/**************************************************************
 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * 
 *************************************************************/


// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_canvas.hxx"

#include "bitmapbackbuffer.hxx"

#include <osl/mutex.hxx>
#include <vos/mutex.hxx>

#include <vcl/svapp.hxx>
#include <vcl/bitmapex.hxx>
#include <vcl/bmpacc.hxx>


namespace vclcanvas
{
    BitmapBackBuffer::BitmapBackBuffer( const BitmapEx& 		rBitmap,
                                        const OutputDevice& 	rRefDevice ) :
        maBitmap( rBitmap ),
        mpVDev( NULL ),
        mrRefDevice( rRefDevice ),
        mbBitmapContentIsCurrent( false ),
        mbVDevContentIsCurrent( false )
    {
    }
        
    BitmapBackBuffer::~BitmapBackBuffer()
    {
        // make sure solar mutex is held on deletion (other methods
        // are supposed to be called with already locked solar mutex)
        ::vos::OGuard aGuard( Application::GetSolarMutex() );
        
        if( mpVDev )
            delete mpVDev;
    }

    OutputDevice& BitmapBackBuffer::getOutDev()
    {
        createVDev();
        updateVDev();
        return *mpVDev;
    }

    const OutputDevice& BitmapBackBuffer::getOutDev() const
    {
        createVDev();
        updateVDev();
        return *mpVDev;
    }

    void BitmapBackBuffer::clear()
    {
        // force current content to bitmap, make all transparent white
        getBitmapReference().Erase(COL_TRANSPARENT);        
    }

    BitmapEx& BitmapBackBuffer::getBitmapReference()
    {
        OSL_ENSURE( !mbBitmapContentIsCurrent || !mbVDevContentIsCurrent,
                    "BitmapBackBuffer::getBitmapReference(): Both bitmap and VDev are valid?!" );

        if( mbVDevContentIsCurrent && mpVDev )
        {
            // VDev content is more current than bitmap - copy contents before!
            mpVDev->EnableMapMode( sal_False );
            mpVDev->SetAntialiasing( ANTIALIASING_ENABLE_B2DDRAW );
            const Point aEmptyPoint;
            *maBitmap = mpVDev->GetBitmapEx( aEmptyPoint,
                                             mpVDev->GetOutputSizePixel() );
        }

        // client queries bitmap, and will possibly alter content -
        // next time, VDev needs to be updated
        mbBitmapContentIsCurrent = true;
        mbVDevContentIsCurrent 	 = false;

        return *maBitmap;
    }

    Size BitmapBackBuffer::getBitmapSizePixel() const
    {
        Size aSize = maBitmap->GetSizePixel();

        if( mbVDevContentIsCurrent && mpVDev )
        {
            mpVDev->EnableMapMode( sal_False );
            mpVDev->SetAntialiasing( ANTIALIASING_ENABLE_B2DDRAW );
            aSize = mpVDev->GetOutputSizePixel();
        }

        return aSize;
    }

    void BitmapBackBuffer::createVDev() const
    {
        if( !mpVDev )
        {
            // VDev not yet created, do it now. Create an alpha-VDev,
            // if bitmap has transparency.
            mpVDev = maBitmap->IsTransparent() ? 
                new VirtualDevice( mrRefDevice, 0, 0 ) :
                new VirtualDevice( mrRefDevice );

            OSL_ENSURE( mpVDev, 
                        "BitmapBackBuffer::createVDev(): Unable to create VirtualDevice" );

            mpVDev->SetOutputSizePixel( maBitmap->GetSizePixel() );

            // #i95645#
#if defined( QUARTZ )
            // use AA on VCLCanvas for Mac
			mpVDev->SetAntialiasing( ANTIALIASING_ENABLE_B2DDRAW | mpVDev->GetAntialiasing() );
#else
            // switch off AA for WIN32 and UNIX, the VCLCanvas does not look good with it and
            // is not required to do AA. It would need to be adapted to use it correctly 
            // (especially gradient painting). This will need extra work.
			mpVDev->SetAntialiasing(mpVDev->GetAntialiasing() & ~ANTIALIASING_ENABLE_B2DDRAW);
#endif
        }
    }

    void BitmapBackBuffer::updateVDev() const
    {
        OSL_ENSURE( !mbBitmapContentIsCurrent || !mbVDevContentIsCurrent,
                    "BitmapBackBuffer::updateVDev(): Both bitmap and VDev are valid?!" );

        if( mpVDev && mbBitmapContentIsCurrent )
        {
            // fill with bitmap content
            mpVDev->EnableMapMode( sal_False );
            mpVDev->SetAntialiasing( ANTIALIASING_ENABLE_B2DDRAW );
            const Point aEmptyPoint;
            mpVDev->DrawBitmapEx( aEmptyPoint, *maBitmap );
        }

        // canvas queried the VDev, and will possibly paint into
        // it. Next time, bitmap must be updated
        mbBitmapContentIsCurrent = false;
        mbVDevContentIsCurrent 	 = true;
    }
}