# Class DefaultTreeSelectionModel

java.lang.Object
javax.swing.tree.DefaultTreeSelectionModel

All Implemented Interfaces:
  `Serializable, Cloneable, TreeSelectionModel`

Direct Known Subclasses:
  `JTree.EmptySelectionModel`

public class DefaultTreeSelectionModel extends Object implements Cloneable, Serializable, TreeSelectionModel
Default implementation of TreeSelectionModel. Listeners are notified whenever the paths in the selection change, not the rows. In order to be able to track row changes you may wish to become a listener for expansion events on the tree and test for changes from there.

resetRowSelection is called from any of the methods that update the selected paths. If you subclass any of these methods to filter what is allowed to be selected, be sure and message `resetRowSelection` if you do not message super. 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 has been added to the `java.beans` package. Please see `XMLEncoder`.

See Also:
  - `JTree`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `protected SwingPropertyChangeSupport`
  `changeSupport`
  Used to messaged registered listeners.
  `protected int`
  `leadIndex`
  Index of the lead path in selection.
  `protected TreePath`
  `leadPath`
  Last path that was added.
  `protected int`
  `leadRow`
  Lead row.
  `protected EventListenerList`
  `listenerList`
  Event listener list.
  `protected DefaultListSelectionModel`
  `listSelectionModel`
  Handles maintaining the list selection model.
  `protected RowMapper`
  `rowMapper`
  Provides a row for a given path.
  `protected TreePath[]`
  `selection`
  Paths that are currently selected.
  `static final String`
  `SELECTION_MODE_PROPERTY`
  Property name for selectionMode.
  `protected int`
  `selectionMode`
  Mode for the selection, will be either SINGLE_TREE_SELECTION, CONTIGUOUS_TREE_SELECTION or DISCONTIGUOUS_TREE_SELECTION.

