// 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 VIEWS_IME_TEXT_INPUT_CLIENT_H_
#define VIEWS_IME_TEXT_INPUT_CLIENT_H_
#pragma once

#include <vector>

#include "base/basictypes.h"
#include "base/callback.h"
#include "base/string16.h"
#include "ui/base/ime/composition_text.h"
#include "ui/base/ime/text_input_type.h"
#include "ui/base/range/range.h"

namespace gfx {
class Rect;
}

namespace views {

class View;

// An interface implemented by a View that needs text input support.
class TextInputClient {
 public:
  virtual ~TextInputClient() {}

  // Input method result -------------------------------------------------------

  // Sets composition text and attributes. If there is composition text already,
  // it’ll be replaced by the new one. Otherwise, current selection will be
  // replaced. If there is no selection, the composition text will be inserted
  // at the insertion point.
  virtual void SetCompositionText(const ui::CompositionText& composition) = 0;

  // Converts current composition text into final content.
  virtual void ConfirmCompositionText() = 0;

  // Removes current composition text.
  virtual void ClearCompositionText() = 0;

  // Inserts a given text at the insertion point. Current composition text or
  // selection will be removed. This method should never be called when the
  // current text input type is TEXT_INPUT_TYPE_NONE.
  virtual void InsertText(const string16& text) = 0;

  // Inserts a single char at the insertion point. Unlike above InsertText()
  // method, this method has an extra |flags| parameter indicating the modifier
  // key states when the character is generated. This method should only be
  // called when a key press is not handled by the input method but still
  // generates a character (eg. by the keyboard driver). In another word, the
  // preceding key press event should not be a VKEY_PROCESSKEY.
  // This method will be called whenever a char is generated by the keyboard,
  // even if the current text input type is TEXT_INPUT_TYPE_NONE.
  virtual void InsertChar(char16 ch, int flags) = 0;

  // Input context information -------------------------------------------------

  // Returns current text input type. It could be changed and even becomes
  // TEXT_INPUT_TYPE_NONE at runtime.
  virtual ui::TextInputType GetTextInputType() = 0;

  // Returns current caret (insertion point) bounds relative to the View’s
  // coordinates. If there is selection, then the selection bounds will be
  // returned.
  virtual gfx::Rect GetCaretBounds() = 0;

  // Returns true if there is composition text.
  virtual bool HasCompositionText() = 0;

  // Document content operations ----------------------------------------------

  // Retrieves the UTF-16 based character range containing all text in the View.
  // Returns false if the information cannot be retrieved right now.
  virtual bool GetTextRange(ui::Range* range) = 0;

  // Retrieves the UTF-16 based character range of current composition text.
  // Returns false if the information cannot be retrieved right now.
  virtual bool GetCompositionTextRange(ui::Range* range) = 0;

  // Retrieves the UTF-16 based character range of current selection.
  // Returns false if the information cannot be retrieved right now.
  virtual bool GetSelectionRange(ui::Range* range) = 0;

  // Selects the given UTF-16 based character range. Current composition text
  // will be confirmed before selecting the range.
  // Returns false if the operation is not supported.
  virtual bool SetSelectionRange(const ui::Range& range) = 0;

  // Deletes contents in the given UTF-16 based character range. Current
  // composition text will be confirmed before deleting the range.
  // The input caret will be moved to the place where the range gets deleted.
  // Returns false if the oepration is not supported.
  virtual bool DeleteRange(const ui::Range& range) = 0;

  // Retrieves the text content in a given UTF-16 based character range.
  // The result will be send back to the input method by calling the given
  // callback, which may happen asynchronously.
  // Returns false if the operation is not supported.
  virtual bool GetTextFromRange(
      const ui::Range& range,
      const base::Callback<void(const string16&)>& callback) = 0;

  // Miscellaneous ------------------------------------------------------------

  // Called whenever current keyboard layout or input method is changed,
  // especially the change of input locale and text direction.
  virtual void OnInputMethodChanged() = 0;

  // Called whenever the user requests to change the text direction and layout
  // alignment of the current text box. It’s for supporting ctrl-shift on
  // Windows.
  // Returns false if the operation is not supported.
  virtual bool ChangeTextDirectionAndLayoutAlignment(
      base::i18n::TextDirection direction) = 0;

  // Gets the View object who owns this TextInputClient instance.
  virtual View* GetOwnerViewOfTextInputClient() = 0;
};

}  // namespace views

#endif  // VIEWS_IME_TEXT_INPUT_CLIENT_H_