JTree (Java 2 Platform SE 5.0) (original) (raw)

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 inHow to Use Trees, a section in The Java Tutorial.

A specific node in a tree can be identified either by aTreePath (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 byTreeModel.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);

NOTE: This example obtains both the path and row, but you only need to get the one you're interested in.

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 andActionMap to associate an Action object with a KeyStroke and execute the action under specified conditions.

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 XMLEncoder.

treeModel

protected transient TreeModel treeModel

The model that defines the tree displayed by this object.

selectionModel

protected transient TreeSelectionModel selectionModel

Models the set of selected nodes in this tree.

rootVisible

protected boolean rootVisible

True if the root node is displayed, false if its children are the highest visible nodes.

cellRenderer

protected transient TreeCellRenderer cellRenderer

The cell used to draw nodes. If null, the UI uses a defaultcellRenderer.

rowHeight

protected int rowHeight

Height to use for each display row. If this is <= 0 the renderer determines the height for each row.

showsRootHandles

protected boolean showsRootHandles

True if handles are displayed at the topmost level of the tree.

A handle is a small icon that displays adjacent to the node which allows the user to click once to expand or collapse the node. A common interface shows a plus sign (+) for a node which can be expanded and a minus sign (-) for a node which can be collapsed. Handles are always shown for nodes below the topmost level.

If the rootVisible setting specifies that the root node is to be displayed, then that is the only node at the topmost level. If the root node is not displayed, then all of its children are at the topmost level of the tree. Handles are always displayed for nodes other than the topmost.

If the root node isn't visible, it is generally a good to make this value true. Otherwise, the tree looks exactly like a list, and users may not know that the "list entries" are actually tree nodes.

See Also:

rootVisible

selectionRedirector

protected transient JTree.TreeSelectionRedirector selectionRedirector

Creates a new event and passed it off theselectionListeners.

cellEditor

protected transient TreeCellEditor cellEditor

Editor for the entries. Default is null (tree is not editable).

editable

protected boolean editable

Is the tree editable? Default is false.

largeModel

protected boolean largeModel

Is this tree a large model? This is a code-optimization setting. A large model can be used when the cell height is the same for all nodes. The UI will then cache very little information and instead continually message the model. Without a large model the UI caches most of the information, resulting in fewer method calls to the model.

This value is only a suggestion to the UI. Not all UIs will take advantage of it. Default value is false.

visibleRowCount

protected int visibleRowCount

Number of rows to make visible at one time. This value is used for the Scrollable interface. It determines the preferred size of the display area.

invokesStopCellEditing

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. If false,cancelCellEditing is invoked, and changes are discarded. Default is false.

scrollsOnExpand

protected boolean scrollsOnExpand

If true, when a node is expanded, as many of the descendants are scrolled to be visible.

toggleClickCount

protected int toggleClickCount

Number of mouse clicks before a node is expanded.

treeModelListener

protected transient TreeModelListener treeModelListener

Updates the expandedState.

CELL_RENDERER_PROPERTY

public static final String CELL_RENDERER_PROPERTY

Bound property name for cellRenderer.

See Also:

Constant Field Values

TREE_MODEL_PROPERTY

public static final String TREE_MODEL_PROPERTY

Bound property name for treeModel.

See Also:

Constant Field Values

ROOT_VISIBLE_PROPERTY

public static final String ROOT_VISIBLE_PROPERTY

Bound property name for rootVisible.

See Also:

Constant Field Values

SHOWS_ROOT_HANDLES_PROPERTY

public static final String SHOWS_ROOT_HANDLES_PROPERTY

Bound property name for showsRootHandles.

See Also:

Constant Field Values

ROW_HEIGHT_PROPERTY

public static final String ROW_HEIGHT_PROPERTY

Bound property name for rowHeight.

See Also:

Constant Field Values

CELL_EDITOR_PROPERTY

public static final String CELL_EDITOR_PROPERTY

Bound property name for cellEditor.

See Also:

Constant Field Values

EDITABLE_PROPERTY

public static final String EDITABLE_PROPERTY

Bound property name for editable.

See Also:

Constant Field Values

LARGE_MODEL_PROPERTY

public static final String LARGE_MODEL_PROPERTY

Bound property name for largeModel.

See Also:

Constant Field Values

SELECTION_MODEL_PROPERTY

public static final String SELECTION_MODEL_PROPERTY

Bound property name for selectionModel.

See Also:

Constant Field Values

VISIBLE_ROW_COUNT_PROPERTY

public static final String VISIBLE_ROW_COUNT_PROPERTY

Bound property name for visibleRowCount.

See Also:

Constant Field Values

INVOKES_STOP_CELL_EDITING_PROPERTY

public static final String INVOKES_STOP_CELL_EDITING_PROPERTY

Bound property name for messagesStopCellEditing.

See Also:

Constant Field Values

SCROLLS_ON_EXPAND_PROPERTY

public static final String SCROLLS_ON_EXPAND_PROPERTY

Bound property name for scrollsOnExpand.

See Also:

Constant Field Values

TOGGLE_CLICK_COUNT_PROPERTY

public static final String TOGGLE_CLICK_COUNT_PROPERTY

Bound property name for toggleClickCount.

See Also:

Constant Field Values

LEAD_SELECTION_PATH_PROPERTY

public static final String LEAD_SELECTION_PATH_PROPERTY

Bound property name for leadSelectionPath.

