DefaultMutableTreeNode (Java Platform SE 6) (original) (raw)
javax.swing.tree
Class DefaultMutableTreeNode
java.lang.Object
javax.swing.tree.DefaultMutableTreeNode
All Implemented Interfaces:
Serializable, Cloneable, MutableTreeNode, TreeNode
Direct Known Subclasses:
public class DefaultMutableTreeNode
extends Object
implements Cloneable, MutableTreeNode, Serializable
A DefaultMutableTreeNode
is a general-purpose node in a tree data structure. For examples of using default mutable tree nodes, seeHow to Use Trees in The Java Tutorial.
A tree node may have at most one parent and 0 or more children.DefaultMutableTreeNode
provides operations for examining and modifying a node's parent and children and also operations for examining the tree that the node is a part of. A node's tree is the set of all nodes that can be reached by starting at the node and following all the possible links to parents and children. A node with no parent is the root of its tree; a node with no children is a leaf. A tree may consist of many subtrees, each node acting as the root for its own subtree.
This class provides enumerations for efficiently traversing a tree or subtree in various orders or for following the path between two nodes. A DefaultMutableTreeNode
may also hold a reference to a user object, the use of which is left to the user. Asking a DefaultMutableTreeNode
for its string representation with toString()
returns the string representation of its user object.
**This is not a thread safe class.**If you intend to use a DefaultMutableTreeNode (or a tree of TreeNodes) in more than one thread, you need to do your own synchronizing. A good convention to adopt is synchronizing on the root node of a tree.
While DefaultMutableTreeNode implements the MutableTreeNode interface and will allow you to add in any implementation of MutableTreeNode not all of the methods in DefaultMutableTreeNode will be applicable to all MutableTreeNodes implementations. Especially with some of the enumerations that are provided, using some of these methods assumes the DefaultMutableTreeNode contains only DefaultMutableNode instances. All of the TreeNode/MutableTreeNode methods will behave as defined no matter what implementations are added.
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.
See Also:
Field Summary | |
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protected boolean | allowsChildren true if the node is able to have children |
protected Vector | children array of children, may be null if this node has no children |
static Enumeration<TreeNode> | EMPTY_ENUMERATION An enumeration that is always empty. |
protected MutableTreeNode | parent this node's parent, or null if this node has no parent |
protected Object | userObject optional user object |
Constructor Summary |
---|
DefaultMutableTreeNode() Creates a tree node that has no parent and no children, but which allows children. |
DefaultMutableTreeNode(Object userObject) Creates a tree node with no parent, no children, but which allows children, and initializes it with the specified user object. |
[DefaultMutableTreeNode](../../../javax/swing/tree/DefaultMutableTreeNode.html#DefaultMutableTreeNode%28java.lang.Object, boolean%29)(Object userObject, boolean allowsChildren) Creates a tree node with no parent, no children, initialized with the specified user object, and that allows children only if specified. |
Method Summary | |
---|---|
void | add(MutableTreeNode newChild) Removes newChild from its parent and makes it a child of this node by adding it to the end of this node's child array. |
Enumeration | breadthFirstEnumeration() Creates and returns an enumeration that traverses the subtree rooted at this node in breadth-first order. |
Enumeration | children() Creates and returns a forward-order enumeration of this node's children. |
Object | clone() Overridden to make clone public. |
Enumeration | depthFirstEnumeration() Creates and returns an enumeration that traverses the subtree rooted at this node in depth-first order. |
boolean | getAllowsChildren() Returns true if this node is allowed to have children. |
TreeNode | getChildAfter(TreeNode aChild) Returns the child in this node's child array that immediately follows aChild, which must be a child of this node. |
TreeNode | getChildAt(int index) Returns the child at the specified index in this node's child array. |
TreeNode | getChildBefore(TreeNode aChild) Returns the child in this node's child array that immediately precedes aChild, which must be a child of this node. |
int | getChildCount() Returns the number of children of this node. |
int | getDepth() Returns the depth of the tree rooted at this node -- the longest distance from this node to a leaf. |
TreeNode | getFirstChild() Returns this node's first child. |
DefaultMutableTreeNode | getFirstLeaf() Finds and returns the first leaf that is a descendant of this node -- either this node or its first child's first leaf. |
int | getIndex(TreeNode aChild) Returns the index of the specified child in this node's child array. |
TreeNode | getLastChild() Returns this node's last child. |
DefaultMutableTreeNode | getLastLeaf() Finds and returns the last leaf that is a descendant of this node -- either this node or its last child's last leaf. |
