Introduce InputMethodAuraAndroid for Aura on Android

ui/base/ime/input_method_android.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 "ui/base/ime/input_method_android.h"
+
+#include "ui/base/ime/text_input_client.h"
+#include "ui/events/event.h"
+
+// TODO(bshe): This is currently very similar to InputMethodMUS. Consider unify
+// them in the furture if the two have reasonable similarity.
+
+namespace ui {
+
+////////////////////////////////////////////////////////////////////////////////
+// InputMethodAndroid, public:
+
+InputMethodAndroid::InputMethodAndroid(
+    internal::InputMethodDelegate* delegate) {
+  SetDelegate(delegate);
+}
+
+InputMethodAndroid::~InputMethodAndroid() {}
+
+bool InputMethodAndroid::OnUntranslatedIMEMessage(
+    const base::NativeEvent& event,
+    NativeEventResult* result) {
+  return false;
+}
+
+void InputMethodAndroid::DispatchKeyEvent(ui::KeyEvent* event) {
+  DCHECK(event->type() == ui::ET_KEY_PRESSED ||
+         event->type() == ui::ET_KEY_RELEASED);
+
+  // If no text input client, do nothing.
+  if (!GetTextInputClient()) {
+    ignore_result(DispatchKeyEventPostIME(event));
+    return;
+  }
+
+  // Here is where we change the differ from our base class's logic. Instead of
+  // always dispatching a key down event, and then sending a synthesized
+  // character event, we instead check to see if this is a character event and
+  // send out the key if it is. (We fallback to normal dispatch if it isn't.)
+  if (event->is_char()) {

[Shu Chen, 2015/10/21 01:54:23]

Are you sure this is the case for Android? I suppose is_char() only returns true
on Windows.

[bshe, 2015/10/21 14:20:25]

This is basically a copy of InputMethodMUS. In aura android, we set is_char
manually to true to insert character as a temporary hack. I removed the code
here in this CL. In the future we may bring it back though if we decide to use
the hack for early prototype.

+    GetTextInputClient()->InsertChar(*event);
+    event->StopPropagation();
+    return;
+  }
+
+  ignore_result(DispatchKeyEventPostIME(event));
+}
+
+void InputMethodAndroid::OnCaretBoundsChanged(
+    const ui::TextInputClient* client) {
+}
+
+void InputMethodAndroid::CancelComposition(
+    const ui::TextInputClient* client) {
+}
+
+void InputMethodAndroid::OnInputLocaleChanged() {}
+
+std::string InputMethodAndroid::GetInputLocale() {
+  return "";
+}
+
+bool InputMethodAndroid::IsCandidatePopupOpen() const {
+  return false;
+}
+
+}  // namespace ui