IME (input method editor) support for Aura, part 1 of 3: Add ui/base/ime/ classes

ui/base/ime/input_method_ibus.h

+// Copyright (c) 2011 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_BASE_IME_INPUT_METHOD_IBUS_H_
+#define UI_BASE_IME_INPUT_METHOD_IBUS_H_
+#pragma once
+
+#include <set>
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
+#include "ui/base/glib/glib_integers.h"
+#include "ui/base/glib/glib_signal.h"
+#include "ui/base/ime/character_composer.h"
+#include "ui/base/ime/composition_text.h"
+#include "ui/base/ime/input_method_base.h"
+
+// Forward declarations, so that we don't need to include ibus.h in this file.
+typedef struct _GAsyncResult GAsyncResult;
+typedef struct _IBusBus IBusBus;
+typedef struct _IBusInputContext IBusInputContext;
+typedef struct _IBusText IBusText;
+
+namespace ui {
+
+// A ui::InputMethod implementation based on IBus.
+class UI_EXPORT InputMethodIBus : public InputMethodBase {
+ public:
+  explicit InputMethodIBus(internal::InputMethodDelegate* delegate);
+  virtual ~InputMethodIBus();
+
+  // Overridden from InputMethod:
+  virtual void OnFocus() OVERRIDE;
+  virtual void OnBlur() OVERRIDE;
+  virtual void Init(const base::NativeWindow& system_toplevel_window) OVERRIDE;
+  virtual void DispatchKeyEvent(
+      const base::NativeEvent& native_key_event) OVERRIDE;
+  virtual void OnTextInputTypeChanged(const TextInputClient* client) OVERRIDE;
+  virtual void OnCaretBoundsChanged(const TextInputClient* client) OVERRIDE;
+  virtual void CancelComposition(const TextInputClient* client) OVERRIDE;
+  virtual std::string GetInputLocale() OVERRIDE;
+  virtual base::i18n::TextDirection GetInputTextDirection() OVERRIDE;
+  virtual bool IsActive() OVERRIDE;
+
+ private:
+  // A class to hold all data related to a key event being processed by the
+  // input method but still has no result back yet.
+  class PendingKeyEvent;
+
+  // A class to hold information of a pending request for creating an ibus input
+  // context.
+  class PendingCreateICRequest;
+
+  // Overridden from InputMethodBase:
+  virtual void OnWillChangeFocusedClient(
+      TextInputClient* focused_before, TextInputClient* focused) OVERRIDE;
+  virtual void OnDidChangeFocusedClient(
+      TextInputClient* focused_before, TextInputClient* focused) OVERRIDE;
+
+  // Creates |context_| instance asynchronously.
+  void CreateContext();
+
+  // Sets |context_| and hooks necessary signals.
+  void SetContext(IBusInputContext* ic);
+
+  // Destroys |context_| instance.
+  void DestroyContext();
+
+  // Asks the client to confirm current composition text.
+  void ConfirmCompositionText();
+
+  // Resets |context_| and abandon all pending results and key events.
+  void ResetContext();
+
+  // Checks the availability of focused text input client and update focus state
+  // of |context_|.
+  void UpdateContextFocusState();
+
+  // Process a key returned from the input method.
+  void ProcessKeyEventPostIME(const base::NativeEvent& native_key_event,
+                              guint32 ibus_keycode,
+                              bool handled);
+
+  // Processes a key event that was already filtered by the input method.
+  // A VKEY_PROCESSKEY may be dispatched to the focused View.
+  void ProcessFilteredKeyPressEvent(const base::NativeEvent& native_key_event);
+
+  // Processes a key event that was not filtered by the input method.
+  void ProcessUnfilteredKeyPressEvent(const base::NativeEvent& native_key_event,
+                                      guint32 ibus_keycode);
+  void ProcessUnfilteredFabricatedKeyPressEvent(
+      EventType type, KeyboardCode key_code, int flags, guint32 ibus_keyval);
+
+  // Sends input method result caused by the given key event to the focused text
+  // input client.
+  void ProcessInputMethodResult(const base::NativeEvent& native_key_event,
+                                bool filtered);
+
+  // Checks if the pending input method result needs inserting into the focused
+  // text input client as a single character.
