How to use

DefaultAbstractTree

in

org.apache.wicket.extensions.markup.html.tree

/**
 * @deprecated node icons should be created in {@link #newNodeIcon(MarkupContainer, String, TreeNode)}.
 */
@Override
@Deprecated
protected final ResourceReference getNodeIcon(TreeNode node) {
  return super.getNodeIcon(node);
}

/**
 * Returns the resource reference for icon of specified tree node.
 *
 * @param node
 *            The node
 * @return The package resource reference
 */
protected ResourceReference getNodeIcon(TreeNode node)
{
  if (node.isLeaf() == true)
  {
    return getItem();
  }
  else
  {
    if (isNodeExpanded(node))
    {
      return getFolderOpen();
    }
    else
    {
      return getFolderClosed();
    }
  }
}

final ILinkCallback callback)
if (getLinkType() == LinkType.REGULAR)
else if (getLinkType() == LinkType.AJAX)

  public void onClick(AjaxRequestTarget target)
  {
    getTreeState().selectNode(node, !getTreeState().isNodeSelected(node));
    onNodeLinkClicked(target, node);
    updateTree(target);
  }
});

  public void onClick(AjaxRequestTarget target)
  {
    if (isNodeExpanded(node))
    {
      getTreeState().collapseNode(node);
    }
    else
    {
      getTreeState().expandNode(node);
    }
    onJunctionLinkClicked(target, node);
    updateTree(target);
  }
});

  @Override
  public void onClick(final AjaxRequestTarget target)
  {
    if (isNodeExpanded(node))
    {
      getTreeState().collapseNode(node);
    }
    else
    {
      getTreeState().expandNode(node);
    }
    onJunctionLinkClicked(target, node);
    if (target != null)
    {
      updateTree(target);
    }
  }
});

junctionLink = newLink(parent, id, new ILinkCallback()
junctionLink.add(newJunctionImage(junctionLink, imageId, node));

/**
 * Performs the tree initialization. Adds header contribution for the stylesheet.
 */
private void init()
{
  ResourceReference css = getCSS();
  if (css != null)
  {
    add(CSSPackageResource.getHeaderContribution(css.getScope(), css.getName()));
  }
}

/**
 * Sets the type of links on tree items. After the link type is changed, the whole tree is
 * rebuild and re-rendered.
 *
 * @param linkType
 *            type of links
 */
public void setLinkType(LinkType linkType)
{
  if (this.linkType != linkType)
  {
    this.linkType = linkType;
    invalidateAll();
  }
}

  /**
   * {@inheritDoc}
   */
  @Override
  public void renderHead(final IHeaderResponse response)
  {
    super.renderHead(response);
    ResourceReference css = getCSS();
    if (css != null)
    {
      response.render(CssHeaderItem.forReference(css));
    }
  }
}

  /**
   * {@inheritDoc}
   */
  @Override
  protected void onComponentTag(final ComponentTag tag)
  {
    super.onComponentTag(tag);
    final String cssClassInner;
    if (node.isLeaf() == false)
    {
      cssClassInner = isNodeExpanded(node) ? "minus" : "plus";
    }
    else
    {
      cssClassInner = "corner";
    }
    final String cssClassOuter = isNodeLast(node) ? "junction-last" : "junction";
    Response response = RequestCycle.get().getResponse();
    response.write("<span class=\"" + cssClassOuter + "\"><span class=\"" +
      cssClassInner + "\"></span></span>");
  }
}.setRenderBodyOnly(true);

  @Override
  public void onClick(final AjaxRequestTarget target)
  {
    getTreeState().selectNode(node, !getTreeState().isNodeSelected(node));
    onNodeLinkClicked(target, node);
    if (target != null)
    {
      updateTree(target);
    }
  }
});

junctionLink = newLink(parent, id, new ILinkCallback()
junctionLink.add(newJunctionImage(junctionLink, imageId, node));

/**
 * Sets the type of links on tree items. After the link type is changed, the whole tree is
 * rebuild and re-rendered.
 * 
 * @param linkType
 *            type of links
 */
public void setLinkType(final LinkType linkType)
{
  if (this.linkType != linkType)
  {
    this.linkType = linkType;
    invalidateAll();
  }
}

/**
 * Returns the resource reference for icon of specified tree node.
 * 
 * @param node
 *            The node
 * @return The package resource reference
 */
protected ResourceReference getNodeIcon(final TreeNode node)
{
  if (node.isLeaf() == true)
  {
    return getItem();
  }
  else
  {
    if (isNodeExpanded(node))
    {
      return getFolderOpen();
    }
    else
    {
      return getFolderClosed();
    }
  }
}

@Override
protected Component newNodeIcon(final MarkupContainer parent, final String id, final TreeNode node) {
  ResourceReference nodeIcon = super.getNodeIcon(node);
  return HippoIcon.fromResource(id, nodeIcon);
}

final ILinkCallback callback)
if (getLinkType() == LinkType.REGULAR)
else if (getLinkType() == LinkType.AJAX)

  @Override
  protected void onComponentTag(ComponentTag tag)
  {
    super.onComponentTag(tag);
    tag.put("style", "background-image: url('" +
      RequestCycle.get().urlFor(getNodeIcon(node)) + "')");
  }
};

  /**
   * {@inheritDoc}
   */
  @Override
  protected void onComponentTag(final ComponentTag tag)
  {
    super.onComponentTag(tag);
    IRequestHandler handler = new ResourceReferenceRequestHandler(getNodeIcon(node));
    tag.put("style", "background-image: url('" + RequestCycle.get().urlFor(handler) +
      "')");
  }
};