/**
    * This file Copyright (c) 2010-2018 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.ui.vaadin.gwt.client.magnoliashell.viewport.connector;
  
  import info.magnolia.ui.vaadin.gwt.client.magnoliashell.viewport.widget.ViewportWidget;
  import info.magnolia.ui.vaadin.gwt.client.shared.magnoliashell.ViewportType;
  import info.magnolia.ui.vaadin.magnoliashell.viewport.ShellViewport;
  
  import java.util.List;
  
  import com.google.gwt.core.client.Scheduler;
  import com.google.gwt.dom.client.Element;
  import com.google.gwt.dom.client.Style;
  import com.google.gwt.dom.client.Style.Display;
  import com.google.gwt.dom.client.Style.Unit;
  import com.google.gwt.user.client.ui.Widget;
  import com.google.web.bindery.event.shared.EventBus;
  import com.vaadin.client.ComponentConnector;
  import com.vaadin.client.ConnectorHierarchyChangeEvent;
  import com.vaadin.client.LayoutManager;
  import com.vaadin.client.communication.StateChangeEvent;
  import com.vaadin.client.communication.StateChangeEvent.StateChangeHandler;
  import com.vaadin.client.ui.AbstractLayoutConnector;
  import com.vaadin.client.ui.layout.ElementResizeEvent;
  import com.vaadin.client.ui.layout.ElementResizeListener;
  import com.vaadin.shared.ui.Connect;
  
  /**
   * ViewportConnector.
   */
  @Connect(ShellViewport.class)
  public class ViewportConnector extends AbstractLayoutConnector {
  
      protected EventBus eventBus;
  
      protected ElementResizeListener childCenterer = new ElementResizeListener() {
          @Override
          public void onElementResize(ElementResizeEvent e) {
              alignContent(e.getElement(), e.getLayoutManager());
          }
      };
  
      @Override
      protected void init() {
          addStateChangeHandler("activeComponent", new StateChangeHandler() {
              @Override
              public void onStateChanged(StateChangeEvent event) {
                  final ComponentConnector newActiveComponent = (ComponentConnector) getState().activeComponent;
                  if (newActiveComponent != null && getWidget().getVisibleChild() != newActiveComponent) {
                      newActiveComponent.getWidget().getElement().getStyle().clearOpacity();
                  }
              }
          });
      }
  
      protected void alignContent(Element e, LayoutManager layoutManager) {
          if (getWidget().isVisible() && !Display.NONE.getCssName().equals(e.getStyle().getDisplay())) {
              int width = layoutManager.getInnerWidth(e);
              final Style style = e.getStyle();
              style.setLeft(50, Unit.PCT);
              style.setMarginLeft(-width / 2, Unit.PX);
          }
      }
  
      @Override
      public void updateCaption(ComponentConnector connector) {
      }
  
     @Override
     public void onConnectorHierarchyChange(ConnectorHierarchyChangeEvent event) {
         final ViewportWidget viewport = getWidget();
         final List<ComponentConnector> children = getChildComponents();
         final List<ComponentConnector> oldChildren = event.getOldChildren();
         int index = 0;
         for (final ComponentConnector cc : children) {
             final Widget w = cc.getWidget();
             if (w.getParent() != viewport) {
                 viewport.insert(w, index);
                 getLayoutManager().addElementResizeListener(w.getElement(), childCenterer);
                 w.getElement().getStyle().setOpacity(0d);
                 Scheduler.get().scheduleDeferred(new Scheduler.ScheduledCommand() {
                     @Override
                     public void execute() {
                         if (getWidget().getVisibleChild() != cc.getWidget()) {
                             w.getElement().getStyle().setDisplay(Display.NONE);
                         }
                         w.getElement().getStyle().clearOpacity();
                     }
                 });
 
             }
             ++index;
         }
 
         oldChildren.removeAll(children);
         for (final ComponentConnector cc : oldChildren) {
             cc.getLayoutManager().removeElementResizeListener(cc.getWidget().getElement(), childCenterer);
             getWidget().removeChild(cc.getWidget());
         }
     }
 
     public void setEventBus(EventBus eventBus) {
         this.eventBus = eventBus;
     }
 
     @Override
     public ViewportWidget getWidget() {
         return (ViewportWidget) super.getWidget();
     }
 
     @Override
     public ViewportState getState() {
         return (ViewportState) super.getState();
     }
 
     public ViewportType getType() {
         return getState().type;
     }
 
 }