public void setBuses(List<ProviderBusFigure> buses) {
		
		// remove old buses
		if (this.buses != null) {
			for (ProviderBusFigure bus : this.buses) {
				remove(bus);
			}
		}
		
		// add new buses
		this.buses = buses;
		for (ProviderBusFigure bus : this.buses) {
			add(bus);
		}
		
		repaint();
	}