int | getLeafCount() Returns the total number of leaves that are descendants of this node. |
int | getLevel() Returns the number of levels above this node -- the distance from the root to this node. |
DefaultMutableTreeNode | getNextLeaf() Returns the leaf after this node or null if this node is the last leaf in the tree. |
DefaultMutableTreeNode | getNextNode() Returns the node that follows this node in a preorder traversal of this node's tree. |
DefaultMutableTreeNode | getNextSibling() Returns the next sibling of this node in the parent's children array. |
TreeNode | getParent() Returns this node's parent or null if this node has no parent. |
TreeNode[] | getPath() Returns the path from the root, to get to this node. |
protected TreeNode[] | [getPathToRoot](../../../javax/swing/tree/DefaultMutableTreeNode.html#getPathToRoot%28javax.swing.tree.TreeNode, int%29)(TreeNode aNode, int depth) Builds the parents of node up to and including the root node, where the original node is the last element in the returned array. |
DefaultMutableTreeNode | getPreviousLeaf() Returns the leaf before this node or null if this node is the first leaf in the tree. |
DefaultMutableTreeNode | getPreviousNode() Returns the node that precedes this node in a preorder traversal of this node's tree. |
DefaultMutableTreeNode | getPreviousSibling() Returns the previous sibling of this node in the parent's children array. |
TreeNode | getRoot() Returns the root of the tree that contains this node. |
TreeNode | getSharedAncestor(DefaultMutableTreeNode aNode) Returns the nearest common ancestor to this node and aNode. |
int | getSiblingCount() Returns the number of siblings of this node. |
Object | getUserObject() Returns this node's user object. |
Object[] | getUserObjectPath() Returns the user object path, from the root, to get to this node. |
void | [insert](../../../javax/swing/tree/DefaultMutableTreeNode.html#insert%28javax.swing.tree.MutableTreeNode, int%29)(MutableTreeNode newChild, int childIndex) Removes newChild from its present parent (if it has a parent), sets the child's parent to this node, and then adds the child to this node's child array at index childIndex. |
boolean | isLeaf() Returns true if this node has no children. |
boolean | isNodeAncestor(TreeNode anotherNode) Returns true if anotherNode is an ancestor of this node -- if it is this node, this node's parent, or an ancestor of this node's parent. |
boolean | isNodeChild(TreeNode aNode) Returns true if aNode is a child of this node. |
boolean | isNodeDescendant(DefaultMutableTreeNode anotherNode) Returns true if anotherNode is a descendant of this node -- if it is this node, one of this node's children, or a descendant of one of this node's children. |
boolean | isNodeRelated(DefaultMutableTreeNode aNode) Returns true if and only if aNode is in the same tree as this node. |
boolean | isNodeSibling(TreeNode anotherNode) Returns true if anotherNode is a sibling of (has the same parent as) this node. |
boolean | isRoot() Returns true if this node is the root of the tree. |
Enumeration | pathFromAncestorEnumeration(TreeNode ancestor) Creates and returns an enumeration that follows the path fromancestor to this node. |
Enumeration | postorderEnumeration() Creates and returns an enumeration that traverses the subtree rooted at this node in postorder. |
Enumeration | preorderEnumeration() Creates and returns an enumeration that traverses the subtree rooted at this node in preorder. |
void | remove(int childIndex) Removes the child at the specified index from this node's children and sets that node's parent to null. |
void | remove(MutableTreeNode aChild) Removes aChild from this node's child array, giving it a null parent. |
void | removeAllChildren() Removes all of this node's children, setting their parents to null. |
void | removeFromParent() Removes the subtree rooted at this node from the tree, giving this node a null parent. |
void | setAllowsChildren(boolean allows) Determines whether or not this node is allowed to have children. |
void | setParent(MutableTreeNode newParent) Sets this node's parent to newParent but does not change the parent's child array. |
void | setUserObject(Object userObject) Sets the user object for this node to userObject. |
String | toString() Returns the result of sending toString() to this node's user object, or null if this node has no user object. |
Methods inherited from class java.lang.Object |
---|
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, [wait](../../../java/lang/Object.html#wait%28long, int%29) |
Field Detail |
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EMPTY_ENUMERATION
public static final Enumeration<TreeNode> EMPTY_ENUMERATION
An enumeration that is always empty. This is used when an enumeration of a leaf node's children is requested.
parent
protected MutableTreeNode parent
this node's parent, or null if this node has no parent
children
protected Vector children
array of children, may be null if this node has no children
userObject
protected transient Object userObject
optional user object
allowsChildren
protected boolean allowsChildren
true if the node is able to have children
Constructor Detail |
---|
DefaultMutableTreeNode
public DefaultMutableTreeNode()
Creates a tree node that has no parent and no children, but which allows children.
