content: /*
   * This library is part of OpenCms -
   * the Open Source Content Management System
   *
   * Copyright (C) Alkacon Software (https://www.alkacon.com)
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   * Lesser General Public License for more details.
   *
   * For further information about Alkacon Software, please see the
   * company website: https://www.alkacon.com
   *
   * For further information about OpenCms, please see the
   * project website: https://www.opencms.org
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package org.opencms.acacia.client.ui;
  
  import org.opencms.acacia.client.CmsChoiceMenuEntryBean;
  import org.opencms.acacia.client.css.I_CmsLayoutBundle;
  
  import com.google.gwt.core.client.Scheduler;
  import com.google.gwt.core.client.Scheduler.ScheduledCommand;
  import com.google.gwt.dom.client.Element;
  import com.google.gwt.dom.client.Style;
  import com.google.gwt.dom.client.Style.Unit;
  import com.google.gwt.user.client.Window;
  import com.google.gwt.user.client.ui.Composite;
  import com.google.gwt.user.client.ui.FlowPanel;
  
  /**
   * A choice submenu widget.<p>
   */
  public class CmsChoiceSubmenu extends Composite {
  
      /** The composite widget. */
      private FlowPanel m_root = new FlowPanel();
  
      /**
       * Creates a new submenu.<p>
       *
       * @param parentEntry the parent menu entry bean
       */
      public CmsChoiceSubmenu(CmsChoiceMenuEntryBean parentEntry) {
  
          initWidget(m_root);
          addStyleName(I_CmsLayoutBundle.INSTANCE.attributeChoice().choices());
          addStyleName(I_CmsLayoutBundle.INSTANCE.attributeChoice().submenu());
      }
  
      /**
       * Adds a new choice widget.<p>
       *
       * @param choice the choice widget
       */
      public void addChoice(CmsChoiceMenuEntryWidget choice) {
  
          m_root.add(choice);
      }
  
      /**
       * Checks whether the submenu should be opened above instead of below.<p>
       *
       * @param referenceElement the reference element
       * @return true if the new submenu should be opened above
       */
      public boolean openAbove(Element referenceElement) {
  
          int windowTop = Window.getScrollTop();
          int windowBottom = Window.getScrollTop() + Window.getClientHeight();
          int spaceAbove = referenceElement.getAbsoluteTop() - windowTop;
          int spaceBelow = windowBottom - referenceElement.getAbsoluteBottom();
          return spaceAbove > spaceBelow;
      }
  
      /**
       * Positions a new submenu asynchronously.<p>
       *
       * @param widgetEntry the menu entry relative to which the submenu should be positioned
       */
      public void positionDeferred(final CmsChoiceMenuEntryWidget widgetEntry) {
  
          getElement().getStyle().setPosition(Style.Position.ABSOLUTE);
          getElement().getStyle().setVisibility(Style.Visibility.HIDDEN);
          Scheduler.get().scheduleDeferred(new ScheduledCommand() {
  
              public void execute() {
  
                  positionNextToMenuEntry(widgetEntry);
                  getElement().getStyle().setVisibility(Style.Visibility.VISIBLE);
              }
  
          });
      }
  
      /**
       * Helper method to position a submenu on the left side of a menu entry.<p>
       *
       * @param widgetEntry the widget entry relative to which the submenu should  be positioned
       */
      protected void positionNextToMenuEntry(final CmsChoiceMenuEntryWidget widgetEntry) {
  
          Element elem = getElement();
          elem.getStyle().setPosition(Style.Position.ABSOLUTE);
          Element referenceElement = null;
          int startX = -2000;
          int startY = -2000;
          int deltaX = 0;
          int deltaY = 0;
          referenceElement = widgetEntry.getElement();
          Style style = elem.getStyle();
          style.setLeft(startX, Unit.PX);
          style.setTop(startY, Unit.PX);
          int myRight = elem.getAbsoluteRight();
          int myTop = elem.getAbsoluteTop();
          int refLeft = referenceElement.getAbsoluteLeft();
          int refTop = referenceElement.getAbsoluteTop();
          int newLeft = startX + (refLeft - myRight) + deltaX;
          int newTop;
          if (openAbove(referenceElement)) {
              int myHeight = elem.getOffsetHeight();
              int refHeight = referenceElement.getOffsetHeight();
              newTop = startY + ((refTop + refHeight) - (myTop + myHeight)) + deltaY;
          } else {
              newTop = startY + (refTop - myTop) + deltaY;
          }
          style.setLeft(newLeft, Unit.PX);
          style.setTop(newTop, Unit.PX);
      }
  
  }
  