  ### Fields declared in interface TreeSelectionModel

  `CONTIGUOUS_TREE_SELECTION, DISCONTIGUOUS_TREE_SELECTION, SINGLE_TREE_SELECTION`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `DefaultTreeSelectionModel()`
  Creates a new instance of DefaultTreeSelectionModel that is empty, with a selection mode of DISCONTIGUOUS_TREE_SELECTION.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `addPropertyChangeListener(PropertyChangeListener listener)`
  Adds a PropertyChangeListener to the listener list.
  `void`
  `addSelectionPath(TreePath path)`
  Adds path to the current selection.
  `void`
  `addSelectionPaths(TreePath[] paths)`
  Adds paths to the current selection.
  `void`
  `addTreeSelectionListener(TreeSelectionListener x)`
  Adds x to the list of listeners that are notified each time the set of selected TreePaths changes.
  `protected boolean`
  `arePathsContiguous(TreePath[] paths)`
  Returns true if the paths are contiguous, or this object has no RowMapper.
  `protected boolean`
  `canPathsBeAdded(TreePath[] paths)`
  Used to test if a particular set of `TreePath`s can be added.
  `protected boolean`
  `canPathsBeRemoved(TreePath[] paths)`
  Returns true if the paths can be removed without breaking the continuity of the model.
  `void`
  `clearSelection()`
  Empties the current selection.
  `Object`
  `clone()`
  Returns a clone of this object with the same selection.
  `protected void`
  `fireValueChanged(TreeSelectionEvent e)`
  Notifies all listeners that are registered for tree selection events on this object.
  `TreePath`
  `getLeadSelectionPath()`
  Returns the last path that was added.
  `int`
  `getLeadSelectionRow()`
  Returns the lead selection index.
  `<T extends EventListener>
  T[]`
  `getListeners(Class<T> listenerType)`
  Returns an array of all the objects currently registered as `FooListener`s upon this model.
  `int`
  `getMaxSelectionRow()`
  Returns the largest value obtained from the RowMapper for the current set of selected TreePaths.
  `int`
  `getMinSelectionRow()`
  Returns the smallest value obtained from the RowMapper for the current set of selected TreePaths.
  `PropertyChangeListener[]`
  `getPropertyChangeListeners()`
  Returns an array of all the property change listeners registered on this `DefaultTreeSelectionModel`.
  `RowMapper`
  `getRowMapper()`
  Returns the RowMapper instance that is able to map a TreePath to a row.
  `int`
  `getSelectionCount()`
  Returns the number of paths that are selected.
  `int`
  `getSelectionMode()`
  Returns the selection mode, one of `SINGLE_TREE_SELECTION`, `DISCONTIGUOUS_TREE_SELECTION` or `CONTIGUOUS_TREE_SELECTION`.
  `TreePath`
  `getSelectionPath()`
  Returns the first path in the selection.
  `TreePath[]`
  `getSelectionPaths()`
  Returns the selection.
  `int[]`
  `getSelectionRows()`
  Returns the selection in terms of rows.
  `TreeSelectionListener[]`
  `getTreeSelectionListeners()`
  Returns an array of all the tree selection listeners registered on this model.
  `protected void`
  `insureRowContinuity()`
  Makes sure the currently selected `TreePath`s are valid for the current selection mode.
  `protected void`
  `insureUniqueness()`
  This method is obsolete and its implementation is now a noop.
  `boolean`
  `isPathSelected(TreePath path)`
  Returns true if the path, `path`, is in the current selection.
  `boolean`
  `isRowSelected(int row)`
  Returns true if the row identified by `row` is selected.
  `boolean`
  `isSelectionEmpty()`
  Returns true if the selection is currently empty.
  `protected void`
  `notifyPathChange(Vector<?> changedPaths, TreePath oldLeadSelection)`
  Deprecated.
  As of JDK version 1.7
  `void`
  `removePropertyChangeListener(PropertyChangeListener listener)`
  Removes a PropertyChangeListener from the listener list.
  `void`
  `removeSelectionPath(TreePath path)`
  Removes path from the selection.
  `void`
  `removeSelectionPaths(TreePath[] paths)`
  Removes paths from the selection.
  `void`
  `removeTreeSelectionListener(TreeSelectionListener x)`
  Removes x from the list of listeners that are notified each time the set of selected TreePaths changes.
  `void`
  `resetRowSelection()`
  Updates this object's mapping from TreePath to rows.
  `void`
  `setRowMapper(RowMapper newMapper)`
  Sets the RowMapper instance.
  `void`
  `setSelectionMode(int mode)`
  Sets the selection model, which must be one of SINGLE_TREE_SELECTION, CONTIGUOUS_TREE_SELECTION or DISCONTIGUOUS_TREE_SELECTION.
  `void`
  `setSelectionPath(TreePath path)`
  Sets the selection to path.
  `void`
  `setSelectionPaths(TreePath[] pPaths)`
  Sets the selection.
  `String`
  `toString()`
  Returns a string that displays and identifies this object's properties.
  `protected void`
  `updateLeadIndex()`
  Updates the leadIndex instance variable.

  ### Methods declared in class Object

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

- ## Field Details

  - ### SELECTION_MODE_PROPERTY

    public static final String SELECTION_MODE_PROPERTY
    Property name for selectionMode.
    See Also:
      - Constant Field Values

  - ### changeSupport

    protected SwingPropertyChangeSupport changeSupport
    Used to messaged registered listeners.

  - ### selection

    protected TreePath[] selection
    Paths that are currently selected. Will be null if nothing is currently selected.

  - ### listenerList

    protected EventListenerList listenerList
    Event listener list.

  - ### rowMapper

    protected transient RowMapper rowMapper
    Provides a row for a given path.

  - ### listSelectionModel

    protected DefaultListSelectionModel listSelectionModel
    Handles maintaining the list selection model. The RowMapper is used to map from a TreePath to a row, and the value is then placed here.

  - ### selectionMode

    protected int selectionMode
    Mode for the selection, will be either SINGLE_TREE_SELECTION, CONTIGUOUS_TREE_SELECTION or DISCONTIGUOUS_TREE_SELECTION.

