Tree Renderer

From Documentation

When a tree (Tree) is assigned with a model, a default renderer is assigned too[1]. The default renderer will assume that each tree item has only one column, and it converts the data into a string directly[2]. If you want to display multiple columns or retrieve a particular field of the data, you have to implement TreeitemRenderer to handle the rendering.

For example,

public class HostTreeRenderer implements TreeitemRenderer {
	public void render(Treeitem treeitem, Object data, int index) throws Exception {
		Treerow row = treeitem.getTreerow();
		if (row == null) { // tree row not create yet.
			row = new Treerow();
		if (data instanceof HostTreeModel.FakeGroup) {
			treeitem.getTreerow().appendChild(new Treecell(((HostTreeModel.FakeGroup)data).getName()));
		} else if (data instanceof HostTreeModel.FakeHost) {
			treeitem.getTreerow().appendChild(new Treecell(((HostTreeModel.FakeHost)data).getName()));
		} else if (data instanceof HostTreeModel.FakeProcess) {
			treeitem.getTreerow().appendChild(new Treecell(((HostTreeModel.FakeProcess)data).getName()));

  1. For the concept about component, model and renderer, please refer to the Model-driven Display section.
  2. If the tree is assigned a template called model, then the template will be used to render the tree. For more information, please refer to the Tree Template section.

Version History

Version Date Content
6.0.0 February 2012 The index argument was introduced.

Last Update : 2022/07/08

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