CODEWITHSUNDEEP
qtqgraphicsscene
Sid411
Sid411

Reputation: 703

Remove path from QGraphicsScene

I am drawing a polygon on qgraphicsscene using QPainterPath. However after sometime when I want to delete the path I am unable to delete it. Can someone tell me how to delete/erase the drawn path. I am trying the following code.

 In header File:

 QGraphicsScene *scene;
 QGraphicsPixmapItem *m_pixItem;
 QPainterPath m_pathTrack;
 QPolygon m_qpolygon;


 In cpp file

void MyClass::AddPath()
{
  //Slot to add path to the scene

 QImage l_img("Path");
 graphicsView->setScene(&scene);
 m_pixtemItem->setPixmap(QPixmap::fromImage(image));

 //Code here to Adding points to polygon. The points are coming at regular interval
 m_qpolygon.append(Point);

 m_pathTrack.addPolygon(m_qpolygon);
 scene.addPath(m_pathTrack);
}

// In slot to delete path

 void MyClass::DeletePath()
 {
    //I tried doing this but the path does not erase

    m_pathTrack = QPainterPath();
 }

Thank You.

Upvotes: 2

Views: 1962

Answers (2)

lovenjak
lovenjak

Reputation: 35

Remember to include the corresponding head file, QGraphicsItem. Or you will not able to call the function.

Upvotes: 0

epsilon
epsilon

Reputation: 2969

Just retain a pointer on QGraphicsPathItem create when adding your path

QGraphicsPathItem* pathItem = scene.addPath(m_pathTrack);

Then you will be able to remove it from scene:

scene->removeItem(pathItem);

EDIT (credits to thuga):

If you don't plan to put again this item in your scene, you can free its memory once you have removed it from the scene.

scene->removeItem(pathItem);
delete pathItem;

Upvotes: 3

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