  - ### leadPath

    protected TreePath leadPath
    Last path that was added.

  - ### leadIndex

    protected int leadIndex
    Index of the lead path in selection.

  - ### leadRow

    protected int leadRow
    Lead row.

- ## Constructor Details

  - ### DefaultTreeSelectionModel

    public DefaultTreeSelectionModel()
    Creates a new instance of DefaultTreeSelectionModel that is empty, with a selection mode of DISCONTIGUOUS_TREE_SELECTION.

- ## Method Details

  - ### setRowMapper

    public void setRowMapper(RowMapper newMapper)
    Sets the RowMapper instance. This instance is used to determine the row for a particular TreePath.
    Specified by:
      `setRowMapper` in interface `TreeSelectionModel`
    Parameters:
      `newMapper` - RowMapper to be set

  - ### getRowMapper

    public RowMapper getRowMapper()
    Returns the RowMapper instance that is able to map a TreePath to a row.
    Specified by:
      `getRowMapper` in interface `TreeSelectionModel`
    Returns:
      the RowMapper instance that is able to map a TreePath to a row

  - ### setSelectionMode

    public void setSelectionMode(int mode)
    Sets the selection model, which must be one of SINGLE_TREE_SELECTION, CONTIGUOUS_TREE_SELECTION or DISCONTIGUOUS_TREE_SELECTION. If mode is not one of the defined value, `DISCONTIGUOUS_TREE_SELECTION` is assumed.

    This may change the selection if the current selection is not valid for the new mode. For example, if three TreePaths are selected when the mode is changed to `SINGLE_TREE_SELECTION`, only one TreePath will remain selected. It is up to the particular implementation to decide what TreePath remains selected.

    Setting the mode to something other than the defined types will result in the mode becoming `DISCONTIGUOUS_TREE_SELECTION`.

    Specified by:
      `setSelectionMode` in interface `TreeSelectionModel`
    Parameters:
      `mode` - selection mode to be set

  - ### getSelectionMode

    public int getSelectionMode()
    Returns the selection mode, one of `SINGLE_TREE_SELECTION`, `DISCONTIGUOUS_TREE_SELECTION` or `CONTIGUOUS_TREE_SELECTION`.
    Specified by:
      `getSelectionMode` in interface `TreeSelectionModel`
    Returns:
      the current selection mode

  - ### setSelectionPath

    public void setSelectionPath(TreePath path)
    Sets the selection to path. If this represents a change, then the TreeSelectionListeners are notified. If `path` is null, this has the same effect as invoking `clearSelection`.
    Specified by:
      `setSelectionPath` in interface `TreeSelectionModel`
    Parameters:
      `path` - new path to select

  - ### setSelectionPaths

    public void setSelectionPaths(TreePath[] pPaths)
    Sets the selection. Whether the supplied paths are taken as the new selection depends upon the selection mode. If the supplied array is `null`, or empty, the selection is cleared. If the selection mode is `SINGLE_TREE_SELECTION`, only the first path in `pPaths` is used. If the selection mode is `CONTIGUOUS_TREE_SELECTION` and the supplied paths are not contiguous, then only the first path in `pPaths` is used. If the selection mode is `DISCONTIGUOUS_TREE_SELECTION`, then all paths are used.

    All `null` paths in `pPaths` are ignored.

    If this represents a change, all registered `TreeSelectionListener`s are notified.

    The lead path is set to the last unique path.

    The paths returned from `getSelectionPaths` are in the same order as those supplied to this method.

    Specified by:
      `setSelectionPaths` in interface `TreeSelectionModel`
    Parameters:
      `pPaths` - the new selection

  - ### addSelectionPath

    public void addSelectionPath(TreePath path)
    Adds path to the current selection. If path is not currently in the selection the TreeSelectionListeners are notified. This has no effect if `path` is null.
    Specified by:
      `addSelectionPath` in interface `TreeSelectionModel`
    Parameters:
      `path` - the new path to add to the current selection

  - ### addSelectionPaths

    public void addSelectionPaths(TreePath[] paths)
    Adds paths to the current selection. If any of the paths in paths are not currently in the selection the TreeSelectionListeners are notified. This has no effect if `paths` is null.

