/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"

interface nsIURI;
interface nsIAccessible;

/**
 * A cross-platform interface that supports hyperlink-specific properties and
 * methods.  Anchors, image maps, xul:labels with class="text-link" implement this interface.
 */
[scriptable, uuid(38c60bfa-6040-4bfe-93f2-acd6a909bb60)]
interface nsIAccessibleHyperLink : nsISupports
{
  /**
   * Returns the offset of the link within the parent accessible.
   */
  readonly attribute long startIndex;

  /**
   * Returns the end index of the link within the parent accessible.
   *
   * @note  The link itself is represented by one embedded character within the
   * parent text, so the endIndex should be startIndex + 1.
   */
  readonly attribute long endIndex;

  /**
   * Determines whether the link is valid (e. g. points to a valid URL).
   *
   * @note  XXX Currently only used with ARIA links, and the author has to
   * specify that the link is invalid via the aria-invalid="true" attribute.
   * In all other cases, TRUE is returned.
   */
  readonly attribute boolean valid;

  /**
   * Determines whether the element currently has the focus, e. g. after
   * returning from the destination page.
   *
   * @note  ARIA links can only be focused if they have the tabindex
   * attribute set.  Also, state_focused should then be set on the accessible
   * for this link.
   */
  readonly attribute boolean selected;

  /**
   * The numbber of anchors within this Hyperlink. Is normally 1 for anchors.
   * This anchor is, for example, the visible output of the html:a tag.
   * With an Image Map, reflects the actual areas within the map.
   */
  readonly attribute long anchorCount;

  /**
   * Returns the URI at the given index.
   *
   * @note  ARIA hyperlinks do not have an URI to point to, since clicks are
   * processed via JavaScript. Therefore this property does not work on ARIA
   * links.
   *
   * @param index  The 0-based index of the URI to be returned.
   *
   * @return the nsIURI object containing the specifications for the URI.
   */
  nsIURI getURI (in long index);

  /**
   * Returns a reference to the object at the given index.
   *
   * @param index  The 0-based index whose object is to be returned.
   *
   * @return the nsIAccessible object at the desired index.
   */
  nsIAccessible getAnchor (in long index);
};

/*
 Assumptions:

 The object associated with object or anchor index
 is an nsIAccessible.
 A URI can be represented by the nsIURI interface
 (or nsIURL interface).

 Note that an object which supports nsIAccessibleHyperlink
 does *not* generally implement nsIAccessible, unlike the
    case of the other nsiAccessible* interfaces in this directory.

    Aaron: would the nsISupports return from
    getObject be queryable for nsIURI and nsIURL directly?

*/