accessible/interfaces/nsIAccessible.idl

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsISupports.idl"
   7 #include "nsIArray.idl"
   8
   9 interface nsIPersistentProperties;
  10 interface nsIAccessibleDocument;
  11 interface nsIAccessibleRelation;
  12
  13 webidl Node;
  14
  15 %{C++
  16 namespace mozilla {
  17 namespace a11y {
  18 class Accessible;
  19 }
  20 }
  21 %}
  22
  23 /**
  24  * A cross-platform interface that supports platform-specific
  25  * accessibility APIs like MSAA and ATK. Contains the sum of what's needed
  26  * to support IAccessible as well as ATK's generic accessibility objects.
  27  * Can also be used by in-process accessibility clients to get information
  28  * about objects in the accessible tree. The accessible tree is a subset of
  29  * nodes in the DOM tree -- such as documents, focusable elements and text.
  30  * Mozilla creates the implementations of nsIAccessible on demand.
  31  * See http://www.mozilla.org/projects/ui/accessibility for more information.
  32  */
  33 [scriptable, builtinclass, uuid(de2869d9-563c-4943-996b-31a4daa4d097)]
  34 interface nsIAccessible : nsISupports
  35 {
  36   /**
  37    * Parent node in accessible tree.
  38    */
  39   readonly attribute nsIAccessible parent;
  40
  41   /**
  42    * Next sibling in accessible tree
  43    */
  44   readonly attribute nsIAccessible nextSibling;
  45
  46   /**
  47    * Previous sibling in accessible tree
  48    */
  49   readonly attribute nsIAccessible previousSibling;
  50
  51   /**
  52    * First child in accessible tree
  53    */
  54   readonly attribute nsIAccessible firstChild;
  55
  56   /**
  57    * Last child in accessible tree
  58    */
  59   readonly attribute nsIAccessible lastChild;
  60
  61   /**
  62    * Array of all this element's children.
  63    */
  64   readonly attribute nsIArray children;
  65
  66   /**
  67    * Number of accessible children
  68    */
  69   readonly attribute long childCount;
  70
  71   /**
  72    * The 0-based index of this accessible in its parent's list of children,
  73    * or -1 if this accessible does not have a parent.
  74    */
  75   readonly attribute long indexInParent;
  76
  77   /**
  78    * The unique identifier of the accessible. ID is only guaranteed to be unique
  79    * per document (Windows IDs are unique even across documents, but that is
  80    * Windows specific and not exposed to core).
  81    */
  82   readonly attribute long long uniqueID;
  83
  84   /**
  85    * The DOM node this nsIAccessible is associated with.
  86    */
  87   readonly attribute Node DOMNode;
  88
  89   /**
  90     * For remote accessibles the id of the related DOM node.
  91     */
  92   readonly attribute AString id;
  93
  94   /**
  95    * The document accessible that this access node resides in.
  96    */
  97   readonly attribute nsIAccessibleDocument document;
  98
  99   /**
 100    * The root document accessible that this access node resides in.
 101    */
 102   readonly attribute nsIAccessibleDocument rootDocument;
 103
 104   /**
 105    * The language for the current DOM node, e.g. en, de, etc.
 106    */
 107   readonly attribute AString language;
 108
 109   /**
 110    * Accessible name -- the main text equivalent for this node. The name is
 111    * specified by ARIA or by native markup. Example of ARIA markup is
 112    * aria-labelledby attribute placed on element of this accessible. Example
 113    * of native markup is HTML label linked with HTML element of this accessible.
 114    *
 115    * Value can be string or null. A null value indicates that AT may attempt to
 116    * compute the name. Any string value, including the empty string, should be
 117    * considered author-intentional, and respected.
