- All Implemented Interfaces:
Serializable
public class TreeModelEvent extends EventObject
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
.
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Field Summary
Fields Modifier and Type Field Description protected int[]
childIndices
Indices identifying the position of where the children were.protected Object[]
children
Children that have been removed.protected TreePath
path
Path to the parent of the nodes that have changed.Fields declared in class java.util.EventObject
source
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Constructor Summary
Constructors Constructor Description TreeModelEvent(Object source, Object[] path)
Used to create an event when the node structure has changed in some way, identifying the path to the root of a modified subtree as an array of Objects.TreeModelEvent(Object source, Object[] path, int[] childIndices, Object[] children)
Used to create an event when nodes have been changed, inserted, or removed, identifying the path to the parent of the modified items as an array of Objects.TreeModelEvent(Object source, TreePath path)
Used to create an event when the node structure has changed in some way, identifying the path to the root of the modified subtree as a TreePath object.TreeModelEvent(Object source, TreePath path, int[] childIndices, Object[] children)
Used to create an event when nodes have been changed, inserted, or removed, identifying the path to the parent of the modified items as a TreePath object. -
Method Summary
Modifier and Type Method Description int[]
getChildIndices()
Returns the values of the child indexes.Object[]
getChildren()
Returns the objects that are children of the node identified bygetPath
at the locations specified bygetChildIndices
.Object[]
getPath()
Convenience method to get the array of objects from the TreePath instance that this event wraps.TreePath
getTreePath()
For all events, except treeStructureChanged, returns the parent of the changed nodes.String
toString()
Returns a string that displays and identifies this object's properties.Methods declared in class java.util.EventObject
getSource
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Field Details
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path
Path to the parent of the nodes that have changed. -
childIndices
protected int[] childIndicesIndices identifying the position of where the children were. -
children
Children that have been removed.
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Constructor Details
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TreeModelEvent
Used to create an event when nodes have been changed, inserted, or removed, identifying the path to the parent of the modified items as an array of Objects. All of the modified objects are siblings which are direct descendents (not grandchildren) of the specified parent. The positions at which the inserts, deletes, or changes occurred are specified by an array ofint
. The indexes in that array must be in order, from lowest to highest.For changes, the indexes in the model correspond exactly to the indexes of items currently displayed in the UI. As a result, it is not really critical if the indexes are not in their exact order. But after multiple inserts or deletes, the items currently in the UI no longer correspond to the items in the model. It is therefore critical to specify the indexes properly for inserts and deletes.
For inserts, the indexes represent the final state of the tree, after the inserts have occurred. Since the indexes must be specified in order, the most natural processing methodology is to do the inserts starting at the lowest index and working towards the highest. Accumulate a Vector of
Integer
objects that specify the insert-locations as you go, then convert the Vector to an array ofint
to create the event. When the postition-index equals zero, the node is inserted at the beginning of the list. When the position index equals the size of the list, the node is "inserted" at (appended to) the end of the list.For deletes, the indexes represent the initial state of the tree, before the deletes have occurred. Since the indexes must be specified in order, the most natural processing methodology is to use a delete-counter. Start by initializing the counter to zero and start work through the list from lowest to highest. Every time you do a delete, add the current value of the delete-counter to the index-position where the delete occurred, and append the result to a Vector of delete-locations, using
addElement()
. Then increment the delete-counter. The index positions stored in the Vector therefore reflect the effects of all previous deletes, so they represent each object's position in the initial tree. (You could also start at the highest index and working back towards the lowest, accumulating a Vector of delete-locations as you go using theinsertElementAt(Integer, 0)
.) However you produce the Vector of initial-positions, you then need to convert the Vector ofInteger
objects to an array ofint
to create the event.Notes:
- Like the
insertNodeInto
method in theDefaultTreeModel
class,insertElementAt
appends to theVector
when the index matches the size of the vector. So you can useinsertElementAt(Integer, 0)
even when the vector is empty. - To create a node changed event for the root node, specify the parent
and the child indices as
null
.
- Parameters:
source
- the Object responsible for generating the event (typically the creator of the event object passesthis
for its value)path
- an array of Object identifying the path to the parent of the modified item(s), where the first element of the array is the Object stored at the root node and the last element is the Object stored at the parent nodechildIndices
- an array ofint
that specifies the index values of the removed items. The indices must be in sorted order, from lowest to highestchildren
- an array of Object containing the inserted, removed, or changed objects- See Also:
TreePath
- Like the
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TreeModelEvent
Used to create an event when nodes have been changed, inserted, or removed, identifying the path to the parent of the modified items as a TreePath object. For more information on how to specify the indexes and objects, seeTreeModelEvent(Object,Object[],int[],Object[])
.- Parameters:
source
- the Object responsible for generating the event (typically the creator of the event object passesthis
for its value)path
- a TreePath object that identifies the path to the parent of the modified item(s)childIndices
- an array ofint
that specifies the index values of the modified itemschildren
- an array of Object containing the inserted, removed, or changed objects- See Also:
TreeModelEvent(Object,Object[],int[],Object[])
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TreeModelEvent
Used to create an event when the node structure has changed in some way, identifying the path to the root of a modified subtree as an array of Objects. A structure change event might involve nodes swapping position, for example, or it might encapsulate multiple inserts and deletes in the subtree stemming from the node, where the changes may have taken place at different levels of the subtree.Note:
JTree collapses all nodes under the specified node, so that only its immediate children are visible.- Parameters:
source
- the Object responsible for generating the event (typically the creator of the event object passesthis
for its value)path
- an array of Object identifying the path to the root of the modified subtree, where the first element of the array is the object stored at the root node and the last element is the object stored at the changed node- See Also:
TreePath
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TreeModelEvent
Used to create an event when the node structure has changed in some way, identifying the path to the root of the modified subtree as a TreePath object. For more information on this event specification, seeTreeModelEvent(Object,Object[])
.- Parameters:
source
- the Object responsible for generating the event (typically the creator of the event object passesthis
for its value)path
- a TreePath object that identifies the path to the change. In the DefaultTreeModel, this object contains an array of user-data objects, but a subclass of TreePath could use some totally different mechanism -- for example, a node ID number- See Also:
TreeModelEvent(Object,Object[])
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Method Details
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getTreePath
For all events, except treeStructureChanged, returns the parent of the changed nodes. For treeStructureChanged events, returns the ancestor of the structure that has changed. This andgetChildIndices
are used to get a list of the effected nodes.The one exception to this is a treeNodesChanged event that is to identify the root, in which case this will return the root and
getChildIndices
will return null.- Returns:
- the TreePath used in identifying the changed nodes.
- See Also:
TreePath.getLastPathComponent()
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getPath
Convenience method to get the array of objects from the TreePath instance that this event wraps.- Returns:
- an array of Objects, where the first Object is the one stored at the root and the last object is the one stored at the node identified by the path
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getChildren
Returns the objects that are children of the node identified bygetPath
at the locations specified bygetChildIndices
. If this is a removal event the returned objects are no longer children of the parent node.- Returns:
- an array of Object containing the children specified by the event
- See Also:
getPath()
,getChildIndices()
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getChildIndices
public int[] getChildIndices()Returns the values of the child indexes. If this is a removal event the indexes point to locations in the initial list where items were removed. If it is an insert, the indices point to locations in the final list where the items were added. For node changes, the indices point to the locations of the modified nodes.- Returns:
- an array of
int
containing index locations for the children specified by the event
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toString
Returns a string that displays and identifies this object's properties.- Overrides:
toString
in classEventObject
- Returns:
- a String representation of this object
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