private void changeDrawnSurfacesList(int currentY, boolean isAdd) { ArrayList<SurfaceEvent> events = listSurfacesEvents.getEvent(currentY); if (events == null) { return; } events .stream() .forEach( event -> { if (isAdd && event.isStart) { drawnSurfaces.add(event.surface); } else if (!isAdd && !event.isStart) { drawnSurfaces.remove(event.surface); } }); }