/*      _______   __   __   __   ______   __   __   _______   __   __                 
 *     / _____/\ / /\ / /\ / /\ / ____/\ / /\ / /\ / ___  /\ /  |\/ /\                
 *    / /\____\// / // / // / // /\___\// /_// / // /\_/ / // , |/ / /                 
 *   / / /__   / / // / // / // / /    / ___  / // ___  / // /| ' / /                  
 *  / /_// /\ / /_// / // / // /_/_   / / // / // /\_/ / // / |  / /                   
 * /______/ //______/ //_/ //_____/\ /_/ //_/ //_/ //_/ //_/ /|_/ /                    
 * \______\/ \______\/ \_\/ \_____\/ \_\/ \_\/ \_\/ \_\/ \_\/ \_\/                      
 *
 * 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
 * Redistribution and use in source and          _dV>ws?a-?'      ._/L  #'
 * binary forms, with or without                 )4d[#7r, .   '     )d`)[
 * modification, are permitted provided         _Q-5'5W..j/?'   -?!\)cam'
 * that the following conditions are met:       j<<WP+k/);.        _W=j f
 * 1. Redistributions of source code must       .$%w\/]Q  . ."'  .  mj$
 *    retain the above copyright notice,        ]E.pYY(Q]>.   a     J@\
 *    this list of conditions and the           j(]1u<sE"L,. .   ./^ ]{a
 *    following disclaimer.                     4'_uomm\.  )L);-4     (3=
 * 2. Redistributions in binary form must        )_]X{Z('a_"a7'<a"a,  ]"[
 *    reproduce the above copyright notice,       #}<]m7`Za??4,P-"'7. ).m
 *    this list of conditions and the            ]d2e)Q(<Q(  ?94   b-  LQ/
 *    following disclaimer in the                <B!</]C)d_, '(<' .f. =C+m
 *    documentation and/or other materials      .Z!=J ]e []('-4f _ ) -.)m]'
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 * 3. Neither the name of Guichan nor the      :$we` _! + _/ .        j?
 *    names of its contributors may be used     =3)= _f  (_yQmWW$#(    "
 *    to endorse or promote products derived     -   W,  sQQQQmZQ#Wwa]..
 *    from this software without specific        (js, \[QQW$QWW#?!V"".
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 *                                                 -]n w/ '         [.
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT       )/ )/           !
 * HOLDERS AND CONTRIBUTORS "AS IS" AND ANY         <  (; sac    ,    '
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 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES               _Pa,)!f/<[]/  ?"
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 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,     ?a.<%"'  " -'.a_ _,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION)                     ^
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * For comments regarding functions please see the header file. 
 */

#include "guichan/focushandler.h"
#include "guichan/exception.h"

namespace gcn
{
    FocusHandler::FocusHandler()
    {
        mFocusedWidget = NULL;
        mDraggedWidget = NULL; 
        mToBeFocused = NULL;
        mToBeDragged = NULL;
        mModalFocusedWidget = NULL;
    }

    void FocusHandler::requestFocus(Widget* widget)
    {
        mToBeFocused = widget;        
    }

    void FocusHandler::setFocus(Widget* widget)
    {
        mFocusedWidget = widget;
    }

    void FocusHandler::requestDrag(Widget* widget)
    {
        mToBeDragged = widget;
    }

    void FocusHandler::requestModalFocus(Widget* widget)
    {
        if (mModalFocusedWidget != NULL && mModalFocusedWidget != widget)
        {
            throw GCN_EXCEPTION("Another widget allready has modal focus.");
        }

        mModalFocusedWidget = widget;

        if (mFocusedWidget != NULL && !mFocusedWidget->hasModalFocus())
        {
            focusNone();
        }

        if (mDraggedWidget != NULL && !mDraggedWidget->hasModalFocus())
        {
            dragNone();
        }
    }

    void FocusHandler::releaseModalFocus(Widget* widget)
    {
        if (mModalFocusedWidget == widget)
        {
            mModalFocusedWidget = NULL;
        }
    }
    
    Widget* FocusHandler::getFocused() const
    {
        return mFocusedWidget;
    }

    Widget* FocusHandler::getDragged() const
    {
        return mDraggedWidget;
    }

    Widget* FocusHandler::getModalFocused() const
    {
        return mModalFocusedWidget;
    }
    
    void FocusHandler::focusNext()
    {
        int i;
        int focusedWidget = -1;
        for (i = 0; i < (int)mWidgets.size(); ++i)
        {
            if (mWidgets[i] == mFocusedWidget)
            {
                focusedWidget = i;
            }
        }
        int focused = focusedWidget;
        
