Java Module java.desktop Package javax.swing.tree Class DefaultTreeModel（JDK11）

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("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.

  Parameters:

  newValue - if 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.

  Parameters:

  root - new value of tree root

• 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

  index - index of child to be returned

  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.

  Parameters:

  newChild - child node to be inserted

  parent - node to which children new node will be added

  index - index of parent's children

• 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 - the node to be removed from it's parrent

• nodeChanged

  public void nodeChanged​(TreeNode node)

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

  Parameters:

  node - the changed node

• 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.

  Parameters:

  node - parent node which children count been incremented

  childIndices - indexes of inserted children

• 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 - parent node which childred were removed

  childIndices - indexes of removed childs

  removedChildren - 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.

  Parameters:

  node - changed node

  childIndices - indexes of changed children

• 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.

  Parameters:

  node - changed node

• 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

  Returns:

  an array of TreeNodes giving the path from the root

• 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.

  Type Parameters:

  T - the listener type

  Parameters:

  listenerType - the type of listeners requested

  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()