    The lead path is set to the last element in `paths`.

    If the selection mode is `CONTIGUOUS_TREE_SELECTION`, and adding the new paths would make the selection discontiguous. Then two things can result: if the TreePaths in `paths` are contiguous, then the selection becomes these TreePaths, otherwise the TreePaths aren't contiguous and the selection becomes the first TreePath in `paths`.

    Specified by:
      `addSelectionPaths` in interface `TreeSelectionModel`
    Parameters:
      `paths` - the new path to add to the current selection

  - ### removeSelectionPath

    public void removeSelectionPath(TreePath path)
    Removes path from the selection. If path is in the selection The TreeSelectionListeners are notified. This has no effect if `path` is null.
    Specified by:
      `removeSelectionPath` in interface `TreeSelectionModel`
    Parameters:
      `path` - the path to remove from the selection

  - ### removeSelectionPaths

    public void removeSelectionPaths(TreePath[] paths)
    Removes paths from the selection. If any of the paths in paths are in the selection the TreeSelectionListeners are notified. This has no effect if `paths` is null.
    Specified by:
      `removeSelectionPaths` in interface `TreeSelectionModel`
    Parameters:
      `paths` - the paths to remove from the selection

  - ### getSelectionPath

    public TreePath getSelectionPath()
    Returns the first path in the selection. This is useful if there if only one item currently selected.
    Specified by:
      `getSelectionPath` in interface `TreeSelectionModel`
    Returns:
      the first path in the selection

  - ### getSelectionPaths

    public TreePath[] getSelectionPaths()
    Returns the selection.
    Specified by:
      `getSelectionPaths` in interface `TreeSelectionModel`
    Returns:
      the selection

  - ### getSelectionCount

    public int getSelectionCount()
    Returns the number of paths that are selected.
    Specified by:
      `getSelectionCount` in interface `TreeSelectionModel`
    Returns:
      the number of paths that are selected

  - ### isPathSelected

    public boolean isPathSelected(TreePath path)
    Returns true if the path, `path`, is in the current selection.
    Specified by:
      `isPathSelected` in interface `TreeSelectionModel`
    Parameters:
      `path` - the path to be looked for
    Returns:
      whether the `path` is in the current selection

  - ### isSelectionEmpty

    public boolean isSelectionEmpty()
    Returns true if the selection is currently empty.
    Specified by:
      `isSelectionEmpty` in interface `TreeSelectionModel`
    Returns:
      whether the selection is currently empty

  - ### clearSelection

    public void clearSelection()
    Empties the current selection. If this represents a change in the current selection, the selection listeners are notified.
    Specified by:
      `clearSelection` in interface `TreeSelectionModel`

  - ### addTreeSelectionListener

    public void addTreeSelectionListener(TreeSelectionListener x)
    Adds x to the list of listeners that are notified each time the set of selected TreePaths changes.
    Specified by:
      `addTreeSelectionListener` in interface `TreeSelectionModel`
    Parameters:
      `x` - the new listener to be added

  - ### removeTreeSelectionListener

    public void removeTreeSelectionListener(TreeSelectionListener x)
    Removes x from the list of listeners that are notified each time the set of selected TreePaths changes.
    Specified by:
      `removeTreeSelectionListener` in interface `TreeSelectionModel`
    Parameters:
      `x` - the listener to remove

  - ### getTreeSelectionListeners

    public TreeSelectionListener[] getTreeSelectionListeners()
    Returns an array of all the tree selection listeners registered on this model.
    Returns:
      all of this model's `TreeSelectionListener`s or an empty array if no tree selection listeners are currently registered
    Since:
      1.4
    See Also:
      - `addTreeSelectionListener(TreeSelectionListener)`
      - `removeTreeSelectionListener(TreeSelectionListener)`

