/**

  * Copyright 2010 The Kuali Foundation Licensed under the

  * Educational Community License, Version 2.0 (the "License"); you may

  * not use this file except in compliance with the License. You may

  * obtain a copy of the License at

  *

  * http://www.osedu.org/licenses/ECL-2.0

  *

  * Unless required by applicable law or agreed to in writing,

  * software distributed under the License is distributed on an "AS IS"

  * BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express

  * or implied. See the License for the specific language governing

  * permissions and limitations under the License.

  */

 package org.kuali.student.common.ui.client.widgets.notification;

 import org.kuali.student.common.ui.client.mvc.Holder;

 import org.kuali.student.common.ui.client.util.Elements;

 import com.google.gwt.event.logical.shared.CloseEvent;

 import com.google.gwt.event.logical.shared.CloseHandler;

 import com.google.gwt.event.shared.HandlerRegistration;

 import com.google.gwt.user.client.Timer;

 import com.google.gwt.user.client.ui.FlowPanel;

 import com.google.gwt.user.client.ui.RootPanel;

 public class KSNotifier {

     private static final FlowPanel notifier = new FlowPanel();

     public static final int FADE_DURATION = 1000;

     private static final int DEFAULT_FADE_DURATION = 4000;

     static {

         notifier.setStyleName("ks-notification-container");

     }

     private KSNotifier() {

     }

     public static void show(String message) {

         add(new KSNotification(message, false, DEFAULT_FADE_DURATION));

     }

     public static void add(final KSNotification notification) {

         if (notifier.getWidgetCount() == 0) {

             RootPanel.get().add(notifier);

         }

         final Holder<HandlerRegistration> reg = new Holder<HandlerRegistration>();

         reg.set(notification.addCloseHandler(new CloseHandler<KSNotification>() {

             @Override

             public void onClose(CloseEvent<KSNotification> event) {

                 reg.get().removeHandler();

                 remove(notification, false);

             }

         }));

         Elements.setOpacity(notification.getElement(), 0);

         notifier.add(notification);

         Elements.fadeIn(notification, FADE_DURATION, 85, new Elements.FadeCallback() {

             @Override

             public void onFadeStart() {

                 // do nothing

             }

             @Override

             public void onFadeComplete() {

                 new Timer() {

                     @Override

                     public void run() {

                         reg.get().removeHandler();

                         remove(notification, true);

                     }

                 }.schedule(notification.getDuration());

             }

         });

     }

     public static void remove(final KSNotification notification, final boolean fireEvents) {

         if (notifier.getWidgetIndex(notification) != -1) {

             Elements.fadeOut(notification, FADE_DURATION, 0, new Elements.FadeCallback() {

                 @Override

                 public void onFadeStart() {

                     // do nothing

                 }

                 @Override

                 public void onFadeComplete() {

                     notifier.remove(notification);

                     if (fireEvents) {

                         CloseEvent.fire(notification, notification);

                     }

                     if (notifier.getWidgetCount() == 0) {

                         RootPanel.get().remove(notifier);

                     }

                 }

             });

         }

     }

 }