DefaultMutableTreeNode
public DefaultMutableTreeNode(Object userObject)
Creates a tree node with no parent, no children, but which allows children, and initializes it with the specified user object.
Parameters:
userObject
- an Object provided by the user that constitutes the node's data
DefaultMutableTreeNode
public DefaultMutableTreeNode(Object userObject, boolean allowsChildren)
Creates a tree node with no parent, no children, initialized with the specified user object, and that allows children only if specified.
Parameters:
userObject
- an Object provided by the user that constitutes the node's data
allowsChildren
- if true, the node is allowed to have child nodes -- otherwise, it is always a leaf node
Method Detail |
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insert
public void insert(MutableTreeNode newChild, int childIndex)
Removes newChild
from its present parent (if it has a parent), sets the child's parent to this node, and then adds the child to this node's child array at index childIndex
.newChild
must not be null and must not be an ancestor of this node.
Specified by:
[insert](../../../javax/swing/tree/MutableTreeNode.html#insert%28javax.swing.tree.MutableTreeNode, int%29)
in interface [MutableTreeNode](../../../javax/swing/tree/MutableTreeNode.html "interface in javax.swing.tree")
Parameters:
newChild
- the MutableTreeNode to insert under this node
childIndex
- the index in this node's child array where this node is to be inserted
Throws:
[ArrayIndexOutOfBoundsException](../../../java/lang/ArrayIndexOutOfBoundsException.html "class in java.lang")
- ifchildIndex
is out of bounds
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- ifnewChild
is null or is an ancestor of this node
[IllegalStateException](../../../java/lang/IllegalStateException.html "class in java.lang")
- if this node does not allow children
See Also:
isNodeDescendant(javax.swing.tree.DefaultMutableTreeNode)
remove
public void remove(int childIndex)
Removes the child at the specified index from this node's children and sets that node's parent to null. The child node to remove must be a MutableTreeNode
.
Specified by:
[remove](../../../javax/swing/tree/MutableTreeNode.html#remove%28int%29)
in interface [MutableTreeNode](../../../javax/swing/tree/MutableTreeNode.html "interface in javax.swing.tree")
Parameters:
childIndex
- the index in this node's child array of the child to remove
Throws:
[ArrayIndexOutOfBoundsException](../../../java/lang/ArrayIndexOutOfBoundsException.html "class in java.lang")
- ifchildIndex
is out of bounds
setParent
public void setParent(MutableTreeNode newParent)
Sets this node's parent to newParent
but does not change the parent's child array. This method is called frominsert()
and remove()
to reassign a child's parent, it should not be messaged from anywhere else.
Specified by:
[setParent](../../../javax/swing/tree/MutableTreeNode.html#setParent%28javax.swing.tree.MutableTreeNode%29)
in interface [MutableTreeNode](../../../javax/swing/tree/MutableTreeNode.html "interface in javax.swing.tree")
Parameters:
newParent
- this node's new parent
getParent
public TreeNode getParent()
Returns this node's parent or null if this node has no parent.
Specified by:
[getParent](../../../javax/swing/tree/TreeNode.html#getParent%28%29)
in interface [TreeNode](../../../javax/swing/tree/TreeNode.html "interface in javax.swing.tree")
Returns:
this node's parent TreeNode, or null if this node has no parent
getChildAt
public TreeNode getChildAt(int index)
Returns the child at the specified index in this node's child array.
Specified by:
[getChildAt](../../../javax/swing/tree/TreeNode.html#getChildAt%28int%29)
in interface [TreeNode](../../../javax/swing/tree/TreeNode.html "interface in javax.swing.tree")
Parameters:
index
- an index into this node's child array
Returns:
the TreeNode in this node's child array at the specified index
Throws:
[ArrayIndexOutOfBoundsException](../../../java/lang/ArrayIndexOutOfBoundsException.html "class in java.lang")
- if index
is out of bounds
getChildCount
public int getChildCount()
Returns the number of children of this node.