 118    */
 119   readonly attribute AString name;
 120
 121   /**
 122    * Accessible value -- a number or a secondary text equivalent for this node
 123    * Widgets that use role attribute can force a value using the valuenow attribute
 124    */
 125   readonly attribute AString value;
 126
 127   /**
 128    * Accessible description -- long text associated with this node
 129    */
 130   readonly attribute AString description;
 131
 132   /**
 133    * Provides localized string of accesskey name, such as Alt+D.
 134    * The modifier may be affected by user and platform preferences.
 135    * Usually alt+letter, or just the letter alone for menu items.
 136    */
 137   readonly attribute AString accessKey;
 138
 139   /**
 140    * Provides localized string of global keyboard accelerator for default
 141    * action, such as Ctrl+O for Open file
 142    */
 143   readonly attribute AString keyboardShortcut;
 144
 145   /**
 146    * Enumerated accessible role (see the constants defined in nsIAccessibleRole).
 147    *
 148    * @note  The values might depend on platform because of variations. Widgets
 149    *        can use ARIA role attribute to force the final role.
 150    */
 151   readonly attribute unsigned long role;
 152
 153   /**
 154    * Accessible states -- bit fields which describe boolean properties of node.
 155    * Many states are only valid given a certain role attribute that supports
 156    * them.
 157    *
 158    * @param aState - the first bit field (see nsIAccessibleStates::STATE_*
 159    *                 constants)
 160    * @param aExtraState - the second bit field
 161    *                      (see nsIAccessibleStates::EXT_STATE_* constants)
 162    */
 163   void getState(out unsigned long aState, out unsigned long aExtraState);
 164
 165   /**
 166    * Help text associated with node
 167    *
 168    * @note As of now, this just returns empty string.
 169    */
 170   readonly attribute AString help;
 171
 172   /**
 173    * Focused accessible child of node
 174    */
 175   readonly attribute nsIAccessible focusedChild;
 176
 177   /**
 178    * Attributes of accessible
 179    */
 180   readonly attribute nsIPersistentProperties attributes;
 181
 182   /**
 183    * Platform specific interface for accessible
 184    */
 185   readonly attribute nsISupports nativeInterface;
 186
 187   /**
 188    * Returns grouping information. Used for tree items, list items, tab panel
 189    * labels, radio buttons, etc. Also used for collectons of non-text objects.
 190    *
 191    * @param groupLevel - 1-based, similar to ARIA 'level' property
 192    * @param similarItemsInGroup - 1-based, similar to ARIA 'setsize' property,
 193    *                              inclusive of the current item
 194    * @param positionInGroup - 1-based, similar to ARIA 'posinset' property
 195    */
 196   void groupPosition(out long aGroupLevel, out long aSimilarItemsInGroup,
 197                      out long aPositionInGroup);
 198
 199   /**
 200    * Accessible child which contains the coordinate at (x, y) in screen pixels.
 201    * If the point is in the current accessible but not in a child, the
 202    * current accessible will be returned.
 203    * If the point is in neither the current accessible or a child, then
 204    * null will be returned.
 205    *
 206    * @param x  screen's x coordinate
 207    * @param y  screen's y coordinate
 208    * @return   the direct accessible child containing the given point
 209    */
 210   nsIAccessible getChildAtPoint(in long x, in long y);
 211
 212   /**
 213    * Deepest accessible child which contains the coordinate at (x, y) in screen
 214    * pixels. If the point is in the current accessible but not in a child, the
 215    * current accessible will be returned. If the point is in neither the current
 216    * accessible or a child, then null will be returned.
 217    *
 218    * @param x  screen's x coordinate
 219    * @param y  screen's y coordinate
 220    * @return   the deepest accessible child containing the given point
 221    */
 222   nsIAccessible getDeepestChildAtPoint(in long x, in long y);
 223
 224 /**
 225    * Like GetDeepestChildAtPoint, but restricted to the current process.
 226    * If the point is within a remote document, the accessible for the browser
 227    * element containing that document will be returned; i.e. this will not
 228    * descend into the document. If called on an accessible inside a remote
 229    * document, this will fail.
