graphicsview.h

#include"derived_nodes.h"
#include<QGraphicsView>
#include<QWheelEvent>
#include<QGraphicsSceneContextMenuEvent>
#include<QMenu>

class GraphicsView:public QGraphicsView{
    void wheelEvent(QWheelEvent *event){
        int delta=event->angleDelta().y();
        float factor=1.1;
        if(delta>0) scale(factor,factor);
        if(delta<0)scale(1/factor,1/factor);
    }
public:
    GraphicsView(QWidget*parent=NULL):QGraphicsView(parent){
        setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
        setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
        setDragMode(QGraphicsView::ScrollHandDrag);
        setRenderHint(QPainter::Antialiasing);
        setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
        setBackgroundBrush(QBrush(QColor(38,38,38)));
    }
};

class canvas:public QGraphicsItem{
    QGraphicsScene*scene;
    GraphicsView*gw;
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr){
        QPen pen(QColor(52,52,52));
        painter->setPen(pen);
        for(int y=-10000;y<=10000;y+=40){
            if(y%200==0){
                pen.setColor(QColor(22,22,22));
                painter->setPen(pen);
            }
            painter->drawLine(-10000,y,10000,y);
            if(y%200==0){
                pen.setColor(QColor(52,52,52));
                painter->setPen(pen);
            }
        }
        for(int x=-10000;x<=10000;x+=40){
            if(x%200==0){
                pen.setColor(QColor(22,22,22));
                painter->setPen(pen);
            }
            painter->drawLine(x,-10000,x,10000);
            if(x%200==0){
                pen.setColor(QColor(52,52,52));
                painter->setPen(pen);
            }
        }
        setZValue(-2);
    }
    void contextMenuEvent(QGraphicsSceneContextMenuEvent *event){
        node*&n=node::connection.first.first;
        QString&type=node::connection.first.second;
        QGraphicsPathItem*&path=node::connection.second;
        if(n!=NULL){
            scene->removeItem(path);
            delete path;
            path=NULL;
            if(type=="ci1" && n->getInput1()==NULL) n->getCI1()->setState(hoverExit);
            else if(type=="ci2" && n->getInput2()==NULL) n->getCI2()->setState(hoverExit);
            else if(type=="co" && n->getOutput()->empty()) n->getCO()->setState(hoverExit);
            type="";
            n=NULL;
            return;
        }

