// vi:ft=cpp
/*
 * Copyright (C) 2012-2014 Kernkonzept GmbH.
 * Author(s): Johannes Richter <johannes.richter@kernkonzept.com>
 *
 * This file is distributed under the terms of the GNU General Public
 * License, version 2.  Please see the COPYING-GPL-2 file for details.
 *
 * As a special exception, you may use this file as part of a free software
 * library without restriction.  Specifically, if other files instantiate
 * templates or use macros or inline functions from this file, or you compile
 * this file and link it with other files to produce an executable, this
 * file does not by itself cause the resulting executable to be covered by
 * the GNU General Public License.  This exception does not however
 * invalidate any other reasons why the executable file might be covered by
 * the GNU General Public License.
 */
#pragma once

#include <l4/scout-gfx/style>
#include <l4/scout-gfx/widget>
#include <l4/mag-gfx/canvas>

namespace Scout_gfx {

/**
 * This mix-in class adds the functionality to a class derived from Widget
 * to handle the keyboard focus.
 *
 * \tparam SUBJECT: the type of class, that is extended with this mixin.
 */
//template <class SUBJECT>
class Focus_mixin: public Widget
{
private:
  bool _focused;
  Color _focus_color;

public:
  /**
   * Creates an instance of a focusable widget.
   *
   * By default this object is not focused initially and draws a light-blue
   * frame if it becomes focused.
   */
  Focus_mixin()
  : _focused(false), _focus_color(Color(0x1C, 0xE8, 0xE8))
  {}

  /**
   * \param focused: true if widget is currently focused, otherwise false
   */
  void keyb_focus(bool focused) { _focused = focused; }

  /**
   * This method sets the color of the focused Widget.
   *
   * \param fcol: new focus color
   */
  void focused_color(Color fcol) { _focus_color = fcol; }

  /// \returns if the widget is focused
  bool is_keyb_focusable() const { return 1; }

  /**
   * This method draws a frame to indicate focused widget
   */
  void draw_focus(Canvas *c, Point const &p)
  {
    //Widget *this_widget = static_cast<Widget *>(this);
    if (_focused)
      {
        Rect n = Rect(p, this->size() );
        c->draw_rect(n.grow(-2), _focus_color , 2);
      }
  }
};

} //namespace