javax.swing
Class JTree

java.lang.Object
  java.awt.Component
      java.awt.Container
          javax.swing.JComponent
              javax.swing.JTree

All Implemented Interfaces:

ImageObserver, MenuContainer, Serializable, Accessible, Scrollable

public class JTree
extends JComponent
implements Scrollable, Accessible

A control that displays a set of hierarchical data as an outline. You can find task-oriented documentation and examples of using trees in How to Use Trees, a section in The Java Tutorial.

A specific node in a tree can be identified either by a TreePath (an object that encapsulates a node and all of its ancestors), or by its display row, where each row in the display area displays one node. An expanded node is a non-leaf node (as identified by TreeModel.isLeaf(node) returning false) that will displays its children when all its ancestors are expanded. A collapsed node is one which hides them. A hidden node is one which is under a collapsed ancestor. All of a viewable nodes parents are expanded, but may or may not be displayed. A displayed node is both viewable and in the display area, where it can be seen.

The following JTree methods use "visible" to mean "displayed":

• isRootVisible()
• setRootVisible()
• scrollPathToVisible()
• scrollRowToVisible()
• getVisibleRowCount()
• setVisibleRowCount()

The next group of JTree methods use "visible" to mean "viewable" (under an expanded parent):

• isVisible()
• makeVisible()

If you are interested in knowing when the selection changes implement the TreeSelectionListener interface and add the instance using the method addTreeSelectionListener. valueChanged will be invoked when the selection changes, that is if the user clicks twice on the same node valueChanged will only be invoked once.

If you are interested in detecting either double-click events or when a user clicks on a node, regardless of whether or not it was selected, we recommend you do the following:

 final JTree tree = ...;

 MouseListener ml = new MouseAdapter() {
     public void mousePressed(MouseEvent e) {
         int selRow = tree.getRowForLocation(e.getX(), e.getY());
         TreePath selPath = tree.getPathForLocation(e.getX(), e.getY());
         if(selRow != -1) {
             if(e.getClickCount() == 1) {
                 mySingleClick(selRow, selPath);
             }
             else if(e.getClickCount() == 2) {
                 myDoubleClick(selRow, selPath);
             }
         }
     }
 };
 tree.addMouseListener(ml);
 

To use JTree to display compound nodes (for example, nodes containing both a graphic icon and text), subclass TreeCellRenderer and use setCellRenderer(javax.swing.tree.TreeCellRenderer) to tell the tree to use it. To edit such nodes, subclass TreeCellEditor and use setCellEditor(javax.swing.tree.TreeCellEditor).

Like all JComponent classes, you can use InputMap and ActionMap to associate an Action object with a KeyStroke and execute the action under specified conditions.

Warning: Swing is not thread safe. For more information see Swing's Threading Policy.

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 XMLEncoder.

Nested Class Summary
protected  class	JTree.AccessibleJTree           This class implements accessibility support for the JTree class.
static class	JTree.DropLocation           A subclass of TransferHandler.DropLocation representing a drop location for a JTree.
static class	JTree.DynamicUtilTreeNode           DynamicUtilTreeNode can wrap vectors/hashtables/arrays/strings and create the appropriate children tree nodes as necessary.
protected static class	JTree.EmptySelectionModel           EmptySelectionModel is a TreeSelectionModel that does not allow anything to be selected.
protected  class	JTree.TreeModelHandler           Listens to the model and updates the expandedState accordingly when nodes are removed, or changed.
protected  class	JTree.TreeSelectionRedirector           Handles creating a new TreeSelectionEvent with the JTree as the source and passing it off to all the listeners.

