/*
                            This file is part of the Opie Project
             =.             Copyright (C) 2004 Rajko 'Alwin' Albrecht <alwin@handhelds.org>
           .=l.             Copyright (C) The Opie Team <opie-devel@handhelds.org>
          .>+-=
_;:,     .>    :=|.         This program is free software; you can
.> <`_,   >  .   <=         redistribute it and/or  modify it under
:`=1 )Y*s>-.--   :          the terms of the GNU Library General Public
.="- .-=="i,     .._        License as published by the Free Software
- .   .-<_>     .<>         Foundation; either version 2 of the License,
    ._= =}       :          or (at your option) any later version.
   .%`+i>       _;_.
   .i_,=:_.      -<s.       This program is distributed in the hope that
    +  .  -:.       =       it will be useful,  but WITHOUT ANY WARRANTY;
   : ..    .:,     . . .    without even the implied warranty of
   =_        +     =;=|`    MERCHANTABILITY or FITNESS FOR A
 _.=:.       :    :=>`:     PARTICULAR PURPOSE. See the GNU
..}^=.=       =       ;     Library General Public License for more
++=   -.     .`     .:      details.
:     =  ...= . :.=-
-.   .:....=;==+<;          You should have received a copy of the GNU
 -_. . .   )=.  =           Library General Public License along with
   --        :-=`           this library; see the file COPYING.LIB.
                            If not, write to the Free Software Foundation,
                            Inc., 59 Temple Place - Suite 330,
                            Boston, MA 02111-1307, USA.
*/

/* QT */
#include <qwindowsystem_qws.h>
#include <qvaluelist.h>

namespace Opie {
namespace Core {
    class ODevice;


/**
 * A singleton which will manage all possible keyboard filters inside opie.
 * It makes sure that key handlers of odevice are checked first than the
 * keyfilters of software.
 * @short a keyfilter proxy
 * @see QWSServer::KeyboardFilter
 * @author Rajko Albrecht
 * @version 1.0
 */
class OKeyFilter
{
    friend class Opie::Core::ODevice;

protected:
    /**
     * Protected constructor - generate class via inst()
     * @see inst()
     */
    OKeyFilter();
    /**
     * Protected constructor - generate class via inst()
     * @see inst()
     */
    OKeyFilter(const OKeyFilter&){};
    /**
     * Append filter to the primary list.
     * This is only allowed for friend classes from odevice
     * @param aFilter a filter to append
     * @see addHandler
     */
    virtual void addPreHandler(QWSServer::KeyboardFilter *aFilter)=0;
    /**
     * Remove the specified filter from list and give back ownership.
     * This is only allowed for friend classes from odevice
     * @param aFilter a filter to remove
     * @see remHandler
     */
    virtual void remPreHandler(QWSServer::KeyboardFilter *aFilter)=0;

public:
    virtual ~OKeyFilter();
    /**
     * Append filter to the secondary list.
     * @param aFilter a filter to append
     * @see addPreHandler
     */
    virtual void addHandler(QWSServer::KeyboardFilter *aFilter)=0;
    /**
     * Remove the specified filter from list and give back ownership.
     * @param aFilter a filter to remove
     * @see remPreHandler
     */
    virtual void remHandler(QWSServer::KeyboardFilter *aFilter)=0;

    /**
     * Returns a handler to an instance of OKeyFilter
     * @return a pointer to a working OKeyFilter
     */
    static OKeyFilter*inst();
};

}
}