# Class TreeUI

java.lang.Object
javax.swing.plaf.ComponentUI
javax.swing.plaf.TreeUI

Direct Known Subclasses:
  `BasicTreeUI, MultiTreeUI`

public abstract class TreeUI extends ComponentUI
Pluggable look and feel interface for JTree.

## Constructor Summary

Constructors
Modifier
Constructor
Description
`protected`
`TreeUI()`
Constructor for subclasses to call.

## Method Summary

Modifier and Type
Method
Description
`abstract void`
`cancelEditing(JTree tree)`
Cancels the current editing session.
`abstract TreePath`
`getClosestPathForLocation(JTree tree, int x, int y)`
Returns the path to the node that is closest to x,y.
`abstract TreePath`
`getEditingPath(JTree tree)`
Returns the path to the element that is being edited.
`abstract Rectangle`
`getPathBounds(JTree tree, TreePath path)`
Returns the Rectangle enclosing the label portion that the last item in path will be drawn into.
`abstract TreePath`
`getPathForRow(JTree tree, int row)`
Returns the path for passed in row.
`abstract int`
`getRowCount(JTree tree)`
Returns the number of rows that are being displayed.
`abstract int`
`getRowForPath(JTree tree, TreePath path)`
Returns the row that the last item identified in path is visible at.
`abstract boolean`
`isEditing(JTree tree)`
Returns true if the tree is being edited.
`abstract void`
`startEditingAtPath(JTree tree, TreePath path)`
Selects the last item in path and tries to edit it.
`abstract boolean`
`stopEditing(JTree tree)`
Stops the current editing session.

### Methods declared in class ComponentUI

`contains, createUI, getAccessibleChild, getAccessibleChildrenCount, getBaseline, getBaselineResizeBehavior, getMaximumSize, getMinimumSize, getPreferredSize, installUI, paint, uninstallUI, update`

### Methods declared in class Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

## Constructor Details

### TreeUI

protected TreeUI()
Constructor for subclasses to call.

## Method Details

### getPathBounds

public abstract Rectangle getPathBounds(JTree tree, TreePath path)
Returns the Rectangle enclosing the label portion that the last item in path will be drawn into. Will return null if any component in path is currently invalid.

Parameters:
  `tree` - the `JTree` for `path`
  `path` - the `TreePath` identifying the node
Returns:
  the `Rectangle` enclosing the label portion that the last item in path will be drawn into, `null` if any component in path is currently valid.

### getPathForRow

public abstract TreePath getPathForRow(JTree tree, int row)
Returns the path for passed in row. If row is not visible null is returned.

Parameters:
  `tree` - a `JTree` object
  `row` - an integer specifying a row
Returns:
  the `path` for `row` or `null` if `row` is not visible

### getRowForPath

public abstract int getRowForPath(JTree tree, TreePath path)
Returns the row that the last item identified in path is visible at. Will return -1 if any of the elements in path are not currently visible.

Parameters:
  `tree` - the `JTree` for `path`
  `path` - the `TreePath` object to look in
Returns:
  an integer specifying the row at which the last item identified is visible, -1 if any of the elements in `path` are not currently visible

### getRowCount

public abstract int getRowCount(JTree tree)
Returns the number of rows that are being displayed.

Parameters:
  `tree` - the `JTree` for which to count rows
Returns:
  an integer specifying the number of row being displayed

### getClosestPathForLocation

public abstract TreePath getClosestPathForLocation(JTree tree, int x, int y)
Returns the path to the node that is closest to x,y. If there is nothing currently visible this will return null, otherwise it'll always return a valid path. If you need to test if the returned object is exactly at x, y you should get the bounds for the returned path and test x, y against that.

Parameters:
  `tree` - a `JTree` object
  `x` - an integer giving the number of pixels horizontally from the left edge of the display area
  `y` - an integer giving the number of pixels vertically from the top of the display area, minus any top margin
Returns:
  the `TreePath` node closest to `x,y` or `null` if there is nothing currently visible

### isEditing

public abstract boolean isEditing(JTree tree)
Returns true if the tree is being edited. The item that is being edited can be returned by getEditingPath().

Parameters:
  `tree` - a `JTree` object
Returns:
  true if `tree` is being edited

### stopEditing

public abstract boolean stopEditing(JTree tree)
Stops the current editing session. This has no effect if the tree isn't being edited. Returns true if the editor allows the editing session to stop.

Parameters:
  `tree` - a `JTree` object
Returns:
  true if the editor allows the editing session to stop

### cancelEditing

public abstract void cancelEditing(JTree tree)
Cancels the current editing session. This has no effect if the tree isn't being edited.

Parameters:
  `tree` - a `JTree` object

### startEditingAtPath

public abstract void startEditingAtPath(JTree tree, TreePath path)
Selects the last item in path and tries to edit it. Editing will fail if the CellEditor won't allow it for the selected item.

Parameters:
  `tree` - the `JTree` being edited
  `path` - the `TreePath` to be edited

### getEditingPath

public abstract TreePath getEditingPath(JTree tree)
Returns the path to the element that is being edited.

Parameters:
  `tree` - the `JTree` for which to return a path
Returns:
  a `TreePath` containing the path to `tree`