basic model

app/src/main/java/chess/model/Move.java

@@ -0,0 +1,42 @@
+package chess.model;
+
+public class Move {
+	private final Coordinate start;
+	private final Coordinate finish;
+
+	public Move(Coordinate start, Coordinate finish) {
+		this.start = start;
+		this.finish = finish;
+	}
+
+	public boolean isValid() {
+		return this.start.isValid() && this.finish.isValid() && !this.start.equals(this.finish);
+	}
+
+	public Coordinate getStart() {
+		return start;
+	}
+
+	public Coordinate getFinish() {
+		return finish;
+	}
+
+	public int traversedCells() {
+		assert isValid() : "Move is invalid!";
+
+		int diffX = getFinish().getX() - getStart().getX();
+		int diffY = getFinish().getY() - getStart().getY();
+
+		assert Math.abs(diffX) < Coordinate.VALUE_MAX : "Move is too big!";
+		assert Math.abs(diffX) < Coordinate.VALUE_MAX : "Move is too big!";
+
+		if (diffX == 0)
+			return Math.abs(diffY);
+		if (diffY == 0)
+			return Math.abs(diffX);
+		if (Math.abs(diffX) == Math.abs(diffY))
+			return Math.abs(diffX);
+		return 0;
+	}
+
+}