It is time.

ui/base/ime/input_method.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_BASE_IME_INPUT_METHOD_H_
-#define UI_BASE_IME_INPUT_METHOD_H_
-
-#include <string>
-
-#include "base/basictypes.h"
-#include "base/event_types.h"
-#include "ui/base/ime/text_input_mode.h"
-#include "ui/base/ime/text_input_type.h"
-
-namespace ui {
-
-namespace internal {
-class InputMethodDelegate;
-}  // namespace internal
-
-class InputMethodObserver;
-class KeyEvent;
-class TextInputClient;
-
-// An interface implemented by an object that encapsulates a native input method
-// service provided by the underlying operating system, and acts as a "system
-// wide" input method for all Chrome windows. A class that implements this
-// interface should behave as follows:
-// - Receives a keyboard event directly from a message dispatcher for the
-//   system through the InputMethod::DispatchKeyEvent API, and forwards it to
-//   an underlying input method for the OS.
-// - The input method should handle the key event either of the following ways:
-//   1) Send the original key down event to the focused window, which is e.g.
-//      a NativeWidgetAura (NWA) or a RenderWidgetHostViewAura (RWHVA), using
-//      internal::InputMethodDelegate::DispatchKeyEventPostIME API, then send
-//      a Char event using TextInputClient::InsertChar API to a text input
-//      client, which is, again, e.g. NWA or RWHVA, and then send the original
-//      key up event to the same window.
-//   2) Send VKEY_PROCESSKEY event to the window using the DispatchKeyEvent API,
-//      then update IME status (e.g. composition text) using TextInputClient,
-//      and then send the original key up event to the window.
-// - Keeps track of the focused TextInputClient to see which client can call
-//   APIs, OnTextInputTypeChanged, OnCaretBoundsChanged, and CancelComposition,
-//   that change the state of the input method.
-// In Aura environment, aura::WindowTreeHost creates an instance of
-// ui::InputMethod and owns it.
-class InputMethod {
- public:
-
-#if defined(OS_WIN)
-  typedef LRESULT NativeEventResult;
-#else
-  typedef int32 NativeEventResult;
-#endif
-
-  virtual ~InputMethod() {}
-
-  // Sets the delegate used by this InputMethod instance. It should only be
-  // called by an object which manages the whole UI.
-  virtual void SetDelegate(internal::InputMethodDelegate* delegate) = 0;
-
-  // Initializes the InputMethod object. Pass true if the system toplevel window
-  // already has keyboard focus.
-  virtual void Init(bool focused) = 0;
-
-  // Called when the top-level system window gets keyboard focus.
-  virtual void OnFocus() = 0;
-
-  // Called when the top-level system window loses keyboard focus.
-  virtual void OnBlur() = 0;
-
-  // Called when the focused window receives native IME messages that are not
-  // translated into other predefined event callbacks. Currently this method is
-  // used only for IME functionalities specific to Windows.
-  // TODO(ime): Break down these messages into platform-neutral methods.
-  virtual bool OnUntranslatedIMEMessage(const base::NativeEvent& event,
-                                        NativeEventResult* result) = 0;
-
-  // Sets the text input client which receives text input events such as
-  // SetCompositionText(). |client| can be NULL. A gfx::NativeWindow which
-  // implementes TextInputClient interface, e.g. NWA and RWHVA, should register
-  // itself by calling the method when it is focused, and unregister itself by
-  // calling the method with NULL when it is unfocused.
-  virtual void SetFocusedTextInputClient(TextInputClient* client) = 0;
-
-  // Detaches and forgets the |client| regardless of whether it has the focus or
-  // not.  This method is meant to be called when the |client| is going to be
-  // destroyed.
-  virtual void DetachTextInputClient(TextInputClient* client) = 0;
-
-  // Gets the current text input client. Returns NULL when no client is set.
-  virtual TextInputClient* GetTextInputClient() const = 0;
-
-  // Dispatches a key event to the input method. The key event will be
-  // dispatched back to the caller via
-  // ui::InputMethodDelegate::DispatchKeyEventPostIME(), once it's processed by
-  // the input method. It should only be called by a message dispatcher.
-  // Returns true if the event was processed.
-  virtual bool DispatchKeyEvent(const ui::KeyEvent& event) = 0;
-
-  // Called by the focused client whenever its text input type is changed.
-  // Before calling this method, the focused client must confirm or clear
-  // existing composition text and call InputMethod::CancelComposition() when
-  // necessary. Otherwise unexpected behavior may happen. This method has no
-  // effect if the client is not the focused client.
-  virtual void OnTextInputTypeChanged(const TextInputClient* client) = 0;
-
-  // Called by the focused client whenever its caret bounds is changed.
-  // This method has no effect if the client is not the focused client.
-  virtual void OnCaretBoundsChanged(const TextInputClient* client) = 0;
-
-  // Called by the focused client to ask the input method cancel the ongoing
-  // composition session. This method has no effect if the client is not the
-  // focused client.
-  virtual void CancelComposition(const TextInputClient* client) = 0;
-
-  // Called by the focused client whenever its input locale is changed.
-  // This method is currently used only on Windows.
-  // This method does not take a parameter of TextInputClient for historical
-  // reasons.
-  // TODO(ime): Consider to take a parameter of TextInputClient.
-  virtual void OnInputLocaleChanged() = 0;
-
-  // Returns the locale of current keyboard layout or input method, as a BCP-47
-  // tag, or an empty string if the input method cannot provide it.
-  virtual std::string GetInputLocale() = 0;
-
-  // Checks if the input method is active, i.e. if it's ready for processing
-  // keyboard event and generate composition or text result.
-  // If the input method is inactive, then it's not necessary to inform it the
-  // changes of caret bounds and text input type.
-  // Note: character results may still be generated and sent to the text input
-  // client by calling TextInputClient::InsertChar(), even if the input method
-  // is not active.
-  virtual bool IsActive() = 0;
-
-  // TODO(yoichio): Following 3 methods(GetTextInputType, GetTextInputMode and
-  // CanComposeInline) calls client's same method and returns its value. It is
-  // not InputMethod itself's infomation. So rename these to
-  // GetClientTextInputType and so on.
-  // Gets the text input type of the focused text input client. Returns
-  // ui::TEXT_INPUT_TYPE_NONE if there is no focused client.
-  virtual TextInputType GetTextInputType() const = 0;
-
-  // Gets the text input mode of the focused text input client. Returns
-  // ui::TEXT_INPUT_TYPE_DEFAULT if there is no focused client.
-  virtual TextInputMode GetTextInputMode() const = 0;
-
-  // Checks if the focused text input client supports inline composition.
-  virtual bool CanComposeInline() const = 0;
-
-  // Returns true if we know for sure that a candidate window (or IME suggest,
-  // etc.) is open.  Returns false if no popup window is open or the detection
-  // of IME popups is not supported.
-  virtual bool IsCandidatePopupOpen() const = 0;
-
-  // Displays an on screen keyboard if enabled.
-  virtual void ShowImeIfNeeded() = 0;
-
-  // Management of the observer list.
-  virtual void AddObserver(InputMethodObserver* observer) = 0;
-  virtual void RemoveObserver(InputMethodObserver* observer) = 0;
-};
-
-}  // namespace ui
-
-#endif  // UI_BASE_IME_INPUT_METHOD_H_