File	Doc	Category	Size	Date	Package
DefaultTreeModel.java	API Doc	Java SE 5 API	24148	Fri Aug 26 14:58:20 BST 2005	javax.swing.tree

DefaultTreeModel

• java.lang.Object

Fields Summary
protected TreeNode	root Root of the tree.
protected EventListenerList	listenerList Listeners.
protected boolean	asksAllowsChildren Determines how the isLeaf method figures out if a node is a leaf node. If true, a node is a leaf node if it does not allow children. (If it allows children, it is not a leaf node, even if no children are present.) That lets you distinguish between folder nodes and file nodes in a file system, for example. If this value is false, then any node which has no children is a leaf node, and any node may acquire children.

Constructors Summary
public DefaultTreeModel(TreeNode root) Creates a tree in which any node can have children. param root a TreeNode object that is the root of the tree see #DefaultTreeModel(TreeNode, boolean) this(root, false);
public DefaultTreeModel(TreeNode root, boolean asksAllowsChildren) Creates a tree specifying whether any node can have children, or whether only certain nodes can have children. param root a TreeNode object that is the root of the tree param asksAllowsChildren a boolean, false if any node can have children, true if each node is asked to see if it can have children see #asksAllowsChildren super(); this.root = root; this.asksAllowsChildren = asksAllowsChildren;