 

Nested classes/interfaces inherited from class javax.swing.JComponent
JComponent.AccessibleJComponent

 

Nested classes/interfaces inherited from class java.awt.Container
Container.AccessibleAWTContainer

 

Nested classes/interfaces inherited from class java.awt.Component
Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy

 

Field Summary
static String	ANCHOR_SELECTION_PATH_PROPERTY           Bound property name for anchor selection path.
static String	CELL_EDITOR_PROPERTY           Bound property name for cellEditor.
static String	CELL_RENDERER_PROPERTY           Bound property name for cellRenderer.
protected  TreeCellEditor	cellEditor           Editor for the entries.
protected  TreeCellRenderer	cellRenderer           The cell used to draw nodes.
protected  boolean	editable           Is the tree editable? Default is false.
static String	EDITABLE_PROPERTY           Bound property name for editable.
static String	EXPANDS_SELECTED_PATHS_PROPERTY           Bound property name for expands selected paths property
static String	INVOKES_STOP_CELL_EDITING_PROPERTY           Bound property name for messagesStopCellEditing.
protected  boolean	invokesStopCellEditing           If true, when editing is to be stopped by way of selection changing, data in tree changing or other means stopCellEditing is invoked, and changes are saved.
static String	LARGE_MODEL_PROPERTY           Bound property name for largeModel.
protected  boolean	largeModel           Is this tree a large model? This is a code-optimization setting.
static String	LEAD_SELECTION_PATH_PROPERTY           Bound property name for leadSelectionPath.
static String	ROOT_VISIBLE_PROPERTY           Bound property name for rootVisible.
protected  boolean	rootVisible           True if the root node is displayed, false if its children are the highest visible nodes.
static String	ROW_HEIGHT_PROPERTY           Bound property name for rowHeight.
protected  int	rowHeight           Height to use for each display row.
static String	SCROLLS_ON_EXPAND_PROPERTY           Bound property name for scrollsOnExpand.
protected  boolean	scrollsOnExpand           If true, when a node is expanded, as many of the descendants are scrolled to be visible.
static String	SELECTION_MODEL_PROPERTY           Bound property name for selectionModel.
protected  TreeSelectionModel	selectionModel           Models the set of selected nodes in this tree.
protected  JTree.TreeSelectionRedirector	selectionRedirector           Creates a new event and passed it off the selectionListeners.
static String	SHOWS_ROOT_HANDLES_PROPERTY           Bound property name for showsRootHandles.
protected  boolean	showsRootHandles           True if handles are displayed at the topmost level of the tree.
static String	TOGGLE_CLICK_COUNT_PROPERTY           Bound property name for toggleClickCount.
protected  int	toggleClickCount           Number of mouse clicks before a node is expanded.
static String	TREE_MODEL_PROPERTY           Bound property name for treeModel.
protected  TreeModel	treeModel           The model that defines the tree displayed by this object.
protected  TreeModelListener	treeModelListener           Updates the expandedState.
static String	VISIBLE_ROW_COUNT_PROPERTY           Bound property name for visibleRowCount.
protected  int	visibleRowCount           Number of rows to make visible at one time.

 

Fields inherited from class javax.swing.JComponent
accessibleContext, listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW

 

Fields inherited from class java.awt.Component
BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

 

Fields inherited from interface java.awt.image.ImageObserver
ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

 

Constructor Summary
JTree()           Returns a JTree with a sample model.
JTree(Hashtable<?,?> value)           Returns a JTree created from a Hashtable which does not display with root.
JTree(Object[] value)           Returns a JTree with each element of the specified array as the child of a new root node which is not displayed.
JTree(TreeModel newModel)           Returns an instance of JTree which displays the root node -- the tree is created using the specified data model.
JTree(TreeNode root)           Returns a JTree with the specified TreeNode as its root, which displays the root node.
JTree(TreeNode root, boolean asksAllowsChildren)           Returns a JTree with the specified TreeNode as its root, which displays the root node and which decides whether a node is a leaf node in the specified manner.
JTree(Vector<?> value)           Returns a JTree with each element of the specified Vector as the child of a new root node which is not displayed.

