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

Last Update : 2022/01/12

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

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