Catching clicked signal on a QgsMapCanvas

I found the solution A lot of post on stackexchange showme the way to do that

Here a sample extract of the code in c++ :

//Declaration
CMyQgsMapCanvas     * mpMapCanvas;
QgsMapToolEmitPoint         * mpClickPoint;

mpMapCanvas = new CMyQgsMapCanvas( this, NULL);
mpMapCanvas->create();
mpMapCanvas->setProjection();

mpClickPoint = new QgsMapToolEmitPoint(mpMapCanvas);
mpMapCanvas->setMapTool(mpClickPoint);

connect(mpClickPoint ,SIGNAL(canvasClicked(QgsPoint,Qt::MouseButton)),this, SLOT(calcPoint(QgsPoint,Qt::MouseButton)));

// the slot
void MainWindow::calcPoint(QgsPoint pPoint,Qt::MouseButton pMouseBtn)
{
    qDebug() << "Mouse Click";
}

Now each you click on the canvas the slot was called. I think that mpClickPoint can be a QgsMapTool cause of inherit of classes