Error when promoting a custom widget

[engin]

hello,
i wrote a class that handles simple drawing actions

here is the header file

#ifndef PARENT_LINE
#define PARENT_LINE
 
#include <QFrame>
#include <QPainter>
#include <QMouseEvent>
 
class parentLine : public QFrame
{
	Q_OBJECT
 
public:
	parentLine(QWidget *parent = 0, Qt::WFlags flags = 0);
	~parentLine();
 
protected:	
	QPoint * tmpFirstPoint;
	bool isDrawing;
 
	void mouseMoveEvent(QMouseEvent *event);
	void mousePressEvent(QMouseEvent *event);
	void mouseReleaseEvent(QMouseEvent *event);
};
#endif

#ifndef PARENT_LINE
#define PARENT_LINE

#include <QFrame>
#include <QPainter>
#include <QMouseEvent>

class parentLine : public QFrame
{
	Q_OBJECT

public:
	parentLine(QWidget *parent = 0, Qt::WFlags flags = 0);
	~parentLine();

protected:	
	QPoint * tmpFirstPoint;
	bool isDrawing;

	void mouseMoveEvent(QMouseEvent *event);
	void mousePressEvent(QMouseEvent *event);
	void mouseReleaseEvent(QMouseEvent *event);
};
#endif

To copy to clipboard, switch view to plain text mode 

and cpp

#include "parentLine.h"
 
parentLine::parentLine(QWidget *parent, Qt::WFlags flags)
	: QFrame(parent, flags)
{
	setMouseTracking(true);	
	isDrawing = false;
	QPoint *tmpFirstPoint = new QPoint(0,0);
}
 
parentLine::~parentLine(){}
 
void parentLine::mouseMoveEvent(QMouseEvent *event){		
	if(isDrawing){
		QPainter painter(this);
		int x1 = tmpFirstPoint->x();
		int y1 = tmpFirstPoint->y();
		int x2 = event->pos().x();
		int y2 = event->pos().y();
		painter.drawLine(x1,y1,x2+5,y2+5);		
		isDrawing = true;
	}	
}
 
void parentLine::mousePressEvent(QMouseEvent *event)
{
	isDrawing = true;	
	tmpFirstPoint = new QPoint(event->pos().x(),event->pos().y());
}
 
void parentLine::mouseReleaseEvent(QMouseEvent *event)
{
	isDrawing = false;
	tmpFirstPoint = 0;
}

#include "parentLine.h"

parentLine::parentLine(QWidget *parent, Qt::WFlags flags)
	: QFrame(parent, flags)
{
	setMouseTracking(true);	
	isDrawing = false;
	QPoint *tmpFirstPoint = new QPoint(0,0);
}

parentLine::~parentLine(){}

void parentLine::mouseMoveEvent(QMouseEvent *event){		
	if(isDrawing){
		QPainter painter(this);
		int x1 = tmpFirstPoint->x();
		int y1 = tmpFirstPoint->y();
		int x2 = event->pos().x();
		int y2 = event->pos().y();
		painter.drawLine(x1,y1,x2+5,y2+5);		
		isDrawing = true;
	}	
}

void parentLine::mousePressEvent(QMouseEvent *event)
{
	isDrawing = true;	
	tmpFirstPoint = new QPoint(event->pos().x(),event->pos().y());
}

void parentLine::mouseReleaseEvent(QMouseEvent *event)
{
	isDrawing = false;
	tmpFirstPoint = 0;
}

To copy to clipboard, switch view to plain text mode 

when i try to promote this class to any widget the designer warns as "parentLine cannot be used as the class of the promoted widget, as a class of that name already exists and extends QWidget"
what i'm doing wrong?

promote-problem.jpg