Support IMM32 reconversion on Windows

views/ime/text_input_client.h

 // Copyright (c) 2011 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 VIEWS_IME_TEXT_INPUT_CLIENT_H_
 #define VIEWS_IME_TEXT_INPUT_CLIENT_H_
 #pragma once
 
 #include <vector>
 
 #include "base/basictypes.h"
-#include "base/callback.h"
 #include "base/string16.h"
 #include "ui/base/ime/composition_text.h"
 #include "ui/base/ime/text_input_type.h"
 #include "ui/base/range/range.h"
 #include "views/views_export.h"
 
 namespace gfx {
 class Rect;
 }
 
@@ skipping 44 matching lines @@
   // Returns current caret (insertion point) bounds relative to the View’s
   // coordinates. If there is selection, then the selection bounds will be
   // returned.
   virtual gfx::Rect GetCaretBounds() = 0;
 
   // Returns true if there is composition text.
   virtual bool HasCompositionText() = 0;
 
   // Document content operations ----------------------------------------------
 
-  // Retrieves the UTF-16 based character range containing all text in the View.
+  // Retrieves the UTF-16 based character range containing accessabled text in
+  // the View. It must cover the composition and selection range.

[James Su, 2011/10/27 18:39:49]

nit: accessabled -> accessible.

[Peng, 2011/10/28 15:42:19]

Done.

   // Returns false if the information cannot be retrieved right now.
   virtual bool GetTextRange(ui::Range* range) = 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(ui::Range* range) = 0;
 
   // Retrieves the UTF-16 based character range of current selection.
   // Returns false if the information cannot be retrieved right now.
   virtual bool GetSelectionRange(ui::Range* range) = 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 ui::Range& range) = 0;
 
   // 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.
   // Returns false if the oepration is not supported.
   virtual bool DeleteRange(const ui::Range& range) = 0;
 
   // Retrieves the text content in a given UTF-16 based character range.
-  // The result will be send back to the input method by calling the given
-  // callback, which may happen asynchronously.
-  // Returns false if the operation is not supported.
-  virtual bool GetTextFromRange(
-      const ui::Range& range,
-      const base::Callback<void(const string16&)>& callback) = 0;
+  // The result will be written in text.

[James Su, 2011/10/27 18:39:49]

nit: The result will be stored into |*text|.

[Peng, 2011/10/28 15:42:19]

Done.

+  // Returns false if the operation is not supported or can not get text for
+  // given range.

[James Su, 2011/10/27 18:39:49]

nit: ... or the specified range is out of the text range returned by
GetTextRange().

Now I understand your intention to remove the |actual_text| parameter. I agree
that it's also a feasible way. Comparing the original API, your proposal moves
the implementation burden to the input method side.

With the original API, the input method can simply call GetTextFromRange() with
a range it wants and rely on the text input client to adjust the range to a
supported range. The input method does not need to care about if the specified
range is out of the text range returned by GetTextRange() or not. Because the
text input client ensures the validity of the actual_range value.
In another word, in the original API, GetTextRange() method is actually not
mandatory.

With your proposal, the input method must make sure the required range is inside
the text range returned by GetTextRange() before calling GetTextFromRange(),
otherwise the call will fail.

So you can see that, your proposal actually does not simplify the code as you
thought. It just moves the code around.

I'd like to see how the code looks with the original API, so that we can compare
these two approach to see which one is better.

[Peng, 2011/10/28 15:42:19]

Done.

+  virtual bool GetTextFromRange(const ui::Range& range, string16* text) = 0;
 
   // Miscellaneous ------------------------------------------------------------
 
   // Called whenever current keyboard layout or input method is changed,
   // especially the change of input locale and text direction.
   virtual void OnInputMethodChanged() = 0;
 
   // Called whenever the user requests to change the text direction and layout
   // alignment of the current text box. It’s for supporting ctrl-shift on
   // Windows.
   // Returns false if the operation is not supported.
   virtual bool ChangeTextDirectionAndLayoutAlignment(
       base::i18n::TextDirection direction) = 0;
 
   // Gets the View object who owns this TextInputClient instance.
   virtual View* GetOwnerViewOfTextInputClient() = 0;
 };
 
 }  // namespace views
 
 #endif  // VIEWS_IME_TEXT_INPUT_CLIENT_H_