Support TSF related event handling on NativeTextField

chrome/browser/ui/views/omnibox/omnibox_view_win.cc

 // 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.
 
 #include "chrome/browser/ui/views/omnibox/omnibox_view_win.h"
 
 #include <algorithm>
 #include <locale>
 #include <string>
 
@@ skipping 899 matching lines @@
         native_view_host_,
         ui::AccessibilityTypes::EVENT_SELECTION_CHANGED,
         true);
   } else if (delete_at_end_pressed_) {
     model()->OnChanged();
   }
 
   return something_changed;
 }
 
-void OmniboxViewWin::OnTextUpdated() {
+void OmniboxViewWin::OnTextUpdated(const ui::Range& /*composition_range*/) {
   if (ignore_ime_messages_)
     return;
   OnAfterPossibleChangeInternal(true);
   // Call OnBeforePossibleChange function here to get correct diff in next IME
   // update. The Text Services Framework does not provide any notification
   // before entering edit session, therefore we don't have good place to call
   // OnBeforePossibleChange.
   OnBeforePossibleChange();
 }
 
+void OmniboxViewWin::OnTsfStartComposition() {}

[Peter Kasting, 2012/10/27 19:00:46]

Does this message give us what we need in order to remove the
OnBeforePossibleChange() call in OnTextUpdated()?

[Seigo Nonaka, 2012/10/27 22:20:18]

Unfortunately no, because OnTsfstartComosition is called after TSF changes
texts, so it's too late to call OnBeforePossibleChange.
Furthermore, we should call OnBeforePossibleChange every before the text updates
but OnTsfStartComposition is only called when the composition is created. Some
input tools (e.g. on-screen keyboard on Win 8) put characters without
composition.

FYI: Editing session is different concept from composition start/end. TSF may
make/update/terminate composition string in each editing session. Compared to
omnibox, find-bar should suppress incremental search if the query string is
composition string. To keep current implementation, I introduced
OnTsfStartComposition/OnTsfEndComposition callbacks as substitute for
WM_IME_STARTCOMPOSITION/WM_IME_END_COMPOSITION which is used in non-Metro mode.

On 2012/10/27 19:00:46, Peter Kasting wrote:

+
+void OmniboxViewWin::OnTsfEndComposition() {}
+
 void OmniboxViewWin::OnCandidateWindowCountChanged(size_t window_count) {
   ime_candidate_window_open_ = (window_count != 0);
   if (ime_candidate_window_open_) {
     CloseOmniboxPopup();
   } else if (model()->user_input_in_progress()) {
     // UpdatePopup assumes user input is in progress, so only call it if
     // that's the case. Otherwise, autocomplete may run on an empty user
     // text.
     UpdatePopup();
   }
@@ skipping 1809 matching lines @@
   return (rect.left - client_rect.left) + (client_rect.right - rect.right);
 }
 
 int OmniboxViewWin::WidthNeededToDisplay(const string16& text) const {
   // Use font_.GetStringWidth() instead of
   // PosFromChar(location_entry_->GetTextLength()) because PosFromChar() is
   // apparently buggy. In both LTR UI and RTL UI with left-to-right layout,
   // PosFromChar(i) might return 0 when i is greater than 1.
   return font_.GetStringWidth(text) + GetHorizontalMargin();
 }