fixes #4. Crashes when changed start without resetting.

Author: vmsaif

src/AStarSearch.java

@@ -9,17 +9,17 @@ public class AStarSearch extends JPanel {
     private Tile start;
     private Tile goal;
     private Ant ant;
-    private LinkedList<LinkedList<Tile>> allPath2D = new LinkedList<LinkedList<Tile>>();
+    private LinkedList<LinkedList<Tile>> allPath2D;
 
     public AStarSearch(Tile[][] tiles, Ant ant, Tile start, Tile goal) {
         this.tiles = tiles;
         this.start = start;
         this.goal = goal;
         this.ant = ant;
+        allPath2D = new LinkedList<LinkedList<Tile>>();
     }
 
     public LinkedList<Tile> search() {
-
         LinkedList<Tile> output = new LinkedList<>();
         LinkedList<Tile> closedSet = new LinkedList<>();
 
@@ -29,6 +29,8 @@ public LinkedList<Tile> search() {
         // add start to openSet
         openSet.add(start);
 
+        
+
         boolean foundGoal = false;
         boolean noPath = false;
 
@@ -106,7 +108,7 @@ public LinkedList<Tile> search() {
             } // end else(not goal)
 
             // if openSet is empty, then no path
-            if (openSet.size() == 0) {
+            if (openSet.size() == 0 && foundGoal == false) {
                 System.out.println("No path found");
                 noPath = true;
             }
@@ -178,6 +180,7 @@ public LinkedList<Tile> reconstructPath(Tile current) {
         LinkedList<Tile> path = new LinkedList<>();
         while (current != null) {
             path.add(current);
+            System.out.println(current);
 
             // move to the previous node
             current = current.getCameFrom();

src/Game.java

@@ -152,8 +152,6 @@ public Game(JFrame frame) {
         setTimerSolving();
     }
 
-
-
     private void resetButton() {
         JButton result = new JButton("Reset");
         result.addActionListener(new ActionListener() {
@@ -184,7 +182,6 @@ public void actionPerformed(ActionEvent e) {
                 setTimerMageCreation();
                 setTimerSolving();
                 repaint();
-
             }
         });
         buttonPanel.add(result);
@@ -257,25 +254,33 @@ public void actionPerformed(ActionEvent e) {
                 if (startTile == null) {
                     System.out.println("Please select start location");
                 }
+
                 if (goalTile == null) {
                     System.out.println("Please select goal location");
                 }
 
                 if (startTile != null && goalTile != null) {
+                    resetCameFrom(tiles); // useful if the user wants to search for the second time or more
                     ant = new Ant(startTile, goalTile, TILE_SIZE, tiles);
                     startClicked = true;
                     startTimeBeforeAnimation = System.currentTimeMillis();
                     ant.search();
                     delayPaint();
                 }
-                
-
             }
         });
         buttonPanel.add(result);
         return result;
     }
 
+    private void resetCameFrom(Tile[][] tiles) {
+        for (int i = 0; i < tiles.length; i++) {
+            for (int j = 0; j < tiles[i].length; j++) {
+                tiles[i][j].resetCameFrom();
+            }
+        }
+    }
+
     private void selectGoalLocation() {
         JButton result = new JButton("Goal Location");
         result.addActionListener(new ActionListener() {
@@ -342,6 +347,19 @@ private void handleStartLocationSelection(Tile clickedTile) {
         if(startTile != null){
             startTile.resetStart();
         }
+
+        startClicked = false;
+        startMovingAnt = false;
+        noPath = false;
+        ant = null;
+        tobeDrawn = new LinkedList<Tile>();
+
+        obstacleCount = 0;
+        swamplandCount = 0;
+        grasslandCount = 0;
+        openTerrainCount = 0;
+
+
         // Set the clicked tile as the start location
         clickedTile.setStart();
         startTile = clickedTile;

src/Tile.java

@@ -292,6 +292,10 @@ public void setCameFrom(Tile current) {
         cameFrom = current;
     }
 
+    public void resetCameFrom() {
+        cameFrom = null;
+    }
+
     public Tile getCameFrom() {
         return cameFrom;
     }