Class Topology

src/main/java/fieldbox/boxes/plugins/Topology.java:29–189

Adds: Hold down T to connect elements with other elements. The elements added are TopologyBox, which are subclasses of Box that have a default drawer that draws arcs between endpoints. This is more proof of concept that anything else. The interpretation of this "topology" is completely up to the

 * concept that anything else. The interpretation of this "topology" is completely up to the code in the boxes themselves.
 */
public class Topology extends Box implements Mouse.OnMouseDown {

	static public final Dict.Prop<FunctionOfBoxValued<BoxChildHelper>> outward = new Dict.Prop<FunctionOfBoxValued<BoxChildHelper>>("outward").doc("a collection of boxes that are the outward connections to this box")
																	.toCanon()
																	.type();
	static public final Dict.Prop<FunctionOfBoxValued<BoxChildHelper>> inward = new Dict.Prop<FunctionOfBoxValued<BoxChildHelper>>("inward").doc("a collection of boxes that are the inward connections to this box")
																      .toCanon()
																      .type();

	private final Box root;
	boolean on = false;

	public Topology(Box root) {
		this.root = root;
		this.properties.put(Planes.plane, "__always__");
		this.properties.putToMap(Mouse.onMouseDown, "__topology__", this);

		root.properties.put(outward, (box) -> {
			return new BoxChildHelper(box.children()
						  .stream()
						  .filter(x -> x.properties.has(TopologyBox.head))
						  .filter(x -> x.properties.get(TopologyBox.head)
									   .get(root) == box)
						  .map(x -> x.properties.get(TopologyBox.tail)
									.get(root))
						  .collect(Collectors.toCollection(() -> new LinkedHashSet<>())));
		});
		root.properties.put(inward, (box) -> {
			return new BoxChildHelper(box.children()
						  .stream()
						  .filter(x -> x.properties.has(TopologyBox.tail))
						  .filter(x -> x.properties.get(TopologyBox.tail)
									   .get(root) == box)
						  .map(x -> x.properties.get(TopologyBox.head)
									.get(root))
						  .collect(Collectors.toCollection(() -> new LinkedHashSet<>())));
		});
	}

	@Override
	public Mouse.Dragger onMouseDown(Window.Event<Window.MouseState> e, int button) {
		if (button == 0) return button0(e);
		return null;
	}

	protected Mouse.Dragger button0(Window.Event<Window.MouseState> e) {
		if (!e.after.keyboardState.keysDown.contains(GLFW_KEY_T)) return null;

		Optional<Drawing> drawing = this.find(Drawing.drawing, both())
						.findFirst();
		Vec2 point = new Vec2(e.after.mx, e.after.my);

		Optional<Box> hit = breadthFirst(both()).filter(b -> frame(b) != null)
							.filter(x -> !x.properties.isTrue(Box.hidden, false))
							.filter(b -> frame(b).intersects(point))
							.sorted((a, b) -> Float.compare(order(frame(a)), order(frame(b))))
							.findFirst();