        QMenu menu;
        QMenu*newNode=menu.addMenu("New Node");
        QAction*newReadNode=newNode->addAction("Read Node");
        QAction*newViewerNode=newNode->addAction("Viewer Node");
        QAction*newWriteNode=newNode->addAction("Write Node");
        QAction*newGradeNode=newNode->addAction("Grade Node");
        QAction*newGammaNode=newNode->addAction("Gamma Node");
        QAction*newSaturateNode=newNode->addAction("Saturate Node");
        QAction*newContrastNode=newNode->addAction("Contrast Node");
        QAction*newBlurNode=newNode->addAction("Blur Node");
        QAction*newCropNode=newNode->addAction("Crop Node");
        QAction*newScaleNode=newNode->addAction("Scale Node");
        QAction*newRotateNode=newNode->addAction("Rotate Node");
        QAction*newMirrorNode=newNode->addAction("Mirror Node");
        QAction*newShuffleNode=newNode->addAction("Shuffle Node");
        QAction*centerView=menu.addAction("Center View");
        QAction*resetZoom=menu.addAction("Reset Zoom");
        QAction*current=menu.exec(event->screenPos());
        if(current==centerView){
            gw->centerOn(0,0);
        }
        if(current==resetZoom){
            gw->resetTransform();
        }
        if(current==newReadNode){
            readNode*n=new readNode(scene);
            n->setPos(event->scenePos());
        }
        if(current==newViewerNode){
            viewerNode*n=new viewerNode(scene);
            n->setPos(event->scenePos());
        }
        if(current==newBlurNode){
            blurNode*n=new blurNode(scene);
            n->setPos(event->scenePos());
        }
        if(current==newSaturateNode){
            saturateNode*n=new saturateNode(scene);
            n->setPos(event->scenePos());
        }
        if(current==newContrastNode){
            contrastNode*n=new contrastNode(scene);
            n->setPos(event->scenePos());
        }
        if(current==newGradeNode){
            gradeNode*n=new gradeNode(scene);
            n->setPos(event->scenePos());
        }
        if(current==newGammaNode){
            gammaNode*n=new gammaNode(scene);
            n->setPos(event->scenePos());
        }
        if(current==newMirrorNode){
            mirrorNode*n=new mirrorNode(scene);
            n->setPos(event->scenePos());
        }
        if(current==newRotateNode){
            rotateNode*n=new rotateNode(scene);
            n->setPos(event->scenePos());
        }
        if(current==newScaleNode){
            scaleNode*n=new scaleNode(scene);
            n->setPos(event->scenePos());
        }
        if(current==newCropNode){
            cropNode*n=new cropNode(scene);
            n->setPos(event->scenePos());
        }
        if(current==newWriteNode){
            writeNode*n=new writeNode(scene);
            n->setPos(event->scenePos());
        }
        if(current==newShuffleNode){
            shuffleNode*n=new shuffleNode(scene);
            n->setPos(event->scenePos());
        }
        delete newNode;
    };
    void hoverMoveEvent(QGraphicsSceneHoverEvent *event){
        pair<node*,QString>&p=node::connection.first;
        node*&n=p.first;
        QString&type=p.second;
        QGraphicsPathItem*&gpath=node::connection.second;
        if(n!=NULL){
            QPainterPath path;
            if(n->getIType()==oneInput){
                if(type=="ci1"){
                    path.moveTo(n->x()+n->getWidth()/2,n->y()+n->getCI1()->getHeight());
                    path.cubicTo(n->x()+n->getWidth()/2,n->y()+n->getCI1()->getHeight()-40,
                                 event->scenePos().x(),event->scenePos().y()+40,event->scenePos().x(),event->scenePos().y());
                }
            }else if(n->getIType()==twoInput){
                if(type=="ci1"){
                    path.moveTo(n->x()+n->getWidth()/4,n->y()+n->getCI1()->getHeight());
                    path.cubicTo(n->x()+n->getWidth()/4,n->y()+n->getCI1()->getHeight()-40,
                                 event->scenePos().x(),event->scenePos().y()+40,event->scenePos().x(),event->scenePos().y());
                }else if(type=="ci2"){
                    path.moveTo(n->x()+3*n->getWidth()/4,n->y()+n->getCI1()->getHeight());
                    path.cubicTo(n->x()+3*n->getWidth()/4,n->y()+n->getCI1()->getHeight()-40,
                                 event->scenePos().x(),event->scenePos().y()+40,event->scenePos().x(),event->scenePos().y());
                }
            }
            if(n->getOType()==oneOutput){
                if(type=="co"){
                    path.moveTo(n->x()+n->getWidth()/2,n->y()+n->getHeight()-n->getCO()->getHeight());
                    path.cubicTo(n->x()+n->getWidth()/2,n->y()+n->getHeight()-n->getCO()->getHeight()+40,
                                 event->scenePos().x(),event->scenePos().y()-40,event->scenePos().x(),event->scenePos().y());
                }
            }
            gpath->setPath(path);
        }
        QGraphicsItem::hoverMoveEvent(event);
    };
public:
    canvas(QGraphicsScene*scene,GraphicsView*gw):scene(scene),gw(gw){
        setCursor(Qt::ArrowCursor);
        scene->addItem(this);
        setAcceptHoverEvents(true);
    }
    QRectF boundingRect() const{
        return QRectF(-10000,-10000,20000,20000);
    };
};