Specified by:
[getChildCount](../../../javax/swing/tree/TreeNode.html#getChildCount%28%29)
in interface [TreeNode](../../../javax/swing/tree/TreeNode.html "interface in javax.swing.tree")
Returns:
an int giving the number of children of this node
getIndex
public int getIndex(TreeNode aChild)
Returns the index of the specified child in this node's child array. If the specified node is not a child of this node, returns-1
. This method performs a linear search and is O(n) where n is the number of children.
Specified by:
[getIndex](../../../javax/swing/tree/TreeNode.html#getIndex%28javax.swing.tree.TreeNode%29)
in interface [TreeNode](../../../javax/swing/tree/TreeNode.html "interface in javax.swing.tree")
Parameters:
aChild
- the TreeNode to search for among this node's children
Returns:
an int giving the index of the node in this node's child array, or -1
if the specified node is a not a child of this node
Throws:
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- if aChild
is null
children
public Enumeration children()
Creates and returns a forward-order enumeration of this node's children. Modifying this node's child array invalidates any child enumerations created before the modification.
Specified by:
[children](../../../javax/swing/tree/TreeNode.html#children%28%29)
in interface [TreeNode](../../../javax/swing/tree/TreeNode.html "interface in javax.swing.tree")
Returns:
an Enumeration of this node's children
setAllowsChildren
public void setAllowsChildren(boolean allows)
Determines whether or not this node is allowed to have children. If allows
is false, all of this node's children are removed.
Note: By default, a node allows children.
Parameters:
allows
- true if this node is allowed to have children
getAllowsChildren
public boolean getAllowsChildren()
Returns true if this node is allowed to have children.
Specified by:
[getAllowsChildren](../../../javax/swing/tree/TreeNode.html#getAllowsChildren%28%29)
in interface [TreeNode](../../../javax/swing/tree/TreeNode.html "interface in javax.swing.tree")
Returns:
true if this node allows children, else false
setUserObject
public void setUserObject(Object userObject)
Sets the user object for this node to userObject
.
Specified by:
[setUserObject](../../../javax/swing/tree/MutableTreeNode.html#setUserObject%28java.lang.Object%29)
in interface [MutableTreeNode](../../../javax/swing/tree/MutableTreeNode.html "interface in javax.swing.tree")
Parameters:
userObject
- the Object that constitutes this node's user-specified data
See Also:
getUserObject
public Object getUserObject()
Returns this node's user object.
Returns:
the Object stored at this node by the user
See Also:
setUserObject(java.lang.Object), toString()
removeFromParent
public void removeFromParent()
Removes the subtree rooted at this node from the tree, giving this node a null parent. Does nothing if this node is the root of its tree.
Specified by:
[removeFromParent](../../../javax/swing/tree/MutableTreeNode.html#removeFromParent%28%29)
in interface [MutableTreeNode](../../../javax/swing/tree/MutableTreeNode.html "interface in javax.swing.tree")
remove
public void remove(MutableTreeNode aChild)
Removes aChild
from this node's child array, giving it a null parent.
Specified by:
[remove](../../../javax/swing/tree/MutableTreeNode.html#remove%28javax.swing.tree.MutableTreeNode%29)
in interface [MutableTreeNode](../../../javax/swing/tree/MutableTreeNode.html "interface in javax.swing.tree")
Parameters:
aChild
- a child of this node to remove
Throws:
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- if aChild
is null or is not a child of this node
removeAllChildren
public void removeAllChildren()
Removes all of this node's children, setting their parents to null. If this node has no children, this method does nothing.
add
public void add(MutableTreeNode newChild)
Removes newChild
from its parent and makes it a child of this node by adding it to the end of this node's child array.
Parameters:
newChild
- node to add as a child of this node
Throws:
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- if newChild
is null
[IllegalStateException](../../../java/lang/IllegalStateException.html "class in java.lang")
- if this node does not allow children
See Also:
[insert(javax.swing.tree.MutableTreeNode, int)](../../../javax/swing/tree/DefaultMutableTreeNode.html#insert%28javax.swing.tree.MutableTreeNode, int%29)
isNodeAncestor
public boolean isNodeAncestor(TreeNode anotherNode)
Returns true if anotherNode
is an ancestor of this node -- if it is this node, this node's parent, or an ancestor of this node's parent. (Note that a node is considered an ancestor of itself.) If anotherNode
is null, this method returns false. This operation is at worst O(h) where h is the distance from the root to this node.
