/**
* Adds a node to the visualization tree as a child of this node. The <code>child</code>'s parent
* is set to be this node. If <code>
* child</code> is currently a child to another node <code>n</code>, then <code>child</code> is
* first {@link #removeChildDisplay(TreeBrowserDisplay) removed} from <code>n</code> and then
* added to this node.
*
* @param child The node to add. Mustn't be <code>null</code>.
* @see DefaultMutableTreeNode
*/
public void addChildDisplay(TreeBrowserDisplay child) {
if (child == null) throw new NullPointerException("No child.");
if (childrenDisplay.contains(child)) return;
if (child.parentDisplay != null) // Was the child of another node.
child.parentDisplay.removeChildDisplay(child);
child.parentDisplay = this;
childrenDisplay.add(child);
}
/**
* Removes the specified <code>child</code> node. If <code>child</code> is not among the children
* of this node, no action is taken. Otherwise, it is removed from the children set and orphaned.
* That is, its parent (which is this node) is set to <code>null</code>.
*
* @param child The node to remove. Mustn't be <code>null</code>.
*/
public void removeChildDisplay(TreeBrowserDisplay child) {
if (child == null) throw new NullPointerException("No child.");
if (childrenDisplay.contains(child)) {
// NOTE: parentDisplay != null b/c child has been added through
// the add method.
child.parentDisplay.childrenDisplay.remove(child);
child.parentDisplay = null;
}
}