DefaultTreeModel

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

All Implemented Interfaces:

Serializable, TreeModel
```
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™ has been added to the java.beans package. Please see XMLEncoder.

Field Summary

Fields

Modifier and Type	Field and Description
`protected boolean`	`asksAllowsChildren` Determines how the `isLeaf` method figures out if a node is a leaf node.
`protected EventListenerList`	`listenerList` Listeners.
`protected TreeNode`	`root` Root of the tree.

Constructor Summary

Constructors

Constructor and Description
`DefaultTreeModel(TreeNode root)` Creates a tree in which any node can have children.
`DefaultTreeModel(TreeNode root, boolean asksAllowsChildren)` Creates a tree specifying whether any node can have children, or whether only certain nodes can have children.

Method Summary

All Methods

Instance Methods

Concrete Methods
Modifier and Type	Method and Description
`void`	`addTreeModelListener(TreeModelListener l)` Adds a listener for the TreeModelEvent posted after the tree changes.
`boolean`	`asksAllowsChildren()` Tells how leaf nodes are determined.
`protected void`	`fireTreeNodesChanged(Object source, Object[] path, int[] childIndices, Object[] children)` Notifies all listeners that have registered interest for notification on this event type.
`protected void`	`fireTreeNodesInserted(Object source, Object[] path, int[] childIndices, Object[] children)` Notifies all listeners that have registered interest for notification on this event type.
`protected void`	`fireTreeNodesRemoved(Object source, Object[] path, int[] childIndices, Object[] children)` Notifies all listeners that have registered interest for notification on this event type.
`protected void`	`fireTreeStructureChanged(Object source, Object[] path, int[] childIndices, Object[] children)` Notifies all listeners that have registered interest for notification on this event type.
`Object`	`getChild(Object parent, int index)` Returns the child of parent at index index in the parent's child array.
`int`	`getChildCount(Object parent)` Returns the number of children of parent.
`int`	`getIndexOfChild(Object parent, Object child)` Returns the index of child in parent.
`<T extends EventListener> T[]`	`getListeners(Class<T> listenerType)` Returns an array of all the objects currently registered as `FooListener`s upon this model.
`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.
`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.
`Object`	`getRoot()` Returns the root of the tree.
`TreeModelListener[]`	`getTreeModelListeners()` Returns an array of all the tree model listeners registered on this model.
`void`	`insertNodeInto(MutableTreeNode newChild, MutableTreeNode parent, int index)` Invoked this to insert newChild at location index in parents children.
`boolean`	`isLeaf(Object node)` Returns whether the specified node is a leaf node.
`void`	`nodeChanged(TreeNode node)` Invoke this method after you've changed how node is to be represented in the tree.
`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.
`void`	`nodeStructureChanged(TreeNode node)` Invoke this method if you've totally changed the children of node and its children's children...
`void`	`nodesWereInserted(TreeNode node, int[] childIndices)` Invoke this method after you've inserted some TreeNodes into node.
`void`	`nodesWereRemoved(TreeNode node, int[] childIndices, Object[] removedChildren)` Invoke this method after you've removed some TreeNodes from node.
`void`	`reload()` Invoke this method if you've modified the `TreeNode`s upon which this model depends.
`void`	`reload(TreeNode node)` Invoke this method if you've modified the `TreeNode`s upon which this model depends.
`void`	`removeNodeFromParent(MutableTreeNode node)` Message this to remove node from its parent.
`void`	`removeTreeModelListener(TreeModelListener l)` Removes a listener previously added with addTreeModelListener().
`void`	`setAsksAllowsChildren(boolean newValue)` Sets whether or not to test leafness by asking getAllowsChildren() or isLeaf() to the TreeNodes.
`void`	`setRoot(TreeNode root)` Sets the root to `root`.
`void`	`valueForPathChanged(TreePath path, Object newValue)` This sets the user object of the TreeNode identified by path and posts a node changed.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - root
```
protected TreeNode root
```
    Root of the tree.
  - listenerList
```
protected EventListenerList listenerList
```
    Listeners.
  - 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.
    
    See Also:
    
    TreeNode.getAllowsChildren(), TreeModel.isLeaf(java.lang.Object), setAsksAllowsChildren(boolean)
- Constructor Detail
  - DefaultTreeModel
```
@ConstructorProperties(value="root")
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
    
    See Also:
    
    DefaultTreeModel(TreeNode, boolean)
  - 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
    
    See Also:
    
    asksAllowsChildren
- Method Detail
  - 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.
  - 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
    
    See Also:
    
    asksAllowsChildren
  - setRoot
```
public void setRoot(TreeNode root)
```
    Sets the root to root. A null root implies the tree is to display nothing, and is legal.
  - getRoot
```
public Object getRoot()
```
    Returns the root of the tree. Returns null only if the tree has no nodes.
    
