// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef UI_ACCESSIBILITY_AX_TEXT_UTILS_H_
#define UI_ACCESSIBILITY_AX_TEXT_UTILS_H_
#include <vector>
#include "base/basictypes.h"
#include "base/strings/string16.h"
#include "ui/accessibility/ax_export.h"
namespace ui {
// Boundaries that can be passed to FindAccessibleTextBoundary,
// representing various visual boundaries in (potentially multi-line)
// text. This is used by assistive technology in order to, for example,
// retrieve the nearest word to the cursor, or retrieve all of the
// text from the current cursor position to the end of the line.
// These should be self-explanatory; "line" here refers to the visual
// line as currently displayed (possibly affected by wrapping).
enum TextBoundaryType {
CHAR_BOUNDARY,
WORD_BOUNDARY,
LINE_BOUNDARY,
SENTENCE_BOUNDARY,
PARAGRAPH_BOUNDARY,
ALL_BOUNDARY
};
// A direction when searching for the next boundary.
enum TextBoundaryDirection {
// Search forwards for the next boundary past the starting position.
FORWARDS_DIRECTION,
// Search backwards for the previous boundary before the starting position.
BACKWARDS_DIRECTION
};
// Convenience method needed to implement platform-specific text
// accessibility APIs like IAccessible2. Search forwards or backwards
// (depending on |direction|) from the given |start_offset| until the
// given boundary is found, and return the offset of that boundary,
// using the vector of line break character offsets in |line_breaks|.
size_t AX_EXPORT
FindAccessibleTextBoundary(const base::string16& text,
const std::vector<int>& line_breaks,
TextBoundaryType boundary,
size_t start_offset,
TextBoundaryDirection direction);
} // namespace ui
#endif // UI_ACCESSIBILITY_AX_TEXT_UTILS_H_