/**
    * This file Copyright (c) 2010-2015 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.dialog.connector;
  
  import info.magnolia.ui.vaadin.dialog.FormDialog;
  import info.magnolia.ui.vaadin.gwt.client.dialog.widget.BaseDialogView;
  import info.magnolia.ui.vaadin.gwt.client.form.widget.FormViewImpl;
  
  import java.util.Arrays;
  import java.util.List;
  
  import com.google.gwt.dom.client.Node;
  import com.google.gwt.dom.client.NodeList;
  import com.google.gwt.event.logical.shared.ResizeEvent;
  import com.google.gwt.event.logical.shared.ResizeHandler;
  import com.google.gwt.event.shared.HandlerRegistration;
  import com.google.gwt.user.client.Element;
  import com.google.gwt.user.client.Window;
  import com.google.gwt.user.client.ui.Widget;
  import com.vaadin.client.ui.layout.ElementResizeEvent;
  import com.vaadin.client.ui.layout.ElementResizeListener;
  import com.vaadin.shared.ui.Connect;
  
  /**
   * DialogContainingForm assumes that content of dialog is
   * FormView. This connector will set the height of form view
   * based on how much space this dialog can provide to the form.
   */
  @Connect(FormDialog.class)
  public class DialogContainingFormConnector extends BaseDialogConnector implements ResizeHandler {
  
      private BaseDialogView view;
      private HandlerRegistration registration;
  
      @Override
      protected BaseDialogView createView() {
          this.view = super.createView();
          return this.view;
      }
  
      @Override
      protected void init() {
          super.init();
          getLayoutManager().addElementResizeListener(getWidget().getElement(), listener);
          registration = Window.addResizeHandler(this);
      }
  
      private final ElementResizeListener listener = new ElementResizeListener() {
          @Override
          public void onElementResize(ElementResizeEvent e) {
              doResize();
          }
      };
  
      @Override
      public void onUnregister() {
          registration.removeHandler();
          getLayoutManager().removeElementResizeListener(getWidget().getElement(), listener);
      }
  
      /**
       * Calculates and sets the max height of form view.
       */
      @Override
      public void onResize(ResizeEvent event) {
          doResize();
      }
  
     // The light dialog should have a bottom margin equivalent to the UI bottom margin, which would be 40. Subtracted 2 so that it lines up nicely in practice.
     private static int LIGHT_DIALOG_BOTTOM_MARGIN = (40-2);
 
     private void doResize() {
         Widget content = getContent().getWidget();
         if (content instanceof FormViewImpl) {
             FormViewImpl formView = (FormViewImpl) content;
             Element element = view.asWidget().getElement();
             NodeList<Node> childNodes = element.getChild(0).getChildNodes();
             int footerHeight = 0, headerHeight = 0, marginHeight = 0;
             List<String> marginElements = Arrays.asList("dialog-description", "dialog-error", "dialog-content", "dialog-footer");
             for (int i = 0; i < childNodes.getLength(); i++) {
                 Node item = childNodes.getItem(i);
                 if (item.getNodeType() == Node.ELEMENT_NODE) {
                     Element child = (Element) item;
                     if (child.getClassName().equalsIgnoreCase("dialog-footer")) {
                         footerHeight = child.getOffsetHeight();
                     } else if (child.getClassName().isEmpty()) {
                         headerHeight = child.getOffsetHeight();
                     }
                     if (marginElements.contains(child.getClassName())) {
                         marginHeight += 2;
                     }
                 }
             }
             int topMargin = element.getOffsetTop();
             int bottomMargin = 0;
             if ("light".equals(getState().modalityLevel)){
                 bottomMargin = LIGHT_DIALOG_BOTTOM_MARGIN;
             }
             formView.setMaxHeight(view.asWidget().getElement().getOffsetHeight() - footerHeight - headerHeight - marginHeight - topMargin - bottomMargin);
         }
     }
 }