Parameters:
anotherNode
- node to test as an ancestor of this node
Returns:
true if this node is a descendant of anotherNode
See Also:
isNodeDescendant(javax.swing.tree.DefaultMutableTreeNode), getSharedAncestor(javax.swing.tree.DefaultMutableTreeNode)
isNodeDescendant
public boolean isNodeDescendant(DefaultMutableTreeNode anotherNode)
Returns true if anotherNode
is a descendant of this node -- if it is this node, one of this node's children, or a descendant of one of this node's children. Note that a node is considered a descendant of itself. If anotherNode
is null, returns false. This operation is at worst O(h) where h is the distance from the root to anotherNode
.
Parameters:
anotherNode
- node to test as descendant of this node
Returns:
true if this node is an ancestor of anotherNode
See Also:
isNodeAncestor(javax.swing.tree.TreeNode), getSharedAncestor(javax.swing.tree.DefaultMutableTreeNode)
getSharedAncestor
public TreeNode getSharedAncestor(DefaultMutableTreeNode aNode)
Returns the nearest common ancestor to this node and aNode
. Returns null, if no such ancestor exists -- if this node andaNode
are in different trees or if aNode
is null. A node is considered an ancestor of itself.
Parameters:
aNode
- node to find common ancestor with
Returns:
nearest ancestor common to this node and aNode
, or null if none
See Also:
isNodeAncestor(javax.swing.tree.TreeNode), isNodeDescendant(javax.swing.tree.DefaultMutableTreeNode)
isNodeRelated
public boolean isNodeRelated(DefaultMutableTreeNode aNode)
Returns true if and only if aNode
is in the same tree as this node. Returns false if aNode
is null.
Returns:
true if aNode
is in the same tree as this node; false if aNode
is null
See Also:
getSharedAncestor(javax.swing.tree.DefaultMutableTreeNode), getRoot()
getDepth
public int getDepth()
Returns the depth of the tree rooted at this node -- the longest distance from this node to a leaf. If this node has no children, returns 0. This operation is much more expensive thangetLevel()
because it must effectively traverse the entire tree rooted at this node.
Returns:
the depth of the tree whose root is this node
See Also:
getLevel
public int getLevel()
Returns the number of levels above this node -- the distance from the root to this node. If this node is the root, returns 0.
Returns:
the number of levels above this node
See Also:
getPath
public TreeNode[] getPath()
Returns the path from the root, to get to this node. The last element in the path is this node.
Returns:
an array of TreeNode objects giving the path, where the first element in the path is the root and the last element is this node.
getPathToRoot
protected TreeNode[] getPathToRoot(TreeNode aNode, int depth)
Builds the parents of node up to and including the root node, where the original node is the last element in the returned array. The length of the returned array gives the node's depth in the tree.
Parameters:
aNode
- the TreeNode to get the path for
depth
- an int giving the number of steps already taken towards the root (on recursive calls), used to size the returned array
Returns:
an array of TreeNodes giving the path from the root to the specified node
getUserObjectPath
public Object[] getUserObjectPath()
Returns the user object path, from the root, to get to this node. If some of the TreeNodes in the path have null user objects, the returned path will contain nulls.
getRoot
public TreeNode getRoot()
Returns the root of the tree that contains this node. The root is the ancestor with a null parent.
Returns:
the root of the tree that contains this node
See Also:
isNodeAncestor(javax.swing.tree.TreeNode)
isRoot
public boolean isRoot()
Returns true if this node is the root of the tree. The root is the only node in the tree with a null parent; every tree has exactly one root.
Returns:
true if this node is the root of its tree
getNextNode
public DefaultMutableTreeNode getNextNode()
Returns the node that follows this node in a preorder traversal of this node's tree. Returns null if this node is the last node of the traversal. This is an inefficient way to traverse the entire tree; use an enumeration, instead.
Returns:
the node that follows this node in a preorder traversal, or null if this node is last
See Also:
getPreviousNode
public DefaultMutableTreeNode getPreviousNode()
Returns the node that precedes this node in a preorder traversal of this node's tree. Returns null
if this node is the first node of the traversal -- the root of the tree. This is an inefficient way to traverse the entire tree; use an enumeration, instead.
