/**
    * 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);
                     }
                 }
             });
         }
     }
 }