File indexing completed on 2024-05-12 15:54:13

 /*
  * Copyright (C) 2001-2015 Klaralvdalens Datakonsult AB.  All rights reserved.
  *
  * This file is part of the KD Chart library.
  *
  * This program 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 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 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 <https://www.gnu.org/licenses/>.
  */
 
 #include "KChartAbstractProxyModel.h"
 
 #include "KChartMath_p.h"
 
 #include <QDebug>
 
 #ifdef __GNUC__
 #if __GNUC__ > 3
 #define MAY_ALIAS __attribute__((__may_alias__))
 #endif
 #else
 #define MAY_ALIAS
 #endif
 
 namespace KChart {  
 
   AbstractProxyModel::AbstractProxyModel(QObject* parent) 
   : QAbstractProxyModel(parent) {}
 
 // Allows access to QModelIndex's private data via type punning and a compatible data layout.
 // Due to inlining in Qt and no d-pointer, it is safe to assume that the layout won't change except
 // between major Qt versions. As it happens, the layout is the same in Qt4 and Qt5.
 // The only change is void * -> quintptr.
 struct MAY_ALIAS KDPrivateModelIndex
 {
   int r, c;
   void *p;
   const QAbstractItemModel *m;
 };
 
 QModelIndex AbstractProxyModel::mapFromSource( const QModelIndex & sourceIndex ) const
 {
   if ( !sourceIndex.isValid() )
     return QModelIndex();
   //qDebug() << "sourceIndex.model()="<<sourceIndex.model();
   //qDebug() << "model()="<<sourceModel();
   Q_ASSERT( sourceIndex.model() == sourceModel() );
 
   // Create an index that preserves the internal pointer from the source;
   // this way AbstractProxyModel preserves the structure of the source model
   return createIndex( sourceIndex.row(), sourceIndex.column(), sourceIndex.internalPointer() );
 }
 
 QModelIndex AbstractProxyModel::mapToSource( const QModelIndex &proxyIndex ) const
 {
   if ( !proxyIndex.isValid() )
     return QModelIndex();
   if ( proxyIndex.model() != this )
     qDebug() << proxyIndex.model() << this;
   Q_ASSERT( proxyIndex.model() == this );
   // So here we need to create a source index which holds that internal pointer.
   // No way to pass it to sourceModel()->index... so we have to do the ugly way:
   QModelIndex sourceIndex;
   KDPrivateModelIndex* hack = reinterpret_cast<KDPrivateModelIndex*>(&sourceIndex);
   hack->r = proxyIndex.row();
   hack->c = proxyIndex.column();
   hack->p = proxyIndex.internalPointer();
   hack->m = sourceModel();
   Q_ASSERT( sourceIndex.isValid() );
   return sourceIndex;
 }
 
 QModelIndex AbstractProxyModel::index( int row, int col, const QModelIndex& index ) const
 {
     Q_ASSERT(sourceModel());
     return mapFromSource(sourceModel()->index( row, col, mapToSource(index) ));
 }
 
 QModelIndex AbstractProxyModel::parent( const QModelIndex& index ) const
 {
     Q_ASSERT(sourceModel());
     return mapFromSource(sourceModel()->parent( mapToSource(index) ));
 }
 
 }