ATK_ROLE_COLUMN_HEADER: The header for a column of data
 *@ATK_ROLE_COMBO_BOX: A list of choices the user can select from
 *@ATK_ROLE_DATE_EDITOR: An object whose purpose is to allow a user to edit a date
 *@ATK_ROLE_DESKTOP_ICON: An inconifed internal frame within a DESKTOP_PANE
 *@ATK_ROLE_DESKTOP_FRAME: A pane that supports internal frames and iconified versions of those internal frames
 *@ATK_ROLE_DIAL: An object whose purpose is to allow a user to set a value
 *@ATK_ROLE_DIALOG: A top level window with title bar and a border
 *@ATK_ROLE_DIRECTORY_PANE: A pane that allows the user to navigate through and select the contents of a directory
 *@ATK_ROLE_DRAWING_AREA: An object used for drawing custom user interface elements
 *@ATK_ROLE_FILE_CHOOSER: A specialized dialog that lets the user choose a file
 *@ATK_ROLE_FILLER: A object that fills up space in a user interface
 *@ATK_ROLE_FONT_CHOOSER: A specialized dialog that lets the user choose a font
 *@ATK_ROLE_FRAME: A top level window with a title bar, border, menubar, etc.
 *@ATK_ROLE_GLASS_PANE: A pane that is guaranteed to be painted on top of all panes beneath it
 *@ATK_ROLE_HTML_CONTAINER: A document container for HTML, whose children represent the document content
 *@ATK_ROLE_ICON: A small fixed size picture, typically used to decorate components
 *@ATK_ROLE_IMAGE: An object whose primary purpose is to display an image
 *@ATK_ROLE_INTERNAL_FRAME: A frame-like object that is clipped by a desktop pane
 *@ATK_ROLE_LABEL: An object used to present an icon or short string in an interface
 *@ATK_ROLE_LAYERED_PANE: A specialized pane that allows its children to be drawn in layers, providing a form of stacking order
 *@ATK_ROLE_LIST: An object that presents a list of objects to the user and allows the user to select one or more of them 
 *@ATK_ROLE_LIST_ITEM: An object that represents an element of a list 
 *@ATK_ROLE_MENU: An object usually found inside a menu bar that contains a list of actions the user can choose from
 *@ATK_ROLE_MENU_BAR: An object usually drawn at the top of the primary dialog box of an application that contains a list of menus the user can choose from 
 *@ATK_ROLE_MENU_ITEM: An object usually contained in a menu that presents an action the user can choose
 *@ATK_ROLE_OPTION_PANE: A specialized pane whose primary use is inside a DIALOG
 *@ATK_ROLE_PAGE_TAB: An object that is a child of a page tab list
 *@ATK_ROLE_PAGE_TAB_LIST: An object that presents a series of panels (or page tabs), one at a time, through some mechanism provided by the object 
 *@ATK_ROLE_PANEL: A generic container that is often used to group objects
 *@ATK_ROLE_PASSWORD_TEXT: A text object uses for passwords, or other places where the text content is not shown visibly to the user
 *@ATK_ROLE_POPUP_MENU: A temporary window that is usually used to offer the user a list of choices, and then hides when the user selects one of those choices
 *@ATK_ROLE_PROGRESS_BAR: An object used to indicate how much of a task has been completed
 *@ATK_ROLE_PUSH_BUTTON: An object the user can manipulate to tell the application to do something
 *@ATK_ROLE_RADIO_BUTTON: A specialized check box that will cause other radio buttons in the same group to become unchecked when this one is checked
 *@ATK_ROLE_RADIO_MENU_ITEM: A check menu item which belongs to a group. At each instant exactly one of the radio menu items from a group is selected
 *@ATK_ROLE_ROOT_PANE: A specialized pane that has a glass pane and a layered pane as its children
