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.applib.services.menu;
  
  import java.util.Optional;
  
  import org.apache.causeway.applib.layout.menubars.MenuBars;
  
  import org.jspecify.annotations.NonNull;
  
  /**
   * Returns the {@link MenuBars} instance for the UI.
   *
   * <p>
   *     The default implementation de-serializes the `menubars.layout...` file
   *     read from the classpath.
   * </p>
   *
   * <p>
   *     The service is <i>called</i> by the default implementation of
   *     {@link MenuBarsService}.
   * </p>
   *
   * @since 1.x - revised for 2.0 {@index}
   */
  public interface MenuBarsLoaderService {
  
      /**
       * Whether dynamic reloading of layouts is enabled.
       *
       * <p>
       * If not, then the calling {@link MenuBarsService}will cache the layout
       * once loaded.
       * </p>
       */
      boolean supportsReloading();
  
      /**
       * Optionally returns a new instance of a {@link MenuBars},
       * based on whether the underlying resource could be found, loaded and parsed.
       * @throws UnsupportedOperationException - when format is not supported
       */
      <T extends MenuBars> Optional<T> menuBars(@NonNull MenuBarsMarshallerService<T> marshaller);
  
  }
  