qgsexpressionfieldbuffer.h

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/***************************************************************************
                          qgsexpressionfieldbuffer.h
                          ---------------------------
    begin                : May 27, 2014
    copyright            : (C) 2014 by Matthias Kuhn
    email                : matthias at opengis dot ch
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef QGSEXPRESSIONFIELDBUFFER_H
#define QGSEXPRESSIONFIELDBUFFER_H

#include <QString>
#include <QList>
#include <QDomNode>

#include "qgsfield.h"
#include "qgsexpression.h"

class CORE_EXPORT QgsExpressionFieldBuffer
{
  public:
    typedef struct ExpressionField
    {
      ExpressionField() : cachedExpression( expression ) {}
      ExpressionField( const QString& exp, const QgsField& fld )
          : expression( exp )
          , cachedExpression( exp )
          , field( fld )
      {}

      QString expression;
      QgsExpression cachedExpression;
      QgsField field;
    } ExpressionField;

    QgsExpressionFieldBuffer();

    void addExpression( const QString& exp, const QgsField& fld );

    void removeExpression( int index );

    void renameExpression( int index, const QString& name );

    void updateExpression( int index, const QString& exp );

    void writeXml( QDomNode& layer_node, QDomDocument& document ) const;

    void readXml( const QDomNode& layer_node );

    void updateFields( QgsFields& flds );

    const QList<ExpressionField>& expressions() const { return mExpressions; }

  private:
    QList<ExpressionField> mExpressions;
};

#endif // QGSEXPRESSIONFIELDBUFFER_H