refactoring, deploy Position and XYGridIterator

- try to use more Position instead of (x,y)
  - create PositionWithDpeth for its specific usage in path finding
- create a XYGridITerator that walk cells from grid X then Y.

java/org/artisanlogiciel/games/maze/Position.java

@@ -4,22 +4,20 @@ package org.artisanlogiciel.games.maze;
 public class Position
 {
     private int x, y;
-    private int depth;
-
-    public Position(int x, int y, int depth)
-    {
-        this.x = x;
-        this.y = y;
-        this.depth = depth;
-    }
 
     public Position(int x, int y)
     {
         this.x = x;
         this.y = y;
-        this.depth = 0;
     }
 
+    public Position(Position other)
+    {
+        this.x = other.x;
+        this.y = other.y;
+    }
+
+
     public int getX()
     {
         return this.x;
@@ -30,29 +28,58 @@ public class Position
         return this.y;
     }
 
-    public int getDepth()
-    {
-        return depth;
+    public Position translate(Position other) {
+        return new Position(x + other.x, y + other.y);
     }
 
+    public Position doTranslate(Position other) {
+        x += other.x;
+        y += other.y;
+        return this;
+    }
+
+
+    public void limitToMax(int mx, int my)
+    {
+        x = Math.min(x,mx);
+        y = Math.min(y,my);
+    }
+
+    public void limitToMin(int mx, int my)
+    {
+        x = Math.max(x,mx);
+        y = Math.max(y,my);
+    }
+
+    public Position setX(int x)
+    {
+        this.x = x;
+        return this;
+    }
+
+    public Position setY(int y)
+    {
+        this.y = y;
+        return this;
+    }
+
+
     public String toString()
     {
-        return "(" + x + "," + y + ")" + "/" + depth;
+        return "(" + x + "," + y + ")";
     }
 
     public boolean equals(Object other)
     {
-	// disregards depth
-	if (other instanceof Position )
-	    {
-		Position p = (Position) other;
-		return (p.getX() == x) && (p.getY() == y);
-	    }
-	else
-	    {
-		return false;
-	    }
-		
-		
+        // disregards depth
+        if (other instanceof Position )
+            {
+            Position p = (Position) other;
+            return (p.getX() == x) && (p.getY() == y);
+            }
+        else
+            {
+            return false;
+            }
     }
 }