 

Method Summary
void	addSelectionInterval(int index0, int index1)           Adds the paths between index0 and index1, inclusive, to the selection.
void	addSelectionPath(TreePath path)           Adds the node identified by the specified TreePath to the current selection.
void	addSelectionPaths(TreePath[] paths)           Adds each path in the array of paths to the current selection.
void	addSelectionRow(int row)           Adds the path at the specified row to the current selection.
void	addSelectionRows(int[] rows)           Adds the paths at each of the specified rows to the current selection.
void	addTreeExpansionListener(TreeExpansionListener tel)           Adds a listener for TreeExpansion events.
void	addTreeSelectionListener(TreeSelectionListener tsl)           Adds a listener for TreeSelection events.
void	addTreeWillExpandListener(TreeWillExpandListener tel)           Adds a listener for TreeWillExpand events.
void	cancelEditing()           Cancels the current editing session.
void	clearSelection()           Clears the selection.
protected  void	clearToggledPaths()           Clears the cache of toggled tree paths.
void	collapsePath(TreePath path)           Ensures that the node identified by the specified path is collapsed and viewable.
void	collapseRow(int row)           Ensures that the node in the specified row is collapsed.
String	convertValueToText(Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus)           Called by the renderers to convert the specified value to text.
protected static TreeModel	createTreeModel(Object value)           Returns a TreeModel wrapping the specified object.
protected  TreeModelListener	createTreeModelListener()           Creates and returns an instance of TreeModelHandler.
void	expandPath(TreePath path)           Ensures that the node identified by the specified path is expanded and viewable.
void	expandRow(int row)           Ensures that the node in the specified row is expanded and viewable.
void	fireTreeCollapsed(TreePath path)           Notifies all listeners that have registered interest for notification on this event type.
void	fireTreeExpanded(TreePath path)           Notifies all listeners that have registered interest for notification on this event type.
void	fireTreeWillCollapse(TreePath path)           Notifies all listeners that have registered interest for notification on this event type.
void	fireTreeWillExpand(TreePath path)           Notifies all listeners that have registered interest for notification on this event type.
protected  void	fireValueChanged(TreeSelectionEvent e)           Notifies all listeners that have registered interest for notification on this event type.
AccessibleContext	getAccessibleContext()           Gets the AccessibleContext associated with this JTree.
TreePath	getAnchorSelectionPath()           Returns the path identified as the anchor.
TreeCellEditor	getCellEditor()           Returns the editor used to edit entries in the tree.
TreeCellRenderer	getCellRenderer()           Returns the current TreeCellRenderer that is rendering each cell.
TreePath	getClosestPathForLocation(int x, int y)           Returns the path to the node that is closest to x,y.
int	getClosestRowForLocation(int x, int y)           Returns the row to the node that is closest to x,y.
protected static TreeModel	getDefaultTreeModel()           Creates and returns a sample TreeModel.
protected  Enumeration<TreePath>	getDescendantToggledPaths(TreePath parent)           Returns an Enumeration of TreePaths that have been expanded that are descendants of parent.
boolean	getDragEnabled()           Returns whether or not automatic drag handling is enabled.
JTree.DropLocation	getDropLocation()           Returns the location that this component should visually indicate as the drop location during a DnD operation over the component, or null if no location is to currently be shown.
DropMode	getDropMode()           Returns the drop mode for this component.
TreePath	getEditingPath()           Returns the path to the element that is currently being edited.
Enumeration<TreePath>	getExpandedDescendants(TreePath parent)           Returns an Enumeration of the descendants of the path parent that are currently expanded.
boolean	getExpandsSelectedPaths()           Returns the expandsSelectedPaths property.
boolean	getInvokesStopCellEditing()           Returns the indicator that tells what happens when editing is interrupted.
Object	getLastSelectedPathComponent()           Returns the last path component in the first node of the current selection.
TreePath	getLeadSelectionPath()           Returns the path identified as the lead.
int	getLeadSelectionRow()           Returns the row index corresponding to the lead path.
int	getMaxSelectionRow()           Returns the last selected row.
int	getMinSelectionRow()           Gets the first selected row.
TreeModel	getModel()           Returns the TreeModel that is providing the data.
TreePath	getNextMatch(String prefix, int startingRow, Position.Bias bias)           Returns the TreePath to the next tree element that begins with a prefix.