Methods Summary
public void	addTreeModelListener(javax.swing.event.TreeModelListener l) Adds a listener for the TreeModelEvent posted after the tree changes. see #removeTreeModelListener param l the listener to add listenerList.add(TreeModelListener.class, l);
public boolean	asksAllowsChildren() Tells how leaf nodes are determined. return true if only nodes which do not allow children are leaf nodes, false if nodes which have no children (even if allowed) are leaf nodes see #asksAllowsChildren return asksAllowsChildren;
protected void	fireTreeNodesChanged(java.lang.Object source, java.lang.Object[] path, int[] childIndices, java.lang.Object[] children) Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the parameters passed into the fire method. param source the node being changed param path the path to the root node param childIndices the indices of the changed elements param children the changed elements see EventListenerList // Guaranteed to return a non-null array Object[] listeners = listenerList.getListenerList(); TreeModelEvent e = null; // Process the listeners last to first, notifying // those that are interested in this event for (int i = listeners.length-2; i>=0; i-=2) { if (listeners[i]==TreeModelListener.class) { // Lazily create the event: if (e == null) e = new TreeModelEvent(source, path, childIndices, children); ((TreeModelListener)listeners[i+1]).treeNodesChanged(e); } }
protected void	fireTreeNodesInserted(java.lang.Object source, java.lang.Object[] path, int[] childIndices, java.lang.Object[] children) Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the parameters passed into the fire method. param source the node where new elements are being inserted param path the path to the root node param childIndices the indices of the new elements param children the new elements see EventListenerList // Guaranteed to return a non-null array Object[] listeners = listenerList.getListenerList(); TreeModelEvent e = null; // Process the listeners last to first, notifying // those that are interested in this event for (int i = listeners.length-2; i>=0; i-=2) { if (listeners[i]==TreeModelListener.class) { // Lazily create the event: if (e == null) e = new TreeModelEvent(source, path, childIndices, children); ((TreeModelListener)listeners[i+1]).treeNodesInserted(e); } }
protected void	fireTreeNodesRemoved(java.lang.Object source, java.lang.Object[] path, int[] childIndices, java.lang.Object[] children) Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the parameters passed into the fire method. param source the node where elements are being removed param path the path to the root node param childIndices the indices of the removed elements param children the removed elements see EventListenerList // Guaranteed to return a non-null array Object[] listeners = listenerList.getListenerList(); TreeModelEvent e = null; // Process the listeners last to first, notifying // those that are interested in this event for (int i = listeners.length-2; i>=0; i-=2) { if (listeners[i]==TreeModelListener.class) { // Lazily create the event: if (e == null) e = new TreeModelEvent(source, path, childIndices, children); ((TreeModelListener)listeners[i+1]).treeNodesRemoved(e); } }
protected void	fireTreeStructureChanged(java.lang.Object source, java.lang.Object[] path, int[] childIndices, java.lang.Object[] children) Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the parameters passed into the fire method. param source the node where the tree model has changed param path the path to the root node param childIndices the indices of the affected elements param children the affected elements see EventListenerList // Guaranteed to return a non-null array Object[] listeners = listenerList.getListenerList(); TreeModelEvent e = null; // Process the listeners last to first, notifying // those that are interested in this event for (int i = listeners.length-2; i>=0; i-=2) { if (listeners[i]==TreeModelListener.class) { // Lazily create the event: if (e == null) e = new TreeModelEvent(source, path, childIndices, children); ((TreeModelListener)listeners[i+1]).treeStructureChanged(e); } }
private void	fireTreeStructureChanged(java.lang.Object source, javax.swing.tree.TreePath path) // Guaranteed to return a non-null array Object[] listeners = listenerList.getListenerList(); TreeModelEvent e = null; // Process the listeners last to first, notifying // those that are interested in this event for (int i = listeners.length-2; i>=0; i-=2) { if (listeners[i]==TreeModelListener.class) { // Lazily create the event: if (e == null) e = new TreeModelEvent(source, path); ((TreeModelListener)listeners[i+1]).treeStructureChanged(e); } }
public java.lang.Object	getChild(java.lang.Object parent, int index) Returns the child of parent at index index in the parent's child array. parent must be a node previously obtained from this data source. This should not return null if index is a valid index for parent (that is index >= 0 && index < getChildCount(parent)). param parent a node in the tree, obtained from this data source return the child of parent at index index return ((TreeNode)parent).getChildAt(index);
public int	getChildCount(java.lang.Object parent) Returns the number of children of parent. Returns 0 if the node is a leaf or if it has no children. parent must be a node previously obtained from this data source. param parent a node in the tree, obtained from this data source return the number of children of the node parent return ((TreeNode)parent).getChildCount();
public int	getIndexOfChild(java.lang.Object parent, java.lang.Object child) Returns the index of child in parent. If either the parent or child is null, returns -1. param parent a note in the tree, obtained from this data source param child the node we are interested in return the index of the child in the parent, or -1 if either the parent or the child is null if(parent == null || child == null) return -1; return ((TreeNode)parent).getIndex((TreeNode)child);
public T[]	getListeners(java.lang.Class listenerType) Returns an array of all the objects currently registered as FooListeners upon this model. FooListeners are registered using the addFooListener method. You can specify the listenerType argument with a class literal, such as FooListener.class. For example, you can query a DefaultTreeModel m for its tree model listeners with the following code: TreeModelListener[] tmls = (TreeModelListener[])(m.getListeners(TreeModelListener.class)); If no such listeners exist, this method returns an empty array. param listenerType the type of listeners requested; this parameter should specify an interface that descends from java.util.EventListener return an array of all objects registered as FooListeners on this component, or an empty array if no such listeners have been added exception ClassCastException if listenerType doesn't specify a class or interface that implements java.util.EventListener see #getTreeModelListeners since 1.3 return listenerList.getListeners(listenerType);
public javax.swing.tree.TreeNode[]	getPathToRoot(javax.swing.tree.TreeNode aNode) Builds the parents of node up to and including the root node, where the original node is the last element in the returned array. The length of the returned array gives the node's depth in the tree. param aNode the TreeNode to get the path for return getPathToRoot(aNode, 0);