Since:

1.3

See Also:

Constant Field Values

ANCHOR_SELECTION_PATH_PROPERTY

public static final String ANCHOR_SELECTION_PATH_PROPERTY

Bound property name for anchor selection path.

Since:

1.3

See Also:

Constant Field Values

EXPANDS_SELECTED_PATHS_PROPERTY

public static final String EXPANDS_SELECTED_PATHS_PROPERTY

Bound property name for expands selected paths property

Since:

1.3

See Also:

Constant Field Values

JTree

public JTree()

Returns a JTree with a sample model. The default model used by the tree defines a leaf node as any node without children.

See Also:

DefaultTreeModel.asksAllowsChildren

JTree

public 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. By default, the tree defines a leaf node as any node without children.

Parameters:

value - an array of Objects

See Also:

DefaultTreeModel.asksAllowsChildren

JTree

public JTree(Vector<?> value)

Returns a JTree with each element of the specifiedVector as the child of a new root node which is not displayed. By default, the tree defines a leaf node as any node without children.

Parameters:

value - a Vector

See Also:

DefaultTreeModel.asksAllowsChildren

JTree

public JTree(Hashtable value)

Returns a JTree created from a Hashtable which does not display with root. Each value-half of the key/value pairs in the HashTable becomes a child of the new root node. By default, the tree defines a leaf node as any node without children.

Parameters:

value - a Hashtable

See Also:

DefaultTreeModel.asksAllowsChildren

JTree

public JTree(TreeNode root)

Returns a JTree with the specifiedTreeNode as its root, which displays the root node. By default, the tree defines a leaf node as any node without children.

Parameters:

root - a TreeNode object

See Also:

DefaultTreeModel.asksAllowsChildren

JTree

public 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.

Parameters:

root - a TreeNode object

asksAllowsChildren - if false, any node without children is a leaf node; if true, only nodes that do not allow children are leaf nodes

See Also:

DefaultTreeModel.asksAllowsChildren

JTree

public JTree(TreeModel newModel)

Returns an instance of JTree which displays the root node -- the tree is created using the specified data model.

Parameters:

newModel - the TreeModel to use as the data model

getDefaultTreeModel

protected static TreeModel getDefaultTreeModel()

Creates and returns a sample TreeModel. Used primarily for beanbuilders to show something interesting.

Returns:

the default TreeModel

createTreeModel

protected static TreeModel createTreeModel(Object value)

Returns a TreeModel wrapping the specified object. If the object is:

• an array of Objects,
• a Hashtable, or
• a Vector then a new root node is created with each of the incoming objects as children. Otherwise, a new root is created with the specified object as its value.

Parameters:

value - the Object used as the foundation for the TreeModel

Returns:

a TreeModel wrapping the specified object

getUI

public TreeUI getUI()

Returns the L&F object that renders this component.

Returns:

the TreeUI object that renders this component

setUI

public void setUI(TreeUI ui)

Sets the L&F object that renders this component.

Parameters:

ui - the TreeUI L&F object

See Also:

UIDefaults.getUI(javax.swing.JComponent)

updateUI

public void updateUI()

Notification from the UIManager that the L&F has changed. Replaces the current UI object with the latest version from the UIManager.

Overrides:

[updateUI](../../javax/swing/JComponent.html#updateUI%28%29) in class [JComponent](../../javax/swing/JComponent.html "class in javax.swing")

See Also:

JComponent.updateUI()

getUIClassID

public String getUIClassID()

Returns the name of the L&F class that renders this component.

Overrides:

[getUIClassID](../../javax/swing/JComponent.html#getUIClassID%28%29) in class [JComponent](../../javax/swing/JComponent.html "class in javax.swing")

Returns:

the string "TreeUI"

See Also:

JComponent.getUIClassID(), UIDefaults.getUI(javax.swing.JComponent)

getCellRenderer

public TreeCellRenderer getCellRenderer()

Returns the current TreeCellRenderer that is rendering each cell.

Returns:

the TreeCellRenderer that is rendering each cell

setCellRenderer

public void setCellRenderer(TreeCellRenderer x)

Sets the TreeCellRenderer that will be used to draw each cell.

Parameters:

x - the TreeCellRenderer that is to render each cell

setEditable

public void setEditable(boolean flag)

Determines whether the tree is editable. Fires a property change event if the new setting is different from the existing setting.

Parameters:

flag - a boolean value, true if the tree is editable

isEditable

public boolean isEditable()

Returns true if the tree is editable.

Returns:

true if the tree is editable

setCellEditor

public void setCellEditor(TreeCellEditor cellEditor)

Sets the cell editor. A null value implies that the tree cannot be edited. If this represents a change in thecellEditor, the propertyChange method is invoked on all listeners.

Parameters:

cellEditor - the TreeCellEditor to use

getCellEditor

public TreeCellEditor getCellEditor()

Returns the editor used to edit entries in the tree.

Returns:

the TreeCellEditor in use, or null if the tree cannot be edited

getModel

public TreeModel getModel()

Returns the TreeModel that is providing the data.

Returns:

the TreeModel that is providing the data

setModel

public void setModel(TreeModel newModel)

Sets the TreeModel that will provide the data.

Parameters:

newModel - the TreeModel that is to provide the data

isRootVisible

public boolean isRootVisible()

Returns true if the root node of the tree is displayed.

