package com.vaadin.tests.components.treegrid; import com.vaadin.data.TreeData; import com.vaadin.server.VaadinRequest; import com.vaadin.tests.components.AbstractTestUI; import com.vaadin.ui.Button; import com.vaadin.ui.TreeGrid; import com.vaadin.ui.UI; import com.vaadin.ui.Window; public class TreeGridInWindow extends AbstractTestUI { @Override protected void setup(VaadinRequest request) { TreeGrid treeGrid = new TreeGrid<>(); treeGrid.addColumn(Object::toString).setCaption("Column"); TreeData data = treeGrid.getTreeData(); data.addRootItems("parent"); data.addItems("parent", "child1", "child2"); data.addItems("child1", "grandchild1", "grandchild2"); data.addItems("child2", "grandchild3", "grandchild4"); treeGrid.expand("parent", "child1", "child2"); Window window = new Window("Window", treeGrid); Button openWindow = new Button("Open window", event -> UI.getCurrent().addWindow(window)); getLayout().addComponent(openWindow); } }