content: package act.util;
  
  /*-
   * #%L
   * ACT Framework
   * %%
   * Copyright (C) 2014 - 2017 ActFramework
   * %%
   * Licensed 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.
   * #L%
   */
  
  import act.app.App;
  import act.app.event.SysEventId;
  import act.event.SysEventListenerBase;
  import act.plugin.AppServicePlugin;
  import org.osgl.$;
  import org.osgl.logging.L;
  import org.osgl.logging.Logger;
  import org.osgl.util.E;
  
  import java.util.EventObject;
  
  /**
   * Find classes that extends a specified type directly
   * or indirectly, or implement a specified type directly
   * or indirectly
   */
  public abstract class SubTypeFinder<T> extends AppServicePlugin {
  
      protected static Logger logger = L.get(SubTypeFinder.class);
  
      private Class<T> targetType;
      private SysEventId bindingEvent = SysEventId.DEPENDENCY_INJECTOR_PROVISIONED;
  
      public SubTypeFinder(Class<T> target) {
          E.NPE(target);
          targetType = target;
      }
  
      public SubTypeFinder(Class<T> target, SysEventId bindingEvent) {
          this(target);
          this.bindingEvent = $.requireNotNull(bindingEvent);
      }
  
      protected abstract void found(Class<? extends T> target, App app);
  
      @Override
      public final void applyTo(final App app) {
          app.eventBus().bind(bindingEvent, new SysEventListenerBase() {
              @Override
              public void on(EventObject event) throws Exception {
                  ClassInfoRepository repo = app.classLoader().classInfoRepository();
                  ClassNode parent = repo.node(targetType.getName());
                  parent.visitPublicNotAbstractTreeNodes(new $.Visitor<ClassNode>() {
                      @Override
                      public void visit(ClassNode classNode) throws $.Break {
                          final Class<T> c = app.classForName(classNode.name());
                          if (!c.isAnnotationPresent(NoAutoRegister.class)) {
                              found(c, app);
                          }
                      }
                  });
              }
          });
      }
  }
  