@Override
	public void locationFocusChanged(AttributedVertex vertex) {
		Address address = getAddress(vertex);
		if (address != null) {
			ProgramLocation location = new ProgramLocation(program, address);
			tool.firePluginEvent(new ProgramLocationPluginEvent(name, location, program));
		}
	}
Base class for GraphDisplay listeners whose nodes represent addresses.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/graph/AddressBasedGraphDisplayListener.java