protected  TreePath[]	getPathBetweenRows(int index0, int index1)           Returns JTreePath instances representing the path between index0 and index1 (including index1).
Rectangle	getPathBounds(TreePath path)           Returns the Rectangle that the specified node will be drawn into.
TreePath	getPathForLocation(int x, int y)           Returns the path for the node at the specified location.
TreePath	getPathForRow(int row)           Returns the path for the specified row.
Dimension	getPreferredScrollableViewportSize()           Returns the preferred display size of a JTree.
Rectangle	getRowBounds(int row)           Returns the Rectangle that the node at the specified row is drawn in.
int	getRowCount()           Returns the number of rows that are currently being displayed.
int	getRowForLocation(int x, int y)           Returns the row for the specified location.
int	getRowForPath(TreePath path)           Returns the row that displays the node identified by the specified path.
int	getRowHeight()           Returns the height of each row.
int	getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction)           Returns the amount for a block increment, which is the height or width of visibleRect, based on orientation.
boolean	getScrollableTracksViewportHeight()           Returns false to indicate that the height of the viewport does not determine the height of the table, unless the preferred height of the tree is smaller than the viewports height.
boolean	getScrollableTracksViewportWidth()           Returns false to indicate that the width of the viewport does not determine the width of the table, unless the preferred width of the tree is smaller than the viewports width.
int	getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction)           Returns the amount to increment when scrolling.
boolean	getScrollsOnExpand()           Returns the value of the scrollsOnExpand property.
int	getSelectionCount()           Returns the number of nodes selected.
TreeSelectionModel	getSelectionModel()           Returns the model for selections.
TreePath	getSelectionPath()           Returns the path to the first selected node.
TreePath[]	getSelectionPaths()           Returns the paths of all selected values.
int[]	getSelectionRows()           Returns all of the currently selected rows.
boolean	getShowsRootHandles()           Returns the value of the showsRootHandles property.
int	getToggleClickCount()           Returns the number of mouse clicks needed to expand or close a node.
String	getToolTipText(MouseEvent event)           Overrides JComponent's getToolTipText method in order to allow renderer's tips to be used if it has text set.
TreeExpansionListener[]	getTreeExpansionListeners()           Returns an array of all the TreeExpansionListeners added to this JTree with addTreeExpansionListener().
TreeSelectionListener[]	getTreeSelectionListeners()           Returns an array of all the TreeSelectionListeners added to this JTree with addTreeSelectionListener().
TreeWillExpandListener[]	getTreeWillExpandListeners()           Returns an array of all the TreeWillExpandListeners added to this JTree with addTreeWillExpandListener().
TreeUI	getUI()           Returns the L&F object that renders this component.
String	getUIClassID()           Returns the name of the L&F class that renders this component.
int	getVisibleRowCount()           Returns the number of rows that are displayed in the display area.
boolean	hasBeenExpanded(TreePath path)           Returns true if the node identified by the path has ever been expanded.
boolean	isCollapsed(int row)           Returns true if the node at the specified display row is collapsed.
boolean	isCollapsed(TreePath path)           Returns true if the value identified by path is currently collapsed, this will return false if any of the values in path are currently not being displayed.
boolean	isEditable()           Returns true if the tree is editable.
boolean	isEditing()           Returns true if the tree is being edited.
boolean	isExpanded(int row)           Returns true if the node at the specified display row is currently expanded.
boolean	isExpanded(TreePath path)           Returns true if the node identified by the path is currently expanded,
boolean	isFixedRowHeight()           Returns true if the height of each display row is a fixed size.
boolean	isLargeModel()           Returns true if the tree is configured for a large model.
boolean	isPathEditable(TreePath path)           Returns isEditable.
boolean	isPathSelected(TreePath path)           Returns true if the item identified by the path is currently selected.
boolean	isRootVisible()           Returns true if the root node of the tree is displayed.
boolean	isRowSelected(int row)           Returns true if the node identified by row is selected.
boolean	isSelectionEmpty()           Returns true if the selection is currently empty.
boolean	isVisible(TreePath path)           Returns true if the value identified by path is currently viewable, which means it is either the root or all of its parents are expanded.
