Examples of com.vaadin.ui.UI

com.vaadin.ui.UI

The topmost component in any component hierarchy. There is one UI for every Vaadin instance in a browser window. A UI may either represent an entire browser window (or tab) or some part of a html page where a Vaadin application is embedded.

The UI is the server side entry point for various client side features that are not represented as components added to a layout, e.g notifications, sub windows, and executing javascript in the browser.

When a new UI instance is needed, typically because the user opens a URL in a browser window which points to e.g. {@link VaadinServlet}, all {@link UIProvider}s registered to the current {@link VaadinSession} arequeried for the UI class that should be used. The selection is by default based on the UI init parameter from web.xml.

After a UI has been created by the application, it is initialized using {@link #init(VaadinRequest)}. This method is intended to be overridden by the developer to add components to the user interface and initialize non-component functionality. The component hierarchy must be initialized by passing a {@link Component} with the main layout or other content of the viewto {@link #setContent(Component)} or to the constructor of the UI.

@see #init(VaadinRequest) @see UIProvider @since 7.0

     * connector has not been attached, <code>null</code> is returned.
     * 
     * @return The connector's session, or <code>null</code> if not attached
     */
    protected VaadinSession getSession() {
        UI uI = getUI();
        if (uI == null) {
            return null;
        } else {
            return uI.getSession();
        }
    }


    protected ChartOptions() {
    }


    private void notifyListeners() {
        UI ui = getUI();


        if (ui == null) {
            return;
        }

     * extension has not yet been added, a new one is created and added.
     * 
     * @return a ChartOptions instance connected to the currently active UI
     */
    public static ChartOptions get() {
        UI ui = UI.getCurrent();


        if (ui == null) {
            throw new IllegalStateException(
                    "This method must be used from UI thread");
        }

Examples of com.vaadin.ui.UI

Related Classes of com.vaadin.ui.UI