Move modifier remapping code from X to Ash

chrome/browser/ui/views/ash/key_rewriter.cc

Index: chrome/browser/ui/views/ash/key_rewriter.cc
diff --git a/chrome/browser/ui/views/ash/key_rewriter.cc b/chrome/browser/ui/views/ash/key_rewriter.cc
index e7f28c4327d0ef553bc540c3221014627d3c00cd..8e4aa05b3ebca686cadfa5fc55bc701180ebc7a3 100644
--- a/chrome/browser/ui/views/ash/key_rewriter.cc
+++ b/chrome/browser/ui/views/ash/key_rewriter.cc
@@ -9,6 +9,8 @@
 #include "ash/shell.h"
 #include "base/logging.h"
 #include "base/string_util.h"
+#include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/profiles/profile_manager.h"
 #include "ui/aura/event.h"
 #include "ui/aura/root_window.h"
 #include "ui/base/keycodes/keyboard_code_conversion.h"
@@ -19,18 +21,100 @@
 #include <X11/Xlib.h>
 
 #include "base/chromeos/chromeos_version.h"
+#include "chrome/browser/chromeos/input_method/input_method_manager.h"
+#include "chrome/browser/chromeos/input_method/xkeyboard.h"
 #include "chrome/browser/chromeos/xinput_hierarchy_changed_event_listener.h"
+#include "chrome/common/pref_names.h"
 #include "ui/base/keycodes/keyboard_code_conversion_x.h"
 #include "ui/base/x/x11_util.h"
+
+using chromeos::input_method::InputMethodManager;
 #endif
 
 namespace {
 
 const int kBadDeviceId = -1;
 
+#if defined(OS_CHROMEOS)
+// A key code and a flag we should use when a key is remapped to |remap_to|.
+const struct ModifierRemapping {
+  int remap_to;
+  int flag;
+  unsigned int native_modifier;
+  ui::KeyboardCode keycode;
+  KeySym native_keysyms[4];  // left, right, shift+left, shift+right.
+} kModifierRemappings[] = {
+  { chromeos::input_method::kSearchKey, 0, Mod4Mask, ui::VKEY_LWIN,
+    { XK_Super_L, XK_Super_L, XK_Super_L, XK_Super_L }},
+  { chromeos::input_method::kControlKey, ui::EF_CONTROL_DOWN, ControlMask,
+    ui::VKEY_CONTROL,
+    { XK_Control_L, XK_Control_R, XK_Control_L, XK_Control_R }},
+  { chromeos::input_method::kAltKey, ui::EF_ALT_DOWN, Mod1Mask,
+    ui::VKEY_MENU, { XK_Alt_L, XK_Alt_R, XK_Meta_L, XK_Meta_R }},
+  { chromeos::input_method::kVoidKey, 0, 0U, ui::VKEY_UNKNOWN,
+    { XK_VoidSymbol, XK_VoidSymbol, XK_VoidSymbol, XK_VoidSymbol }},
+  { chromeos::input_method::kCapsLockKey, 0, 0U, ui::VKEY_CAPITAL,
+    { XK_Caps_Lock, XK_Caps_Lock, XK_Caps_Lock, XK_Caps_Lock }},
+};
+
+// A structure for converting |native_modifier| to a pair of |flag| and
+// |pref_name|.
+const struct ModifierFlagToPrefName {
+  unsigned int native_modifier;
+  int flag;
+  const char* pref_name;
+} kModifierFlagToPrefName[] = {
+  { Mod4Mask, 0, prefs::kLanguageXkbRemapSearchKeyTo },
+  { ControlMask, ui::EF_CONTROL_DOWN, prefs::kLanguageXkbRemapControlKeyTo },
+  { Mod1Mask, ui::EF_ALT_DOWN, prefs::kLanguageXkbRemapAltKeyTo },
+};
+
+// Gets a remapped key for |pref_name| key. For example, to find out which
+// key Search is currently remapped to, call the function with
+// prefs::kLanguageXkbRemapSearchKeyTo.
+const ModifierRemapping* GetRemappedKey(const std::string& pref_name,
+                                        const PrefService& pref_service) {
+  if (!pref_service.FindPreference(pref_name.c_str()))
+    return NULL;  // The |pref_name| hasn't been registered. On login screen?
+  const int value = pref_service.GetInteger(pref_name.c_str());
+  for (size_t i = 0; i < arraysize(kModifierRemappings); ++i) {
+    if (value == kModifierRemappings[i].remap_to)
+      return &kModifierRemappings[i];
+  }
+  return NULL;
+}
+
+bool IsRight(KeySym native_keysym) {
+  switch (native_keysym) {
+    case XK_Alt_R:
+    case XK_Control_R:
+    case XK_Hyper_R:
+    case XK_Meta_R:
+    case XK_Shift_R:
+    case XK_Super_R:
+      return true;
+    default:
+      break;
+  }
+  return false;
+}
+#endif
+
+const PrefService* GetPrefService() {
+  Profile* profile = ProfileManager::GetDefaultProfile();
+  if (profile)
+    return profile->GetPrefs();
+  return NULL;
+}
+
 }  // namespace
 
