Added tree recursion stuff

src/main/java/net/vhati/modmanager/ui/tree/TreeState.java

@@ -1,6 +1,7 @@
 package net.vhati.modmanager.ui.tree;
 
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
 
 
@@ -10,7 +11,7 @@ import java.util.List;
  */
 public class TreeState {
 
-	protected TreeNodeState rootNodeState;
+	protected TreeNodeState rootNodeState = null;
 
 
 	public TreeState() {
@@ -26,39 +27,160 @@ public class TreeState {
 	}
 
 
+	public List<TreeNodeState> findNodeStates( TreeNodeStateFilter filter ) {
+		return findNodeStates( getRootNodeState(), filter );
+	}
+
+	/**
+	 * Returns a list of descendant node states which match a given filter.
+	 */
+	public List<TreeNodeState> findNodeStates( TreeNodeState currentNodeState, TreeNodeStateFilter filter ) {
+		List<TreeNodeState> results = new ArrayList<TreeNodeState>( 1 );
+		collectNodeStates( currentNodeState, filter, results );
+		return results;
+	}
+
+	public boolean collectNodeStates( TreeNodeState currentNodeState, TreeNodeStateFilter filter, List<TreeNodeState> results ) {
+		int maxResultCount = filter.getMaxResultCount();
+		boolean found = false;
+
+		if ( filter.accept( currentNodeState ) ) {
+			results.add( currentNodeState );
+			if ( maxResultCount > 0 && maxResultCount >= results.size() ) return true;
+		}
+
+		if ( currentNodeState.getAllowsChildren() ) {
+			for ( Iterator<TreeNodeState> it = currentNodeState.children(); it.hasNext(); ) {
+				TreeNodeState childNodeState = it.next();
+				found = collectNodeStates( childNodeState, filter, results );
+				if ( found && maxResultCount > 0 && maxResultCount >= results.size() ) return true;
+			}
+		}
+
+		return found;
+	}
+
+
+	public boolean containsUserObject( Object o ) {
+		UserObjectTreeNodeStateFilter filter = new UserObjectTreeNodeStateFilter( o );
+		filter.setMaxResultCount( 1 );
+		List<TreeNodeState> results = findNodeStates( filter );
+
+		return ( !results.isEmpty() );
+	}
+
+
+
+	public static interface TreeNodeStateFilter {
+		public int getMaxResultCount();
+		public boolean accept( TreeNodeState nodeState );
+	}
+
+
+
+	public static class UserObjectTreeNodeStateFilter implements TreeNodeStateFilter {
+
+		private Class objectClass = null;
+		private Object o = null;
+		private int maxResultCount = 0;
+
+
+		/**
+		 * Constructs a filter matching objects of a given class (or subclass).
+		 */
+		public UserObjectTreeNodeStateFilter( Class objectClass ) {
+			this.objectClass = objectClass;
+		}
+
+		/**
+		 * Constructs a filter matching objects equal to a given object.
+		 */
+		public UserObjectTreeNodeStateFilter( Object o ) {
+			this.o = o;
+		}
+
+
+		public void setMaxResultCount( int n ) { maxResultCount = n; }
+
+		@Override
+		public int getMaxResultCount() { return maxResultCount; }
+
+		@Override
+		public boolean accept( TreeNodeState nodeState ) {
+			Object nodeObject = nodeState.getUserObject();
+			if ( objectClass != null && nodeObject != null ) {
+				return ( objectClass.isAssignableFrom( nodeObject.getClass() ) );
+			}
+			else if ( o != null ) {
+				return ( o.equals( nodeState.getUserObject() ) );
+			}
+			return false;
+		}
+	}
+
 
 	public static class TreeNodeState {
-	
+
 		protected Object userObject = null;
 		protected boolean expand = false;
 		protected List<TreeNodeState> children = null;
-	
-	
+		private TreeNodeState parentNodeState = null;
+
+
 		public TreeNodeState() {
 			this( false, false );
 		}
-	
+
 		public TreeNodeState( boolean allowsChildren, boolean expand ) {
 			if ( allowsChildren ) {
 				this.expand = expand;
 				children = new ArrayList<TreeNodeState>();
 			}
 		}
-	
-	
+
+
+		/**
+		 * Sets this node's parent to newParent but does not change the
+		 * parent's child array.
+		 */
+		public void setParent( TreeNodeState nodeState ) {
+			parentNodeState = nodeState;
+		}
+
+		public TreeNodeState getParent() {
+			return parentNodeState;
+		}
+
+
 		public boolean getAllowsChildren() {
 			return ( children != null );
 		}
-	
-		public List<TreeNodeState> getChildren() {
-			return children;
+
+		public void addChild( TreeNodeState childNodeState ) {
+			TreeNodeState oldParent = childNodeState.getParent();
+			if ( oldParent != null ) oldParent.removeChild( childNodeState );
+
+			childNodeState.setParent( this );
+			children.add( childNodeState );
 		}
-	
-	
+
+		public void removeChild( TreeNodeState childNodeState ) {
+			children.remove( childNodeState );
+			childNodeState.setParent( null );
+		}
+
+		/**
+		 * Returns an iterator over this node state's children.
+		 */
+		public Iterator<TreeNodeState> children() {
+			return children.iterator();
+		}
+
+
 		public void setUserObject( Object userObject ) {
 			this.userObject = userObject;
 		}
-	
+
 		public Object getUserObject() {
 			return userObject;
 		}