void	makeVisible(TreePath path)           Ensures that the node identified by path is currently viewable.
protected  String	paramString()           Returns a string representation of this JTree.
protected  boolean	removeDescendantSelectedPaths(TreePath path, boolean includePath)           Removes any paths in the selection that are descendants of path.
protected  void	removeDescendantToggledPaths(Enumeration<TreePath> toRemove)           Removes any descendants of the TreePaths in toRemove that have been expanded.
void	removeSelectionInterval(int index0, int index1)           Removes the nodes between index0 and index1, inclusive, from the selection.
void	removeSelectionPath(TreePath path)           Removes the node identified by the specified path from the current selection.
void	removeSelectionPaths(TreePath[] paths)           Removes the nodes identified by the specified paths from the current selection.
void	removeSelectionRow(int row)           Removes the row at the index row from the current selection.
void	removeSelectionRows(int[] rows)           Removes the rows that are selected at each of the specified rows.
void	removeTreeExpansionListener(TreeExpansionListener tel)           Removes a listener for TreeExpansion events.
void	removeTreeSelectionListener(TreeSelectionListener tsl)           Removes a TreeSelection listener.
void	removeTreeWillExpandListener(TreeWillExpandListener tel)           Removes a listener for TreeWillExpand events.
void	scrollPathToVisible(TreePath path)           Makes sure all the path components in path are expanded (except for the last path component) and scrolls so that the node identified by the path is displayed.
void	scrollRowToVisible(int row)           Scrolls the item identified by row until it is displayed.
void	setAnchorSelectionPath(TreePath newPath)           Sets the path identified as the anchor.
void	setCellEditor(TreeCellEditor cellEditor)           Sets the cell editor.
void	setCellRenderer(TreeCellRenderer x)           Sets the TreeCellRenderer that will be used to draw each cell.
void	setDragEnabled(boolean b)           Turns on or off automatic drag handling.
void	setDropMode(DropMode dropMode)           Sets the drop mode for this component.
void	setEditable(boolean flag)           Determines whether the tree is editable.
protected  void	setExpandedState(TreePath path, boolean state)           Sets the expanded state of this JTree.
void	setExpandsSelectedPaths(boolean newValue)           Configures the expandsSelectedPaths property.
void	setInvokesStopCellEditing(boolean newValue)           Determines what happens when editing is interrupted by selecting another node in the tree, a change in the tree's data, or by some other means.
void	setLargeModel(boolean newValue)           Specifies whether the UI should use a large model.
void	setLeadSelectionPath(TreePath newPath)           Sets the path identifies as the lead.
void	setModel(TreeModel newModel)           Sets the TreeModel that will provide the data.
void	setRootVisible(boolean rootVisible)           Determines whether or not the root node from the TreeModel is visible.
void	setRowHeight(int rowHeight)           Sets the height of each cell, in pixels.
void	setScrollsOnExpand(boolean newValue)           Sets the scrollsOnExpand property, which determines whether the tree might scroll to show previously hidden children.
void	setSelectionInterval(int index0, int index1)           Selects the nodes between index0 and index1, inclusive.
void	setSelectionModel(TreeSelectionModel selectionModel)           Sets the tree's selection model.
void	setSelectionPath(TreePath path)           Selects the node identified by the specified path.
void	setSelectionPaths(TreePath[] paths)           Selects the nodes identified by the specified array of paths.
void	setSelectionRow(int row)           Selects the node at the specified row in the display.
void	setSelectionRows(int[] rows)           Selects the nodes corresponding to each of the specified rows in the display.
void	setShowsRootHandles(boolean newValue)           Sets the value of the showsRootHandles property, which specifies whether the node handles should be displayed.
void	setToggleClickCount(int clickCount)           Sets the number of mouse clicks before a node will expand or close.
void	setUI(TreeUI ui)           Sets the L&F object that renders this component.
void	setVisibleRowCount(int newCount)           Sets the number of rows that are to be displayed.
void	startEditingAtPath(TreePath path)           Selects the node identified by the specified path and initiates editing.
boolean	stopEditing()           Ends the current editing session.
void	treeDidChange()           Sent when the tree has changed enough that we need to resize the bounds, but not enough that we need to remove the expanded node set (e.g nodes were expanded or collapsed, or nodes were inserted into the tree).
void	updateUI()           Notification from the UIManager that the L&F has changed.

 

Methods inherited from class javax.swing.JComponent
addAncestorListener, addNotify, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscro