setViewportUpdateMode(QGraphicsView::BoundingRectViewportUpdate);
setTransformationAnchor(QGraphicsView::NoAnchor);
_scene = new ChatScene(filter, filter->idString(), viewport()->width() - 2, this); // see below: resizeEvent()
connect(_scene, SIGNAL(sceneRectChanged(const QRectF &)), this, SLOT(sceneRectChanged(const QRectF &)));
setViewportUpdateMode(QGraphicsView::BoundingRectViewportUpdate);
setTransformationAnchor(QGraphicsView::NoAnchor);
_scene = new ChatScene(filter, filter->idString(), viewport()->width() - 2, this); // see below: resizeEvent()
connect(_scene, SIGNAL(sceneRectChanged(const QRectF &)), this, SLOT(sceneRectChanged(const QRectF &)));