javax.swing.tree
class DefaultTreeModel

java.lang.Object javax.swing.tree.DefaultTreeModel

All Implemented Interfaces:

Serializable, TreeModel

Most common ways to construct:

DefaultMutableTreeNode root = …;

DefaultTreeModel model = new DefaultTreeModel(root);

Based on 25 examples

 

JTree tree = …;

DefaultTreeModel model = (DefaultTreeModel)tree.getModel();

Based on 18 examples

public class DefaultTreeModel
extends Object
implements Serializable, TreeModel

A simple tree data model that uses TreeNodes. For further information and examples that use DefaultTreeModel, see How to Use Trees in The Java Tutorial.

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeans^TM has been added to the java.beans package. Please see {@link java.beans.XMLEncoder}.

asksAllowsChildren

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.

listenerList

protected EventListenerList listenerList

Listeners.

root

protected TreeNode root

Root of the tree.

DefaultTreeModel

public DefaultTreeModel(TreeNode root)

Creates a tree in which any node can have children.

Parameters:

root - a TreeNode object that is the root of the tree

DefaultTreeModel

public DefaultTreeModel(TreeNode root,
                        boolean asksAllowsChildren)

Creates a tree specifying whether any node can have children, or whether only certain nodes can have children.

Parameters:

root - a TreeNode object that is the root of the tree

asksAllowsChildren - a boolean, false if any node can have children, true if each node is asked to see if it can have children

addTreeModelListener

public void addTreeModelListener(TreeModelListener l)

Adds a listener for the TreeModelEvent posted after the tree changes.

Parameters:

l - the listener to add

asksAllowsChildren

public boolean asksAllowsChildren()

Tells how leaf nodes are determined.

Returns:

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

fireTreeNodesChanged

protected void fireTreeNodesChanged(Object source,
                                    Object[] path,
                                    int[] childIndices,
                                    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.

Parameters:

source - the node being changed

path - the path to the root node

childIndices - the indices of the changed elements

children - the changed elements

fireTreeNodesInserted

protected void fireTreeNodesInserted(Object source,
                                     Object[] path,
                                     int[] childIndices,
                                     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.

Parameters:

source - the node where new elements are being inserted

path - the path to the root node

childIndices - the indices of the new elements

children - the new elements

fireTreeNodesRemoved

protected void fireTreeNodesRemoved(Object source,
                                    Object[] path,
                                    int[] childIndices,
                                    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.

Parameters:

source - the node where elements are being removed

path - the path to the root node

childIndices - the indices of the removed elements

children - the removed elements

fireTreeStructureChanged

protected void fireTreeStructureChanged(Object source,
                                        Object[] path,
                                        int[] childIndices,
                                        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.

Parameters:

source - the node where the tree model has changed

path - the path to the root node

childIndices - the indices of the affected elements

children - the affected elements

getChild

public Object getChild(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)).

Parameters:

parent - a node in the tree, obtained from this data source

index

Returns:

the child of parent at index index

getChildCount

public int getChildCount(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.

Parameters:

parent - a node in the tree, obtained from this data source

Returns:

the number of children of the node parent

getIndexOfChild

public int getIndexOfChild(Object parent,
                           Object child)

Returns the index of child in parent. If either the parent or child is null, returns -1.

Parameters:

parent - a note in the tree, obtained from this data source

child - the node we are interested in

Returns:

the index of the child in the parent, or -1 if either the parent or the child is null

getListeners

public EventListener[] getListeners(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.

Parameters:

listenerType - the type of listeners requested; this parameter should specify an interface that descends from java.util.EventListener

Returns:

an array of all objects registered as FooListeners on this component, or an empty array if no such listeners have been added

getPathToRoot

public TreeNode[] getPathToRoot(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.

Parameters:

aNode - the TreeNode to get the path for

getPathToRoot

protected TreeNode[] getPathToRoot(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.

Parameters:

aNode - the TreeNode to get the path for

depth - an int giving the number of steps already taken towards the root (on recursive calls), used to size the returned array

Returns:

an array of TreeNodes giving the path from the root to the specified node

getRoot

public Object getRoot()

Returns the root of the tree. Returns null only if the tree has no nodes.

Returns:

the root of the tree

getTreeModelListeners

public TreeModelListener[] getTreeModelListeners()

Returns an array of all the tree model listeners registered on this model.

Returns:

all of this model's TreeModelListeners or an empty array if no tree model listeners are currently registered

insertNodeInto

public void insertNodeInto(MutableTreeNode newChild,
                           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.

Parameters:

newChild

parent

index

isLeaf

public boolean isLeaf(Object node)

Returns whether the specified node is a leaf node. The way the test is performed depends on the askAllowsChildren setting.

Parameters:

node - the node to check

Returns:

true if the node is a leaf node

nodeChanged

public void nodeChanged(TreeNode node)

Invoke this method after you've changed how node is to be represented in the tree.

Parameters:

node

nodesChanged

public void nodesChanged(TreeNode node,
                         int[] childIndices)

Invoke this method after you've changed how the children identified by childIndicies are to be represented in the tree.

Parameters:

node

childIndices

nodeStructureChanged

public void nodeStructureChanged(TreeNode node)

Invoke this method if you've totally changed the children of node and its childrens children... This will post a treeStructureChanged event.

Parameters:

node

nodesWereInserted

public void nodesWereInserted(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.

Parameters:

node

childIndices

nodesWereRemoved

public void nodesWereRemoved(TreeNode node,
                             int[] childIndices,
                             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.

Parameters:

node

childIndices

removedChildren

reload

public void reload()

Invoke this method if you've modified the {@code TreeNode}s upon which this model depends. The model will notify all of its listeners that the model has changed.

reload

public void reload(TreeNode node)

Invoke this method if you've modified the {@code TreeNode}s upon which this model depends. The model will notify all of its listeners that the model has changed below the given node.

Parameters:

node - the node below which the model has changed

removeNodeFromParent

public void removeNodeFromParent(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.

Parameters:

node

removeTreeModelListener

public void removeTreeModelListener(TreeModelListener l)

Removes a listener previously added with addTreeModelListener().

Parameters:

l - the listener to remove

setAsksAllowsChildren

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.

Parameters:

newValue

setRoot

public void setRoot(TreeNode root)

Sets the root to root. A null root implies the tree is to display nothing, and is legal.

Parameters:

root

valueForPathChanged

public void valueForPathChanged(TreePath path,
                                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.

Parameters:

path

newValue