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// 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 <stdint.h>
#include <memory>
#include <string>
#include <vector>
#include "base/event_types.h"
#include "build/build_config.h"
#include "ui/base/ime/text_input_mode.h"
#include "ui/base/ime/text_input_type.h"
namespace extensions {
class InputImeApiTest;
} // namespace extensions
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:
InputMethod() : track_key_events_for_testing_(false) {}
#if defined(OS_WIN)
typedef LRESULT NativeEventResult;
#else
typedef int32_t 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;
// 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.
virtual void DispatchKeyEvent(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 whether the system input locale is in CJK languages.
// This is only used in Windows platforms.
virtual bool IsInputLocaleCJK() const = 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;
// Gets the text input flags of the focused text input client. Returns
// 0 if there is no focused client.
virtual int GetTextInputFlags() 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;
protected:
friend class extensions::InputImeApiTest;
// Gets the tracked key events of using input.ime.sendKeyEvents API.
virtual const std::vector<std::unique_ptr<ui::KeyEvent>>&
GetKeyEventsForTesting() = 0;
// Whether the key events will be tracked. Only used for testing.
bool track_key_events_for_testing_;
};
} // namespace ui
#endif // UI_BASE_IME_INPUT_METHOD_H_