1  package hlt;
 2  
 3  import java.util.ArrayList;
 4  import java.util.Collection;
 5  
 6  public class Position {
 7      public final int x;
 8      public final int y;
 9  
10      public Position(final int x, final int y) {
11          this.x = x;
12          this.y = y;
13      }
14  
15      public Position directionalOffset(final Direction d) {
16          final int dx;
17          final int dy;
18  
19          switch (d) {
20              case NORTH:
21                  dx = 0;
22                  dy = -1;
23                  break;
24              case SOUTH:
25                  dx = 0;
26                  dy = 1;
27                  break;
28              case EAST:
29                  dx = 1;
30                  dy = 0;
31                  break;
32              case WEST:
33                  dx = -1;
34                  dy = 0;
35                  break;
36              case STILL:
37                  dx = 0;
38                  dy = 0;
39                  break;
40              default:
41                  throw new IllegalStateException("Unknown direction " + d);
42          }
43  
44          return new Position(x + dx, y + dy);
45      }
46  
47      /**
48       * Does not normalize the position
49       * @return The position at offset (dx, dy) from this position
50       */
51      public Position offset(final int dx, final int dy) {
52          return new Position(x + dx, y + dy);
53      }
54  
55      /**
56       * Does not normalize the position
57       * @return A collection of the 4 positions adjacent to this position
58       */
59      public Collection<Position> adjacentPositions(){
60          ArrayList<Position> surrounding = new ArrayList<>();
61          for (Direction d : Direction.ALL_CARDINALS){
62              surrounding.add(directionalOffset(d));
63          }
64          return surrounding;
65      }
66  
67      @Override
68      public boolean equals(Object o) {
69          if (this == o) return true;
70          if (o == null || getClass() != o.getClass()) return false;
71  
72          Position position = (Position) o;
73  
74          if (x != position.x) return false;
75          return y == position.y;
76      }
77  
78      @Override
79      public int hashCode() {
80          int result = x;
81          result = 31 * result + y;
82          return result;
83      }
84  
85      @Override
86      public String toString() {
87          return "(" + x + ", " + y + ")";
88      }
89  }