Returns:
the node that precedes this node in a preorder traversal, or null if this node is the first
See Also:
preorderEnumeration
public Enumeration preorderEnumeration()
Creates and returns an enumeration that traverses the subtree rooted at this node in preorder. The first node returned by the enumeration'snextElement()
method is this node.
Modifying the tree by inserting, removing, or moving a node invalidates any enumerations created before the modification.
Returns:
an enumeration for traversing the tree in preorder
See Also:
postorderEnumeration
public Enumeration postorderEnumeration()
Creates and returns an enumeration that traverses the subtree rooted at this node in postorder. The first node returned by the enumeration'snextElement()
method is the leftmost leaf. This is the same as a depth-first traversal.
Modifying the tree by inserting, removing, or moving a node invalidates any enumerations created before the modification.
Returns:
an enumeration for traversing the tree in postorder
See Also:
depthFirstEnumeration(), preorderEnumeration()
breadthFirstEnumeration
public Enumeration breadthFirstEnumeration()
Creates and returns an enumeration that traverses the subtree rooted at this node in breadth-first order. The first node returned by the enumeration's nextElement()
method is this node.
Modifying the tree by inserting, removing, or moving a node invalidates any enumerations created before the modification.
Returns:
an enumeration for traversing the tree in breadth-first order
See Also:
depthFirstEnumeration
public Enumeration depthFirstEnumeration()
Creates and returns an enumeration that traverses the subtree rooted at this node in depth-first order. The first node returned by the enumeration's nextElement()
method is the leftmost leaf. This is the same as a postorder traversal.
Modifying the tree by inserting, removing, or moving a node invalidates any enumerations created before the modification.
Returns:
an enumeration for traversing the tree in depth-first order
See Also:
breadthFirstEnumeration(), postorderEnumeration()
pathFromAncestorEnumeration
public Enumeration pathFromAncestorEnumeration(TreeNode ancestor)
Creates and returns an enumeration that follows the path fromancestor
to this node. The enumeration'snextElement()
method first returns ancestor
, then the child of ancestor
that is an ancestor of this node, and so on, and finally returns this node. Creation of the enumeration is O(m) where m is the number of nodes between this node and ancestor
, inclusive. Each nextElement()
message is O(1).
Modifying the tree by inserting, removing, or moving a node invalidates any enumerations created before the modification.
Returns:
an enumeration for following the path from an ancestor of this node to this one
Throws:
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- if ancestor
is not an ancestor of this node
See Also:
isNodeAncestor(javax.swing.tree.TreeNode), isNodeDescendant(javax.swing.tree.DefaultMutableTreeNode)
isNodeChild
public boolean isNodeChild(TreeNode aNode)
Returns true if aNode
is a child of this node. IfaNode
is null, this method returns false.
Returns:
true if aNode
is a child of this node; false if aNode
is null
getFirstChild
public TreeNode getFirstChild()
Returns this node's first child. If this node has no children, throws NoSuchElementException.
Returns:
the first child of this node
Throws:
[NoSuchElementException](../../../java/util/NoSuchElementException.html "class in java.util")
- if this node has no children
getLastChild
public TreeNode getLastChild()
Returns this node's last child. If this node has no children, throws NoSuchElementException.
Returns:
the last child of this node
Throws:
[NoSuchElementException](../../../java/util/NoSuchElementException.html "class in java.util")
- if this node has no children
getChildAfter
public TreeNode getChildAfter(TreeNode aChild)
Returns the child in this node's child array that immediately follows aChild
, which must be a child of this node. IfaChild
is the last child, returns null. This method performs a linear search of this node's children foraChild
and is O(n) where n is the number of children; to traverse the entire array of children, use an enumeration instead.
Returns:
the child of this node that immediately followsaChild
Throws:
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- if aChild
is null or is not a child of this node
See Also:
getChildBefore
public TreeNode getChildBefore(TreeNode aChild)
Returns the child in this node's child array that immediately precedes aChild
, which must be a child of this node. IfaChild
is the first child, returns null. This method performs a linear search of this node's children for aChild
and is O(n) where n is the number of children.
Returns:
the child of this node that immediately precedesaChild
Throws:
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- if aChild
is null or is not a child of this node
isNodeSibling
public boolean isNodeSibling(TreeNode anotherNode)
Returns true if anotherNode
is a sibling of (has the same parent as) this node. A node is its own sibling. IfanotherNode
is null, returns false.