  - ### fireValueChanged

    protected void fireValueChanged(TreeSelectionEvent e)
    Notifies all listeners that are registered for tree selection events on this object.
    Parameters:
      `e` - the event that characterizes the change
    See Also:
      - `addTreeSelectionListener(TreeSelectionListener)`
      - `EventListenerList`

  - ### getListeners

    public <T extends EventListener> T[] getListeners(Class<T> listenerType)
    Returns an array of all the objects currently registered as `FooListener`s upon this model. `FooListener`s 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 `DefaultTreeSelectionModel` `m` for its tree selection listeners with the following code:

        TreeSelectionListener[] tsls = (TreeSelectionListener[])(m.getListeners(TreeSelectionListener.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 `FooListener`s 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:
      - `getTreeSelectionListeners()`
      - `getPropertyChangeListeners()`

  - ### getSelectionRows

    public int[] getSelectionRows()
    Returns the selection in terms of rows. There is not necessarily a one-to-one mapping between the `TreePath`s returned from `getSelectionPaths` and this method. In particular, if a `TreePath` is not viewable (the `RowMapper` returns `-1` for the row corresponding to the `TreePath`), then the corresponding row is not included in the returned array. For example, if the selection consists of two paths, `A` and `B`, with `A` at row `10`, and `B` not currently viewable, then this method returns an array with the single entry `10`.
    Specified by:
      `getSelectionRows` in interface `TreeSelectionModel`
    Returns:
      the selection in terms of rows

  - ### getMinSelectionRow

    public int getMinSelectionRow()
    Returns the smallest value obtained from the RowMapper for the current set of selected TreePaths. If nothing is selected, or there is no RowMapper, this will return -1.
    Specified by:
      `getMinSelectionRow` in interface `TreeSelectionModel`
    Returns:
      the smallest value obtained from the RowMapper for the current set of selected TreePaths

  - ### getMaxSelectionRow

    public int getMaxSelectionRow()
    Returns the largest value obtained from the RowMapper for the current set of selected TreePaths. If nothing is selected, or there is no RowMapper, this will return -1.
    Specified by:
      `getMaxSelectionRow` in interface `TreeSelectionModel`
    Returns:
      the largest value obtained from the RowMapper for the current set of selected TreePaths

  - ### isRowSelected

    public boolean isRowSelected(int row)
    Returns true if the row identified by `row` is selected.
    Specified by:
      `isRowSelected` in interface `TreeSelectionModel`
    Parameters:
      `row` - row to check
    Returns:
      whether the row is selected

  - ### resetRowSelection

    public void resetRowSelection()
    Updates this object's mapping from TreePath to rows. This should be invoked when the mapping from TreePaths to integers has changed (for example, a node has been expanded).

    You do not normally have to call this, JTree and its associated Listeners will invoke this for you. If you are implementing your own View class, then you will have to invoke this.

    This will invoke `insureRowContinuity` to make sure the currently selected TreePaths are still valid based on the selection mode.

    Specified by:
      `resetRowSelection` in interface `TreeSelectionModel`

  - ### getLeadSelectionRow

    public int getLeadSelectionRow()
    Returns the lead selection index. That is the last index that was added.
    Specified by:
      `getLeadSelectionRow` in interface `TreeSelectionModel`
    Returns:
      the lead selection index

  - ### getLeadSelectionPath

    public TreePath getLeadSelectionPath()
    Returns the last path that was added. This may differ from the leadSelectionPath property maintained by the JTree.
    Specified by:
      `getLeadSelectionPath` in interface `TreeSelectionModel`
    Returns:
      the last path that was added

  - ### addPropertyChangeListener

    public void addPropertyChangeListener(PropertyChangeListener listener)
    Adds a PropertyChangeListener to the listener list. The listener is registered for all properties.

    A PropertyChangeEvent will get fired when the selection mode changes.