-KeyRewriter::KeyRewriter() : last_device_id_(kBadDeviceId) {
+KeyRewriter::KeyRewriter()
+    : last_device_id_(kBadDeviceId),
+#if defined(OS_CHROMEOS)
+      xkeyboard_(NULL),
+#endif
+      pref_service_(NULL) {
   // The ash shell isn't instantiated for our unit tests.
   if (ash::Shell::HasInstance())
     ash::Shell::GetPrimaryRootWindow()->AddRootWindowObserver(this);
@@ -155,6 +239,13 @@ void KeyRewriter::RefreshKeycodes() {
   Display* display = ui::GetXDisplay();
   control_l_xkeycode_ = XKeysymToKeycode(display, XK_Control_L);
   control_r_xkeycode_ = XKeysymToKeycode(display, XK_Control_R);
+  alt_l_xkeycode_ = XKeysymToKeycode(display, XK_Alt_L);
+  alt_r_xkeycode_ = XKeysymToKeycode(display, XK_Alt_R);
+  meta_l_xkeycode_ = XKeysymToKeycode(display, XK_Meta_L);
+  meta_r_xkeycode_ = XKeysymToKeycode(display, XK_Meta_R);
+  windows_l_xkeycode_ = XKeysymToKeycode(display, XK_Super_L);
+  caps_lock_xkeycode_ = XKeysymToKeycode(display, XK_Caps_Lock);
+  void_symbol_xkeycode_ = XKeysymToKeycode(display, XK_VoidSymbol);
   kp_0_xkeycode_ = XKeysymToKeycode(display, XK_KP_0);
   kp_1_xkeycode_ = XKeysymToKeycode(display, XK_KP_1);
   kp_2_xkeycode_ = XKeysymToKeycode(display, XK_KP_2);
@@ -167,13 +258,61 @@ void KeyRewriter::RefreshKeycodes() {
   kp_9_xkeycode_ = XKeysymToKeycode(display, XK_KP_9);
   kp_decimal_xkeycode_ = XKeysymToKeycode(display, XK_KP_Decimal);
 }
+
+KeyCode KeyRewriter::NativeKeySymToNativeKeycode(KeySym keysym) {
+  switch (keysym) {
+    case XK_Control_L:
+      return control_l_xkeycode_;
+    case XK_Control_R:
+      return control_r_xkeycode_;
+    case XK_Alt_L:
+      return alt_l_xkeycode_;
+    case XK_Alt_R:
+      return alt_r_xkeycode_;
+    case XK_Meta_L:
+      return meta_l_xkeycode_;
+    case XK_Meta_R:
+      return meta_r_xkeycode_;
+    case XK_Super_L:
+      return windows_l_xkeycode_;
+    case XK_Caps_Lock:
+      return caps_lock_xkeycode_;
+    case XK_VoidSymbol:
+      return void_symbol_xkeycode_;
+    case XK_KP_0:
+      return kp_0_xkeycode_;
+    case XK_KP_1:
+      return kp_1_xkeycode_;
+    case XK_KP_2:
+      return kp_2_xkeycode_;
+    case XK_KP_3:
+      return kp_3_xkeycode_;
+    case XK_KP_4:
+      return kp_4_xkeycode_;
+    case XK_KP_5:
+      return kp_5_xkeycode_;
+    case XK_KP_6:
+      return kp_6_xkeycode_;
+    case XK_KP_7:
+      return kp_7_xkeycode_;
+    case XK_KP_8:
+      return kp_8_xkeycode_;
+    case XK_KP_9:
+      return kp_9_xkeycode_;
+    case XK_KP_Decimal:
+      return kp_decimal_xkeycode_;
+    default:
+      break;
+  }
+  return 0U;
+}
 #endif
 
 void KeyRewriter::Rewrite(aura::KeyEvent* event) {
   RewriteCommandToControl(event);
+  RewriteModifiers(event);
   RewriteNumPadKeys(event);
-  // TODO(yusukes): Implement crbug.com/115112 (Search/Ctrl/Alt remapping) and
-  // crosbug.com/27167 (allow sending function keys) here.
+  // TODO(yusukes): Implement crosbug.com/27167 (allow sending function keys).
 }
 
 bool KeyRewriter::RewriteCommandToControl(aura::KeyEvent* event) {
@@ -232,6 +371,95 @@ bool KeyRewriter::RewriteCommandToControl(aura::KeyEvent* event) {
   return rewritten;
 }
 
