content: /*
   *  Licensed to the Apache Software Foundation (ASF) under one
   *  or more contributor license agreements.  See the NOTICE file
   *  distributed with this work for additional information
   *  regarding copyright ownership.  The ASF licenses this file
   *  to you under the Apache 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.apache.org/licenses/LICENSE-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.apache.causeway.viewer.wicket.model.timetaken;
  
  import java.util.Locale;
  
  import org.apache.wicket.model.IModel;
  import org.apache.wicket.model.Model;
  import org.apache.wicket.request.cycle.RequestCycle;
  
  import org.apache.causeway.core.metamodel.context.MetaModelContext;
  
  /**
   * Produces render/response timing info when in prototyping mode.
   * <p>
   * Currently used to add a 'took seconds' label to bottom of data tables.
   *
   * @since 2.0
   */
  public class TimeTakenModel
  implements IModel<String> {
      private static final long serialVersionUID = 1L;
  
      public static IModel<String> createForPrototypingElseBlank(final MetaModelContext mmc) {
          return mmc.getSystemEnvironment().isPrototyping()
              ? new TimeTakenModel()
              : Model.of("");
      }
  
      protected TimeTakenModel() {
      }
  
      @Override
      public String getObject() {
  
          var requestCycle = RequestCycle.get();
          if(requestCycle==null) return ""; // guard against no RequestCycle available on current Thread
  
          final long t0Millis = requestCycle.getStartTime();
          final long t1Millis = System.currentTimeMillis();
          final double secondsSinceRequestStart = 0.001 * (t1Millis - t0Millis);
  
          return String.format(Locale.US, "... took %.2f seconds", secondsSinceRequestStart);
      }
  
  }
  