 *@ATK_ROLE_ROW_HEADER: The header for a row of data
 *@ATK_ROLE_SCROLL_BAR: An object usually used to allow a user to incrementally view a large amount of data.
 *@ATK_ROLE_SCROLL_PANE: An object that allows a user to incrementally view a large amount of information
 *@ATK_ROLE_SEPARATOR: An object usually contained in a menu to provide a visible and logical separation of the contents in a menu
 *@ATK_ROLE_SLIDER: An object that allows the user to select from a bounded range
 *@ATK_ROLE_SPLIT_PANE: A specialized panel that presents two other panels at the same time
 *@ATK_ROLE_SPIN_BUTTON: An object used to get an integer or floating point number from the user
 *@ATK_ROLE_STATUSBAR: An object which reports messages of minor importance to the user
 *@ATK_ROLE_TABLE: An object used to represent information in terms of rows and columns
 *@ATK_ROLE_TABLE_CELL: A cell in a table
 *@ATK_ROLE_TABLE_COLUMN_HEADER: The header for a column of a table
 *@ATK_ROLE_TABLE_ROW_HEADER: The header for a row of a table
 *@ATK_ROLE_TEAR_OFF_MENU_ITEM: A menu item used to tear off and reattach its menu
 *@ATK_ROLE_TERMINAL: An object that represents an accessible terminal
 *@ATK_ROLE_TEXT: An object that presents text to the user
 *@ATK_ROLE_TOGGLE_BUTTON: A specialized push button that can be checked or unchecked, but does not provide a separate indicator for the current state
 *@ATK_ROLE_TOOL_BAR: A bar or palette usually composed of push buttons or toggle buttons
 *@ATK_ROLE_TOOL_TIP: An object that provides information about another object
 *@ATK_ROLE_TREE: An object used to represent hierarchical information to the user
 *@ATK_ROLE_UNKNOWN: The object contains some Accessible information, but its role is not known
 *@ATK_ROLE_VIEWPORT: An object usually used in a scroll pane
 *@ATK_ROLE_WINDOW: A top level window with no title or border
 *@ATK_ROLE_LAST_DEFINED: not a valid role, used for finding end of enumeration
 * 
 *Describes the role of an object
 **/
typedef enum
{
  ATK_ROLE_INVALID,
  ATK_ROLE_ACCEL_LABEL,
  ATK_ROLE_ALERT,
  ATK_ROLE_ANIMATION,
  ATK_ROLE_ARROW,
  ATK_ROLE_CALENDAR,
  ATK_ROLE_CANVAS,
  ATK_ROLE_CHECK_BOX,
  ATK_ROLE_CHECK_MENU_ITEM,
  ATK_ROLE_COLOR_CHOOSER,
  ATK_ROLE_COLUMN_HEADER,
  ATK_ROLE_COMBO_BOX,
  ATK_ROLE_DATE_EDITOR,
  ATK_ROLE_DESKTOP_ICON,
  ATK_ROLE_DESKTOP_FRAME,
  ATK_ROLE_DIAL,
  ATK_ROLE_DIALOG,
  ATK_ROLE_DIRECTORY_PANE,
  ATK_ROLE_DRAWING_AREA,
  ATK_ROLE_FILE_CHOOSER,
  ATK_ROLE_FILLER,
  ATK_ROLE_FONT_CHOOSER,
  ATK_ROLE_FRAME,
  ATK_ROLE_GLASS_PANE,
  ATK_ROLE_HTML_CONTAINER,
  ATK_ROLE_ICON,
  ATK_ROLE_IMAGE,
  ATK_ROLE_INTERNAL_FRAME,
  ATK_ROLE_LABEL,
  ATK_ROLE_LAYERED_PANE,
  ATK_ROLE_LIST,
  ATK_ROLE_LIST_ITEM,
  ATK_ROLE_MENU,
  ATK_ROLE_MENU_BAR,
  ATK_ROLE_MENU_ITEM,
  ATK_ROLE_OPTION_PANE,
  ATK_ROLE_PAGE_TAB,
  ATK_ROLE_PAGE_TAB_LIST,
  ATK_ROLE_PANEL,
  ATK_ROLE_PASSWORD_TEXT,
  ATK_ROLE_POPUP_MENU,
  ATK_ROLE_PROGRESS_BAR,
  ATK_ROLE_PUSH_BUTTON,
  ATK_ROLE_RADIO_BUTTON,
  ATK_ROLE_RADIO_MENU_ITEM,
  ATK_ROLE_ROOT_PANE,
  ATK_ROLE_ROW_HEADER,
  ATK_ROLE_SCROLL_BAR,
  ATK_ROLE_SCROLL_PANE,
  ATK_ROLE_SEPARATOR,
  ATK_ROLE_SLIDER,
  ATK_ROLE_SPLIT_PANE,
  ATK_ROLE_SPIN_BUTTON,
  ATK_ROLE_STATUSBAR,
  ATK_ROLE_TABLE,
  ATK_ROLE_TABLE_CELL,
  ATK_ROLE_TABLE_COLUMN_HEADER,
  ATK_ROLE_TABLE_ROW_HEADER,
  ATK_ROLE_TEAR_OFF_MENU_ITEM,
  ATK_ROLE_TERMINAL,
  ATK_ROLE_TEXT,
  ATK_ROLE_TOGGLE_BUTTON,
  ATK_ROLE_TOOL_BAR,
  ATK_ROLE_TOOL_TIP,
  ATK_ROLE_TREE,
  ATK_ROLE_UNKNOWN,
  ATK_ROLE_VIEWPORT,
  ATK_ROLE_WINDOW,
  ATK_ROLE_LAST_DEFINED
} AtkRole;