        // i is a counter that ensures that the following loop
        // won't get stuck in an infinite loop
        i = (int)mWidgets.size();
        do
        {
            ++focusedWidget;
            
            if (i==0)
            {
                focusedWidget = -1;
                break;
            }
            
            --i;

            if (focusedWidget >= (int)mWidgets.size())
            {
                focusedWidget = 0;      
            }

            if (focusedWidget == focused)
            {
                return;
            }            
        }
        while (!mWidgets.at(focusedWidget)->isFocusable());

        if (focusedWidget >= 0)
        {
            mFocusedWidget = mWidgets.at(focusedWidget);
            mWidgets.at(focusedWidget)->gotFocus();         
        }
        
        if (focused >= 0)
        {
            mWidgets.at(focused)->lostFocus();
        }    
    }
    
    void FocusHandler::focusPrevious()
    {        
        if (mWidgets.size() == 0)
        {
            mFocusedWidget = NULL;
            return;
        }    

        int i;
        int focusedWidget = -1;
        for (i = 0; i < (int)mWidgets.size(); ++i)
        {
            if (mWidgets[i] == mFocusedWidget)
            {
                focusedWidget = i;
            }
        }
        int focused = focusedWidget;               
        
        // i is a counter that ensures that the following loop
        // won't get stuck in an infinite loop
        i = (int)mWidgets.size();
        do
        {
            --focusedWidget;

            if (i==0)
            {
                focusedWidget = -1;
                break;
            }

            --i;
            
            if (focusedWidget <= 0)
            {
                focusedWidget = mWidgets.size() - 1;      
            }

            if (focusedWidget == focused)
            {
                return;
            }
        }
        while (!mWidgets.at(focusedWidget)->isFocusable());

        if (focusedWidget >= 0)
        {
            mFocusedWidget = mWidgets.at(focusedWidget);
            mWidgets.at(focusedWidget)->gotFocus();
        }
                
        if (focused >= 0)
        {
            mWidgets.at(focused)->lostFocus();
        }    
    }

    bool FocusHandler::hasFocus(const Widget* widget) const
    {
        return mFocusedWidget == widget;
    }

     bool FocusHandler::isDragged(const Widget* widget) const
     {
        return mDraggedWidget == widget;
     }

    void FocusHandler::add(Widget* widget)
    {
        mWidgets.push_back(widget);    
    }
    
    void FocusHandler::remove(Widget* widget)
    {
        if (widget == mFocusedWidget)
        {
            mFocusedWidget = NULL;
        }
        if (widget == mDraggedWidget)
        {
            mDraggedWidget = NULL;
        }
        if (widget == mToBeFocused)
        {
            mToBeFocused = NULL;
        }
        if (widget == mToBeDragged)
        {
            mToBeDragged = NULL;
        }

        if (hasFocus(widget))
        {
            mFocusedWidget = NULL;
            mToBeFocused = NULL;
        }
        
        int i = 0;
        WidgetIterator iter;
        
        for (iter = mWidgets.begin(); iter != mWidgets.end(); ++iter)
        {
            ++i;
            
            if ((*iter) == widget)
            {        
                mWidgets.erase(iter);                
                return;
            }      
        }        
    }
    
    void FocusHandler::focusNone()
    {
         
        if (mFocusedWidget != NULL)
        {
            Widget* focused = mFocusedWidget;
            mFocusedWidget = NULL; 
            focused->lostFocus();            
        }
        
        mToBeFocused = NULL;
    }

    void FocusHandler::dragNone()
    {
        mDraggedWidget = NULL;
    }

    void FocusHandler::checkHotKey(const KeyInput &keyInput)
    {
        int keyin = keyInput.getKey().getValue();

        for (int i = 0; i < (int)mWidgets.size(); ++i)
        {
            int hotKey = mWidgets[i]->getHotKey();

            if (hotKey == 0)
            {
                continue;
            }

            if ((isascii(keyin) && tolower(keyin) == hotKey) || keyin == hotKey)
            {
                if (keyInput.getType() == KeyInput::PRESS)
                {
                    mWidgets[i]->hotKeyPress();
                    if (mWidgets[i]->isFocusable())
                    {
                        this->requestFocus(mWidgets[i]);
                    }
                }
                else
                {
                    mWidgets[i]->hotKeyRelease();
                }
                break;
            }
        }
    }
    
    void FocusHandler::tabNext()
    {
        if (mFocusedWidget != NULL)
        {
            if (!mFocusedWidget->isTabOutEnabled())
            {
                return;
            }
        }

        if (mWidgets.size() == 0)
        {
            mFocusedWidget = NULL;
            return;
        }    

        int i;
        int focusedWidget = -1;
        for (i = 0; i < (int)mWidgets.size(); ++i)
        {
            if (mWidgets[i] == mFocusedWidget)
            {
                focusedWidget = i;
            }
        }
        int focused = focusedWidget;               
        bool done = false;
        
