InputMethod should stop TextInputClient::InsertChar/InsertText calls when the event is stopped prop…

ash/ime/input_method_event_handler.cc

 // Copyright 2015 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 "ash/ime/input_method_event_handler.h"
 
 #include "ui/base/ime/input_method.h"
 #include "ui/events/event.h"
 
 namespace ash {
@@ skipping 12 matching lines @@
   post_ime_ = post_ime;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // InputMethodEventHandler, EventFilter implementation:
 
 void InputMethodEventHandler::OnKeyEvent(ui::KeyEvent* event) {
   // Never send synthesized key event.
   if (event->flags() & ui::EF_IS_SYNTHESIZED)
     return;
-  if (!post_ime_ && input_method_->DispatchKeyEvent(*event))
-    event->StopPropagation();
+  if (post_ime_)
+    return;
+  input_method_->DispatchKeyEvent(*event);

[oshima, 2015/06/30 15:15:50]

Why we're ignoring the result now? Looks like the current impl returns true
only, but the code should be written based on API spec, not
particular impl.

[Shu Chen, 2015/07/01 02:02:42]

I will change the API spec in a separated CL.
The InputMethod::DispatchKeyEvent() return type should be void.
And its parameter should be KeyEvent* instead of const KeyEvent&.
Always return true in InputMethodChromeOS::DispatchKeyEvent() is actually a
workaround.

DispatchKeyEventPostIME() used to returns event.handled() but now
event.stopped_propagation(), which means sometimes it will return false. As I
noticed, some Views will do event.SetHandled() after handling the events, while
EventHandlers do event.StopPropagation().
If DispatchKeyEvent() uses DispatchKeyEventPostIME()'s return value to return
(not happen on ChromeOS but for other platforms), event->StopPropagation() won't
be called and there would be duplicated handling.

From another perspective, the key event flow should be always using
DispatchKeyEventPostIME() to continue dispatching instead of leveraging event
bits. So that IMEH should always consume the key events.

+  event->StopPropagation();
 }
-}
+
+}  // namespace ash