AtkRole                  atk_role_register        (const gchar *name);


#define ATK_TYPE_OBJECT                           (atk_object_get_type ())
#define ATK_OBJECT(obj)                           (G_TYPE_CHECK_INSTANCE_CAST ((obj), ATK_TYPE_OBJECT, AtkObject))
#define ATK_OBJECT_CLASS(klass)                   (G_TYPE_CHECK_CLASS_CAST ((klass), ATK_TYPE_OBJECT, AtkObjectClass))
#define ATK_IS_OBJECT(obj)                        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), ATK_TYPE_OBJECT))
#define ATK_IS_OBJECT_CLASS(klass)                (G_TYPE_CHECK_CLASS_TYPE ((klass), ATK_TYPE_OBJECT))
#define ATK_OBJECT_GET_CLASS(obj)                 (G_TYPE_INSTANCE_GET_CLASS ((obj), ATK_TYPE_OBJECT, AtkObjectClass))

#define ATK_TYPE_IMPLEMENTOR                      (atk_implementor_get_type ())
#define ATK_IS_IMPLEMENTOR(obj)                   G_TYPE_CHECK_INSTANCE_TYPE ((obj), ATK_TYPE_IMPLEMENTOR)
#define ATK_IMPLEMENTOR(obj)                      G_TYPE_CHECK_INSTANCE_CAST ((obj), ATK_TYPE_IMPLEMENTOR, AtkImplementor)
#define ATK_IMPLEMENTOR_GET_IFACE(obj)            (G_TYPE_INSTANCE_GET_INTERFACE ((obj), ATK_TYPE_IMPLEMENTOR, AtkImplementorIface))


typedef struct _AtkImplementor            AtkImplementor; /* dummy typedef */
typedef struct _AtkImplementorIface       AtkImplementorIface;


typedef struct _AtkObject                 AtkObject;
typedef struct _AtkObjectClass            AtkObjectClass;
typedef struct _AtkRelationSet            AtkRelationSet;
typedef struct _AtkStateSet               AtkStateSet;

struct _AtkPropertyValues
{
  gchar  *property_name;
  GValue old_value;
  GValue new_value;
};

typedef struct _AtkPropertyValues        AtkPropertyValues;

/*
 * For most properties the old_value field of AtkPropertyValues will
 * not contain a valid value.
 *
 * Currently, the only property for which old_value is used is
 * accessible-state; for instance if there is a focus state the
 * property change handler will be called for the object which lost the focus
 * with the old_value containing an AtkState value corresponding to focused
 * and the property change handler will be called for the object which
 * received the focus with the new_value containing an AtkState value
 * corresponding to focused.
 */
typedef void (*AtkPropertyChangeHandler) (AtkObject*, AtkPropertyValues*);


struct _AtkObject
{
  GObject parent;

  gchar *description;
  gchar *name;
  AtkObject *accessible_parent;
  AtkRole role;
  AtkRelationSet *relation_set;
};

struct _AtkObjectClass
{
  GObjectClass parent;