Parameters:
anotherNode
- node to test as sibling of this node
Returns:
true if anotherNode
is a sibling of this node
getSiblingCount
public int getSiblingCount()
Returns the number of siblings of this node. A node is its own sibling (if it has no parent or no siblings, this method returns1
).
Returns:
the number of siblings of this node
getNextSibling
public DefaultMutableTreeNode getNextSibling()
Returns the next sibling of this node in the parent's children array. Returns null if this node has no parent or is the parent's last child. This method performs a linear search that is O(n) where n is the number of children; to traverse the entire array, use the parent's child enumeration instead.
Returns:
the sibling of this node that immediately follows this node
See Also:
getPreviousSibling
public DefaultMutableTreeNode getPreviousSibling()
Returns the previous sibling of this node in the parent's children array. Returns null if this node has no parent or is the parent's first child. This method performs a linear search that is O(n) where n is the number of children.
Returns:
the sibling of this node that immediately precedes this node
isLeaf
public boolean isLeaf()
Returns true if this node has no children. To distinguish between nodes that have no children and nodes that cannot have children (e.g. to distinguish files from empty directories), use this method in conjunction with getAllowsChildren
Specified by:
[isLeaf](../../../javax/swing/tree/TreeNode.html#isLeaf%28%29)
in interface [TreeNode](../../../javax/swing/tree/TreeNode.html "interface in javax.swing.tree")
Returns:
true if this node has no children
See Also:
getFirstLeaf
public DefaultMutableTreeNode getFirstLeaf()
Finds and returns the first leaf that is a descendant of this node -- either this node or its first child's first leaf. Returns this node if it is a leaf.
Returns:
the first leaf in the subtree rooted at this node
See Also:
isLeaf(), isNodeDescendant(javax.swing.tree.DefaultMutableTreeNode)
getLastLeaf
public DefaultMutableTreeNode getLastLeaf()
Finds and returns the last leaf that is a descendant of this node -- either this node or its last child's last leaf. Returns this node if it is a leaf.
Returns:
the last leaf in the subtree rooted at this node
See Also:
isLeaf(), isNodeDescendant(javax.swing.tree.DefaultMutableTreeNode)
getNextLeaf
public DefaultMutableTreeNode getNextLeaf()
Returns the leaf after this node or null if this node is the last leaf in the tree.
In this implementation of the MutableNode
interface, this operation is very inefficient. In order to determine the next node, this method first performs a linear search in the parent's child-list in order to find the current node.
That implementation makes the operation suitable for short traversals from a known position. But to traverse all of the leaves in the tree, you should use depthFirstEnumeration
to enumerate the nodes in the tree and use isLeaf
on each node to determine which are leaves.
Returns:
returns the next leaf past this node
See Also:
depthFirstEnumeration(), isLeaf()
getPreviousLeaf
public DefaultMutableTreeNode getPreviousLeaf()
Returns the leaf before this node or null if this node is the first leaf in the tree.
In this implementation of the MutableNode
interface, this operation is very inefficient. In order to determine the previous node, this method first performs a linear search in the parent's child-list in order to find the current node.
That implementation makes the operation suitable for short traversals from a known position. But to traverse all of the leaves in the tree, you should use depthFirstEnumeration
to enumerate the nodes in the tree and use isLeaf
on each node to determine which are leaves.
Returns:
returns the leaf before this node
See Also:
depthFirstEnumeration(), isLeaf()
getLeafCount
public int getLeafCount()
Returns the total number of leaves that are descendants of this node. If this node is a leaf, returns 1
. This method is O(n) where n is the number of descendants of this node.
Returns:
the number of leaves beneath this node
See Also:
isNodeAncestor(javax.swing.tree.TreeNode)
toString
public String toString()
Returns the result of sending toString()
to this node's user object, or null if this node has no user object.
Overrides:
[toString](../../../java/lang/Object.html#toString%28%29)
in class [Object](../../../java/lang/Object.html "class in java.lang")
Returns:
a string representation of the object.
See Also:
clone
public Object clone()
Overridden to make clone public. Returns a shallow copy of this node; the new node has no parent or children and has a reference to the same user object, if any.
Overrides:
[clone](../../../java/lang/Object.html#clone%28%29)
in class [Object](../../../java/lang/Object.html "class in java.lang")
Returns:
a copy of this node
See Also:
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