Send control characters as a KeyEvent.

Android IMEs can call CommitText() with control characters, but
InputMethodEngine::CommitText expects only text characters.
This CL adds IsControlChar() and SendControlKeyEvent() to send those
control characters as a KeyEvent.

Bug: 845079
Test: Omnibox works with Gboard.
Change-Id: I6d3dadb3879ada22993b9b5a330e08c634521380
Reviewed-on: https://chromium-review.googlesource.com/c/1275465
Commit-Queue: Yuichiro Hanada <yhanada@chromium.org>
Reviewed-by: Yusuke Sato <yusukes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#598704}

chrome/browser/chromeos/arc/input_method_manager/arc_input_method_manager_service_unittest.cc

@@ -159,9 +159,23 @@ class TestIMEInputContextHandler : public ui::MockIMEInputContextHandler {
 
   ui::InputMethod* GetInputMethod() override { return input_method_; }
 
+  void SendKeyEvent(ui::KeyEvent* event) override {
+    ui::MockIMEInputContextHandler::SendKeyEvent(event);
+    ++send_key_event_call_count_;
+  }
+
+  void Reset() {
+    ui::MockIMEInputContextHandler::Reset();
+    send_key_event_call_count_ = 0;
+  }
+
+  int send_key_event_call_count() const { return send_key_event_call_count_; }
+
  private:
   ui::InputMethod* const input_method_;
 
+  int send_key_event_call_count_ = 0;
+
   DISALLOW_COPY_AND_ASSIGN(TestIMEInputContextHandler);
 };
 
@@ -757,6 +771,13 @@ TEST_F(ArcInputMethodManagerServiceTest, IMEOperations) {
   EXPECT_EQ(1, bridge()->update_text_input_state_calls_count_);
   EXPECT_TRUE(bridge()->last_text_input_state->first_update_after_operation);
 
+  // Calling CommitText() with '\n' doesn't invoke
+  // InputMethodEngine::CommitText.
+  EXPECT_EQ(0, test_context_handler.send_key_event_call_count());
+  connection->CommitText(base::ASCIIToUTF16("\n"), 0);
+  EXPECT_EQ(1, test_context_handler.commit_text_call_count());
+  EXPECT_EQ(2, test_context_handler.send_key_event_call_count());
+
   test_context_handler.Reset();
   connection->DeleteSurroundingText(1, 1);
   EXPECT_EQ(1, test_context_handler.delete_surrounding_text_call_count());

chrome/browser/chromeos/arc/input_method_manager/input_connection_impl.cc

@@ -4,9 +4,12 @@
 
 #include "chrome/browser/chromeos/arc/input_method_manager/input_connection_impl.h"
 
+#include <tuple>
+
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "ui/base/ime/ime_bridge.h"
+#include "ui/events/keycodes/keyboard_codes.h"
 
 namespace arc {
 
@@ -20,6 +23,22 @@ namespace {
 // send the current text input state right after the IME operation completion.
 constexpr base::TimeDelta kStateUpdateTimeout = base::TimeDelta::FromSeconds(1);
 
+// Characters which should be sent as a KeyEvent and attributes of generated
+// KeyEvent.
+constexpr std::tuple<char, ui::KeyboardCode, const char*>
+    kControlCharToKeyEvent[] = {{'\n', ui::VKEY_RETURN, "Enter"}};
+
+bool IsControlChar(const base::string16& text) {
+  const std::string str = base::UTF16ToUTF8(text);
+  if (str.length() != 1)
+    return false;
+  for (const auto& t : kControlCharToKeyEvent) {
+    if (str[0] == std::get<0>(t))
+      return true;
+  }
+  return false;
+}
+
 }  // namespace
 
 InputConnectionImpl::InputConnectionImpl(
@@ -80,6 +99,12 @@ void InputConnectionImpl::CommitText(const base::string16& text,
   // Clear the current composing text at first.
   if (!ime_engine_->ClearComposition(input_context_id_, &error))
     LOG(ERROR) << "ClearComposition failed: error=\"" << error << "\"";
+
+  if (IsControlChar(text)) {
+    SendControlKeyEvent(text);
+    return;
+  }
+
   if (!ime_engine_->CommitText(input_context_id_,
                                base::UTF16ToUTF8(text).c_str(), &error))
     LOG(ERROR) << "CommitText failed: error=\"" << error << "\"";
@@ -164,4 +189,25 @@ void InputConnectionImpl::StartStateUpdateTimer() {
                      true /* is_input_state_update_requested */));
 }
 
+void InputConnectionImpl::SendControlKeyEvent(const base::string16& text) {
+  DCHECK(IsControlChar(text));
+
+  const std::string str = base::UTF16ToUTF8(text);
+  DCHECK_EQ(1u, str.length());
+
+  for (const auto& t : kControlCharToKeyEvent) {
+    if (std::get<0>(t) == str[0]) {
+      chromeos::InputMethodEngine::KeyboardEvent press;
+      press.type = "keydown";
+      press.key_code = std::get<1>(t);
+      press.key = press.code = std::get<2>(t);
+      chromeos::InputMethodEngine::KeyboardEvent release(press);
+      release.type = "keyup";
+      ime_engine_->SendKeyEvents(input_context_id_, {press, release});
+      break;
+    }
+  }
+  return;
+}
+
 }  // namespace arc

chrome/browser/chromeos/arc/input_method_manager/input_connection_impl.h

@@ -55,6 +55,8 @@ class InputConnectionImpl : public mojom::InputConnection {
   // starting timer is after API call, the timer won't be cancelled.
   void StartStateUpdateTimer();
 
+  void SendControlKeyEvent(const base::string16& text);
+
   chromeos::InputMethodEngine* const ime_engine_;  // Not owned
   ArcInputMethodManagerBridge* const imm_bridge_;  // Not owned
   const int input_context_id_;