Merge pull request #5098 from kwvanderlinde/fixup/5089-selection-set-…

…robustness

Simplify SelectionSet null checks case work

src/main/java/net/rptools/maptool/client/ui/zone/RenderPathWorker.java

@@ -27,14 +27,14 @@ public class RenderPathWorker extends SwingWorker<Void, Void> {
   // private static final Logger log = LogManager.getLogger(RenderPathWorker.class);
 
   ZoneRenderer zoneRenderer;
-  ZoneWalker walker;
+  @Nonnull ZoneWalker walker;
   CellPoint startPoint, endPoint;
   private final boolean restrictMovement;
   private final Set<TerrainModifierOperation> terrainModifiersIgnored;
   private final @Nonnull Token keyToken;
 
   public RenderPathWorker(
-      ZoneWalker walker,
+      @Nonnull ZoneWalker walker,
       CellPoint endPoint,
       boolean restrictMovement,
       Set<TerrainModifierOperation> terrainModifiersIgnored,

src/main/java/net/rptools/maptool/client/ui/zone/renderer/SelectionSet.java

@@ -20,6 +20,7 @@
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 import net.rptools.maptool.client.MapTool;
 import net.rptools.maptool.client.ui.zone.RenderPathWorker;
 import net.rptools.maptool.client.walker.ZoneWalker;
@@ -31,12 +32,13 @@
 public class SelectionSet {
 
   private final ZoneRenderer renderer;
+  private final Grid grid;
   private final Logger log = LogManager.getLogger(SelectionSet.class);
 
   private final Set<GUID> selectionSet = new HashSet<GUID>();
   private final GUID keyToken;
   private final String playerId;
-  private ZoneWalker walker;
+  private @Nullable ZoneWalker walker;
   private final Token token;
 
   private Path<ZonePoint> gridlessPath;
@@ -69,12 +71,13 @@ public SelectionSet(
     startPoint = new ZonePoint(anchorPoint);
     currentPoint = new ZonePoint(anchorPoint);
 
-    if (token.isSnapToGrid() && renderer.zone.getGrid().getCapabilities().isSnapToGridSupported()) {
-      if (renderer.zone.getGrid().getCapabilities().isPathingSupported()) {
-        CellPoint tokenPoint = renderer.zone.getGrid().convert(currentPoint);
+    grid = renderer.getZone().getGrid();
+    if (token.isSnapToGrid() && grid.getCapabilities().isSnapToGridSupported()) {
+      if (grid.getCapabilities().isPathingSupported()) {
+        CellPoint tokenPoint = grid.convert(currentPoint);
 
-        walker = renderer.zone.getGrid().createZoneWalker();
-        walker.setFootprint(token.getFootprint(renderer.zone.getGrid()));
+        walker = grid.createZoneWalker();
+        walker.setFootprint(token.getFootprint(grid));
         walker.setWaypoints(tokenPoint, tokenPoint);
       }
     } else {
@@ -114,29 +117,32 @@ public boolean contains(Token token) {
 
   /** Aborts the movement for this selection. */
   public void cancel() {
-    walker.close();
+    if (walker != null) {
+      walker.close();
 
-    renderPathTask.cancel(true);
+      if (renderPathTask != null) {
+        renderPathTask.cancel(true);
+      }
+    }
   }
 
   // This is called when movement is committed/done. It'll let the last thread either finish or
   // timeout
   public void renderFinalPath() {
-    walker.close();
-
-    if (renderer.zone.getGrid().getCapabilities().isPathingSupported()
-        && token.isSnapToGrid()
-        && renderPathTask != null) {
-
-      log.trace("Waiting on Path Rendering... ");
-      while (true) {
-        try {
-          renderPathTask.get();
-          break;
-        } catch (InterruptedException e) {
-        } catch (ExecutionException e) {
-          log.error("Error while waiting for task to finish", e);
-          break;
+    if (walker != null) {
+      walker.close();
+
+      if (renderPathTask != null) {
+        log.trace("Waiting on Path Rendering... ");
+        while (true) {
+          try {
+            renderPathTask.get();
+            break;
+          } catch (InterruptedException e) {
+          } catch (ExecutionException e) {
+            log.error("Error while waiting for task to finish", e);
+            break;
+          }
         }
       }
     }
@@ -146,8 +152,8 @@ public void update(ZonePoint newAnchorPosition) {
     currentPoint.x = newAnchorPosition.x;
     currentPoint.y = newAnchorPosition.y;
 
-    if (renderer.zone.getGrid().getCapabilities().isPathingSupported() && token.isSnapToGrid()) {
-      CellPoint point = renderer.zone.getGrid().convert(currentPoint);
+    if (walker != null) {
+      CellPoint point = grid.convert(currentPoint);
       // walker.replaceLastWaypoint(point, restrictMovement); // OLD WAY
 
       // New way threaded, off the swing UI thread...
@@ -174,8 +180,8 @@ public void update(ZonePoint newAnchorPosition) {
    * @param location The point where the waypoint is toggled.
    */
   public void toggleWaypoint(ZonePoint location) {
-    if (walker != null && token.isSnapToGrid() && renderer.getZone().getGrid() != null) {
-      walker.toggleWaypoint(renderer.getZone().getGrid().convert(location));
+    if (walker != null) {
+      walker.toggleWaypoint(grid.convert(location));
     } else {
       gridlessPath.appendWaypoint(location);
     }
@@ -189,17 +195,14 @@ public void toggleWaypoint(ZonePoint location) {
    */
   public ZonePoint getLastWaypoint() {
     ZonePoint zp;
-    if (walker != null && token.isSnapToGrid() && renderer.getZone().getGrid() != null) {
+    if (walker != null) {
       CellPoint cp = walker.getLastPoint();
 
       if (cp == null) {
-        // log.info("cellpoint is null! FIXME! You have Walker class updating outside of
-        // thread..."); // Why not save last waypoint to this class?
-        cp = renderer.zone.getGrid().convert(token.getDragAnchor(renderer.zone));
-        // log.info("So I set it to: " + cp);
+        cp = grid.convert(token.getDragAnchor(renderer.zone));
       }
 
-      zp = renderer.getZone().getGrid().convert(cp);
+      zp = grid.convert(cp);
     } else {
       // Gridless path will never be empty if set.
       zp = gridlessPath.getWayPointList().getLast();