libreoffice/canvas/source/vcl/bitmapbackbuffer.hxx

/*************************************************************************
 *
 *  $RCSfile: bitmapbackbuffer.hxx,v $
 *
 *  $Revision: 1.3 $
 *
 *  last change: $Author: vg $ $Date: 2005-03-10 11:56:43 $
 *
 *  The Contents of this file are made available subject to the terms of
 *  either of the following licenses
 *
 *         - GNU Lesser General Public License Version 2.1
 *         - Sun Industry Standards Source License Version 1.1
 *
 *  Sun Microsystems Inc., October, 2000
 *
 *  GNU Lesser General Public License Version 2.1
 *  =============================================
 *  Copyright 2000 by Sun Microsystems, Inc.
 *  901 San Antonio Road, Palo Alto, CA 94303, USA
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License version 2.1, as published by the Free Software Foundation.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *  MA  02111-1307  USA
 *
 *
 *  Sun Industry Standards Source License Version 1.1
 *  =================================================
 *  The contents of this file are subject to the Sun Industry Standards
 *  Source License Version 1.1 (the "License"); You may not use this file
 *  except in compliance with the License. You may obtain a copy of the
 *  License at http://www.openoffice.org/license.html.
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 *  WITHOUT LIMITATION, WARRANTIES THAT THE SOFTWARE IS FREE OF DEFECTS,
 *  MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE, OR NON-INFRINGING.
 *  See the License for the specific provisions governing your rights and
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 *  The Initial Developer of the Original Code is: Sun Microsystems, Inc.
 *
 *  Copyright: 2000 by Sun Microsystems, Inc.
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 *  All Rights Reserved.
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 *  Contributor(s): _______________________________________
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 *
 ************************************************************************/

#ifndef _VCLCANVAS_BITMAPBACKBUFFER_HXX_
#define _VCLCANVAS_BITMAPBACKBUFFER_HXX_

#ifndef _SV_VIRDEV_HXX
#include <vcl/virdev.hxx>
#endif

#include <canvas/vclwrapper.hxx>
#include "outdevprovider.hxx"


namespace vclcanvas
{
    /** OutDevProvider implementation for canvas bitmap.

        This class implements the OutDevProvider interface for the
        bitmap canvas. The actual VirtualDevice is only created when
        necessary, which makes read-only bitmaps a lot smaller.
    */
    class BitmapBackBuffer : public OutDevProvider
    {
    public:
        /** Create a backbuffer for given reference device
         */
        BitmapBackBuffer( const BitmapEx&       rBitmap,
                          const OutputDevice&   rRefDevice );

        ~BitmapBackBuffer();

        virtual OutputDevice&           getOutDev();
        virtual const OutputDevice&     getOutDev() const;

        VirtualDevice&                  getVirDev();
        const VirtualDevice&            getVirDev() const;

        /** Exposing our internal bitmap. Only to be used from
            CanvasBitmapHelper

            @internal
        */
        BitmapEx&                       getBitmapReference();

    private:
        void createVDev() const;
        void updateVDev() const;

        ::canvas::vcltools::VCLObject<BitmapEx> maBitmap;
        mutable VirtualDevice*                  mpVDev; // created only on demand

        const OutputDevice&                     mrRefDevice;

        /** When true, the bitmap contains the last valid
            content. When false, and mbVDevContentIsCurrent is true,
            the VDev contains the last valid content (which must be
            copied back to the bitmap, when getBitmapReference() is
            called). When both are false, this object is just
            initialized.
         */
        mutable bool                            mbBitmapContentIsCurrent;

        /** When true, and mpVDev is non-NULL, the VDev contains the
            last valid content. When false, and
            mbBitmapContentIsCurrent is true, the bitmap contains the
            last valid content. When both are false, this object is
            just initialized.
         */
        mutable bool                            mbVDevContentIsCurrent;
    };

    typedef ::boost::shared_ptr< BitmapBackBuffer > BitmapBackBufferSharedPtr;

}

#endif /* #ifndef _VCLCANVAS_BITMAPBACKBUFFER_HXX_ */