Problem with 'm_backgroundColor' in a QGraphicsScene's subclass

Hi!

I'm trying to do a subclass of QGraphicsScene to draw a OpenGL scene into a QT's widget and when I compile this it give me the follow error:

'm_backgroundColor' was not declared in this scope

I am looking for the problem and I don't find it.
Please, I hope someone can help me.

I'm using KDevelop 3.5.10 and QT4
This is my code:

Code:

//************************ 
// openglscene.h 
//************************ 
#ifndef OPENGLSCENE_H 
#define OPENGLSCENE_H 
 
#include <QtCore/QString> 
#include <QtCore/QTimer> 
#include <QtGui/QKeyEvent> 
#include <QtGui/QApplication> 
#include <QtOpenGL/QGLWidget> 
#include <QtGui/QMainWindow> 
#include <QtGui/QMdiSubWindow> 
#include <QtGui/QMdiArea> 
#include <QGraphicsView> 
#include <QGraphicsScene> 
#include <QTextCursor> 
#include <QDialog> 
#include <QKeyEvent> 
#include <QFile> 
#include <QTextStream> 
#include <QMessageBox> 
#include <QMenu> 
#include <QTextDocumentFragment> 
#include <QScrollBar> 
#include <QPainter> 
#include <QDebug> 
#include <QListWidget> 
#include <QProcess> 
#include <QClipboard> 
#include <QFileInfo> 
#include <QPrintDialog> 
#include <QTime> 
#include <QTextLayout> 
#include <QTextCodec> 
#include <QDir> 
#include <QPaintEngine> 
#include <QColormap> 
#include <QtCore> 
#include <QtGui> 
#include <QtOpenGL> 
 
using namespace std; 
 
class OpenGLScene : public QGraphicsScene{	
   public: 
      OpenGLScene(); 
 
   protected: 
      void drawBackground ( QPainter *painter, const QRectF & ); 
}; 
#endif 
 
//************************ 
// openglscene.cpp 
//************************ 
#include "openglscene.h" 
 
OpenGLScene:penGLScene(){} 
 
void OpenGLScene::drawBackground ( QPainter *painter, const QRectF & ){ 
   if ( painter->paintEngine()->type() != QPaintEngine:penGL ){ 
      qWarning ( "OpenGLScene: drawBackground needs a QGLWidget to be set as viewport on the graphics view" ); 
      return; 
   } 
 
   glClearColor( m_backgroundColor.redF(), m_backgroundColor.greenF(), m_backgroundColor.blueF(), 1.0f ); 
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 
}