    Specified by:
      `addPropertyChangeListener` in interface `TreeSelectionModel`
    Parameters:
      `listener` - the PropertyChangeListener to be added

  - ### removePropertyChangeListener

    public void removePropertyChangeListener(PropertyChangeListener listener)
    Removes a PropertyChangeListener from the listener list. This removes a PropertyChangeListener that was registered for all properties.
    Specified by:
      `removePropertyChangeListener` in interface `TreeSelectionModel`
    Parameters:
      `listener` - the PropertyChangeListener to be removed

  - ### getPropertyChangeListeners

    public PropertyChangeListener[] getPropertyChangeListeners()
    Returns an array of all the property change listeners registered on this `DefaultTreeSelectionModel`.
    Returns:
      all of this model's `PropertyChangeListener`s or an empty array if no property change listeners are currently registered
    Since:
      1.4
    See Also:
      - `addPropertyChangeListener(PropertyChangeListener)`
      - `removePropertyChangeListener(PropertyChangeListener)`

  - ### insureRowContinuity

    protected void insureRowContinuity()
    Makes sure the currently selected `TreePath`s are valid for the current selection mode. If the selection mode is `CONTIGUOUS_TREE_SELECTION` and a `RowMapper` exists, this will make sure all the rows are contiguous, that is, when sorted all the rows are in order with no gaps. If the selection isn't contiguous, the selection is reset to contain the first set, when sorted, of contiguous rows.

    If the selection mode is `SINGLE_TREE_SELECTION` and more than one TreePath is selected, the selection is reset to contain the first path currently selected.

  - ### arePathsContiguous

    protected boolean arePathsContiguous(TreePath[] paths)
    Returns true if the paths are contiguous, or this object has no RowMapper.
    Parameters:
      `paths` - array of paths to check
    Returns:
      whether the paths are contiguous, or this object has no RowMapper

  - ### canPathsBeAdded

    protected boolean canPathsBeAdded(TreePath[] paths)
    Used to test if a particular set of `TreePath`s can be added. This will return true if `paths` is null (or empty), or this object has no RowMapper, or nothing is currently selected, or the selection mode is `DISCONTIGUOUS_TREE_SELECTION`, or adding the paths to the current selection still results in a contiguous set of `TreePath`s.
    Parameters:
      `paths` - array of `TreePaths` to check
    Returns:
      whether the particular set of `TreePaths` can be added

  - ### canPathsBeRemoved

    protected boolean canPathsBeRemoved(TreePath[] paths)
    Returns true if the paths can be removed without breaking the continuity of the model. This is rather expensive.
    Parameters:
      `paths` - array of `TreePath` to check
    Returns:
      whether the paths can be removed without breaking the continuity of the model

  - ### notifyPathChange

    @Deprecated protected void notifyPathChange(Vector<?> changedPaths, TreePath oldLeadSelection)
    Deprecated.
    As of JDK version 1.7
    Notifies listeners of a change in path. changePaths should contain instances of PathPlaceHolder.
    Parameters:
      `changedPaths` - the vector of the changed paths
      `oldLeadSelection` - the old selection path

  - ### updateLeadIndex

    protected void updateLeadIndex()
    Updates the leadIndex instance variable.

  - ### insureUniqueness

    protected void insureUniqueness()
    This method is obsolete and its implementation is now a noop. It's still called by setSelectionPaths and addSelectionPaths, but only for backwards compatibility.

  - ### toString

    public String toString()
    Returns a string that displays and identifies this object's properties.
    Overrides:
      `toString` in class `Object`
    Returns:
      a String representation of this object

  - ### clone

    public Object clone() throws CloneNotSupportedException
    Returns a clone of this object with the same selection. This method does not duplicate selection listeners and property listeners.
    Overrides:
      `clone` in class `Object`
    Returns:
      a clone of this instance.
    Throws:
      `CloneNotSupportedException` - never thrown by instances of this class
    See Also:
      - `Cloneable`