protected javax.swing.tree.TreeNode[]	getPathToRoot(javax.swing.tree.TreeNode aNode, int depth) Builds the parents of node up to and including the root node, where the original node is the last element in the returned array. The length of the returned array gives the node's depth in the tree. param aNode the TreeNode to get the path for param depth an int giving the number of steps already taken towards the root (on recursive calls), used to size the returned array return an array of TreeNodes giving the path from the root to the specified node TreeNode[] retNodes; // This method recurses, traversing towards the root in order // size the array. On the way back, it fills in the nodes, // starting from the root and working back to the original node. /* Check for null, in case someone passed in a null node, or they passed in an element that isn't rooted at root. */ if(aNode == null) { if(depth == 0) return null; else retNodes = new TreeNode[depth]; } else { depth++; if(aNode == root) retNodes = new TreeNode[depth]; else retNodes = getPathToRoot(aNode.getParent(), depth); retNodes[retNodes.length - depth] = aNode; } return retNodes;
public java.lang.Object	getRoot() Returns the root of the tree. Returns null only if the tree has no nodes. return the root of the tree return root;
public javax.swing.event.TreeModelListener[]	getTreeModelListeners() Returns an array of all the tree model listeners registered on this model. return all of this model's TreeModelListeners or an empty array if no tree model listeners are currently registered see #addTreeModelListener see #removeTreeModelListener since 1.4 return (TreeModelListener[])listenerList.getListeners( TreeModelListener.class);
public void	insertNodeInto(javax.swing.tree.MutableTreeNode newChild, javax.swing.tree.MutableTreeNode parent, int index) Invoked this to insert newChild at location index in parents children. This will then message nodesWereInserted to create the appropriate event. This is the preferred way to add children as it will create the appropriate event. parent.insert(newChild, index); int[] newIndexs = new int[1]; newIndexs[0] = index; nodesWereInserted(parent, newIndexs);
public boolean	isLeaf(java.lang.Object node) Returns whether the specified node is a leaf node. The way the test is performed depends on the askAllowsChildren setting. param node the node to check return true if the node is a leaf node see #asksAllowsChildren see TreeModel#isLeaf if(asksAllowsChildren) return !((TreeNode)node).getAllowsChildren(); return ((TreeNode)node).isLeaf();
public void	nodeChanged(javax.swing.tree.TreeNode node) Invoke this method after you've changed how node is to be represented in the tree. if(listenerList != null && node != null) { TreeNode parent = node.getParent(); if(parent != null) { int anIndex = parent.getIndex(node); if(anIndex != -1) { int[] cIndexs = new int[1]; cIndexs[0] = anIndex; nodesChanged(parent, cIndexs); } } else if (node == getRoot()) { nodesChanged(node, null); } }
public void	nodeStructureChanged(javax.swing.tree.TreeNode node) Invoke this method if you've totally changed the children of node and its childrens children... This will post a treeStructureChanged event. if(node != null) { fireTreeStructureChanged(this, getPathToRoot(node), null, null); }
public void	nodesChanged(javax.swing.tree.TreeNode node, int[] childIndices) Invoke this method after you've changed how the children identified by childIndicies are to be represented in the tree. if(node != null) { if (childIndices != null) { int cCount = childIndices.length; if(cCount > 0) { Object[] cChildren = new Object[cCount]; for(int counter = 0; counter < cCount; counter++) cChildren[counter] = node.getChildAt (childIndices[counter]); fireTreeNodesChanged(this, getPathToRoot(node), childIndices, cChildren); } } else if (node == getRoot()) { fireTreeNodesChanged(this, getPathToRoot(node), null, null); } }
public void	nodesWereInserted(javax.swing.tree.TreeNode node, int[] childIndices) Invoke this method after you've inserted some TreeNodes into node. childIndices should be the index of the new elements and must be sorted in ascending order. if(listenerList != null && node != null && childIndices != null && childIndices.length > 0) { int cCount = childIndices.length; Object[] newChildren = new Object[cCount]; for(int counter = 0; counter < cCount; counter++) newChildren[counter] = node.getChildAt(childIndices[counter]); fireTreeNodesInserted(this, getPathToRoot(node), childIndices, newChildren); }
public void	nodesWereRemoved(javax.swing.tree.TreeNode node, int[] childIndices, java.lang.Object[] removedChildren) Invoke this method after you've removed some TreeNodes from node. childIndices should be the index of the removed elements and must be sorted in ascending order. And removedChildren should be the array of the children objects that were removed. if(node != null && childIndices != null) { fireTreeNodesRemoved(this, getPathToRoot(node), childIndices, removedChildren); }
private void	readObject(java.io.ObjectInputStream s) s.defaultReadObject(); Vector values = (Vector)s.readObject(); int indexCounter = 0; int maxCounter = values.size(); if(indexCounter < maxCounter && values.elementAt(indexCounter). equals("root")) { root = (TreeNode)values.elementAt(++indexCounter); indexCounter++; }
public void	reload() Invoke this method if you've modified the TreeNodes upon which this model depends. The model will notify all of its listeners that the model has changed. reload(root);
public void	reload(javax.swing.tree.TreeNode node) Invoke this method if you've modified the TreeNodes upon which this model depends. The model will notify all of its listeners that the model has changed below the node node (PENDING). if(node != null) { fireTreeStructureChanged(this, getPathToRoot(node), null, null); }
public void	removeNodeFromParent(javax.swing.tree.MutableTreeNode node) Message this to remove node from its parent. This will message nodesWereRemoved to create the appropriate event. This is the preferred way to remove a node as it handles the event creation for you. MutableTreeNode parent = (MutableTreeNode)node.getParent(); if(parent == null) throw new IllegalArgumentException("node does not have a parent."); int[] childIndex = new int[1]; Object[] removedArray = new Object[1]; childIndex[0] = parent.getIndex(node); parent.remove(childIndex[0]); removedArray[0] = node; nodesWereRemoved(parent, childIndex, removedArray);
public void	removeTreeModelListener(javax.swing.event.TreeModelListener l) Removes a listener previously added with addTreeModelListener(). see #addTreeModelListener param l the listener to remove listenerList.remove(TreeModelListener.class, l);
public void	setAsksAllowsChildren(boolean newValue) Sets whether or not to test leafness by asking getAllowsChildren() or isLeaf() to the TreeNodes. If newvalue is true, getAllowsChildren() is messaged, otherwise isLeaf() is messaged. asksAllowsChildren = newValue;
public void	setRoot(javax.swing.tree.TreeNode root) Sets the root to root. A null root implies the tree is to display nothing, and is legal. Object oldRoot = this.root; this.root = root; if (root == null && oldRoot != null) { fireTreeStructureChanged(this, null); } else { nodeStructureChanged(root); }
public void	valueForPathChanged(javax.swing.tree.TreePath path, java.lang.Object newValue) This sets the user object of the TreeNode identified by path and posts a node changed. If you use custom user objects in the TreeModel you're going to need to subclass this and set the user object of the changed node to something meaningful. MutableTreeNode aNode = (MutableTreeNode)path.getLastPathComponent(); aNode.setUserObject(newValue); nodeChanged(aNode);
private void	writeObject(java.io.ObjectOutputStream s) Vector values = new Vector(); s.defaultWriteObject(); // Save the root, if its Serializable. if(root != null && root instanceof Serializable) { values.addElement("root"); values.addElement(root); } s.writeObject(values);