    Specified by:
    
    getRoot in interface TreeModel
    
    Returns:
    
    the root of the tree
  - 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.
    
    Specified by:
    
    getIndexOfChild in interface TreeModel
    
    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
  - 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)).
    
    Specified by:
    
    getChild in interface TreeModel
    
    Parameters:
    
    parent - a node in the tree, obtained from this data source
    
    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.
    
    Specified by:
    
    getChildCount in interface TreeModel
    
    Parameters:
    
    parent - a node in the tree, obtained from this data source
    
    Returns:
    
    the number of children of the node parent
  - 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.
    
    Specified by:
    
    isLeaf in interface TreeModel
    
    Parameters:
    
    node - the node to check
    
    Returns:
    
    true if the node is a leaf node
    
    See Also:
    
    asksAllowsChildren, TreeModel.isLeaf(java.lang.Object)
  - reload
```
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.
  - 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.
    
    Specified by:
    
    valueForPathChanged in interface TreeModel
    
    Parameters:
    
    path - path to the node that the user has altered
    
    newValue - the new value from the TreeCellEditor
  - 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.
  - 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.
  - nodeChanged
```
public void nodeChanged(TreeNode node)
```
    Invoke this method after you've changed how node is to be represented in the tree.
  - reload
```
public void reload(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 given node.
    
    Parameters:
    
    node - the node below which the model has changed
  - 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.
  - 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.
  - 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.
  - nodeStructureChanged
```
public void nodeStructureChanged(TreeNode node)
```
    Invoke this method if you've totally changed the children of node and its children's children... This will post a treeStructureChanged event.
  - 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
  - addTreeModelListener
```
public void addTreeModelListener(TreeModelListener l)
```
    Adds a listener for the TreeModelEvent posted after the tree changes.
    
    Specified by:
    
    addTreeModelListener in interface TreeModel
    
    Parameters:
    
    l - the listener to add
    
    See Also:
    
    removeTreeModelListener(javax.swing.event.TreeModelListener)
  - removeTreeModelListener
```
public void removeTreeModelListener(TreeModelListener l)
```
    Removes a listener previously added with addTreeModelListener().
    
    Specified by:
    
    removeTreeModelListener in interface TreeModel
    
    Parameters:
    
    l - the listener to remove
    
    See Also:
    
    addTreeModelListener(javax.swing.event.TreeModelListener)
  - 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
    
    Since:
    
    1.4
    
    See Also:
    
    addTreeModelListener(javax.swing.event.TreeModelListener), removeTreeModelListener(javax.swing.event.TreeModelListener)
  - 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 source of the TreeModelEvent; typically this
    
    path - the path to the parent of the nodes that changed; use null to identify the root has changed
    
    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 source of the TreeModelEvent; typically this
    
    path - the path to the parent the nodes were added to
    
    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 source of the TreeModelEvent; typically this
    
    path - the path to the parent the nodes were removed from
    
    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 source of the TreeModelEvent; typically this
    
    path - the path to the parent of the structure that has changed; use null to identify the root has changed
    
    childIndices - the indices of the affected elements
    
    children - the affected elements
  - getListeners
```
public <T extends EventListener> T[] getListeners(Class<T> 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
    
    Throws:
    
    ClassCastException - if listenerType doesn't specify a class or interface that implements java.util.EventListener
    
    Since:
    
    1.3
    
    See Also:
    
    getTreeModelListeners()

Class DefaultTreeModel

Field Summary

Fields

Constructor Summary

Constructors

Method Summary

Methods inherited from class java.lang.Object

Field Detail

root

listenerList

asksAllowsChildren

Constructor Detail

DefaultTreeModel

DefaultTreeModel

Method Detail

setAsksAllowsChildren

asksAllowsChildren

setRoot

getRoot

getIndexOfChild

getChild

getChildCount

isLeaf

reload

valueForPathChanged

insertNodeInto

removeNodeFromParent

nodeChanged

reload

nodesWereInserted

nodesWereRemoved

nodesChanged

nodeStructureChanged

getPathToRoot

getPathToRoot

addTreeModelListener

removeTreeModelListener

getTreeModelListeners

fireTreeNodesChanged

fireTreeNodesInserted

fireTreeNodesRemoved

fireTreeStructureChanged

getListeners