  /*
   * Gets the accessible name of the object
   */
  G_CONST_RETURN gchar*    (* get_name)            (AtkObject                *accessible);
  /*
   * Gets the accessible description of the object
   */
  G_CONST_RETURN gchar*    (* get_description)     (AtkObject                *accessible);
  /*
   * Gets the accessible parent of the object
   */
  AtkObject*               (*get_parent)           (AtkObject                *accessible);

  /*
   * Gets the number of accessible children of the object
   */
  gint                    (* get_n_children)       (AtkObject                *accessible);
  /*
   * Returns a reference to the specified accessible child of the object.
   * The accessible children are 0-based so the first accessible child is
   * at index 0, the second at index 1 and so on.
   */
  AtkObject*              (* ref_child)            (AtkObject                *accessible,
                                                    gint                      i);
  /*
   * Gets the 0-based index of this object in its parent; returns -1 if the
   * object does not have an accessible parent.
   */
  gint                    (* get_index_in_parent) (AtkObject                 *accessible);
  /*
   * Gets the RelationSet associated with the object
   */
  AtkRelationSet*         (* ref_relation_set)    (AtkObject                 *accessible);
  /*
   * Gets the role of the object
   */
  AtkRole                 (* get_role)            (AtkObject                 *accessible);
  /*
   * Gets the state set of the object
   */
  AtkStateSet*            (* ref_state_set)       (AtkObject                 *accessible);
  /*
   * Sets the accessible name of the object
   */
  void                    (* set_name)            (AtkObject                 *accessible,
                                                   const gchar               *name);
  /*
   * Sets the accessible description of the object
   */
  void                    (* set_description)     (AtkObject                 *accessible,
                                                   const gchar               *description);
  /*
   * Sets the accessible parent of the object
   */
  void                    (* set_parent)          (AtkObject                 *accessible,
                                                   AtkObject                 *parent);
  /*
   * Sets the accessible role of the object
   */
  void                    (* set_role)            (AtkObject                 *accessible,
                                                   AtkRole                   role);
  /*
   * Specifies a function to be called when a property changes value
   */
guint                     (* connect_property_change_handler)    (AtkObject
                 *accessible,
                                                                  AtkPropertyChangeHandler       *handler);
  /*
   * Removes a property change handler which was specified using
   * connect_property_change_handler
   */
void                      (* remove_property_change_handler)     (AtkObject
                *accessible,
                                                                  guint
                handler_id);
  /*
   * The signal handler which is executed when there is a change in the
   * children of the object
   */
  void                    (* children_changed)    (AtkObject                  *accessible,
                                                   gint                       change_index,
                                                   AtkObject                  *changed_child);
  /*
   * The signal handler which is executed  when there is a focus event
   * for an object.
   */
  void                    (*focus_event)          (AtkObject                  *accessible,
                                                   gboolean                   focus_in);
  /*
   * The signal handler which is executed  when there is a property_change 
   * signal for an object.
   */
  gint                    (*property_change)      (AtkObject                 *accessible,
                                                   AtkPropertyValues         *values);

};

GType            atk_object_get_type   (void);

struct _AtkImplementorIface
{
  GTypeInterface parent;

  AtkObject*   (*ref_accessible) (AtkImplementor *implementor);
};
GType atk_implementor_get_type (void);

/*
 * This method uses the ref_accessible method in AtkImplementorIface,
 * if the object's class implements AtkImplementorIface.
 * Otherwise it returns %NULL.
 *
 * IMPORTANT:
 * Note also that because this method may return flyweight objects,
 * it increments the returned AtkObject's reference count.
 * Therefore it is the responsibility of the calling
 * program to unreference the object when no longer needed.
 * (c.f. gtk_widget_get_accessible() where this is not the case).
 */
AtkObject*              atk_implementor_ref_accessible            (AtkImplementor *implementor);

