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Diffstat (limited to 'ui/base/ime/input_method.h')
-rw-r--r-- | ui/base/ime/input_method.h | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/ui/base/ime/input_method.h b/ui/base/ime/input_method.h new file mode 100644 index 0000000..2112660 --- /dev/null +++ b/ui/base/ime/input_method.h @@ -0,0 +1,124 @@ +// 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_H_ +#define UI_BASE_IME_INPUT_METHOD_H_ +#pragma once + +#include <string> + +#include "base/basictypes.h" +#include "base/event_types.h" +#include "base/i18n/rtl.h" +#include "ui/base/ime/text_input_type.h" +#include "ui/base/keycodes/keyboard_codes.h" +#include "ui/base/ui_export.h" + +namespace ui { + +namespace internal { +class InputMethodDelegate; +} // namespace internal + +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::DesktopHost creates an instance of ui::InputMethod +// and owns it. +class UI_EXPORT InputMethod { + public: + virtual ~InputMethod() {} + + // Sets the delegate used by this InputMethod instance. It should only be + // called by an object which manages the whole UI (e.g. aura::DesktopHost). + 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; + + // 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 metho with NULL when it is unfocused. + virtual void SetFocusedTextInputClient(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(const base::NativeEvent& native_key_event) = 0; + + // TODO(yusukes): Add DispatchFabricatedKeyEvent to support virtual keyboards. + + // 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; + + // 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; + + // Returns the text direction of current keyboard layout or input method, or + // base::i18n::UNKNOWN_DIRECTION if the input method cannot provide it. + virtual base::i18n::TextDirection GetInputTextDirection() = 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; + + // 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; +}; + +} // namespace ui + +#endif // UI_BASE_IME_INPUT_METHOD_H_ |