TreeModelpublic interface TreeModel The model used by JTree.
JTree and its related classes make extensive use of
TreePaths for indentifying nodes in the TreeModel.
If a TreeModel returns the same object, as compared by
equals, at two different indices under the same parent
than the resulting TreePath objects will be considered equal
as well. Some implementations may assume that if two
TreePaths are equal, they identify the same node. If this
condition is not met, painting problems and other oddities may result.
In other words, if getChild for a given parent returns
the same Object (as determined by equals) problems may
result, and it is recommended you avoid doing this.
Similarly JTree and its related classes place
TreePaths in Maps. As such if
a node is requested twice, the return values must be equal
(using the equals method) and have the same
hashCode.
For further information on tree models,
including an example of a custom implementation,
see How to Use Trees
in The Java Tutorial. |
| Methods Summary |
|---|
| public void | addTreeModelListener(TreeModelListener l)Adds a listener for the TreeModelEvent
posted after the tree changes.
| | public java.lang.Object | getChild(java.lang.Object parent, int index)Returns the child of parent at index index
in the parent's
child array. parent must be a node previously obtained
from this data source. This should not return null
if index
is a valid index for parent (that is index >= 0 &&
index < getChildCount(parent)).
| | public int | getChildCount(java.lang.Object parent)Returns the number of children of parent.
Returns 0 if the node
is a leaf or if it has no children. parent must be a node
previously obtained from this data source.
| | public int | getIndexOfChild(java.lang.Object parent, java.lang.Object child)Returns the index of child in parent. If either parent
or child is null, returns -1.
If either parent or child don't
belong to this tree model, returns -1.
| | public java.lang.Object | getRoot()Returns the root of the tree. Returns null
only if the tree has no nodes.
| | public boolean | isLeaf(java.lang.Object node)Returns true if node is a leaf.
It is possible for this method to return false
even if node has no children.
A directory in a filesystem, for example,
may contain no files; the node representing
the directory is not a leaf, but it also has no children.
| | public void | removeTreeModelListener(TreeModelListener l)Removes a listener previously added with
addTreeModelListener.
| | public void | valueForPathChanged(TreePath path, java.lang.Object newValue)Messaged when the user has altered the value for the item identified
by path to newValue.
If newValue signifies a truly new value
the model should post a treeNodesChanged event.
|
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