 230    *
 231    * @param x  screen's x coordinate
 232    * @param y  screen's y coordinate
 233    * @return   the deepest accessible child in this process containing the given
 234    *           point
 235    */
 236   nsIAccessible getDeepestChildAtPointInProcess(in long x, in long y);
 237
 238   /**
 239    * Nth accessible child using zero-based index or last child if index less than zero
 240    */
 241   nsIAccessible getChildAt(in long aChildIndex);
 242
 243   /**
 244    * Return accessible relation by the given relation type (see.
 245    * constants defined in nsIAccessibleRelation).
 246    */
 247   nsIAccessibleRelation getRelationByType(in unsigned long aRelationType);
 248
 249   /**
 250    * Returns multiple accessible relations for this object.
 251    */
 252   nsIArray getRelations();
 253
 254   /**
 255    * Return accessible's x and y coordinates relative to the screen and
 256    * accessible's width and height in Dev pixels.
 257    */
 258   void getBounds(out long x, out long y, out long width, out long height);
 259
 260   /**
 261    * Return accessible's x and y coordinates relative to the screen and
 262    * accessible's width and height in CSS pixels.
 263    */
 264   void getBoundsInCSSPixels(out long aX, out long aY, out long aWidth, out long aHeight);
 265
 266   /**
 267    * Add or remove this accessible to the current selection
 268    */
 269   void setSelected(in boolean isSelected);
 270
 271   /**
 272    * Select this accessible node only
 273    */
 274   void takeSelection();
 275
 276   /**
 277    * Focus this accessible node,
 278    * The state STATE_FOCUSABLE indicates whether this node is normally focusable.
 279    * It is the callers responsibility to determine whether this node is focusable.
 280    * accTakeFocus on a node that is not normally focusable (such as a table),
 281    * will still set focus on that node, although normally that will not be visually
 282    * indicated in most style sheets.
 283    */
 284   void takeFocus();
 285
 286   /**
 287    * The number of accessible actions associated with this accessible
 288    */
 289   readonly attribute uint8_t actionCount;
 290
 291   /**
 292    * The name of the accessible action at the given zero-based index
 293    */
 294   AString getActionName(in uint8_t index);
 295
 296   /**
 297    * The description of the accessible action at the given zero-based index
 298    */
 299   AString getActionDescription(in uint8_t aIndex);
 300
 301   /**
 302    * Perform the accessible action at the given zero-based index
 303    * Action number 0 is the default action
 304    */
 305   void doAction(in uint8_t index);
 306
 307   /**
 308    * Makes an object visible on screen.
 309    *
 310    * @param scrollType - defines where the object should be placed on
 311    *                     the screen (see nsIAccessibleScrollType for
 312    *                     available constants).
 313    */
 314   [can_run_script]
 315   void scrollTo(in unsigned long aScrollType);
 316
 317   /**
 318    * Moves the top left of an object to a specified location.
 319    *
 320    * @param coordinateType [in] - specifies whether the coordinates are relative to
 321    *                         the screen or the parent object (for available
 322    *                         constants refer to nsIAccessibleCoordinateType)
 323    * @param x [in] - defines the x coordinate
 324    * @param y [in] - defines the y coordinate
 325   */
 326   void scrollToPoint(in unsigned long coordinateType, in long x, in long y);
 327
 328   /**
 329    * Dispatches an ANNOUNCEMENT event with this accessible as target.
 330    *
 331    * @param announcement [in] - string to use in announcement.
 332    * @param priority [in] - priority for announcement, could be
 333    *                      nsIAccessibleAnnouncementEvent.POLITE or
 334    *                      nsIAccessibleAnnouncementEvent.ASSERTIVE.
 335    */
 336   void announce(in AString announcement, in unsigned short priority);
 337
 338   %{C++
 339   virtual mozilla::a11y::Accessible* ToInternalAccessible() const = 0;
 340   %}
 341
 342 };
 343