Returns:

true if the root node of the tree is displayed

See Also:

rootVisible

setRootVisible

public void setRootVisible(boolean rootVisible)

Determines whether or not the root node from the TreeModel is visible.

Parameters:

rootVisible - true if the root node of the tree is to be displayed

See Also:

rootVisible

setShowsRootHandles

public void setShowsRootHandles(boolean newValue)

Sets the value of the showsRootHandles property, which specifies whether the node handles should be displayed. The default value of this property depends on the constructor used to create the JTree. Some look and feels might not support handles; they will ignore this property.

Parameters:

newValue - true if root handles should be displayed; otherwise, false

See Also:

showsRootHandles, getShowsRootHandles()

getShowsRootHandles

public boolean getShowsRootHandles()

Returns the value of the showsRootHandles property.

Returns:

the value of the showsRootHandles property

See Also:

showsRootHandles

setRowHeight

public void setRowHeight(int rowHeight)

Sets the height of each cell, in pixels. If the specified value is less than or equal to zero the current cell renderer is queried for each row's height.

Parameters:

rowHeight - the height of each cell, in pixels

getRowHeight

public int getRowHeight()

Returns the height of each row. If the returned value is less than or equal to 0 the height for each row is determined by the renderer.

isFixedRowHeight

public boolean isFixedRowHeight()

Returns true if the height of each display row is a fixed size.

Returns:

true if the height of each row is a fixed size

setLargeModel

public void setLargeModel(boolean newValue)

Specifies whether the UI should use a large model. (Not all UIs will implement this.) Fires a property change for the LARGE_MODEL_PROPERTY.

Parameters:

newValue - true to suggest a large model to the UI

See Also:

largeModel

isLargeModel

public boolean isLargeModel()

Returns true if the tree is configured for a large model.

Returns:

true if a large model is suggested

See Also:

largeModel

setInvokesStopCellEditing

public 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. Setting this property to true causes the changes to be automatically saved when editing is interrupted.

Fires a property change for the INVOKES_STOP_CELL_EDITING_PROPERTY.

Parameters:

newValue - true means that stopCellEditing is invoked when editing is interrupted, and data is saved; false means thatcancelCellEditing is invoked, and changes are lost

getInvokesStopCellEditing

public boolean getInvokesStopCellEditing()

Returns the indicator that tells what happens when editing is interrupted.

Returns:

the indicator that tells what happens when editing is interrupted

See Also:

setInvokesStopCellEditing(boolean)

setScrollsOnExpand

public void setScrollsOnExpand(boolean newValue)

Sets the scrollsOnExpand property, which determines whether the tree might scroll to show previously hidden children. If this property is true (the default), when a node expands the tree can use scrolling to make the maximum possible number of the node's descendants visible. In some look and feels, trees might not need to scroll when expanded; those look and feels will ignore this property.

Parameters:

newValue - false to disable scrolling on expansion;true to enable it

See Also:

getScrollsOnExpand()

getScrollsOnExpand

public boolean getScrollsOnExpand()

Returns the value of the scrollsOnExpand property.

Returns:

the value of the scrollsOnExpand property

setToggleClickCount

public void setToggleClickCount(int clickCount)

Sets the number of mouse clicks before a node will expand or close. The default is two.

Since:

1.3

getToggleClickCount

public int getToggleClickCount()

Returns the number of mouse clicks needed to expand or close a node.

Returns:

number of mouse clicks before node is expanded

Since:

1.3

setExpandsSelectedPaths

public void setExpandsSelectedPaths(boolean newValue)

Configures the expandsSelectedPaths property. If true, any time the selection is changed, either via theTreeSelectionModel, or the cover methods provided by JTree, the TreePaths parents will be expanded to make them visible (visible meaning the parent path is expanded, not necessarily in the visible rectangle of theJTree). If false, when the selection changes the nodes parent is not made visible (all its parents expanded). This is useful if you wish to have your selection model maintain paths that are not always visible (all parents expanded).

Parameters:

newValue - the new value for expandsSelectedPaths

Since:

1.3

getExpandsSelectedPaths

public boolean getExpandsSelectedPaths()

Returns the expandsSelectedPaths property.

Returns:

true if selection changes result in the parent path being expanded

Since:

1.3

See Also:

setExpandsSelectedPaths(boolean)

setDragEnabled

public void setDragEnabled(boolean b)

Sets the dragEnabled property, which must be true to enable automatic drag handling (the first part of drag and drop) on this component. The transferHandler property needs to be set to a non-null value for the drag to do anything. The default value of the dragEnabled property is false.

When automatic drag handling is enabled, most look and feels begin a drag-and-drop operation whenever the user presses the mouse button over a selection and then moves the mouse a few pixels. Setting this property to true can therefore have a subtle effect on how selections behave.

Some look and feels might not support automatic drag and drop; they will ignore this property. You can work around such look and feels by modifying the component to directly call the exportAsDrag method of aTransferHandler.

Parameters:

b - the value to set the dragEnabled property to

Throws:

[HeadlessException](../../java/awt/HeadlessException.html "class in java.awt") - ifb is true andGraphicsEnvironment.isHeadless() returns true

Since:

1.4

See Also:

GraphicsEnvironment.isHeadless(), getDragEnabled(), JComponent.setTransferHandler(javax.swing.TransferHandler), TransferHandler

getDragEnabled

public boolean getDragEnabled()

Gets the value of the dragEnabled property.