/*
 * Properties directly supported by AtkObject
 */

G_CONST_RETURN gchar*   atk_object_get_name                       (AtkObject *accessible);
G_CONST_RETURN gchar*   atk_object_get_description                (AtkObject *accessible);
AtkObject*              atk_object_get_parent                     (AtkObject *accessible);
gint                    atk_object_get_n_accessible_children      (AtkObject *accessible);
AtkObject*              atk_object_ref_accessible_child           (AtkObject *accessible,
                                                                   gint        i);
AtkRelationSet*         atk_object_ref_relation_set               (AtkObject *accessible);
AtkRole                 atk_object_get_role                       (AtkObject *accessible);
AtkStateSet*            atk_object_ref_state_set                  (AtkObject *accessible);
gint                    atk_object_get_index_in_parent            (AtkObject *accessible);
void                    atk_object_set_name                       (AtkObject *accessible,
                                                                   const gchar *name);
void                    atk_object_set_description                (AtkObject *accessible,
                                                                   const gchar *description);
void                    atk_object_set_parent                     (AtkObject *accessible,
                                                                   AtkObject *parent);
void                    atk_object_set_role                       (AtkObject *accessible,
                                                                   AtkRole   role);


/*
 * to install property change listener, one must
 * install signal handler for gobject "properties_changed" signal.
 * (for single notifications of multiple changes).
 * We could use the "notify" signal instead.
 *
 */
guint                atk_object_connect_property_change_handler  (AtkObject                      *accessible,
                                                                  AtkPropertyChangeHandler       *handler);
void                 atk_object_remove_property_change_handler   (AtkObject                      *accessible,
                                                                  guint                          handler_id);

void                 atk_object_notify_state_change              (AtkObject                      *accessible,
                                                                  AtkState                       state,
                                                                  gboolean                       value);
                                    
/*
 * Note: the properties which are registered with the GType
 *   property registry, for type ATK_TYPE_OBJECT, are as follows:
 *
 *   "accessible-name"
 *   "accessible-description"
 *   "accessible-parent"
 *   "accessible-child"
 *   "accessible-role"
 *   "accessible-state"
 *   "accessible-parent"
 *   "accessible-text"
 *   "accessible-caret"
 *   "accessible-selection"
 *   "accessible-value"
 *   "accessible-visible-data"
 *   "accessible-table-caption"
 *   "accessible-table-column-header"
 *   "accessible-table-row-heaer"
 *   "accessible-table-summary"
 *   "accessible-model"
 *
 * accessibility property change listeners should use the
 *   normal GObject property interfaces and "properties_changed"
 *   signal handler semantics to interpret the property change
 *   information relayed from AtkObject.
 *   (AtkObject instances will connect to the "properties_changed"
 *   signal in their host objects, and relay the signals when appropriate).
 */

/* For other signals, see related interfaces
 *
 *    AtkActionIface,
 *    AtkComponentIface,
 *    AtkHypertextIface,
 *    AtkImageIface,
 *    AtkSelectionIface,
 *    AtkTableIface,
 *    AtkTextIface,
 *    AtkValueIface.
 *
 *  The usage model for obtaining these interface instances is:
 *    ATK_<interfacename>_GET_IFACE(GObject *accessible),
 *    where accessible, though specified as a GObject, is
 *    the AtkObject instance being queried.
 *  More usually, the interface will be used via a cast to the
 *    interface's corresponding "type":
 *
 *    AtkText textImpl = ATK_TEXT(accessible);
 *    if (textImpl)
 *      {
 *        cpos = atk_text_get_caret_position(textImpl);
 *      }
 *
 *  If it's known in advance that accessible implements AtkTextIface,
 *    this is shortened to:
 *
 *    cpos = atk_text_get_caret_position (ATK_TEXT (accessible));
 */

#ifdef __cplusplus
}
#endif /* __cplusplus */


#endif /* __ATK_OBJECT_H__ */