function node = getTreeNodeInterface(this)
% GETTREENODEINTERFACE Returns handle to Java Tree Node associated with this
% object.

% Author(s): Bora Eryilmaz
% Revised:
% Copyright 1986-2004 The MathWorks, Inc.
% $Revision: 1.1.6.3 $ $Date: 2004/04/19 01:31:13 $

if isempty( this.TreeNode )
  this.TreeNode = com.mathworks.toolbox.control.explorer.ExplorerTreeNode(this);
  
  % Add property change callbacks
  h = handle( this.TreeNode, 'callbackproperties' );
  h.PropertyChangeCallback = { @LocalJavaPropertyChange, this };
  
  % Add property listeners
  props = [ findprop(this, 'Label'); findprop(this, 'Description') ];
  L = [ handle.listener( this, props, 'PropertyPostSet', ...
                         @LocalUDDPropertyChange ) ];
  
  set(L, 'CallbackTarget', this);
  this.TreeListeners = [ this.TreeListeners; L(:) ];
end

node = this.TreeNode;

% ----------------------------------------------------------------------------- %
% Update UDD object when a property changes on the java side
function LocalJavaPropertyChange(hSrc, hData, this)
import com.mathworks.toolbox.control.explorer.ExplorerTreeNode;

name  = char( hData.getPropertyName );
value = hData.getNewValue;
Node  = hData.getSource;

switch name
case char( ExplorerTreeNode.LABEL_CHANGED_PROPERTY )
  currentname  = this.Label;
  proposedname = value;
  
  if isUniqueName(this, currentname, proposedname)
    this.Label = proposedname;
  else
    Node.setLabel( currentname );
    
    % Get top node and fire event.
    newData = { Node };
    wksp = handle( Node.getRoot.getObject );
    wksp.firePropertyChange('NODE_CHANGED', [], newData);
  end
case char( ExplorerTreeNode.DESCRIPTION_CHANGED_PROPERTY )
  this.Description = value;
end

% ----------------------------------------------------------------------------- %
% Update Java objects when a UDD property changes.
function LocalUDDPropertyChange(this, hData)
name  = hData.Source.Name;
value = hData.NewValue;
Node  = this.TreeNode;

switch name
case 'Label'
  % Fire event only if Java label has really changed.
  if ~strcmp(Node.getLabel, this.Label)
    currentname  = char( Node.getLabel );
    proposedname = this.Label;
    
    if isUniqueName(this, currentname, proposedname)
      Node.setLabel( proposedname );
    
      % Get top node and fire event.
      newData = { Node };
      wksp = handle( Node.getRoot.getObject );
      wksp.firePropertyChange('NODE_CHANGED', [], newData);
    else
      this.Label = currentname;
    end
  end
  
case 'Description'
  % Fire event only if Java label has really changed.
  if ~strcmp( Node.getDescription, value )
    Node.setDescription( this.Description );
  end
end

% -----------------------------------------------------------------------------
function flag = isUniqueName(this, currentname, proposedname)
flag = true;

% If no parent, name doesn't matter
parent = this.up;
if isempty(parent)
  return
end

nodes = this.up.getChildren;
peers = nodes( nodes ~= this);
names = get( peers, {'Label'});

if any( strcmp( proposedname, names) )
  errmsg = sprintf( ['Cannot rename %s to %s: A node with the name you ' ...
                     'specified already exists. Specify a different name.'], ...
                    currentname, proposedname );
  uiwait( errordlg( errmsg, 'Error Renaming Node', 'modal') );
  flag = false;
elseif isempty( strtrim(proposedname) )
  errmsg = sprintf( 'Cannot rename %s: New name should not be empty.', ...
                    currentname );
  uiwait( errordlg( errmsg, 'Error Renaming Node', 'modal') );
  flag = false;
end