vaadin-framework/uitest/src/main/java/com/vaadin/tests/TestComponentAddAndRecursion.java

package com.vaadin.tests;

import com.vaadin.server.Page;
import com.vaadin.ui.Button;
import com.vaadin.ui.CustomComponent;
import com.vaadin.ui.GridLayout;
import com.vaadin.ui.Label;
import com.vaadin.ui.Notification;
import com.vaadin.ui.Panel;
import com.vaadin.ui.VerticalLayout;

/**
 * @author marc
 *
 */
public class TestComponentAddAndRecursion extends CustomComponent {
    Panel p;
    VerticalLayout pl;
    Panel p2;
    VerticalLayout p2l;
    Label l;
    Label l2;
    Panel p3;
    VerticalLayout p3l;

    public TestComponentAddAndRecursion() {

        VerticalLayout main = new VerticalLayout();
        setCompositionRoot(main);

        l = new Label("A");
        l2 = new Label("B");
        pl = new VerticalLayout();
        pl.setMargin(true);
        p = new Panel("p", pl);
        pl.addComponent(l);
        pl.addComponent(l2);
        main.addComponent(p);
        p2l = new VerticalLayout();
        p2l.setMargin(true);
        p2 = new Panel("p2", p2l);
        p2l.addComponent(l);
        main.addComponent(p2);
        p3l = new VerticalLayout();
        p3l.setMargin(true);
        p3 = new Panel("p3", p3l);
        p2l.addComponent(p3);

        Button b = new Button("use gridlayout", event -> {
            p.setContent(new GridLayout());
            p2.setContent(new GridLayout());
            p3.setContent(new GridLayout());
        });
        main.addComponent(b);
        b = new Button("use orderedlayout", event -> {
            p.setContent(new VerticalLayout());
            p2.setContent(new VerticalLayout());
            p3.setContent(new VerticalLayout());
        });
        main.addComponent(b);
        b = new Button("move B", event -> p2l.addComponent(l2));
        main.addComponent(b);
        b = new Button("move p", event -> p3l.addComponent(p));
        main.addComponent(b);
        b = new Button("add to both", event -> {
            Label l = new Label("both");
            pl.addComponent(l);
            p2l.addComponent(l);
        });
        main.addComponent(b);
        b = new Button("recurse", event -> {
            try {
                p3l.addComponent(p2);
                new Notification("ERROR", "This should have failed",
                        Notification.TYPE_ERROR_MESSAGE)
                                .show(Page.getCurrent());
            } catch (Exception e) {
                new Notification("OK", "threw, as expected",
                        Notification.TYPE_ERROR_MESSAGE)
                                .show(Page.getCurrent());
            }
        });
        main.addComponent(b);
        b = new Button("recurse2", event -> {
            VerticalLayout layout = new VerticalLayout();
            Panel p = new Panel("dynamic", layout);
            layout.addComponent(p2);
            try {
                p3l.addComponent(p);
                new Notification("ERROR", "This should have failed",
                        Notification.TYPE_ERROR_MESSAGE)
                                .show(Page.getCurrent());
            } catch (Exception e) {
                new Notification("OK", "threw, as expected",
                        Notification.TYPE_ERROR_MESSAGE)
                                .show(Page.getCurrent());
            }
        });
        main.addComponent(b);
        /*
         * And that's it! The framework will display the main window and its
         * contents when the application is accessed with the terminal.
         */
    }
}