echopoint.tree
Interface TreeModel

All Known Implementing Classes:

DefaultTreeModel

public interface TreeModel

The interface that defines a suitable data model for a Tree.

Method Summary

void	addTreeModelListener(TreeModelListener l) Adds a listener for the TreeModelEvent posted after the tree changes.
java.lang.Object	getChild(java.lang.Object parent, int index) Returns the child of parent at index index in the parent's child array.
int	getChildCount(java.lang.Object parent) Returns the number of children of parent.
java.lang.String	getIdString(java.lang.Object node) This returns a unique id string for the tree cell.
int	getIndexOfChild(java.lang.Object parent, java.lang.Object child) Returns the index of child in parent.
java.lang.Object	getParent(java.lang.Object child) Returns the parent of child.
java.lang.Object[]	getPathToRoot(java.lang.Object node) Builds the parents of node up to and including the root node, where the original node is the last element in the returned array.
java.lang.Object[]	getPathToRoot(java.lang.String idString) Builds the parents of node up to and including the root node, where the original node is the last element in the returned array.
java.lang.Object	getRoot() Returns the root of the tree.
boolean	isLeaf(java.lang.Object node) Returns true if node is a leaf.
void	removeTreeModelListener(TreeModelListener l) Removes a listener previously added with addTreeModelListener().
void	valueForPathChanged(TreePath path, java.lang.Object newValue) Messaged when the user has altered the value for the item identified by path to newValue.

Method Detail

addTreeModelListener

public void addTreeModelListener(TreeModelListener l)

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

Parameters:

l - the listener to add

getChild

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)).

Parameters:

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

Returns:

the child of parent at index index

getChildCount

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.

Parameters:

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

Returns:

the number of children of the node parent

getIdString

public java.lang.String getIdString(java.lang.Object node)

This returns a unique id string for the tree cell. If you do not have a handy unique value, then simply return System.identityHashCode(value);

Parameters:

node - a node in the tree

getIndexOfChild

public int getIndexOfChild(java.lang.Object parent,
                           java.lang.Object child)

Returns the index of child in parent.

getParent

public java.lang.Object getParent(java.lang.Object child)

Returns the parent of child. Returns null if the node has no parent or the tree model does not support traversing from a child to a parent node.

Parameters:

child - a node in the tree

Returns:

the parent of the node child

getPathToRoot

public java.lang.Object[] getPathToRoot(java.lang.Object node)

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:

node - the node to get the path for

getPathToRoot

public java.lang.Object[] getPathToRoot(java.lang.String idString)

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.

The idString value used depends on the what the TreeCellRenderer returns in its getIdString(Tree tree, Object value) method. If your TreeModel uses TreeNodes then this handled for you. If you build your own TreeModel (but not using TreeNode) then you will need to use the same idString value as the TreeCellRenderer generates. The default TreeCellRenderer generates System.identityHashCode(value) as a string.

Parameters:

idString - of the node to get the path for

getRoot

public java.lang.Object getRoot()

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

Returns:

the root of the tree

isLeaf

public boolean isLeaf(java.lang.Object node)

Returns true if node is a leaf. It is possible for this method to return false even if node has no children. A directory in a filesystem, for example, may contain no files; the node representing the directory is not a leaf, but it also has no children.

Parameters:

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

Returns:

true if node is a leaf

removeTreeModelListener

public void removeTreeModelListener(TreeModelListener l)

Removes a listener previously added with addTreeModelListener().

valueForPathChanged

public void valueForPathChanged(TreePath path,
                                java.lang.Object newValue)

Messaged when the user has altered the value for the item identified by path to newValue. If newValue signifies a truly new value the model should post a treeNodesChanged event.

Parameters:

path - path to the node that the user has altered.

newValue - the new value from the Tree.