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DefaultTreeModel.javaAPI DocJaudiotagger 2.0.424208Wed Mar 30 16:11:42 BST 2011org.jaudiotagger.utils.tree

DefaultTreeModel

public class DefaultTreeModel extends Object implements TreeModel, Serializable
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 JavaBeansTM has been added to the java.beans package. Please see {@link java.beans.XMLEncoder}.

version
1.58 03/23/10
author
Rob Davis
author
Ray Ryan
author
Scott Violet

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 voidaddTreeModelListener(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 booleanasksAllowsChildren()
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 voidfireTreeNodesChanged(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 voidfireTreeNodesInserted(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 voidfireTreeNodesRemoved(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 voidfireTreeStructureChanged(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 voidfireTreeStructureChanged(java.lang.Object source, 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.ObjectgetChild(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 intgetChildCount(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 intgetIndexOfChild(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 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.

param
aNode the TreeNode to get the path for

        return getPathToRoot(aNode, 0);
    
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.

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

return
the root of the tree

        return root;
    
public 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 voidinsertNodeInto(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.

        parent.insert(newChild, index);

        int[]           newIndexs = new int[1];

        newIndexs[0] = index;
        nodesWereInserted(parent, newIndexs);
    
public booleanisLeaf(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 voidnodeChanged(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 voidnodeStructureChanged(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 voidnodesChanged(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 voidnodesWereInserted(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 voidnodesWereRemoved(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 voidreadObject(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 voidreload()
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(root);
    
public voidreload(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.

param
node the node below which the model has changed

        if(node != null) {
            fireTreeStructureChanged(this, getPathToRoot(node), null, null);
        }
    
public voidremoveNodeFromParent(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 voidremoveTreeModelListener(TreeModelListener l)
Removes a listener previously added with addTreeModelListener().

see
#addTreeModelListener
param
l the listener to remove

        listenerList.remove(TreeModelListener.class, l);
    
public voidsetAsksAllowsChildren(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 voidsetRoot(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 voidvalueForPathChanged(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 voidwriteObject(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);