Implement Linux IME support

services/keyboard/linux/keyboard_service_impl.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 "services/keyboard/linux/keyboard_service_impl.h"
+
+#include "base/logging.h"
+#include "base/strings/string16.h"
+#include "base/strings/utf_string_conversions.h"
+#include "mojo/public/cpp/application/application_connection.h"
+#include "mojo/public/cpp/application/connect.h"
+#include "mojo/services/input_events/interfaces/input_key_codes.mojom.h"
+
+namespace keyboard {
+
+LinuxKeyboardServiceImpl::LinuxKeyboardServiceImpl(
+    mojo::InterfaceRequest<::keyboard::KeyboardService> request,
+    mojo::InterfaceRequest<NativeViewportEventDispatcher> dispatcher)
+    : binding_(this, request.Pass()),
+      event_dispatcher_binding_(this, dispatcher.Pass()) {
+}
+
+LinuxKeyboardServiceImpl::~LinuxKeyboardServiceImpl() {
+}
+
+void LinuxKeyboardServiceImpl::Show(
+    ::keyboard::KeyboardClientPtr client,
+    ::keyboard::KeyboardType type) {
+  client_ = client.Pass();
+}
+
+void LinuxKeyboardServiceImpl::ShowByRequest() {
+}
+
+void LinuxKeyboardServiceImpl::Hide() {
+  client_ = nullptr;
+}
+
+void LinuxKeyboardServiceImpl::SetText(const mojo::String& text) {
+  text_ = text;
+}
+
+void LinuxKeyboardServiceImpl::SetSelection(int32_t start, int32_t end) {
+  // Not applicable for physical keyboards
+}
+
+/*

[jamesr, 2015/11/19 23:47:33]

don't check in commented out code

+  void commitCompletion(CompletionData completion);
+  void commitCorrection(CorrectionData correction);
+  void commitText(String text, int newCursorPosition);
+  void deleteSurroundingText(int beforeLength, int afterLength);
+  void setComposingRegion(int start, int end);
+  void setComposingText(String text, int newCursorPosition);
+  void setSelection(int start, int end);
+  void submit(SubmitAction action);
+*/
+
+// |mojo::NativeViewportEventDispatcher| implementation:
+void LinuxKeyboardServiceImpl::OnEvent(
+    mojo::EventPtr event,
+    const mojo::Callback<void()>& callback) {
+  if (event->action == mojo::EventType::KEY_PRESSED &&
+      event->key_data->is_char) {
+    if (client_) {
+      switch(event->key_data->windows_key_code) {
+        case mojo::KeyboardCode::BACK: // backspace
+          client_->DeleteSurroundingText(1, 0);
+          break;
+        case mojo::KeyboardCode::DELETE:
+          client_->DeleteSurroundingText(0, 1);
+          break;
+        case mojo::KeyboardCode::HOME:
+          client_->SetSelection(0, 0);
+          break;
+        case mojo::KeyboardCode::END:
+          client_->SetSelection(text_.size()-1, text_.size()-1);
+          break;
+        case mojo::KeyboardCode::TAB: // tab

[jamesr, 2015/11/19 23:47:33]

nit: delete the "// tab" part

+          // TODO: Advance focus, in reverse if shifted
+          break;
+        case mojo::KeyboardCode::RETURN:
+          client_->Submit(::keyboard::SubmitAction::DONE);

[jamesr, 2015/11/19 23:47:33]

omit :: in ::keyboard

+          break;
+        default:
+          base::string16 character;
+          character.push_back(event->key_data->character);
+          std::string s = base::UTF16ToUTF8(character);

[jamesr, 2015/11/19 23:47:33]

there's gotta be a better way to do this, although nothing sticks out. i think
the reason the source data is 16 bits is compat with win32 APIs which is a
pretty poor reason. we can fix it later

+          text_ += s;
+          client_->CommitText(mojo::String(s), 1);
+          break;
+      }
+    }
+  }
+  callback.Run();
+}
+
+}  // namespace keyboard