/******************************************************************************
*
* Copyright (C) 2002 Hugo PEREIRA <mailto: hugo.pereira@free.fr>
*
* This is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option) any later
* version.
*
* This software 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 General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along with
* this program.  If not, see <http://www.gnu.org/licenses/>.
*
*******************************************************************************/

#include "SessionFilesView.h"

#include "XmlFileRecord.h"

#include <QDomDocument>
#include <QDrag>
#include <QMimeData>
#include <QPainter>


//____________________________________________________________________
SessionFilesView::SessionFilesView( QWidget* parent ):
    TreeView( parent )
{}

//____________________________________________________________________
void SessionFilesView::startDrag( Qt::DropActions supportedActions )
{

    Debug::Throw()
        << "SessionFilesView::startDrag -"
        << " state: " << state()
        << " supported: " << supportedActions
        << endl;

    // check lock to prevent recursive calls
    if( locked_ )
    {
        locked_ = false;
        return;
    } else { locked_ = true; }

    // get list of dragable indexes
    QModelIndexList indexes;
    for( const auto& index:selectionModel()->selectedIndexes() )
    { if( model()->flags( index ) & Qt::ItemIsDragEnabled ) indexes.append( index ); }
    if( indexes.isEmpty() ) return;

    // get mime data
    QMimeData* data = model()->mimeData( indexes );
    if( !data ) return;

    // create drag
    QDrag* drag = new QDrag(this);
    drag->setMimeData(data);

    // generate pixmap
    QRect boundingRect;
    drag->setPixmap( _renderToPixmap( indexes, boundingRect ) );

    if( !drag->exec( supportedActions, defaultDropAction() ) )
    {

        // get dropped file record (use XML)
        // dom document
        QDomDocument document;
        if( !document.setContent( data->data( FileRecord::MimeType ), false ) ) return;
        const auto records( XmlFileRecord::Helper::list( document.documentElement() ) );

        if( records.empty() ) return;
        const File target( records.front().file() );
        bool first( true );
        for( const auto& record:records )
        {

            if( first )
            {
                first = false;
                emit detach( record.file() );
            } else emit reparentFilesToMain( record.file(), target );

        }

    }

    // unlock
    locked_ = false;

}

//____________________________________________________________________
QPixmap SessionFilesView::_renderToPixmap( const QModelIndexList& indexes, QRect& rect ) const
{

    // generate pixmap
    rect = QRect();
    for( const auto& index:indexes )
    { rect |= visualRect( index ); }

    QPixmap pixmap( rect.size() );
    pixmap.fill( Qt::transparent );
    QPainter painter( &pixmap );
    for( const auto& index:indexes )
    {
        QStyleOptionViewItemV4 option;

        // set option state
        option.showDecorationSelected = true;
        option.state = QStyle::State_Selected | QStyle::State_Active;
        const Qt::ItemFlags flags( model()->flags( index ) );
        if( flags & Qt::ItemIsEnabled ) option.state |= QStyle::State_Enabled;

        option.rect  = visualRect( index ).translated( -rect.topLeft() );
        option.displayAlignment = Qt::AlignCenter;

        itemDelegate()->paint( &painter, option, index );

    }

    return pixmap;
}