GWT Button EventListener not fired

Question

I have a <div id="test"><input type="button" value="OK" /></div> html tag.

I used:

((HasClickHandlers)RootPanel.get("test").getWidget(0)).addClickHandler(new ClickHandler() {
  @Override
  public void onClick(ClickEvent event) {
    Window.alert('sss');
  }
}

I executed but no action.

Update:

package com.example.client;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.event.dom.client.*;
import com.google.gwt.user.client.*;
import com.google.gwt.user.client.ui.RootPanel;

public class ExampleWebApp implements EntryPoint {
  public void onModuleLoad() { 
    ((HasClickHandlers) RootPanel.get("test").getWidget(0)).addClickHandler(new ClickHandler() { 
      @Override
      public void onClick(ClickEvent event) {
        Window.alert("i got it");
      }
    });
   }
 }

HTML:

<table>
  <tr>
    <div id="test">
      <input type=button onClick="" value='click here'>
    </div>
  </tr>
</table>

Answer 1

The GWT Button widget is a button tag and not a input tag. Which means you can't use the GWT Button widget in this case. To make it work you need to create your own widget, which can be based on the widget ButtonBase, but needs to be initialized with an InputElement object instead of a ButtonElement.

The next step to get tag from html is to add something similar to the static wrap method present in most widgets. Here is how it would be used in your example when the input would have been a button tag:

Button.wrap(RootPanel.get("test").getWidget(0).getElement()).addClickHandler(
    new ClickHandler() {
       @Override public void onClick(ClickEvent event) { 
          Window.alert('sss');
       }
    });

In you case you could add a wrap method to your custom input widget. See the Button widget implementation of te wrap method, it's the same, expect of course for the creation of the widget itself.

Answer 2

You can't just take an html button and try to add click handlers to it. You need to create the button using gwt code. Try:

<div id="test"></div>

And then:

Button button = new Button("OK");
RootPanel.get("test").add(button);
button.addClickHandler(new ClickHandler() {...});