made Spatial iterable

Author: codex128

jme3-core/src/main/java/com/jme3/scene/Geometry.java

@@ -49,6 +49,7 @@
 import com.jme3.util.clone.IdentityCloneFunction;
 import com.jme3.vulkan.material.NewMaterial;
 import com.jme3.vulkan.mesh.NewMesh;
+import com.jme3.vulkan.scene.NotSpatial;
 
 import java.io.IOException;
 import java.util.Queue;
@@ -781,4 +782,10 @@ public void read(JmeImporter im) throws IOException {
             }
         }
     }
+
+    @Override
+    protected void findNextIteration(GraphIterator iterator) {
+        iterator.moveUp();
+    }
+
 }

jme3-core/src/main/java/com/jme3/scene/Node.java

@@ -40,6 +40,8 @@
 import com.jme3.material.Material;
 import com.jme3.util.SafeArrayList;
 import com.jme3.util.clone.Cloner;
+import com.jme3.vulkan.material.NewMaterial;
+
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
@@ -561,7 +563,7 @@ public List<Spatial> getChildren() {
     }
 
     @Override
-    public void setMaterial(Material mat) {
+    public void setMaterial(NewMaterial mat) {
         for (int i = 0; i < children.size(); i++) {
             children.get(i).setMaterial(mat);
         }
@@ -813,4 +815,15 @@ public void depthFirstTraversal(SceneGraphVisitor visitor, DFSMode mode) {
     protected void breadthFirstTraversal(SceneGraphVisitor visitor, Queue<Spatial> queue) {
         queue.addAll(children);
     }
+
+    @Override
+    protected void findNextIteration(GraphIterator iterator) {
+        int i = iterator.advanceIndex();
+        if (i >= children.size()) {
+            iterator.moveUp();
+        } else {
+            iterator.moveDown(children.get(i));
+        }
+    }
+
 }

jme3-core/src/main/java/com/jme3/scene/Spatial.java

@@ -55,6 +55,7 @@
 import com.jme3.util.clone.IdentityCloneFunction;
 import com.jme3.util.clone.JmeCloneable;
 import com.jme3.vulkan.material.NewMaterial;
+import com.jme3.vulkan.scene.NotSpatial;
 
 import java.io.IOException;
 import java.util.*;
@@ -70,7 +71,7 @@
  * @author Joshua Slack
  * @version $Revision: 4075 $, $Data$
  */
-public abstract class Spatial implements Savable, Cloneable, Collidable,
+public abstract class Spatial implements Iterable<Spatial>, Savable, Cloneable, Collidable,
         CloneableSmartAsset, JmeCloneable, HasLocalTransform {
     private static final Logger logger = Logger.getLogger(Spatial.class.getName());
 
@@ -1876,4 +1877,88 @@ public void breadthFirstTraversal(SceneGraphVisitor visitor) {
     }
 
     protected abstract void breadthFirstTraversal(SceneGraphVisitor visitor, Queue<Spatial> queue);
+
+    protected abstract void findNextIteration(GraphIterator iterator);
+
+    @Override
+    public Iterator<Spatial> iterator() {
+        return new GraphIterator(this);
+    }
+
+    public static class GraphIterator implements Iterator<Spatial> {
+
+        private final Stack<Integer> childIndices = new Stack<>();
+        private Spatial current;
+        private int currentIndex = 0;
+        private int iteration = -1;
+
+        public GraphIterator(Spatial start) {
+            current = Objects.requireNonNull(start);
+        }
+
+        @Override
+        public boolean hasNext() {
+            return current != null;
+        }
+
+        @Override
+        public Spatial next() {
+            if (++iteration > 0) {
+                current.findNextIteration(this);
+            }
+            return current;
+        }
+
+        @Override
+        public void remove() {
+            if (current.getParent() != null) {
+                current.removeFromParent();
+                moveUp();
+                currentIndex--;
+            }
+        }
+
+        protected void moveUp() {
+            if (!childIndices.isEmpty()) {
+                current = current.getParent();
+                currentIndex = childIndices.pop();
+                if (current != null) {
+                    current.findNextIteration(this);
+                }
+            } else {
+                current = null;
+            }
+        }
+
+        protected void moveDown(Spatial node) {
+            if (node.getParent() != current) {
+                throw new IllegalArgumentException("Next node must be a child of the current node.");
+            }
+            current = node;
+            childIndices.push(currentIndex);
+            currentIndex = 0;
+        }
+
+        protected int advanceIndex() {
+            return currentIndex++;
+        }
+
+        protected int getCurrentIndex() {
+            return currentIndex;
+        }
+
+        public void skipChildren() {
+            moveUp();
+        }
+
+        public int getDepth() {
+            return childIndices.size();
+        }
+
+        public int getIteration() {
+            return iteration;
+        }
+
+    }
+
 }