Returns:

the value of the dragEnabled property

Since:

1.4

See Also:

setDragEnabled(boolean)

isPathEditable

public boolean isPathEditable(TreePath path)

Returns isEditable. This is invoked from the UI before editing begins to insure that the given path can be edited. This is provided as an entry point for subclassers to add filtered editing without having to resort to creating a new editor.

Returns:

true if every parent node and the node itself is editable

See Also:

isEditable()

getToolTipText

public String getToolTipText(MouseEvent event)

Overrides JComponent's getToolTipText method in order to allow renderer's tips to be used if it has text set.

NOTE: For JTree to properly display tooltips of its renderers, JTree must be a registered component with theToolTipManager. This can be done by invokingToolTipManager.sharedInstance().registerComponent(tree). This is not done automatically!

Overrides:

[getToolTipText](../../javax/swing/JComponent.html#getToolTipText%28java.awt.event.MouseEvent%29) in class [JComponent](../../javax/swing/JComponent.html "class in javax.swing")

Parameters:

event - the MouseEvent that initiated the ToolTip display

Returns:

a string containing the tooltip or null if event is null

convertValueToText

public 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. This implementation returns value.toString, ignoring all other arguments. To control the conversion, subclass this method and use any of the arguments you need.

Parameters:

value - the Object to convert to text

selected - true if the node is selected

expanded - true if the node is expanded

leaf - true if the node is a leaf node

row - an integer specifying the node's display row, where 0 is the first row in the display

hasFocus - true if the node has the focus

Returns:

the String representation of the node's value

getRowCount

public int getRowCount()

Returns the number of rows that are currently being displayed.

Returns:

the number of rows that are being displayed

setSelectionPath

public void setSelectionPath(TreePath path)

Selects the node identified by the specified path. If any component of the path is hidden (under a collapsed node), andgetExpandsSelectedPaths is true it is exposed (made viewable).

Parameters:

path - the TreePath specifying the node to select

setSelectionPaths

public void setSelectionPaths(TreePath[] paths)

Selects the nodes identified by the specified array of paths. If any component in any of the paths is hidden (under a collapsed node), and getExpandsSelectedPaths is true it is exposed (made viewable).

Parameters:

paths - an array of TreePath objects that specifies the nodes to select

setLeadSelectionPath

public void setLeadSelectionPath(TreePath newPath)

Sets the path identifies as the lead. The lead may not be selected. The lead is not maintained by JTree, rather the UI will update it.

Parameters:

newPath - the new lead path

Since:

1.3

setAnchorSelectionPath

public void setAnchorSelectionPath(TreePath newPath)

Sets the path identified as the anchor. The anchor is not maintained by JTree, rather the UI will update it.

Parameters:

newPath - the new anchor path

Since:

1.3

setSelectionRow

public void setSelectionRow(int row)

Selects the node at the specified row in the display.

Parameters:

row - the row to select, where 0 is the first row in the display

setSelectionRows

public void setSelectionRows(int[] rows)

Selects the nodes corresponding to each of the specified rows in the display. If a particular element of rows is < 0 or >= getRowCount, it will be ignored. If none of the elements in rows are valid rows, the selection will be cleared. That is it will be as if clearSelection was invoked.

Parameters:

rows - an array of ints specifying the rows to select, where 0 indicates the first row in the display

addSelectionPath

public void addSelectionPath(TreePath path)

Adds the node identified by the specified TreePath to the current selection. If any component of the path isn't viewable, and getExpandsSelectedPaths is true it is made viewable.

Note that JTree does not allow duplicate nodes to exist as children under the same parent -- each sibling must be a unique object.

Parameters:

path - the TreePath to add

addSelectionPaths

public void addSelectionPaths(TreePath[] paths)

Adds each path in the array of paths to the current selection. If any component of any of the paths isn't viewable andgetExpandsSelectedPaths is true, it is made viewable.

Note that JTree does not allow duplicate nodes to exist as children under the same parent -- each sibling must be a unique object.

Parameters:

paths - an array of TreePath objects that specifies the nodes to add

addSelectionRow

public void addSelectionRow(int row)

Adds the path at the specified row to the current selection.

Parameters:

row - an integer specifying the row of the node to add, where 0 is the first row in the display

addSelectionRows

public void addSelectionRows(int[] rows)

Adds the paths at each of the specified rows to the current selection.

Parameters:

rows - an array of ints specifying the rows to add, where 0 indicates the first row in the display

getLastSelectedPathComponent

public Object getLastSelectedPathComponent()

Returns the last path component in the first node of the current selection.

Returns:

the last Object in the first selected node'sTreePath, or null if nothing is selected

See Also:

TreePath.getLastPathComponent()

getLeadSelectionPath

public TreePath getLeadSelectionPath()

Returns the path identified as the lead.

Returns:

path identified as the lead

getAnchorSelectionPath

public TreePath getAnchorSelectionPath()

Returns the path identified as the anchor.

Returns:

path identified as the anchor

Since:

1.3

getSelectionPath

public TreePath getSelectionPath()

Returns the path to the first selected node.

Returns:

the TreePath for the first selected node, or null if nothing is currently selected

getSelectionPaths

public TreePath[] getSelectionPaths()

Returns the paths of all selected values.

