private float visibilityRatio = 1;
private Color backgroundColor = Color.WHITE;
private PreviewPreset currentPreset;
public PreviewModelImpl() {
nodeSupervisor = new NodeSupervisorImpl();
globalEdgeSupervisor = new GlobalEdgeSupervisorImpl();
selfLoopSupervisor = new SelfLoopSupervisorImpl();
uniEdgeSupervisor = new UnidirectionalEdgeSupervisorImpl();
biEdgeSupervisor = new BidirectionalEdgeSupervisorImpl();
undirectedEdgeSupervisor = new UndirectedEdgeSupervisorImpl();