Add text offset to OnSurroundingTextChanged

ui/base/ime/text_input_client.h

 // 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_BASE_IME_TEXT_INPUT_CLIENT_H_
 #define UI_BASE_IME_TEXT_INPUT_CLIENT_H_
 
 #include "base/basictypes.h"
 #include "base/i18n/rtl.h"
 #include "base/strings/string16.h"
@@ skipping 81 matching lines @@
   // TODO(ime): Have a clear spec whether the returned value is DIP or not.
   // http://crbug.com/360334
   virtual bool GetCompositionCharacterBounds(uint32 index,
                                              gfx::Rect* rect) const = 0;
 
   // Returns true if there is composition text.
   virtual bool HasCompositionText() const = 0;
 
   // Document content operations ----------------------------------------------
 
-  // Retrieves the UTF-16 based character range containing accessibled text in
+  // Retrieves the UTF-16 based character range containing accessible text in
   // the View. It must cover the composition and selection range.
   // Returns false if the information cannot be retrieved right now.
   virtual bool GetTextRange(gfx::Range* range) const = 0;
 
   // Retrieves the UTF-16 based character range of current composition text.
   // Returns false if the information cannot be retrieved right now.
   virtual bool GetCompositionTextRange(gfx::Range* range) const = 0;
 
   // Retrieves the UTF-16 based character range of current selection.
   // Returns false if the information cannot be retrieved right now.
   virtual bool GetSelectionRange(gfx::Range* range) const = 0;
 
   // Selects the given UTF-16 based character range. Current composition text
   // will be confirmed before selecting the range.
   // Returns false if the operation is not supported.
   virtual bool SetSelectionRange(const gfx::Range& range) = 0;
 
+  // Retrieves the text selection offset. Since only a subset of surrounding
+  // text is cached, this value indicates the offset of the selection relative
+  // to the entire text body.
+  virtual uint32 GetSelectionOffset() const = 0;

[Shu Chen, 2015/08/12 07:23:16]

What's the difference between "GetSelectionRange(&range); range.start();" and
"GetSelectionOffset()"?

[rsadam, 2015/08/12 21:46:52]

Renamed it to GetTextOffset and updated the comment.

+
   // Deletes contents in the given UTF-16 based character range. Current
   // composition text will be confirmed before deleting the range.
   // The input caret will be moved to the place where the range gets deleted.
   // ExtendSelectionAndDelete should be used instead as far as you are deleting
   // characters around current caret. This function with the range based on
   // GetSelectionRange has a race condition due to asynchronous IPCs between
   // browser and renderer.
   // Returns false if the operation is not supported.
   virtual bool DeleteRange(const gfx::Range& range) = 0;
 
@@ skipping 39 matching lines @@
   // This allows a TextInputClient to be informed of a platform-independent edit
   // command that has been derived from the key event currently being dispatched
   // (but not yet sent to the TextInputClient). The edit command will take into
   // account any OS-specific, or user-specified, keybindings that may be set up.
   virtual void SetEditCommandForNextKeyEvent(int command_id) = 0;
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_IME_TEXT_INPUT_CLIENT_H_