Returns:

an array of TreePath objects indicating the selected nodes, or null if nothing is currently selected

getSelectionRows

public int[] getSelectionRows()

Returns all of the currently selected rows. This method is simply forwarded to the TreeSelectionModel. If nothing is selected null or an empty array will be returned, based on the TreeSelectionModel implementation.

Returns:

an array of integers that identifies all currently selected rows where 0 is the first row in the display

getSelectionCount

public int getSelectionCount()

Returns the number of nodes selected.

Returns:

the number of nodes selected

getMinSelectionRow

public int getMinSelectionRow()

Gets the first selected row.

Returns:

an integer designating the first selected row, where 0 is the first row in the display

getMaxSelectionRow

public int getMaxSelectionRow()

Returns the last selected row.

Returns:

an integer designating the last selected row, where 0 is the first row in the display

getLeadSelectionRow

public int getLeadSelectionRow()

Returns the row index corresponding to the lead path.

Returns:

an integer giving the row index of the lead path, where 0 is the first row in the display; or -1 if leadPath is null

isPathSelected

public boolean isPathSelected(TreePath path)

Returns true if the item identified by the path is currently selected.

Parameters:

path - a TreePath identifying a node

Returns:

true if the node is selected

isRowSelected

public boolean isRowSelected(int row)

Returns true if the node identified by row is selected.

Parameters:

row - an integer specifying a display row, where 0 is the first row in the display

Returns:

true if the node is selected

getExpandedDescendants

public Enumeration<TreePath> getExpandedDescendants(TreePath parent)

Returns an Enumeration of the descendants of the path parent that are currently expanded. If parent is not currently expanded, this will return null. If you expand/collapse nodes while iterating over the returned Enumeration this may not return all the expanded paths, or may return paths that are no longer expanded.

Parameters:

parent - the path which is to be examined

Returns:

an Enumeration of the descendents of parent, or null ifparent is not currently expanded

hasBeenExpanded

public boolean hasBeenExpanded(TreePath path)

Returns true if the node identified by the path has ever been expanded.

Returns:

true if the path has ever been expanded

isExpanded

public boolean isExpanded(TreePath path)

Returns true if the node identified by the path is currently expanded,

Parameters:

path - the TreePath specifying the node to check

Returns:

false if any of the nodes in the node's path are collapsed, true if all nodes in the path are expanded

isExpanded

public boolean isExpanded(int row)

Returns true if the node at the specified display row is currently expanded.

Parameters:

row - the row to check, where 0 is the first row in the display

Returns:

true if the node is currently expanded, otherwise false

isCollapsed

public 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.

Parameters:

path - the TreePath to check

Returns:

true if any of the nodes in the node's path are collapsed, false if all nodes in the path are expanded

isCollapsed

public boolean isCollapsed(int row)

Returns true if the node at the specified display row is collapsed.

Parameters:

row - the row to check, where 0 is the first row in the display

Returns:

true if the node is currently collapsed, otherwise false

makeVisible

public void makeVisible(TreePath path)

Ensures that the node identified by path is currently viewable.

Parameters:

path - the TreePath to make visible

isVisible

public 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. Otherwise, this method returns false.

Returns:

true if the node is viewable, otherwise false

getPathBounds

public Rectangle getPathBounds(TreePath path)

Returns the Rectangle that the specified node will be drawn into. Returns null if any component in the path is hidden (under a collapsed parent).

Note:
This method returns a valid rectangle, even if the specified node is not currently displayed.

Parameters:

path - the TreePath identifying the node

Returns:

the Rectangle the node is drawn in, or null

getRowBounds

public Rectangle getRowBounds(int row)

Returns the Rectangle that the node at the specified row is drawn in.

Parameters:

row - the row to be drawn, where 0 is the first row in the display

Returns:

the Rectangle the node is drawn in

scrollPathToVisible

public 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. Only works when thisJTree is contained in a JScrollPane.

Parameters:

path - the TreePath identifying the node to bring into view

scrollRowToVisible

public void scrollRowToVisible(int row)

Scrolls the item identified by row until it is displayed. The minimum of amount of scrolling necessary to bring the row into view is performed. Only works when this JTree is contained in aJScrollPane.

Parameters:

row - an integer specifying the row to scroll, where 0 is the first row in the display

getPathForRow

public TreePath getPathForRow(int row)

Returns the path for the specified row. If row is not visible, null is returned.

Parameters:

row - an integer specifying a row

Returns:

the TreePath to the specified node,null if row < 0 or row > getRowCount()

getRowForPath

public int getRowForPath(TreePath path)

Returns the row that displays the node identified by the specified path.

Parameters:

path - the TreePath identifying a node

Returns:

an integer specifying the display row, where 0 is the first row in the display, or -1 if any of the elements in path are hidden under a collapsed parent.

expandPath

public void expandPath(TreePath path)

Ensures that the node identified by the specified path is expanded and viewable. If the last item in the path is a leaf, this will have no effect.

Parameters:

path - the TreePath identifying a node

expandRow

public void expandRow(int row)

Ensures that the node in the specified row is expanded and viewable.

If row is < 0 or >= getRowCount this will have no effect.

Parameters:

row - an integer specifying a display row, where 0 is the first row in the display

collapsePath

public void collapsePath(TreePath path)

Ensures that the node identified by the specified path is collapsed and viewable.

