Implemented CartesianNodeComparator

drawio/src/main/java/org/nasdanika/drawio/comparators/CartesianNodeComparator.java

@@ -1,7 +1,8 @@
 package org.nasdanika.drawio.comparators;
 
 import java.util.Comparator;
-
+import java.util.Objects;
+import org.nasdanika.drawio.Rectangle;
 import org.nasdanika.drawio.Node;
 
 /**
@@ -10,12 +11,175 @@
  *
  */
 public class CartesianNodeComparator implements Comparator<Node> {
+
+	public enum Direction {
+		rightDown,
+		rightUp,
+		leftDown,
+		leftUp,
+		downRight,
+		downLeft,
+		upRight,
+		upLeft
+	}
+
+	private Direction direction;
+	private Comparator<? super Node> fallback;
+
+	public CartesianNodeComparator(Direction direction, Comparator<? super Node> fallback) {
+		this.direction = direction;
+		this.fallback = fallback;
+	}
 
 	// Modes - right-down, right-up, left-down, left-up, down-right, ... - 3 boolean flags, 8 combinations. enum?
 
 	@Override
 	public int compare(Node o1, Node o2) {
-		// TODO Auto-generated method stub
+		if (Objects.equals(o1, o2)) {
+			return 0;
+		}
+
+		if (o1 == null) {
+			return 1;
+		}
+
+		if (o2 == null) {
+			return -1;
+		}
+
+		if (!Objects.equals(o1.getModel().getPage(), o2.getModel().getPage())) {
+			throw new IllegalArgumentException("Nodes belong to different pages");
+		}		
+
+		switch (direction) {
+		case downLeft: {
+			// Horizontal first - to the left is smaller than to the right
+			int hcmp = compareHorizontal(o1, o2);
+			if (hcmp != 0) {
+				return hcmp;
+			}
+			// Vertical 
+			int vcmp = compareVertical(o1, o2);
+			return vcmp == 0 ? fallback.compare(o1, o2) : vcmp;
+		}
+		case downRight: {
+			// Horizontal first - to the left is smaller than to the right
+			int hcmp = compareHorizontal(o1, o2);
+			if (hcmp != 0) {
+				return -hcmp;
+			}
+			// Vertical 
+			int vcmp = compareVertical(o1, o2);
+			return vcmp == 0 ? fallback.compare(o1, o2) : vcmp;
+		}
+		case leftDown: {
+			// Vertical first - to the left is smaller than to the right
+			int vcmp = compareVertical(o1, o2);
+			if (vcmp != 0) {
+				return vcmp;
+			}
+			// Horizontal 
+			int hcmp = compareHorizontal(o1, o2);
+			return hcmp == 0 ? fallback.compare(o1, o2) : -hcmp;
+		}
+		case leftUp: {
+			// Vertical first - to the left is smaller than to the right
+			int vcmp = compareVertical(o1, o2);
+			if (vcmp != 0) {
+				return -vcmp;
+			}
+			// Horizontal 
+			int hcmp = compareHorizontal(o1, o2);
+			return hcmp == 0 ? fallback.compare(o1, o2) : -hcmp;
+		}
+		case rightUp: {
+			// Vertical first - to the left is smaller than to the right
+			int vcmp = compareVertical(o1, o2);
+			if (vcmp != 0) {
+				return -vcmp;
+			}
+			// Horizontal 
+			int hcmp = compareHorizontal(o1, o2);
+			return hcmp == 0 ? fallback.compare(o1, o2) : hcmp;
+		}
+		case rightDown: {
+			// Vertical first - to the left is smaller than to the right
+			int vcmp = compareVertical(o1, o2);
+			if (vcmp != 0) {
+				return vcmp;
+			}
+			// Horizontal 
+			int hcmp = compareHorizontal(o1, o2);
+			return hcmp == 0 ? fallback.compare(o1, o2) : hcmp;
+		}
+		case upLeft: {
+			// Horizontal first - to the left is smaller than to the right
+			int hcmp = compareHorizontal(o1, o2);
+			if (hcmp != 0) {
+				return -hcmp;
+			}
+			// Vertical 
+			int vcmp = compareVertical(o1, o2);
+			return vcmp == 0 ? fallback.compare(o1, o2) : -vcmp;
+		}
+		case upRight: {
+			// Horizontal first - to the left is smaller than to the right
+			int hcmp = compareHorizontal(o1, o2);
+			if (hcmp != 0) {
+				return -hcmp;
+			}
+			// Vertical 
+			int vcmp = compareVertical(o1, o2);
+			return vcmp == 0 ? fallback.compare(o1, o2) : vcmp;
+		}
+		default:
+			break;
+
+		}
+		return fallback.compare(o1, o2);
+	}
+
+	/**
+	 * Returns true if the second node is below the first node 
+	 * @param o1
+	 * @param o2
+	 */
+	private static boolean below(Node o1, Node o2) {
+//		System.out.println("Below: " + Jsoup.parse(o1.getLabel()).text() + " - " + Jsoup.parse(o2.getLabel()).text());
+
+		Rectangle g1 = AngularNodeComparator.getAbsoluteGeometry(o1);
+		return g1.getY() + g1.getHeight() < AngularNodeComparator.getAbsoluteGeometry(o2).getY();		
+	}	
+
+	/**
+	 * Returns true if the second node is below the first node 
+	 * @param o1
+	 * @param o2
+	 */
+	private static boolean after(Node o1, Node o2) {
+//		System.out.println("After " + Jsoup.parse(o1.getLabel()).text() + " - " + Jsoup.parse(o2.getLabel()).text());
+
+		Rectangle g1 = AngularNodeComparator.getAbsoluteGeometry(o1);
+		return g1.getX() + g1.getWidth() < AngularNodeComparator.getAbsoluteGeometry(o2).getX();		
+	}
+
+	protected int compareVertical(Node o1, Node o2) {
+		if (below(o1, o2)) {
+			return -1;
+		}
+		if (below(o2, o1)) {
+			return 1;
+		}
+		return 0;
+	}
+
+	protected int compareHorizontal(Node o1, Node o2) {
+		if (after(o1, o2)) {
+			return -1;
+		}
+		if (after(o2, o1)) {
+			return 1;
+		}
 		return 0;
 	}