+bool KeyRewriter::RewriteModifiers(aura::KeyEvent* event) {
+  const PrefService* pref_service =
+      pref_service_ ? pref_service_ : GetPrefService();
+  if (!pref_service)
+    return false;
+
+#if defined(OS_CHROMEOS)
+  XEvent* xev = event->native_event();
+  XKeyEvent* xkey = &(xev->xkey);
+  KeySym keysym = XLookupKeysym(xkey, 0);
+
+  ui::KeyboardCode remapped_keycode = event->key_code();
+  KeyCode remapped_native_keycode = xkey->keycode;
+  int remapped_flags = 0;
+  unsigned int remapped_native_modifiers = 0U;
+
+  // First, remap |keysym|.
+  const char* pref_name = NULL;
+  switch (keysym) {
+    case XK_Super_L:
+      pref_name = prefs::kLanguageXkbRemapSearchKeyTo;
+      break;
+    case XK_Control_L:
+    case XK_Control_R:
+      pref_name = prefs::kLanguageXkbRemapControlKeyTo;
+      break;
+    case XK_Alt_L:
+    case XK_Alt_R:
+    case XK_Meta_L:
+    case XK_Meta_R:
+      pref_name = prefs::kLanguageXkbRemapAltKeyTo;
+      break;
+    default:
+      break;
+  }
+  if (pref_name) {
+    const ModifierRemapping* remapped_key =
+        GetRemappedKey(pref_name, *pref_service);
+    if (remapped_key) {
+      remapped_keycode = remapped_key->keycode;
+      const size_t level = (event->IsShiftDown() ? (1 << 1) : 0) +
+          (IsRight(keysym) ? (1 << 0) : 0);
+      const KeySym native_keysym = remapped_key->native_keysyms[level];
+      remapped_native_keycode = NativeKeySymToNativeKeycode(native_keysym);
+    }
+  }
+
+  // Next, remap modifier bits.
+  for (size_t i = 0; i < arraysize(kModifierFlagToPrefName); ++i) {
+    if (xkey->state & kModifierFlagToPrefName[i].native_modifier) {
+      const ModifierRemapping* remapped_key =
+          GetRemappedKey(kModifierFlagToPrefName[i].pref_name, *pref_service);
+      if (remapped_key) {
+        remapped_flags |= remapped_key->flag;
+        remapped_native_modifiers |= remapped_key->native_modifier;
+      } else {
+        remapped_flags |= kModifierFlagToPrefName[i].flag;
+        remapped_native_modifiers |= kModifierFlagToPrefName[i].native_modifier;
+      }
+    }
+  }
+
+  remapped_flags = (event->flags() & ~(ui::EF_CONTROL_DOWN | ui::EF_ALT_DOWN)) |
+      remapped_flags;
+  remapped_native_modifiers =
+      (xkey->state & ~(Mod4Mask | ControlMask | Mod1Mask)) |
+      remapped_native_modifiers;
+
+  // Toggle Caps Lock if the remapped key is ui::VKEY_CAPITAL, but do nothing if
+  // the original key is ui::VKEY_CAPITAL (i.e. a Caps Lock key on an external
+  // keyboard is pressed) since X can handle that case.
+  if ((event->type() == ui::ET_KEY_PRESSED) &&
+      (event->key_code() != ui::VKEY_CAPITAL) &&
+      (remapped_keycode == ui::VKEY_CAPITAL)) {
+    chromeos::input_method::XKeyboard* xkeyboard = xkeyboard_ ?
+        xkeyboard_ : InputMethodManager::GetInstance()->GetXKeyboard();
+    xkeyboard->SetCapsLockEnabled(!xkeyboard->CapsLockIsEnabled());
+  }
+
+  OverwriteEvent(event,
+                 remapped_native_keycode, remapped_native_modifiers,
+                 remapped_keycode, remapped_flags);
+  return true;
+#else
+  // TODO(yusukes): Support Ash on other platforms if needed.
+  return false;
+#endif
+}
+
 bool KeyRewriter::RewriteNumPadKeys(aura::KeyEvent* event) {
   bool rewritten = false;
 #if defined(OS_CHROMEOS)