Parameters:

path - the TreePath identifying a node

collapseRow

public void collapseRow(int row)

Ensures that the node in the specified row is collapsed.

If row is < 0 or >= getRowCount this will have no effect.

Parameters:

row - an integer specifying a display row, where 0 is the first row in the display

getPathForLocation

public TreePath getPathForLocation(int x, int y)

Returns the path for the node at the specified location.

Parameters:

x - an integer giving the number of pixels horizontally from the left edge of the display area, minus any left margin

y - an integer giving the number of pixels vertically from the top of the display area, minus any top margin

Returns:

the TreePath for the node at that location

getRowForLocation

public int getRowForLocation(int x, int y)

Returns the row for the specified location.

Parameters:

x - an integer giving the number of pixels horizontally from the left edge of the display area, minus any left margin

y - an integer giving the number of pixels vertically from the top of the display area, minus any top margin

Returns:

the row corresponding to the location, or -1 if the location is not within the bounds of a displayed cell

See Also:

[getClosestRowForLocation(int, int)](../../javax/swing/JTree.html#getClosestRowForLocation%28int, int%29)

getClosestPathForLocation

public TreePath getClosestPathForLocation(int x, int y)

Returns the path to the node that is closest to x,y. If no nodes are currently viewable, or there is no model, returnsnull, otherwise it always returns a valid path. To test if the node is exactly at x, y, get the node's bounds and test x, y against that.

Parameters:

x - an integer giving the number of pixels horizontally from the left edge of the display area, minus any left margin

y - an integer giving the number of pixels vertically from the top of the display area, minus any top margin

Returns:

the TreePath for the node closest to that location,null if nothing is viewable or there is no model

See Also:

[getPathForLocation(int, int)](../../javax/swing/JTree.html#getPathForLocation%28int, int%29), getPathBounds(javax.swing.tree.TreePath)

getClosestRowForLocation

public int getClosestRowForLocation(int x, int y)

Returns the row to the node that is closest to x,y. If no nodes are viewable or there is no model, returns -1. Otherwise, it always returns a valid row. To test if the returned object is exactly at x, y, get the bounds for the node at the returned row and test x, y against that.

Parameters:

x - an integer giving the number of pixels horizontally from the left edge of the display area, minus any left margin

y - an integer giving the number of pixels vertically from the top of the display area, minus any top margin

Returns:

the row closest to the location, -1 if nothing is viewable or there is no model

See Also:

[getRowForLocation(int, int)](../../javax/swing/JTree.html#getRowForLocation%28int, int%29), getRowBounds(int)

isEditing

public boolean isEditing()

Returns true if the tree is being edited. The item that is being edited can be obtained using getSelectionPath.

Returns:

true if the user is currently editing a node

See Also:

getSelectionPath()

stopEditing

public boolean stopEditing()

Ends the current editing session. (The DefaultTreeCellEditor object saves any edits that are currently in progress on a cell. Other implementations may operate differently.) Has no effect if the tree isn't being edited.

Note:
To make edit-saves automatic whenever the user changes their position in the tree, use setInvokesStopCellEditing(boolean).

Returns:

true if editing was in progress and is now stopped, false if editing was not in progress

cancelEditing

public void cancelEditing()

Cancels the current editing session. Has no effect if the tree isn't being edited.

startEditingAtPath

public void startEditingAtPath(TreePath path)

Selects the node identified by the specified path and initiates editing. The edit-attempt fails if the CellEditor does not allow editing for the specified item.

Parameters:

path - the TreePath identifying a node

getEditingPath

public TreePath getEditingPath()

Returns the path to the element that is currently being edited.

Returns:

the TreePath for the node being edited

setSelectionModel

public void setSelectionModel(TreeSelectionModel selectionModel)

Sets the tree's selection model. When a null value is specified an emtpyselectionModel is used, which does not allow selections.

Parameters:

selectionModel - the TreeSelectionModel to use, or null to disable selections

See Also:

TreeSelectionModel

getSelectionModel

public TreeSelectionModel getSelectionModel()

Returns the model for selections. This should always return a non-null value. If you don't want to allow anything to be selected set the selection model to null, which forces an empty selection model to be used.

See Also:

setSelectionModel(javax.swing.tree.TreeSelectionModel)

getPathBetweenRows

protected TreePath[] getPathBetweenRows(int index0, int index1)

Returns JTreePath instances representing the path between index0 and index1 (including index1). Returns null if there is no tree.

Parameters:

index0 - an integer specifying a display row, where 0 is the first row in the display

index1 - an integer specifying a second display row

Returns:

an array of TreePath objects, one for each node between index0 and index1, inclusive; or null if there is no tree

setSelectionInterval

public void setSelectionInterval(int index0, int index1)

Selects the nodes between index0 and index1, inclusive.

Parameters:

index0 - an integer specifying a display row, where 0 is the first row in the display

index1 - an integer specifying a second display row

addSelectionInterval

public void addSelectionInterval(int index0, int index1)

Adds the paths between index0 and index1, inclusive, to the selection.

Parameters:

index0 - an integer specifying a display row, where 0 is the first row in the display

index1 - an integer specifying a second display row

removeSelectionInterval

public void removeSelectionInterval(int index0, int index1)

Removes the nodes between index0 and index1, inclusive, from the selection.