        // i is a counter that ensures that the following loop
        // won't get stuck in an infinite loop
        i = (int)mWidgets.size();
        do
        {
            ++focusedWidget;
            
            if (i==0)
            {
                focusedWidget = -1;
                break;
            }
            
            --i;

            if (focusedWidget >= (int)mWidgets.size())
            {
                focusedWidget = 0;      
            }

            if (focusedWidget == focused)
            {
                return;
            }
            
            if (mWidgets.at(focusedWidget)->isFocusable() &&
                mWidgets.at(focusedWidget)->isTabInEnabled() &&
                (mModalFocusedWidget == NULL ||
                 mWidgets.at(focusedWidget)->hasModalFocus()))
            {
                done = true;
            }
        }
        while (!done);

        if (focusedWidget >= 0)
        {
            mFocusedWidget = mWidgets.at(focusedWidget);
            mWidgets.at(focusedWidget)->gotFocus();
        }
        
        if (focused >= 0)
        {
            mWidgets.at(focused)->lostFocus();
        }
    }

    void FocusHandler::tabPrevious()
    {
        if (mFocusedWidget != NULL)
        {
            if (!mFocusedWidget->isTabOutEnabled())
            {
                return;
            }
        }
                
        if (mWidgets.size() == 0)
        {
            mFocusedWidget = NULL;
            return;
        }    

        int i;
        int focusedWidget = -1;
        for (i = 0; i < (int)mWidgets.size(); ++i)
        {
            if (mWidgets[i] == mFocusedWidget)
            {
                focusedWidget = i;
            }
        }
        int focused = focusedWidget;               
        bool done = false;
        
        // i is a counter that ensures that the following loop
        // won't get stuck in an infinite loop
        i = (int)mWidgets.size();
        do
        {
            --focusedWidget;

            if (i==0)
            {
                focusedWidget = -1;
                break;
            }

            --i;
            
            if (focusedWidget <= 0)
            {
                focusedWidget = mWidgets.size() - 1;      
            }

            if (focusedWidget == focused)
            {
                return;
            }

            if (mWidgets.at(focusedWidget)->isFocusable() &&
                mWidgets.at(focusedWidget)->isTabInEnabled() &&
                (mModalFocusedWidget == NULL ||
                 mWidgets.at(focusedWidget)->hasModalFocus()))
            {
                done = true;
            }
        }
        while (!done);

        if (focusedWidget >= 0)
        {
            mFocusedWidget = mWidgets.at(focusedWidget);
            mWidgets.at(focusedWidget)->gotFocus();
        }    

        if (focused >= 0)
        {
            mWidgets.at(focused)->lostFocus();
        }    
    }

    void FocusHandler::applyChanges()
    {
        if (mToBeFocused != NULL)
        {
            unsigned int i = 0;
            int toBeFocusedIndex = -1;
            for (i = 0; i < mWidgets.size(); ++i)
            {      
                if (mWidgets[i] == mToBeFocused)
                {
                    toBeFocusedIndex = i;
                    break;                
                }
            }    
            
            if (toBeFocusedIndex < 0)
            {
                throw GCN_EXCEPTION("Trying to focus a none existing widget.");
            }

            Widget *oldFocused = mFocusedWidget;

            if (oldFocused != mToBeFocused)
            {
                mFocusedWidget = mWidgets.at(toBeFocusedIndex);
                
                if (oldFocused != NULL)
                {
                    oldFocused->lostFocus();
                }
                
                mWidgets.at(toBeFocusedIndex)->gotFocus();
            }
            mToBeFocused = NULL;
        }

        if (mToBeDragged != NULL)
        {
            unsigned int i = 0;
            int toBeDraggedIndex = -1;
            for (i = 0; i < mWidgets.size(); ++i)
            {      
                if (mWidgets[i] == mToBeDragged)
                {
                    toBeDraggedIndex = i;                
                    break;
                }
            }    

            if (toBeDraggedIndex < 0)
            {
                throw GCN_EXCEPTION("Trying to give drag to a none existing widget");
            }
            
             mDraggedWidget = mWidgets.at(toBeDraggedIndex);
             mToBeDragged = NULL;            
        }
    }    
}