Inheriting from DefaultMutableTreeNode causes selection problems?
Hi all,
I've a class that represents a node of a JTree and, thus, that I've written on the base of the great DefaultMutableTreeNode adding a few methods that should not clash with the swing structure:
publicclass ContainerTreeNodeextends DefaultMutableTreeNode{
/**
* Defines if this node is a root node, that is have children.
*/
protectedboolean isRoot =false;
/**
* Defines which kind of root this node is.
*/
protected String rootType =null;
/**
* Returns the hashcode of this node. If the node contains a BaseKeyValue, then the
* hashcode of such value is returned, otherwise the DefaultMutableTreeNode is calculated.
*/
publicint hashCode(){
if( this.userObject !=null )return this.userObject.hashCode();
else
return super.hashCode();
}
/**
* Compares two nodes. Two nodes are equal if their values are.
*/
publicboolean equals(Object o){
if( o==null || (! (oinstanceof ContainerTreeNode)))returnfalse;
else{
Object userObject = ((ContainerTreeNode)o).userObject;
Object myObject= this.userObject;
if( userObjectinstanceof BaseKeyValue && myObjectinstanceof BaseKeyValue)
return userObject.equals(myObject);
else
returnfalse;
}
}
/**
* Builds up a tree node with the specified BaseKeyValue.
* @param keyValue the key value object to build up this node.
*/
public ContainerTreeNode(BaseKeyValue keyValue){
super(keyValue);
}
/**
* Builds a tree node with the specified string, used for description nodes.
* @param string the string to initialize this node with
*/
public ContainerTreeNode(String string){
super(string);
}
/**
* To print this element. The userobject is used for printing.
*/
public String toString(){
if( this.userObject !=null )return this.userObject.toString();
elsereturnnull;
}
/**
* Refreshes this node and, in the case, the children nodes. If this node contains a key-value object, then it is
* refreshed, otherwise nothing is done. After this, in any case, if the value of the flag is true, each node is
* forced to be refreshed simply calling this method on each node (that will call on each child node and so on).
* @param refreshChildren true if all the children must be forced to be updated, false otherwise.
*/
publicfinalvoid refreshNode(boolean refreshChildren){
// refresh myself
if( this.userObject !=null && this.userObjectinstanceof BaseKeyValue){
BaseKeyValue myKeyValue = (BaseKeyValue) this.userObject;
myKeyValue.refreshFromDatabase();
}
// if here I've got a basekeyvalue as user object, thus I can update the childs of this node.
if( refreshChildren ){
Enumeration children = this.children();
while (children !=null && children.hasMoreElements()){
ContainerTreeNode element = (ContainerTreeNode) children.nextElement();
element.refreshNode(refreshChildren);
}
}
}
/**
* @return the isRoot
*/
publicsynchronizedfinalboolean isRoot(){
return isRoot;
}
/**
* @param isRoot the isRoot to set
*/
publicsynchronizedfinalvoid setRoot(boolean isRoot){
this.isRoot = isRoot;
}
/**
* @return the rootType
*/
publicsynchronizedfinal String getRootType(){
return rootType;
}
/**
* @param rootType the rootType to set
*/
publicsynchronizedfinalvoid setRootType(String rootType){
this.rootType = rootType;
}
publicstaticvoid main(String argv[])throws Exception{
DefaultMutableTreeNode t1 =new ContainerTreeNode("t1");
DefaultMutableTreeNode t2 =new ContainerTreeNode("t2");
DefaultMutableTreeNode t3 =new ContainerTreeNode("t3");
DefaultMutableTreeNode t4 =new ContainerTreeNode("t4");
DefaultMutableTreeNode t5 =new ContainerTreeNode("t5");
t1.add(t2);
t2.add(t3);
t3.add(t4);
t4.add(t5);
DefaultTreeModel model =new DefaultTreeModel(t1);
JTree tree =new JTree(model);
JFrame f =new JFrame("prova");
f.setSize(300,300);
f.add(tree);
f.setVisible(true);
Thread.currentThread().sleep(5000);
TreePath path = tree.getSelectionModel().getSelectionPath();
t3.removeAllChildren();
t4.removeAllChildren();
t3.add(t5);
//model.reload(t2);
model.reload();
System.out.println("Nodo ricaricato " + path);
tree.getSelectionModel().setSelectionPath(path);
}
}
The problem is that the above main cannot re-select the node the user has clicked onto, while if I convert my nodes in DefaultMutableTreeNode it does. Anyone can explain me why?
Luca
