UpdateLinkScript.java :  » GWT » wogwt » your » app » gwt » Java Open Source

package your.app.gwt;

import wogwt.translatable.WOGWTClientUtil;
import wogwt.translatable.http.AfterDOMUpdateCallback;
import wogwt.translatable.http.UpdateOnClickListener;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.gen2.logging.shared.Log;
import com.google.gwt.http.client.Response;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.ui.Anchor;

public class UpdateLinkScript implements EntryPoint {

  private HandlerRegistration registrar;

  /* This class must be declared as an entry-point in the module. */
  public void onModuleLoad() {
    if (!WOGWTClientUtil.hostPageNameEquals("UpdateLink")) {
      return;
    }
    
    Log.finest(getClass().getName() + ": onModuleLoad");
    
    Anchor outsideLink = Anchor.wrap(DOM.getElementById("outsideLink"));
    outsideLink.addClickHandler(new UpdateOnClickListener("outsideContainer"));
    
    /* Widgets that are inside an update container present a bit of a problem
     * because after the container is updated, the existing Widget is destroyed
     * and a new element is there.  Because of this, we have to re-attach any
     * listeners that are inside the update container after the update completes,
     * which is what the AfterDOMUpdateCallback does here.
     */ 
    attachInsideLinkClickListener();
  }
  
  private void attachInsideLinkClickListener() {
    Anchor insideLink = Anchor.wrap(DOM.getElementById("insideLink"));
    /* removing the listener isn't actually necessary here, but doing things this
     * way can prevent problems in the future.  If the existing widget wasn't 
     * actually destroyed by the DOM update (because our code changed to do
     * something different), then we could accidentally add the same listener
     * multiple times, which would be bad.
     */
    if (registrar != null) {
      registrar.removeHandler();
    }
    registrar = insideLink.addClickHandler(new UpdateOnClickListener("insideContainer", 
        new AfterDOMUpdateCallback() {
          public void afterDOMUpdate(Object sender, String url, Response response) {
            attachInsideLinkClickListener();
          }
        }
    ));
  }
  
}