linux-aura: Supports Compose key with XIM.

ui/events/event.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 UI_EVENTS_EVENT_H_
 #define UI_EVENTS_EVENT_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/event_types.h"
@@ skipping 532 matching lines @@
   // letter A with acute, U+0410 Cyrillic capital letter A).
   void set_character(uint16 character) { character_ = character; }
 
   // Gets the character generated by this key event. It only supports Unicode
   // BMP characters.
   uint16 GetCharacter() const;
 
   KeyboardCode key_code() const { return key_code_; }
   bool is_char() const { return is_char_; }
 
+  bool is_fabricated_by_ime() const { return is_fabricated_by_ime_; }
+
   // This is only intended to be used externally by classes that are modifying
   // events in EventFilter::PreHandleKeyEvent().  set_character() should also be
   // called.
   void set_key_code(KeyboardCode key_code) { key_code_ = key_code; }
 
   // Returns true for [Alt]+<num-pad digit> Unicode alt key codes used by Win.
   // TODO(msw): Additional work may be needed for analogues on other platforms.
   bool IsUnicodeKeyCode() const;
 
   std::string code() const { return code_; }
@@ skipping 14 matching lines @@
   // http://www.w3.org/TR/uievents/#keyboard-key-codes.
   //
   // This value represents the physical position in the keyboard and can be
   // converted from / to keyboard scan code like XKB.
   std::string code_;
 
   // True if this is a translated character event (vs. a raw key down). Both
   // share the same type: ET_KEY_PRESSED.
   bool is_char_;
 
+  // True if the key event is fabricated by the underlying IME and not resulting
+  // from an user action.
+  bool is_fabricated_by_ime_;

[sadrul, 2014/04/18 19:01:48]

How is this different from TranslatedKeyEvent? What's the plan for addressing
crbug.com/339355?

[Yuki, 2014/04/21 02:38:30]

TranslatedKeyEvent represents that:
1. The key event was generated by a real user action as same as KeyEvent, and
2. Our own IMF/IME has already processed the event once, so there is no need to
pass the event to IMF/IME again.  (So we can avoid infinite loop.)

is_fabricated_by_ime_ represents that:
1. The key event was NOT DIRECTLY generated by a user action.  Some IMEs need
hacky tricks that add fake key events to the event queue.  This is that kind of
fake key event.
2. Thus, we need to pass this key event to the underlying IME.

So they're totally different things.  I remember crbug.com/339355 and will
address separately.

[sadrul, 2014/04/22 15:34:29]

I think it will be cleaner to have this as a KeyEventFlag instead.

[Yuki, 2014/04/23 08:08:24]

Done.

+
   uint16 character_;
 };
 
 // A key event which is translated by an input method (IME).
 // For example, if an IME receives a KeyEvent(VKEY_SPACE), and it does not
 // consume the key, the IME usually generates and dispatches a
 // TranslatedKeyEvent(VKEY_SPACE) event. If the IME receives a KeyEvent and
 // it does consume the event, it might dispatch a
 // TranslatedKeyEvent(VKEY_PROCESSKEY) event as defined in the DOM spec.
 class EVENTS_EXPORT TranslatedKeyEvent : public KeyEvent {
@@ skipping 95 matching lines @@
   // The set of indices of ones in the binary representation of
   // touch_ids_bitfield_ is the set of touch_ids associate with this gesture.
   // This value is stored as a bitfield because the number of touch ids varies,
   // but we currently don't need more than 32 touches at a time.
   const unsigned int touch_ids_bitfield_;
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_EVENT_H_