ui/accessibility/ax_text_utils.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_ACCESSIBILITY_AX_TEXT_UTILS_H_
   6 #define UI_ACCESSIBILITY_AX_TEXT_UTILS_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/strings/string16.h"
  12 #include "ui/accessibility/ax_export.h"
  13
  14 namespace ui {
  15
  16 // Boundaries that can be passed to FindAccessibleTextBoundary,
  17 // representing various visual boundaries in (potentially multi-line)
  18 // text. This is used by assistive technology in order to, for example,
  19 // retrieve the nearest word to the cursor, or retrieve all of the
  20 // text from the current cursor position to the end of the line.
  21 // These should be self-explanatory; "line" here refers to the visual
  22 // line as currently displayed (possibly affected by wrapping).
  23 enum TextBoundaryType {
  24   CHAR_BOUNDARY,
  25   WORD_BOUNDARY,
  26   LINE_BOUNDARY,
  27   SENTENCE_BOUNDARY,
  28   PARAGRAPH_BOUNDARY,
  29   ALL_BOUNDARY
  30 };
  31
  32 // A direction when searching for the next boundary.
  33 enum TextBoundaryDirection {
  34   // Search forwards for the next boundary past the starting position.
  35   FORWARDS_DIRECTION,
  36   // Search backwards for the previous boundary before the starting position.
  37   BACKWARDS_DIRECTION
  38 };
  39
  40 // Convenience method needed to implement platform-specific text
  41 // accessibility APIs like IAccessible2. Search forwards or backwards
  42 // (depending on |direction|) from the given |start_offset| until the
  43 // given boundary is found, and return the offset of that boundary,
  44 // using the vector of line break character offsets in |line_breaks|.
  45 size_t AX_EXPORT
  46     FindAccessibleTextBoundary(const base::string16& text,
  47                                const std::vector<int>& line_breaks,
  48                                TextBoundaryType boundary,
  49                                size_t start_offset,
  50                                TextBoundaryDirection direction);
  51
  52 }  // namespace ui
  53
  54 #endif  // UI_ACCESSIBILITY_AX_TEXT_UTILS_H_