[DomKey] Support Japanese (JIS) layout special keys

ui/events/keycodes/platform_key_map_win.cc

 // Copyright (c) 2016 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/events/keycodes/platform_key_map_win.h"
 
 #include <utility>
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
@@ skipping 191 matching lines @@
   WORD primary_language = PRIMARYLANGID(language);
   if (primary_language == LANG_KOREAN) {
     switch (key_code) {
       case VKEY_HANGUL:
         return DomKey::HANGUL_MODE;
       case VKEY_HANJA:
         return DomKey::HANJA_MODE;
       default:
         return DomKey::NONE;
     }
+  } else if (primary_language == LANG_JAPANESE) {
+    switch (key_code) {
+      // VKEY_KANA isn't generated by any modern layouts but is a listed value
+      // that third-party apps might synthesize, so we handle it anyway.
+      case VKEY_KANA:
+      case VKEY_ATTN:
+        return DomKey::KANA_MODE;
+      case VKEY_KANJI:
+        return DomKey::KANJI_MODE;
+      case VKEY_OEM_ATTN:
+        return DomKey::ALPHANUMERIC;
+      case VKEY_OEM_FINISH:
+        return DomKey::KATAKANA;
+      case VKEY_OEM_COPY:
+        return DomKey::HIRAGANA;
+      case VKEY_DBE_SBCSCHAR:
+        return DomKey::HANKAKU;
+      case VKEY_DBE_DBCSCHAR:
+        return DomKey::ZENKAKU;
+      case VKEY_OEM_BACKTAB:
+        return DomKey::ROMAJI;
+      default:
+        return DomKey::NONE;
+    }
   }
-  // TODO(chongz): Handle Japanese keyboard layout keys 0xF0..0xF5, VKEY_KANA,
-  // VKEY_KANJI.
-  // https://crbug.com/612694
   return DomKey::NONE;
 }
 
 DomKey NonPrintableKeyboardCodeToDomKey(KeyboardCode key_code, HKL layout) {
-  // 1. Most |key_codes| have the same meaning regardless of |layout|.
+  // 1. Check if |key_code| has a |layout|-specific meaning.
+  const DomKey key = LanguageSpecificOemKeyboardCodeToDomKey(key_code, layout);
+  if (key != DomKey::NONE)
+    return key;
+
+  // 2. Most |key_codes| have the same meaning regardless of |layout|.
   const NonPrintableKeyEntry* result = std::lower_bound(
       std::begin(kNonPrintableKeyMap), std::end(kNonPrintableKeyMap), key_code,
       [](const NonPrintableKeyEntry& entry, KeyboardCode needle) {
         return entry.key_code < needle;
       });
   if (result != std::end(kNonPrintableKeyMap) && result->key_code == key_code)
     return result->dom_key;
-  // 2. Look up a |layout|-specific meaning for |key_code|.
-  return LanguageSpecificOemKeyboardCodeToDomKey(key_code, layout);
+
+  return DomKey::NONE;
 }
 
 void CleanupKeyMapTls(void* data) {
   PlatformKeyMap* key_map = reinterpret_cast<PlatformKeyMap*>(data);
   delete key_map;
 }
 
 struct PlatformKeyMapInstanceTlsTraits
     : public base::DefaultLazyInstanceTraits<base::ThreadLocalStorage::Slot> {
   static base::ThreadLocalStorage::Slot* New(void* instance) {
@@ skipping 33 matching lines @@
       flags & (EF_SHIFT_DOWN | EF_CAPS_LOCK_ON),
       EF_NONE,
   };
 
   for (auto try_flags : flags_to_try) {
     const auto& it = printable_keycode_to_key_.find(
         std::make_pair(static_cast<int>(key_code), try_flags));
     if (it != printable_keycode_to_key_.end()) {
       key = it->second;
       if (key != DomKey::NONE)
-        break;
+        return key;
     }
   }
 
-  return key;
+  // Return DomKey::UNIDENTIFIED to prevent US layout fall-back.
+  return DomKey::UNIDENTIFIED;
 }
 
 // static
 DomKey PlatformKeyMap::DomKeyFromKeyboardCode(KeyboardCode key_code,
                                               int flags) {
   // Use TLS because KeyboardLayout is per thread.
   // However currently PlatformKeyMap will only be used by the host application,
   // which is just one process and one thread.
   base::ThreadLocalStorage::Slot* platform_key_map_tls =
       g_platform_key_map_tls_lazy.Pointer();
@@ skipping 64 matching lines @@
         }
       } else {
         // TODO(chongz): Handle rv <= -2 and rv >= 2.
       }
     }
   }
   ::SetKeyboardState(keyboard_state_to_restore);
 }
 
 }  // namespace ui