File indexing completed on 2024-05-05 04:48:47

 /****************************************************************************************
  * Copyright (c) 2008-2012 Soren Harward <stharward@gmail.com>                          *
  *                                                                                      *
  * 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 <http://www.gnu.org/licenses/>.                           *
  ****************************************************************************************/
 
 #ifndef APG_CONSTRAINTNODE
 #define APG_CONSTRAINTNODE
 
 #include "core/meta/forward_declarations.h"
 
 #include <QDomElement>
 #include <QList>
 #include <QObject>
 #include <QString>
 
 namespace Collections {
     class QueryMaker;
 }
 
 class QWidget;
 
 /* Abstract base class for all constraints, including ConstraintGroup
  *
  * Inheritance Tree:
  *
  *                       ConstraintNode
  *                              |
  *             +----------------+-----------+
  *             |                            |
  *      ConstraintGroup                 Constraint
  *                                          |
  *          +-----------------+-------------+-----+--------  ... etc
  *          |                 |                   |
  *      Matching     PreventDuplicates     PlaylistDuration
  *          |
  *      TagMatch
  *
  *
  * If you want to write a new Constraint, don't subclass this directly.
  * Subclass Constraint or one of its children instead. -- sth
  */
 
 class ConstraintNode : public QObject {
     Q_OBJECT
     public:
         enum NodeType { ConstraintGroupType, ConstraintType };
 
         ~ConstraintNode() override;
 
         // Functions used in ConstraintModel
         int row() const;
         int getRowCount() const;
 
         ConstraintNode* parent() const;
         bool addChild( ConstraintNode*, int );
         ConstraintNode* getChild( int );
         ConstraintNode* pruneChild( int );
         bool removeChild( int );
 
         virtual QString getName() const = 0;
         virtual int getNodeType() const = 0;
         virtual QWidget* editWidget() const = 0;
         virtual void toXml( QDomDocument&, QDomElement& ) const = 0;
 
         // Set up the initial query for the ConstraintSolver
         virtual Collections::QueryMaker* initQueryMaker( Collections::QueryMaker* qm ) const { return qm; }
 
         // Mathematical function called by the ConstraintSolver
         virtual double satisfaction( const Meta::TrackList& ) const = 0;
 
         // heuristic functions for the ConstraintSolver
         virtual quint32 suggestPlaylistSize() const;
 
     Q_SIGNALS:
         void dataChanged();
 
     protected:
         ConstraintNode(ConstraintNode* parent);
         int where_is(const ConstraintNode*) const;
 
         QList<ConstraintNode*> m_children;
 };
 
 #endif