Parameters:

index0 - an integer specifying a display row, where 0 is the first row in the display

index1 - an integer specifying a second display row

removeSelectionPath

public void removeSelectionPath(TreePath path)

Removes the node identified by the specified path from the current selection.

Parameters:

path - the TreePath identifying a node

removeSelectionPaths

public void removeSelectionPaths(TreePath[] paths)

Removes the nodes identified by the specified paths from the current selection.

Parameters:

paths - an array of TreePath objects that specifies the nodes to remove

removeSelectionRow

public void removeSelectionRow(int row)

Removes the row at the index row from the current selection.

Parameters:

row - the row to remove

removeSelectionRows

public void removeSelectionRows(int[] rows)

Removes the rows that are selected at each of the specified rows.

Parameters:

rows - an array of ints specifying display rows, where 0 is the first row in the display

clearSelection

public void clearSelection()

Clears the selection.

isSelectionEmpty

public boolean isSelectionEmpty()

Returns true if the selection is currently empty.

Returns:

true if the selection is currently empty

addTreeExpansionListener

public void addTreeExpansionListener(TreeExpansionListener tel)

Adds a listener for TreeExpansion events.

Parameters:

tel - a TreeExpansionListener that will be notified when a tree node is expanded or collapsed (a "negative expansion")

removeTreeExpansionListener

public void removeTreeExpansionListener(TreeExpansionListener tel)

Removes a listener for TreeExpansion events.

Parameters:

tel - the TreeExpansionListener to remove

getTreeExpansionListeners

public TreeExpansionListener[] getTreeExpansionListeners()

Returns an array of all the TreeExpansionListeners added to this JTree with addTreeExpansionListener().

Returns:

all of the TreeExpansionListeners added or an empty array if no listeners have been added

Since:

1.4

addTreeWillExpandListener

public void addTreeWillExpandListener(TreeWillExpandListener tel)

Adds a listener for TreeWillExpand events.

Parameters:

tel - a TreeWillExpandListener that will be notified when a tree node will be expanded or collapsed (a "negative expansion")

removeTreeWillExpandListener

public void removeTreeWillExpandListener(TreeWillExpandListener tel)

Removes a listener for TreeWillExpand events.

Parameters:

tel - the TreeWillExpandListener to remove

getTreeWillExpandListeners

public TreeWillExpandListener[] getTreeWillExpandListeners()

Returns an array of all the TreeWillExpandListeners added to this JTree with addTreeWillExpandListener().

Returns:

all of the TreeWillExpandListeners added or an empty array if no listeners have been added

Since:

1.4

fireTreeExpanded

public void fireTreeExpanded(TreePath path)

Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the path parameter.

Parameters:

path - the TreePath indicating the node that was expanded

See Also:

EventListenerList

fireTreeCollapsed

public void fireTreeCollapsed(TreePath path)

Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the path parameter.

Parameters:

path - the TreePath indicating the node that was collapsed

See Also:

EventListenerList

fireTreeWillExpand

public void fireTreeWillExpand(TreePath path) throws ExpandVetoException

Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the path parameter.

Parameters:

path - the TreePath indicating the node that was expanded

Throws:

[ExpandVetoException](../../javax/swing/tree/ExpandVetoException.html "class in javax.swing.tree")

See Also:

EventListenerList

fireTreeWillCollapse

public void fireTreeWillCollapse(TreePath path) throws ExpandVetoException

Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the path parameter.

Parameters:

path - the TreePath indicating the node that was expanded

Throws:

[ExpandVetoException](../../javax/swing/tree/ExpandVetoException.html "class in javax.swing.tree")

See Also:

EventListenerList

addTreeSelectionListener

public void addTreeSelectionListener(TreeSelectionListener tsl)

Adds a listener for TreeSelection events.

Parameters:

tsl - the TreeSelectionListener that will be notified when a node is selected or deselected (a "negative selection")

removeTreeSelectionListener

public void removeTreeSelectionListener(TreeSelectionListener tsl)

Removes a TreeSelection listener.

Parameters:

tsl - the TreeSelectionListener to remove

getTreeSelectionListeners

public TreeSelectionListener[] getTreeSelectionListeners()

Returns an array of all the TreeSelectionListeners added to this JTree with addTreeSelectionListener().

Returns:

all of the TreeSelectionListeners added or an empty array if no listeners have been added

Since:

1.4

fireValueChanged

protected void fireValueChanged(TreeSelectionEvent e)

Notifies all listeners that have registered interest for notification on this event type.

Parameters:

e - the TreeSelectionEvent to be fired; generated by theTreeSelectionModel when a node is selected or deselected

See Also:

EventListenerList

treeDidChange

public 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). You should never have to invoke this, the UI will invoke this as it needs to.

setVisibleRowCount

public void setVisibleRowCount(int newCount)

Sets the number of rows that are to be displayed. This will only work if the tree is contained in a JScrollPane, and will adjust the preferred size and size of that scrollpane.

Parameters:

newCount - the number of rows to display

getVisibleRowCount

public int getVisibleRowCount()

Returns the number of rows that are displayed in the display area.

Returns:

the number of rows displayed

getNextMatch

public TreePath getNextMatch(String prefix, int startingRow, Position.Bias bias)

Returns the TreePath to the next tree element that begins with a prefix. To handle the conversion of aTreePath into a String, convertValueToText is used.

Parameters:

prefix - the string to test for a match

startingRow - the row for starting the search

bias - the search direction, either Position.Bias.Forward or Position.Bias.Backward.