+  bool NeedInsertChar() const;
+
+  // Checks if there is pending input method result.
+  bool HasInputMethodResult() const;
+
+  // Fabricates a key event with VKEY_PROCESSKEY key code and dispatches it to
+  // the focused View.
+  void SendFakeProcessKeyEvent(bool pressed) const;
+
+  // Called when a pending key event has finished. The event will be removed
+  // from |pending_key_events_|.
+  void FinishPendingKeyEvent(PendingKeyEvent* pending_key);
+
+  // Abandons all pending key events. It usually happends when we lose keyboard
+  // focus, the text input type is changed or we are destroyed.
+  void AbandonAllPendingKeyEvents();
+
+  // Event handlers for IBusInputContext:
+  CHROMEG_CALLBACK_1(InputMethodIBus, void, OnCommitText,
+                     IBusInputContext*, IBusText*);
+  CHROMEG_CALLBACK_3(InputMethodIBus, void, OnForwardKeyEvent,
+                     IBusInputContext*, guint, guint, guint);
+  CHROMEG_CALLBACK_0(InputMethodIBus, void, OnShowPreeditText,
+                     IBusInputContext*);
+  CHROMEG_CALLBACK_3(InputMethodIBus, void, OnUpdatePreeditText,
+                     IBusInputContext*, IBusText*, guint, gboolean);
+  CHROMEG_CALLBACK_0(InputMethodIBus, void, OnHidePreeditText,
+                     IBusInputContext*);
+  CHROMEG_CALLBACK_0(InputMethodIBus, void, OnDestroy, IBusInputContext*);
+
+  // Event handlers for IBusBus:
+  CHROMEG_CALLBACK_0(InputMethodIBus, void, OnIBusConnected, IBusBus*);
+  CHROMEG_CALLBACK_0(InputMethodIBus, void, OnIBusDisconnected, IBusBus*);
+
+  // Returns the global IBusBus instance.
+  static IBusBus* GetIBus();
+
+  // Callback function for ibus_input_context_process_key_event_async().
+  static void ProcessKeyEventDone(IBusInputContext* context,
+                                  GAsyncResult* res,
+                                  PendingKeyEvent* data);
+
+  // Callback function for ibus_bus_create_input_context_async().
+  static void CreateInputContextDone(IBusBus* bus,
+                                     GAsyncResult* res,
+                                     PendingCreateICRequest* data);
+
+  // The input context for actual text input. Note that we don't have to support
+  // a "fake" IBus input context anymore since the latest Chrome for Chrome OS
+  // can handle input method hot keys (e.g. Shift+Alt) by itself.
+  IBusInputContext* context_;
+
+  // All pending key events. Note: we do not own these object, we just save
+  // pointers to these object so that we can abandon them when necessary.
+  // They will be deleted in ProcessKeyEventDone().
+  std::set<PendingKeyEvent*> pending_key_events_;
+
+  // The pending request for creating the |context_| instance. We need to keep
+  // this pointer so that we can receive or abandon the result.
+  PendingCreateICRequest* pending_create_ic_request_;
+
+  // Pending composition text generated by the current pending key event.
+  // It'll be sent to the focused text input client as soon as we receive the
+  // processing result of the pending key event.
+  CompositionText composition_;
+
+  // Pending result text generated by the current pending key event.
+  // It'll be sent to the focused text input client as soon as we receive the
+  // processing result of the pending key event.
+  string16 result_text_;
+
+  // Indicates if |context_| is focused or not.
+  bool context_focused_;
+
+  // Indicates if there is an ongoing composition text.
+  bool composing_text_;
+
+  // Indicates if the composition text is changed or deleted.
+  bool composition_changed_;
+
+  // If it's true then all input method result received before the next key
+  // event will be discarded.
+  bool suppress_next_result_;
+
+  // An object to compose a character from a sequence of key presses
+  // including dead key etc.
+  CharacterComposer character_composer_;
+
+  DISALLOW_COPY_AND_ASSIGN(InputMethodIBus);
+};
+
+}  // namespace ui
+
+#endif  // UI_BASE_IME_INPUT_METHOD_IBUS_H_