Pepper IME API for surrounding text retrieval.

ppapi/api/dev/ppb_text_input_dev.idl

 /* 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.
  */
 
 /**
  * This file defines the <code>PPB_TextInput_Dev</code> interface.
  */
 
 label Chrome {
-  M16 = 0.1
+  M16 = 0.1,
+  M19 = 0.2
 };
 
 /**
  * PP_TextInput_Type is used to indicate the status of a plugin in regard to
  * text input.
  */
 [assert_size(4)]
 enum PP_TextInput_Type {
   /**
    * Input caret is not in an editable mode, no input method shall be used.
@@ skipping 37 matching lines @@
    * the browser is to layout IME windows etc.
    */
   void UpdateCaretPosition([in] PP_Instance instance,
                            [in] PP_Rect caret,
                            [in] PP_Rect bounding_box);
 
   /**
    * Cancels the current composition in IME.
    */
   void CancelCompositionText([in] PP_Instance instance);
+
+  /**
+   * In response to the <code>PPP_TextInput_Dev::RequestSurroundingText</code>
+   * call, informs the browser about the current text selection and surrounding
+   * text. <code>text</code> is a UTF-8 string that contains the current range
+   * of text selection in the plugin. <code>caret</code> is the byte-index of
+   * the caret poisition within <code>text</code>. <code>anchor</code> is the
+   * byte-index of the anchor position (i.e., if a range of text is selected,
+   * it is the other edge of selection diffrent from <code>caret</code>. If
+   * there are no selection, <code>anchor</code> is equal to <code>caret</code>.
+   *
+   * Typical use of this information in the browser is to enable "reconversion"
+   * features of IME that puts back the already committed text into the
+   * pre-commit composition state. Another use is to improve the precision
+   * of suggestion of IME by taking the context into account (e.g., if the caret
+   * looks to be on the begining of a sentense, suggest capital letters in a
+   * virtual keyboard).
+   *
+   * When the focus is not on text, call this function setting <code>text</code>
+   * to an empty string and <code>caret</code> and <code>anchor</code> to zero.
+   * Also, the plugin should send the empty text when it does not want to reveal
+   * the selection to IME (e.g., when the surrounding text is containing
+   * password text).
+   */
+  [version=0.2]
+  void UpdateSurroundingText([in] PP_Instance instance,
+                             [in] str_t text,
+                             [in] uint32_t caret,
+                             [in] uint32_t anchor);
+
+  /**
+   * Informs the browser when a range of text selection is changed in a plugin.
+   * When the browser needs to know the content of the updated selection, it
+   * pings back by <code>PPP_TextInput_Dev::RequestSurroundingText</code>. The
+   * plugin then should send the information with
+   * <code>UpdateSurroundingText</code>.
+   */
+  [version=0.2]
+  void SelectionChanged([in] PP_Instance instance);
 };