Solved

removeChild method not removing the children from the tree

Posted on 2009-05-05
5
222 Views
Last Modified: 2012-05-06
Hello Experts,

I'm having problems removing child nodes from a JTreeTable.  Can someone tell me what I'm doing wrong?  

Thanks in advance.


private void traverse (Row row)
   {
      // If we are at the deepest parent level and its children have been loaded then
      // we need to sort the children.
      if ( (row.getLevel () == m_nLevels - 1) && (row.isFullyLoaded ()) )
      {
         ArrayList<Row> list = Collections.list (row.children ());
         for (Row r : list)
            System.out.println ("Row : " + (String) r.getData ().getValue (m_nSortColumn));
            
         Collections.sort (list, this);
         System.out.println ("Sorted ------------------------------");
         for (Row r : list)
            System.out.println ("Row : " + (String) r.getData ().getValue (m_nSortColumn));
         
         for (int i = list.size () - 1; i >= 0; i--)
            removeChild (row, i);
         
         for (int i = 0; i < list.size (); i++)
            appendChild (row, list.get (i).getData ());
      }
      else
      {
         for (int r = 0; r < row.getChildCount (); r++)
         {
            Row child = row.getChild (r);
            traverse (child);
         }
      }
   }
 
 
 
 public void removeChild (Row parent, int index)
   {
      assert (parent != null);
 
      parent.remove (index);
 
      // When this model is first being created we do not have a reference to the
      // tree component because our reference only gets set after we construct the
      // model and tell the tree about it. This is a circular dependency but we do
      // not need to have it then because we only need to notify the component
      // about rows added after the initialization.
      if (m_Tree != null)
         fireModelEvent (NODE_DELETED, buildPath (parent), index, null);
   }

Open in new window

0
Comment
Question by:brohjoe
  • 3
  • 2
5 Comments
 

Author Comment

by:brohjoe
ID: 24311253
I think I should explain a little more and add some points since it seems no one has stepped to the plate yet.  What I'm trying to do is delete the child nodes of this JTreeTable during a sort function which is called after the user clicks on the column header, then append the new children to it.  The append function works perfectly, but the 'removeChild()' function is not deleting the children.  I can't figure out what's wrong.   I'm willing to entertain any reasonable comment here.  
0
 
LVL 92

Expert Comment

by:objects
ID: 24311441
check the event that is getting fired, thats the most common cause of problems

0
 

Author Comment

by:brohjoe
ID: 24314733
//This is the 'event' in question:

for (int i = list.size () - 1; i >= 0; i--)
            removeChild (row, i);


//This method calls:
 public void removeChild (Row parent, int index)
   {
      assert (parent != null);

      parent.remove (index);
   
//which calls:
public void remove(int childIndex) {
      MutableTreeNode child = (MutableTreeNode)getChildAt(childIndex);
      children.removeElementAt(childIndex);
      child.setParent(null);
    }

//if we step over the last function we get::
 if (m_Tree != null)
         fireModelEvent (NODE_DELETED, buildPath (parent), index, null);

//if we step into that 'child.setParent(null) function we get::
 public TreeNode getChildAt(int index) {
      if (children == null) {
          throw new ArrayIndexOutOfBoundsException("node has no children");
      }
      return (TreeNode)children.elementAt(index);
    }

which calls a Vector class:

public synchronized void removeElementAt(int index) {
      modCount++;
      if (index >= elementCount) {
          throw new ArrayIndexOutOfBoundsException(index + " >= " +
                                         elementCount);
      }
      else if (index < 0) {
          throw new ArrayIndexOutOfBoundsException(index);
      }
      int j = elementCount - index - 1;
      if (j > 0) {
          System.arraycopy(elementData, index + 1, elementData, index, j);
      }
      elementCount--;
      elementData[elementCount] = null; /* to let gc do its work */
    }

Everything seems to be in order, it compiles and I get no error messages.

<Points increased by 100>
0
 
LVL 92

Accepted Solution

by:
objects earned 500 total points
ID: 24321325
need to see the code for fireModelEvent() and buildPath()
(any reason why you don't use DefaultTableModel)

0
 

Author Closing Comment

by:brohjoe
ID: 31578198
Thanks objects for your answer.  'fireModelEvent' is exactly where the problem was.   Appreciate ya!
0

Featured Post

Free Tool: Postgres Monitoring System

A PHP and Perl based system to collect and display usage statistics from PostgreSQL databases.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

One of Google's most recent algorithm changes affecting local searches is entitled "The Pigeon Update." This update has dramatically enhanced search inquires for the keyword "Yelp." Google searches with the word "Yelp" included will now yield Yelp a…
Iteration: Iteration is repetition of a process. A student who goes to school repeats the process of going to school everyday until graduation. We go to grocery store at least once or twice a month to buy products. We repeat this process every mont…
This theoretical tutorial explains exceptions, reasons for exceptions, different categories of exception and exception hierarchy.
This tutorial explains how to use the VisualVM tool for the Java platform application. This video goes into detail on the Threads, Sampler, and Profiler tabs.

808 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question