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removeChild method not removing the children from the tree

Posted on 2009-05-05
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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);
   }

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Question by:brohjoe
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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

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