Reland: [DomKey] Expose Korean special keys on Korean keyboard layout only

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 165 matching lines @@
     {VKEY_MEDIA_STOP, DomKey::MEDIA_STOP},
     {VKEY_MEDIA_PLAY_PAUSE, DomKey::MEDIA_PLAY_PAUSE},
     {VKEY_MEDIA_LAUNCH_MAIL, DomKey::LAUNCH_MAIL},
     {VKEY_MEDIA_LAUNCH_MEDIA_SELECT, DomKey::LAUNCH_MEDIA_PLAYER},
     {VKEY_MEDIA_LAUNCH_APP1, DomKey::LAUNCH_MY_COMPUTER},
     {VKEY_MEDIA_LAUNCH_APP2, DomKey::LAUNCH_CALCULATOR},
     // VKEY_OEM_1..8, 102, PLUS, COMMA, MINUS, PERIOD
     {VKEY_ALTGR, DomKey::ALT_GRAPH},
     {VKEY_PROCESSKEY, DomKey::PROCESS},
     // VKEY_PACKET - Used to pass Unicode char, considered as printable key.
-
-    // TODO(chongz): Handle Japanese keyboard layout keys 0xF0..0xF5.
-    // https://crbug.com/612694
     {VKEY_ATTN, DomKey::ATTN},
     {VKEY_CRSEL, DomKey::CR_SEL},
     {VKEY_EXSEL, DomKey::EX_SEL},
     {VKEY_EREOF, DomKey::ERASE_EOF},
     {VKEY_PLAY, DomKey::PLAY},
     {VKEY_ZOOM, DomKey::ZOOM_TOGGLE},
     // TODO(chongz): Handle VKEY_NONAME, VKEY_PA1.
     // https://crbug.com/616910
     {VKEY_OEM_CLEAR, DomKey::CLEAR},
 };
 
-DomKey NonPrintableKeyboardCodeToDomKey(KeyboardCode key_code) {
+// Disambiguates the meaning of certain non-printable keys which have different
+// meanings under different languages, but use the same VKEY code.
+DomKey LanguageSpecificOemKeyboardCodeToDomKey(KeyboardCode key_code,
+                                               HKL layout) {
+  WORD language = LOWORD(layout);
+  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;
+    }
+  }
+  // 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|.
   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;
-  return DomKey::NONE;
+  // 2. Look up a |layout|-specific meaning for |key_code|.
+  return LanguageSpecificOemKeyboardCodeToDomKey(key_code, layout);
 }
 
 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 12 matching lines @@
 PlatformKeyMap::PlatformKeyMap() {}
 
 PlatformKeyMap::PlatformKeyMap(HKL layout) {
   UpdateLayout(layout);
 }
 
 PlatformKeyMap::~PlatformKeyMap() {}
 
 DomKey PlatformKeyMap::DomKeyFromKeyboardCodeImpl(KeyboardCode key_code,
                                                   int flags) const {
-  DomKey key = NonPrintableKeyboardCodeToDomKey(key_code);
+  DomKey key = NonPrintableKeyboardCodeToDomKey(key_code, keyboard_layout_);
   if (key != DomKey::NONE)
     return key;
 
-  // TODO(chongz): Handle VKEY_KANA/VKEY_HANGUL, VKEY_HANJA/VKEY_KANJI based on
-  // layout.
-  // https://crbug.com/612736
-
   const int flags_to_try[] = {
       // Trying to match Firefox's behavior and UIEvents DomKey guidelines.
       // If the combination doesn't produce a printable character, the key value
       // should be the key with no modifiers except for Shift and AltGr.
       // See https://w3c.github.io/uievents/#keys-guidelines
       flags,
       flags & (EF_SHIFT_DOWN | EF_ALTGR_DOWN | EF_CAPS_LOCK_ON),
       flags & (EF_SHIFT_DOWN | EF_CAPS_LOCK_ON),
       EF_NONE,
   };
@@ skipping 86 matching lines @@
         }
       } else {
         // TODO(chongz): Handle rv <= -2 and rv >= 2.
       }
     }
   }
   ::SetKeyboardState(keyboard_state_to_restore);
 }
 
 }  // namespace ui