gecko/accessible/src/base/nsARIAMap.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:expandtab:shiftwidth=2:tabstop=2:
 */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is IBM Corporation
 * Portions created by the Initial Developer are Copyright (C) 2007
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Aaron Leventhal <aleventh@us.ibm.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef _nsARIAMap_H_
#define _nsARIAMap_H_

#include "prtypes.h"
#include "nsAccessibilityAtoms.h"

// Name mapping rule: can the name be computed from descendants?
enum ENameRule
{
  // eNameLabelOrTitle:
  // Collect name from:
  //   1) The content subtrees pointed to by labelledby
  //      which contains the IDs for the label content, or if unspecified
  //   2) The title attribute if specified
  eNameLabelOrTitle,
  
  // eNameOkFromChildren
  // Collect name from:
  //   1) The content subtrees pointed to by labelledby
  //      which contains the IDs for the label content, or if un specified
  //   2) The text and text equivalents from descendents,
  //      as well as the value of controls, collected in depth-first order, or if empty
  //   3) The title attribute if specified
  eNameOkFromChildren
};

// Is nsIAccessible value supported for this role or not?
enum EValueRule
{
  eNoValue,
  eHasValueMinMax    // Supports value, min and max from aria-valuenow, aria-valuemin and aria-valuemax
};

// Used for an nsStateMapEntry if a given state attribute supports "true" and "false"
#define kBoolState 0

// Used in nsRoleMapEntry.state if no nsIAccessibleStates are automatic for a given role
#define kNoReqStates 0

// For this name and value pair, what is the nsIAccessibleStates mapping.
// nsStateMapEntry.state
struct nsStateMapEntry
{
  nsIAtom** attributeName;  // nsnull indicates last entry in map
  const char* attributeValue; // magic value of kBoolState (0) means supports "true" and "false"
  PRUint32 state;             // If match, this is the nsIAccessibleStates to map to
};

// For each ARIA role, this maps the nsIAccessible information
struct nsRoleMapEntry
{
  // ARIA role: string representation such as "button"
  const char *roleString;
  
  // Role mapping rule: maps to this nsIAccessibleRole
  PRUint32 role;
  
  // Name mapping rule: how to compute nsIAccessible name
  ENameRule nameRule;
  
  // Value mapping rule: how to compute nsIAccessible value
  EValueRule valueRule;
  
  // Automatic state mapping rule: always include in nsIAccessibleStates
  PRUint32 state;   // or kNoReqStates if no nsIAccessibleStates are automatic for this role.
  
  // ARIA properties supported for this role
  // (in other words, the aria-foo attribute to nsIAccessibleStates mapping rules)
  // Currently you cannot have unlimited mappings, because
  // a variable sized array would not allow the use of
  // C++'s struct initialization feature.
  nsStateMapEntry attributeMap1;
  nsStateMapEntry attributeMap2;
  nsStateMapEntry attributeMap3;
  nsStateMapEntry attributeMap4;
  nsStateMapEntry attributeMap5;
  nsStateMapEntry attributeMap6;
  nsStateMapEntry attributeMap7;
  nsStateMapEntry attributeMap8;
};

/**
 *  These are currently initialized (hardcoded) in nsARIAMap.cpp, 
 *  and provide the mappings for WAI-ARIA roles and properties using the 
 *  structs defined in this file.
 */
struct nsARIAMap
{
  /**
   * Array of supported ARIA role map entries and its length.
   */
  static nsRoleMapEntry gWAIRoleMap[];
  static PRUint32 gWAIRoleMapLength;

  /**
   * Landmark role map entry. Used when specified ARIA role isn't mapped to
   * accessibility API.
   */
  static nsRoleMapEntry gLandmarkRoleMap;

  /**
   * Empty role map entry. Used by accessibility service to create an accessible
   * if the accessible can't use role of used accessible class. For example,
   * it is used for table cells that aren't contained by table.
   */
  static nsRoleMapEntry gEmptyRoleMap;

  /**
   * State map of ARIA states applied to any accessible not depending on
   * the role.
   */
  static nsStateMapEntry gWAIUnivStateMap[];
};

#endif