ClickHandler on an existing element in GWT

I have an HTML document. In that document, there is an element (like button, div, a) with an ID. I know I can use:

Document.get().getElementById("id");

to find the required element in the HTML file. How can I add a Click h开发者_开发技巧andler to it? ClickHandlers only seem to be available on the Button class.

Thanks

If you're trying to add a ClickHandler to a <button>, you can do that with Button.wrap().

For an <a> yo can use Anchor.wrap() (Anchors only have ClickListeners, not ClickHandlers...yet)

For a <div> you can use Label.wrap() (Labels are just <div>s).

Suggestion : Try learning how to use UiBinder (added in GWT 2.0).

In your case, you could have done :

yourView.ui.xml

...
<g:Button ui:field="btnName" />
...

yourView.java

public class yourView extends Composite {
    interface MyUiBinder extends UiBinder<LayoutPanel, yourView> {}
    private static MyUiBinder uiBinder = GWT.create(MyUiBinder.class);

    @UiField Button btnName;

    public yourView() {
        initWidget(uiBinder.createAndBindUi(this));
    }

    @UiHandler("btnName")
    void handleClick(ClickEvent e) {
        //Do whatever
    }
}

With "@UiHandler" you can add any handler the widget can support (implement Has****Handler). Adding other element to that structure is easy and FAST and you can add any kind of handler to it. @UiField create a variable containing the instance of the element that is manipulatable anywhere in your class.

One other suggestion - use GQuery. It makes it easy to attach a simple event listener to the DOM without creating the extra elements that GWT widgets often do:

$("id").click(new Function() {
  public boolean f(Event e) {
    Window.alert("This is GWT code without widget baggage!");
    return true;
  }
});

See here for more: http://code.google.com/p/gwtquery/wiki/GettingStarted#Add_an_event_handler

It is a shame there is not more progressive enhancement based GWT code. IMHO, CSS/HTML do a great job at design/markup - it is just the Javascript I want to replace.

Just do it by setting an event listener.

Event.sinkEvents(e, Event.ONCLICK);
Event.setEventListener(e, new EventListener() {
     @Override
     public void onBrowserEvent(Event event) {
          Window.alert("Clicked!");
     }
});