Returns:

the TreePath of the next tree element that starts with the prefix; otherwise null

Throws:

[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang") - if prefix is null or startingRow is out of bounds

Since:

1.4

getPreferredScrollableViewportSize

public Dimension getPreferredScrollableViewportSize()

Returns the preferred display size of a JTree. The height is determined from getVisibleRowCount and the width is the current preferred width.

Specified by:

[getPreferredScrollableViewportSize](../../javax/swing/Scrollable.html#getPreferredScrollableViewportSize%28%29) in interface [Scrollable](../../javax/swing/Scrollable.html "interface in javax.swing")

Returns:

a Dimension object containing the preferred size

See Also:

JComponent.getPreferredSize()

getScrollableUnitIncrement

public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction)

Returns the amount to increment when scrolling. The amount is the height of the first displayed row that isn't completely in view or, if it is totally displayed, the height of the next row in the scrolling direction.

Specified by:

[getScrollableUnitIncrement](../../javax/swing/Scrollable.html#getScrollableUnitIncrement%28java.awt.Rectangle, int, int%29) in interface [Scrollable](../../javax/swing/Scrollable.html "interface in javax.swing")

Parameters:

visibleRect - the view area visible within the viewport

orientation - either SwingConstants.VERTICAL or SwingConstants.HORIZONTAL

direction - less than zero to scroll up/left, greater than zero for down/right

Returns:

the "unit" increment for scrolling in the specified direction

See Also:

JScrollBar.setUnitIncrement(int)

getScrollableBlockIncrement

public 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.

Specified by:

[getScrollableBlockIncrement](../../javax/swing/Scrollable.html#getScrollableBlockIncrement%28java.awt.Rectangle, int, int%29) in interface [Scrollable](../../javax/swing/Scrollable.html "interface in javax.swing")

Parameters:

visibleRect - the view area visible within the viewport

orientation - either SwingConstants.VERTICAL or SwingConstants.HORIZONTAL

direction - less than zero to scroll up/left, greater than zero for down/right.

Returns:

the "block" increment for scrolling in the specified direction

See Also:

JScrollBar.setBlockIncrement(int)

getScrollableTracksViewportWidth

public 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. In other words: ensure that the tree is never smaller than its viewport.

Specified by:

[getScrollableTracksViewportWidth](../../javax/swing/Scrollable.html#getScrollableTracksViewportWidth%28%29) in interface [Scrollable](../../javax/swing/Scrollable.html "interface in javax.swing")

Returns:

false

See Also:

Scrollable.getScrollableTracksViewportWidth()

getScrollableTracksViewportHeight

public 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. In other words: ensure that the tree is never smaller than its viewport.

Specified by:

[getScrollableTracksViewportHeight](../../javax/swing/Scrollable.html#getScrollableTracksViewportHeight%28%29) in interface [Scrollable](../../javax/swing/Scrollable.html "interface in javax.swing")

Returns:

false

See Also:

Scrollable.getScrollableTracksViewportHeight()

setExpandedState

protected void setExpandedState(TreePath path, boolean state)

Sets the expanded state of this JTree. If state is true, all parents of path and path are marked as expanded. If state is false, all parents of path are marked EXPANDED, but path itself is marked collapsed.

This will fail if a TreeWillExpandListener vetos it.

getDescendantToggledPaths

protected Enumeration<TreePath> getDescendantToggledPaths(TreePath parent)

Returns an Enumeration of TreePaths that have been expanded that are descendants of parent.

removeDescendantToggledPaths

protected void removeDescendantToggledPaths(Enumeration<TreePath> toRemove)

Removes any descendants of the TreePaths intoRemove that have been expanded.

clearToggledPaths

protected void clearToggledPaths()

Clears the cache of toggled tree paths. This does NOT send out any TreeExpansionListener events.

createTreeModelListener

protected TreeModelListener createTreeModelListener()

Creates and returns an instance of TreeModelHandler. The returned object is responsible for updating the expanded state when theTreeModel changes.

For more information on what expanded state means, see theJTree description above.

removeDescendantSelectedPaths

protected boolean removeDescendantSelectedPaths(TreePath path, boolean includePath)

Removes any paths in the selection that are descendants ofpath. If includePath is true andpath is selected, it will be removed from the selection.

Returns:

true if a descendant was selected

Since:

1.3

paramString

protected String paramString()

Returns a string representation of this JTree. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be null.

Overrides:

[paramString](../../javax/swing/JComponent.html#paramString%28%29) in class [JComponent](../../javax/swing/JComponent.html "class in javax.swing")

Returns:

a string representation of this JTree.

getAccessibleContext

public AccessibleContext getAccessibleContext()

Gets the AccessibleContext associated with this JTree. For JTrees, the AccessibleContext takes the form of an AccessibleJTree. A new AccessibleJTree instance is created if necessary.

Specified by:

[getAccessibleContext](../../javax/accessibility/Accessible.html#getAccessibleContext%28%29) in interface [Accessible](../../javax/accessibility/Accessible.html "interface in javax.accessibility")

Overrides:

[getAccessibleContext](../../javax/swing/JComponent.html#getAccessibleContext%28%29) in class [JComponent](../../javax/swing/JComponent.html "class in javax.swing")

Returns:

an AccessibleJTree that serves as the AccessibleContext of this JTree

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For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

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