Node.h

/*
 *   Copyright 2011, 2012 Lukas Jirkovsky
 *
 *   This file is part of FotoSHOCK.
 *
 *   FotoSHOCK 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, version 3 of the License.
 *
 *   FotoSHOCK 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 FotoSHOCK.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef NODE_H
#define NODE_H

#include "PixelData.hpp"

#include <QGraphicsItem>
#include <QFont>

class Edge;
class Node;
class FotoSHOCKOperation;
namespace FotoSHOCKcore {
    class ImageOperationDescriptor;
    class GraphManager;
    class GraphNode;
}

class Connector : public QGraphicsItem {
    public:
        enum Type {INPUT, OUTPUT};

        Connector(Node* parent, Type type, int ID);

        virtual void paint (QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget = 0);
        virtual QRectF boundingRect() const;
        
        virtual void mousePressEvent(QGraphicsSceneMouseEvent* event);
        virtual void dropEvent (QGraphicsSceneDragDropEvent* event);
        
        virtual void hoverEnterEvent(QGraphicsSceneHoverEvent* event);
        virtual void hoverLeaveEvent(QGraphicsSceneHoverEvent* event);

        Type connectorType() const;
        
        int ID() const;

        void addEdge(Edge* edge);
        void removeEdge();

        void updateEdges();
    private:
        // TODO: check: the edges may have to be freed manually
        QList<Edge*> m_edges;
        int m_ID;
        Type m_type;
        class EdgeMimeData;
};

// declare pointer to connecter as QMetaType
// this allows us to use such pointers in QVariant
Q_DECLARE_METATYPE(Connector*)

class Node : public QGraphicsItem {
    public:

        Node(QGraphicsScene* scene, FotoSHOCKcore::GraphManager* graph, FotoSHOCKcore::ImageOperationDescriptor* operationDescriptor);

        Node(QGraphicsScene* scene, FotoSHOCKcore::GraphManager* graph, FotoSHOCKcore::GraphNode* node);

        QGraphicsScene* parentScene() const;
        
        virtual void paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget = 0);
        // returns the bounding rectangle, if more accurate bounding shape was required,
        // it would be necessary to reimplement the shape() function
        virtual QRectF boundingRect() const;

        bool tryEnable();

        FotoSHOCKcore::GraphManager* GraphManager() const;
        FotoSHOCKcore::GraphNode* GraphNode() const;

        QVector<Connector*> inputConnectors() const;
        QVector<Connector*> outputConnectors() const;

        /*********
         * events
         *********/
        virtual void mouseDoubleClickEvent(QGraphicsSceneMouseEvent* event);

    protected:
        // updates position of connected edges when the node is moved
        virtual QVariant itemChange(GraphicsItemChange change, const QVariant& value);

        // pointer to the node after it has been constructed
        // it is freed automatically when the graphmanager is deleted
        // NOTE: what happens to m_node when Node is removed but GraphManager is still operational?
        FotoSHOCKcore::GraphNode* m_node;

        QVector<Connector*> m_inputs;
        QVector<Connector*> m_outputs;
    private:
        // name whose width fits into the widget
        QString m_shortName;
        // font used for labels
        QFont m_font;

        QGraphicsScene* m_parentScene;
        
        FotoSHOCKcore::GraphManager* m_graph;

        QRectF m_boundingRectangle;
        // position of the node
        QPointF m_position;
};

#endif // NODE_H