Name: sdC67446 Date: 12/23/98


The method FixedHeightLayoutCache.setExpandedState(TreePath path,
boolean state) throws NullPointerException for the root 'path' and
'state' == false.

The doc says:
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public void setExpandedState(TreePath path,
                             boolean isExpanded)

       Marks the path path expanded state to isExpanded.
       Overrides:
              setExpandedState in class AbstractLayoutCache

The test demonstrating the bug:
-----------------Test.java------------------------
import javax.swing.tree.*;

public class Test {

    /* create the TreeModel of deep 1 with specified num of children */
    public static DefaultTreeModel getTreeModelILike(int childrenCount) {
DefaultMutableTreeNode root =
new DefaultMutableTreeNode("root");

for (int i = 0; i < childrenCount; i++) {
DefaultMutableTreeNode child =
new DefaultMutableTreeNode("root.child"+i);
root.insert(child,i);
}
return new DefaultTreeModel(root);
    }

    public static void main(String[] args) {
FixedHeightLayoutCache fhlc = new FixedHeightLayoutCache();
fhlc.setModel(getTreeModelILike(3));
fhlc.setRootVisible(true);
TreePath path = fhlc.getPathForRow(0);
System.out.println("path="+path);
System.out.println("getExpandedState("+path+")="+fhlc.getExpandedState(path));
fhlc.setExpandedState(path,false);
System.out.println("getExpandedState("+path+")="+fhlc.getExpandedState(path));
    }
}

---------Output from the test---------------------
path=[root]
getExpandedState([root])=true
Exception in thread "main" java.lang.NullPointerException
at javax.swing.tree.FixedHeightLayoutCache$FHTreeStateNode.collapse(Compiled Code)
at javax.swing.tree.FixedHeightLayoutCache.setExpandedState(Compiled Code)
at Test.main(Compiled Code)


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