how to write QT openGL code in two classes

[qtUse]

I want to create large openGL models, so I want to divide it in multiple classes. For that, I wrote two classes,

///////////////////  glhandle.cpp ////////////////////////////////////////
 
#include "glhandle.h" //Contains defn of GLHandle class
#include "buildingpainter.h"
 
void  GLHandle::paintGL() {
//SOME DRAWING CODE HERE
BuildingPainter p=BuildingPainter p=BuildingPainter(this->context());
p.draw();
}
 
//ResizeGL(), initializeGL() and other functions

///////////////////  glhandle.cpp ////////////////////////////////////////

#include "glhandle.h" //Contains defn of GLHandle class
#include "buildingpainter.h"

void  GLHandle::paintGL() {
//SOME DRAWING CODE HERE
BuildingPainter p=BuildingPainter p=BuildingPainter(this->context());
p.draw();
}

//ResizeGL(), initializeGL() and other functions

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and

////////////////// BuildingPainter.cpp ///////////////////////////////
 
#include "buildingpainter.h" //Defn of BuildingPainter class
 
BuildingPainter::BuildingPainter(QWidget *parent) :
    QGLWidget(parent)  {
}
 
// This constructor is called: So that openGL states should be copied
BuildingPainter::BuildingPainter(const QGLContext *refs): QGLWidget(refs) {
}
 
void BuildingPainter::draw()    {
//More drawing Code here
}

////////////////// BuildingPainter.cpp ///////////////////////////////

#include "buildingpainter.h" //Defn of BuildingPainter class

BuildingPainter::BuildingPainter(QWidget *parent) :
    QGLWidget(parent)  {
}

// This constructor is called: So that openGL states should be copied
BuildingPainter::BuildingPainter(const QGLContext *refs): QGLWidget(refs) {
}

void BuildingPainter::draw()    {
//More drawing Code here
}

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However, I am getting compile error:
error: ‘QGLWidget::QGLWidget(const QGLWidget&)’ is private
in definition of BuildingPainter.

What is right way to do it so that I can render different parts of my model from different classes?