/*      _______   __   __   __   ______   __   __   _______   __   __                 
 *     / _____/\ / /\ / /\ / /\ / ____/\ / /\ / /\ / ___  /\ /  |\/ /\                
 *    / /\____\// / // / // / // /\___\// /_// / // /\_/ / // , |/ / /                 
 *   / / /__   / / // / // / // / /    / ___  / // ___  / // /| ' / /                  
 *  / /_// /\ / /_// / // / // /_/_   / / // / // /\_/ / // / |  / /                   
 * /______/ //______/ //_/ //_____/\ /_/ //_/ //_/ //_/ //_/ /|_/ /                    
 * \______\/ \______\/ \_\/ \_____\/ \_\/ \_\/ \_\/ \_\/ \_\/ \_\/                      
 *
 * Copyright (c) 2004, 2005 darkbits                        Js_./
 * Per Larsson a.k.a finalman                          _RqZ{a<^_aa
 * Olof Naessén a.k.a jansem/yakslem                _asww7!uY`>  )\a//
 *                                                 _Qhm`] _f "'c  1!5m
 * Visit: http://guichan.darkbits.org             )Qk<P ` _: :+' .'  "{[
 *                                               .)j(] .d_/ '-(  P .   S
 * License: (BSD)                                <Td/Z <fP"5(\"??"\a.  .L
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#ifndef GCN_FOCUSHANDLER_HPP
#define GCN_FOCUSHANDLER_HPP

#include <vector>

#include "guichan/platform.h"
#include "guichan/widget.h"

namespace gcn
{
    class Widget;
  
    /**
     * Used to keep track of widget focus. You will probably not have
     * to use the FocusHandler directly to handle focus. Widget has
     * functions for handling focus which uses a FocusHandler. Use them
     * instead.
     *
     * @see Widget::hasFocus
     * @see Widget::requestFocus
     * @see Widget::setFocusable
     * @see Widget::isFocusable
     * @see Widget::gotFocus
     * @see Widget::lostFocus
     */
    class GCN_CORE_DECLSPEC FocusHandler
    {
    public:
        
        /**
         * Constructor.
         */
        FocusHandler();

        /**
         * Destructor.
         */
        virtual ~FocusHandler() { };
        
        /**
         * Sets focus to a Widget. Widget::lostFocus and
         * Widget::gotFocus will be called.
         *
         * @param widget the Widget to focus.
         */
        virtual void requestFocus(Widget* widget);

        /**
         * Sets focus immediately.
         */
        virtual void setFocus(Widget* widget);

        /**
         * Sets drag to a Widget.
         *
         * @param widget the Widget to drag.
         */
        virtual void requestDrag(Widget* widget);
        
        /**
         * Sets modal focus to a Widget. If another Widget already
         * has modal focus will an exception be thrown.
         *
         * @param widget the Widget to focus modal.
         * @throws Exception when another widget already has modal focus.
         */
        virtual void requestModalFocus(Widget* widget);

        /**
         * Releases modal focus if the Widget has modal focus.
         * Otherwise nothing will be done.
         *
         * @param widget the Widget to release modal focus for.
         */
        virtual void releaseModalFocus(Widget* widget);
        
        /**
         * Gets the Widget with focus.         
         *
         * @return the Widget with focus. NULL will be returned if
         *         no Widget has focus.
         */
        virtual Widget* getFocused() const;
        
        /**
         * Gets the widget that is dragged.
         *
         * @return the widget that is dragged. NULL will be returned
         *         if no Widget is dragged.
         */
        virtual Widget* getDragged() const;

        /**
         * Gets the Widget with modal focus.
         *
         * @return the Widget with modal focus. NULL will be returned
         *         if no Widget has modal focus.
         */
        virtual Widget* getModalFocused() const;
        
        /**
         * Focuses the next Widget. If no Widget has focus the first
         * Widget gets focus. The order in which the Widgets are focused
         * depends on the order you add them to the GUI.
         */
        virtual void focusNext();
    
        /**
         * Focuses the previous Widget. If no Widget has focus the first
         * Widget gets focus. The order in which the widgets are focused
         * depends on the order you add them to the GUI.     
         */
        virtual void focusPrevious();

        /**
         * Checks if a Widget has focus.
         *
         * @param widget widget to check if it has focus..
         * @return true if the widget has focus.
         */
        virtual bool hasFocus(const Widget* widget) const;

        /**
         * Checks if a widget is being dragged
         *
         * @param widget the Widget to check if it is being dragged.
         * @return true if the widget is being dragged.
         */
        virtual bool isDragged(const Widget* widget) const;
        
        /**
         * Adds a widget to the FocusHandler.
         *
         * @param widget the widget to add.
         */
        virtual void add(Widget* widget);
    
        /**
         * Removes a widget from the FocusHandler.
         *
         * @param widget the widget to remove.     
         */
        virtual void remove(Widget* widget);

        /**
         * Focuses nothing.
         */
        virtual void focusNone();
        
        /**
         * Focuses the next Widget which allows tab in unless current focused
         * Widget disallows tab out.
         */
        virtual void tabNext();

        /**
         * Focuses the previous Widget which allows tab in unless current focused
         * Widget disallows tab out.
         */
        virtual void tabPrevious();

        /**
         * Applies the changes.
         */
        virtual void applyChanges();

        /**
         * Drag nothing.
         */
        virtual void dragNone();

		/**
		 * Check if a hot key was pressed.
		 */
		virtual void checkHotKey(const KeyInput &keyInput);
        
    protected:
        typedef std::vector<Widget*> WidgetVector;
        typedef WidgetVector::iterator WidgetIterator;
        WidgetVector mWidgets;
    
        Widget* mFocusedWidget;
        Widget* mDraggedWidget;
        Widget* mToBeFocused;
        Widget* mToBeDragged;
        Widget* mModalFocusedWidget;        
    };  
}

#endif // end GCN_FOCUSHANDLER_HPP
