[[changing-theme-on-the-fly]]
Changing theme on the fly
-------------------------

Starting from Vaadin 7.3, you can change themes in the application
without reloading the page. To do this, simply use the
`UI.setTheme(String)` method.

[source,java]
....
public class ThemeChangeUI extends UI {

  private String[] themes = { "valo", "reindeer", "runo", "chameleon" };

  @Override
  protected void init(VaadinRequest request) {
    ComboBox themePicker = new ComboBox("Theme", Arrays.asList(themes));
    themePicker.setValue(getTheme());

    themePicker.addValueChangeListener(new ValueChangeListener() {
      @Override
      public void valueChange(ValueChangeEvent event) {
        String theme = (String) event.getProperty().getValue();
        setTheme(theme);
      }
    });

    setContent(themePicker);
  }
}
....

In this way, you can let your users choose the look of your application.
The functionality also makes it easier to create applications that are
branded for different customers.