Add power-user keyboard mode for ChromeOS with Search key acting as a typical Fn key.

chrome/browser/ui/ash/event_rewriter.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_UI_ASH_EVENT_REWRITER_H_
 #define CHROME_BROWSER_UI_ASH_EVENT_REWRITER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 77 matching lines @@
   virtual void DeviceRemoved(int device_id) OVERRIDE;
   virtual void DeviceKeyPressedOrReleased(int device_id) OVERRIDE;
 
   // Updates |*_xkeycode_| in response to a keyboard map change.
   void RefreshKeycodes();
   // Converts an X key symbol like XK_Control_L to a key code.
   unsigned char NativeKeySymToNativeKeycode(unsigned long keysym);
 #endif
 
   // Rewrites the |event| by applying all RewriteXXX functions as needed.
-  void Rewrite(ui::KeyEvent* event);
+  // Returns whether the event should be rewritten or dropped.
+  ash::EventRewriterDelegate::Action Rewrite(ui::KeyEvent* event);
 
   // Rewrites a modifier key press/release following the current user
   // preferences.
   bool RewriteModifiers(ui::KeyEvent* event);
 
   // Rewrites Fn key press/release to Control. In some cases, Fn key is not
   // intercepted by the EC, but generates a key event like "XK_F15 + Mod3Mask"
   // as shown in crosbug.com/p/14339.
   bool RewriteFnKey(ui::KeyEvent* event);
 
   // Rewrites a NumPad key press/release without Num Lock to a corresponding key
   // press/release with the lock.  Returns true when |event| is rewritten.
   bool RewriteNumPadKeys(ui::KeyEvent* event);
 
   // Rewrites Backspace and Arrow keys following the Chrome OS keyboard spec.
   //  * Alt+Backspace -> Delete
   //  * Alt+Up -> Prior (aka PageUp)
   //  * Alt+Down -> Next (aka PageDown)
   //  * Ctrl+Alt+Up -> Home
   //  * Ctrl+Alt+Down -> End
+  // When the Search key acts as a function key, it instead maps:
+  //  * Search+Backspace -> Delete
+  //  * Search+Up -> Prior (aka PageUp)
+  //  * Search+Down -> Next (aka PageDown)
+  //  * Search+Left -> Home
+  //  * Search+right -> End
+  // Returns true when the |event| is rewritten.
   bool RewriteBackspaceAndArrowKeys(ui::KeyEvent* event);
 
+#if defined(OS_CHROMEOS)
+  // When the Search key acts as a function key, it drops Search key presses,
+  // and drops the release as well if any key is pressed while Search was down.
+  bool DropSearchKey(ui::KeyEvent* event);
+#endif
+
   // Rewrites the located |event|.
   void RewriteLocatedEvent(ui::LocatedEvent* event);
 
   // Overwrites |event| with the keycodes and flags.
   void OverwriteEvent(ui::KeyEvent* event,
                       unsigned int new_native_keycode,
                       unsigned int new_native_state,
                       ui::KeyboardCode new_keycode,
                       int new_flags);
 
   // Checks the type of the |device_name|, and inserts a new entry to
   // |device_id_to_type_|.
   DeviceType DeviceAddedInternal(int device_id, const std::string& device_name);
 
   // Returns true if |last_device_id_| is Apple's.
   bool IsAppleKeyboard() const;
 
   // Remaps |original_flags| to |remapped_flags| and |original_native_modifiers|
   // to |remapped_native_modifiers| following the current user prefs.
   void GetRemappedModifierMasks(int original_flags,
                                 unsigned int original_native_modifiers,
                                 int* remapped_flags,
                                 unsigned int* remapped_native_modifiers) const;
 
   std::map<int, DeviceType> device_id_to_type_;
   int last_device_id_;
 
 #if defined(OS_CHROMEOS)
+  bool drop_search_key_release_;
+
   // X keycodes corresponding to various keysyms.
   unsigned int control_l_xkeycode_;
   unsigned int control_r_xkeycode_;
   unsigned int alt_l_xkeycode_;
   unsigned int alt_r_xkeycode_;
   unsigned int meta_l_xkeycode_;
   unsigned int meta_r_xkeycode_;
   unsigned int windows_l_xkeycode_;
   unsigned int caps_lock_xkeycode_;
   unsigned int void_symbol_xkeycode_;
@@ skipping 16 matching lines @@
 
   chromeos::input_method::XKeyboard* xkeyboard_;  // for testing.
 #endif
 
   const PrefService* pref_service_;  // for testing.
 
   DISALLOW_COPY_AND_ASSIGN(EventRewriter);
 };
 
 #endif  // CHROME_BROWSER_UI_ASH_EVENT_REWRITER_H_