gecko-dev/accessible/public/nsIAccessibleText.idl

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * 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 the Mozilla browser.
 *
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation. Portions created by Netscape are
 * Copyright (C) 1999 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Original Author: Marc Mulcahy (marc.mulcahy@sun.com)
 *
 * Contributor(s): Paul Sandoz (paul.sandoz@sun.com)
 *                 Bill Haneman (bill.haneman@sun.com)
 *                 John Gaunt (jgaunt@netscape.com)
 */

#include "nsISupports.idl"

typedef long nsAccessibleTextBoundary;
typedef long nsAccessibleCoordType;

[scriptable, uuid(E44D3FA6-9CB2-432A-8BDB-69D72B6ADA00)]
interface nsIAccessibleText : nsISupports
{
  const nsAccessibleTextBoundary BOUNDARY_CHAR = 0;
  const nsAccessibleTextBoundary BOUNDARY_WORD_START = 1;
  const nsAccessibleTextBoundary BOUNDARY_WORD_END = 2;
  const nsAccessibleTextBoundary BOUNDARY_SENTENCE_START = 3;
  const nsAccessibleTextBoundary BOUNDARY_SENTENCE_END = 4;
  const nsAccessibleTextBoundary BOUNDARY_LINE_START = 5;
  const nsAccessibleTextBoundary BOUNDARY_LINE_END = 6;
  const nsAccessibleTextBoundary BOUNDARY_ATTRIBUTE_RANGE = 7;

  const nsAccessibleCoordType COORD_TYPE_SCREEN = 0;
  const nsAccessibleCoordType COORD_TYPE_WINDOW = 1;

  attribute long caretOffset;

  readonly attribute long characterCount;
  readonly attribute long selectionCount;

    /**
      * String methods may need to return multibyte-encoded strings,
      * since some locales can't be encoded using 16-bit chars.
      * So the methods below might return UTF-16 strings, or they could
      * return "string" values which are UTF-8.
      */
  AString getText (in long startOffset, in long endOffset);

  AString getTextAfterOffset (in long offset,
                              in nsAccessibleTextBoundary boundaryType,
                              out long startOffset,
                              out long endOffset);

  AString getTextAtOffset (in long offset,
                           in nsAccessibleTextBoundary boundaryType,
                           out long startOffset,
                           out long endOffset);

  AString getTextBeforeOffset (in long offset,
                               in nsAccessibleTextBoundary boundaryType,
                               out long startOffset,
                               out long endOffset);

    /**
      * It would be better to return an unsigned long here,
      * to allow unicode chars > 16 bits
      */
  wchar getCharacterAtOffset (in long offset);

  nsISupports getAttributeRange (in long offset,
                                 out long rangeStartOffset,
                                 out long rangeEndOffset);

  void getCharacterExtents (in long offset,
                            out long x,
                            out long y,
                            out long width,
                            out long height,
                            in nsAccessibleCoordType coordType);

  long getOffsetAtPoint (in long x, in long y,
                         in nsAccessibleCoordType coordType);

  void getSelectionBounds (in long selectionNum,
                           out long startOffset,
                           out long endOffset);

  void setSelectionBounds (in long selectionNum,
                              in long startOffset,
                              in long endOffset);

  void addSelection (in long startOffset, in long endOffset);

  void removeSelection (in long selectionNum);
};

/*
 Assumptions:

 Using wstring (UCS2) instead of string encoded in UTF-8.
 Multibyte encodings (or at least potentially multi-byte
 encodings) would be preferred for the reasons cited above.

 The following methods will throw an exception on failure
 (since not every text component will allow every operation):
 setSelectionBounds, addSelection, removeSelection, setCaretOffset.

 getRangeAttributes defined to return an nsISupports
 interface instead of a pango specific data structure.
 It may be that some other return type is more appropriate
 for mozilla text attributes.

 we assume that all text components support the idea of
 a caret offset, whether visible or "virtual".  If this
 isn't the case, caretOffset can be made readonly and
 a setCaretOffset method provided which throws an exception
 on failure (as with *selection methods above).
*/