content: /*
   * This library is part of OpenCms -
   * the Open Source Content Management System
   *
   * Copyright (c) Alkacon Software GmbH & Co. KG (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.gwt.client.util;
  
  import java.util.function.Consumer;
  
  import com.google.gwt.core.client.JavaScriptObject;
  
  /**
   * GWT wrapper for  programmatic media query checking.
   *
   *<p>An instance of this class can be created from the media query rule text usign the parse() method.
   * Checking if the media query applies can be either done using the matches() method, or by adding a listener
   * with the addListener method if you need to keep track of changes.
   */
  public final class CmsMediaQuery extends JavaScriptObject {
  
      /**
       * Hidden constructor.
       */
      protected CmsMediaQuery() {}
  
      /**
       * Creates a new instance using the given media query rule.
       *
       * @param text the rule text
       * @return the new media query
       */
      public static native CmsMediaQuery parse(String text) /*-{
          return $wnd.matchMedia(text);
      }-*/;
  
      /**
       * Adds a listener to detect when the matching state of the media query changes.
       *
       * @param callback the callback to call with the matching state as a parameter
       */
      public final native void addListener(Consumer<Boolean> callback) /*-{
          var jsCallback = function(state) {
              var match;
              if (state.matches) {
                  match = @java.lang.Boolean::TRUE;
              } else {
                  match = @java.lang.Boolean::FALSE;
              }
              callback.@java.util.function.Consumer::accept(Ljava/lang/Object;)(match);
          };
  
          try {
              this.addEventListener('change', jsCallback);
          } catch (e) {
              // for older browsers which don't have the addEventListener method
              this.addListener(jsCallback);
          }
      }-*/;
  
      /**
       * Checks if the media query matches.
       *
       * @return true if the media query matches
       */
      public final native boolean matches() /*-{
          return this.matches;
      }-*/;
  
  }
  