gecko/other-licenses/ia2/AccessibleHyperlink.idl

/*************************************************************************
 *
 *  File Name (AccessibleHyperlink.idl)
 *
 *  IAccessible2 IDL Specification
 *
 *  Copyright (c) Linux Foundation 2007, 2008
 *  Copyright (c) IBM Corp. 2006
 *  Copyright (c) Sun Microsystems, Inc. 2000, 2006
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License version 2.1, as published by the Free Software Foundation; either
 *  version 2.1 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02110-1301  USA
 *
 ************************************************************************/

import "objidl.idl";
import "oaidl.idl";
import "oleacc.idl";
import "AccessibleAction.idl";

/** @brief This interface represents hyperlinks.

 This interface represents a hyperlink associated with a single substring 
  of text or single non-text object.  Non-text objects can have either a 
  single link or a collection of links such as when the non-text object is 
  an image map.

 Linked objects and anchors are implementation dependent. This interface is derived
  from IAccessibleAction.  IAccessibleAction::nActions is one greater than the 
  maximum value for the indices used with the methods of this interface.
        
 Furthermore, the object that implements this interface has to be connected 
  implicitly or explicitly with an object that implements IAccessibleText.
  IAccessibleHyperlink::startIndex and IAccessibleHyperlink::endIndex are
  indices with respect to the text exposed by IAccessibleText.

 This interface provides access to a single object which can have multiple actions.
  An example is an image map which is an image with multiple links each of which is
  associated with a separate non-overlapping area of the image.  This interface could
  also be applied to other kinds of objects with multiple actions such as "smart tags"
  which are objects, typically strings, which have multiple actions such as
  "Activate URI", "Bookmark URI", etc.

 An interesting use case is an image map where each area is associated with multiple
  actions, e.g. an image map of smart tags.  In this case you would have to implement
  two levels of accessible hyperlinks.  The first level hyperlinks would only implement
  anchor and anchorTarget.  The anchors would all reference the image object.  The
  anchorTargets would reference the second level accessible hyperlink objects.  None
  of the IAccessibleAction methods would be implemented on the first level hyperlink
  objects.  The second level hyperlink objects would implement the IAccessibleAction
  methods.  Their anchors would also reference the image object and their anchorTargets
  would reference URLs or the objects that would be activated.

 This use case demonstrates that in some cases there is no need for IAccessibleHyperlink
  to derive from IAccessibleAction.  As a result it may be removed in a later version of
  the IDL and it is suggested that implementations should not rely on the inheritance.

*/
[object, uuid(01C20F2B-3DD2-400f-949F-AD00BDAB1D41)]
interface IAccessibleHyperlink : IAccessibleAction
{

  /** @brief Returns an object that represents the link anchor, as appropriate
   for the link at the specified index.       
   @param [in] index
    A 0 based index identifies the anchor when, as in the case of an image map,
    there is more than one link represented by this object.  The valid maximal
    index is indicated by IAccessibleAction::nActions.
   @param [out] anchor
    This is an implementation dependent value.  For example, for a text link this 
	method could return the substring of the containing string where the substring
	is overridden with link behavior, and for an image link this method could return 
	an IUnknown VARIANT for IAccessibleImage.  See the section about 
	@ref _variants "VARIANTs" for additional information.
   @retval S_OK
   @retval S_FALSE if there is nothing to return, [out] value is NULL 
   @retval E_INVALIDARG if bad [in] passed, [out] value is NULL 
  */
  [propget] HRESULT anchor
    (
     [in] long index,
     [out, retval] VARIANT *anchor
    );

  /** @brief Returns an object representing the target of the link, as appropriate
   for the link at the specified index.       
   @param [in] index
    A 0 based index identifies the anchor when, as in the case of an image map,
    there is more than one link represented by this object.  The valid maximal
    index is indicated by IAccessibleAction::nActions.
   @param [out] anchorTarget
    This is an implementation dependent value.  For example this method could
	return a BSTR VARIANT of the URI.  Alternatively this method could return an
	IUnknown VARIANT of a COM interface representing a target object to be 
	activated when the link is activated.  See the section about 
	@ref _variants "VARIANTs" for additional information.
   @retval S_OK
   @retval S_FALSE if there is nothing to return, [out] value is NULL 
   @retval E_INVALIDARG if bad [in] passed, [out] value is NULL 
  */
  [propget] HRESULT anchorTarget
    (
     [in] long index,
     [out, retval] VARIANT *anchorTarget
    );

  /** @brief Returns the 0 based character offset at which the textual representation of the hyperlink starts.

   The returned value is related to the IAccessibleText interface of the object that 
   owns this hyperlink. 
   @param [out] index
   @retval S_OK
  */
  [propget] HRESULT startIndex
    (
     [out, retval] long *index
    );

  /** @brief Returns the 0 based character offset at which the textual representation of the hyperlink ends.
    
   The returned value is related to the IAccessibleText interface of the object that 
   owns this hyperlink. The character at the index is not part of the hypertext.  
   @param [out] index
   @retval S_OK
  */
  [propget] HRESULT endIndex
    (
     [out, retval] long *index
    );

  /** @brief Returns whether the target object referenced by this link is still valid.
        
   This is a volatile state that may change without sending an appropriate event.
   Returns TRUE if the referenced target is still valid and FALSE otherwise.

   This has also been used to indicate whether or not the URI of the anchorTarget
   is malformed.

   Note: This method is not being used, is deprecated, and should not be implemented or
   used.  It is likely that this method will be removed in a later version of the IDL.

   @param [out] valid
   @retval S_OK
   @retval S_FALSE if there is nothing to return, [out] value is FALSE 
  */
  [propget] HRESULT valid
    (
     [out, retval] boolean *valid
    );
}