Java tutorial
/* * Copyright 2000-2018 Vaadin Ltd. * * 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. */ package com.vaadin.event; import java.lang.reflect.Method; import com.vaadin.ui.Component; import com.vaadin.util.ReflectTools; /** * An event that is fired when an item is expanded in a listing component that * displays hierarchical data. * * @author Vaadin Ltd * @since 8.1 * @param <T> * the expanded item's type */ public class ExpandEvent<T> extends Component.Event implements HasUserOriginated { private final T expandedItem; private final boolean userOriginated; /** * Construct an expand event. * * @param source * the hierarchical component this event originated from * @param expandedItem * the item that was expanded * @param userOriginated * whether the expand was triggered by a user interaction or the * server */ public ExpandEvent(Component source, T expandedItem, boolean userOriginated) { super(source); this.expandedItem = expandedItem; this.userOriginated = userOriginated; } /** * Get the expanded item that triggered this event. * * @return the expanded item */ public T getExpandedItem() { return expandedItem; } @Override public boolean isUserOriginated() { return userOriginated; } /** * Item expand event listener. * * @param <T> * the expanded item's type * @since 8.1 */ @FunctionalInterface public interface ExpandListener<T> extends SerializableEventListener { public static final Method EXPAND_METHOD = ReflectTools.findMethod(ExpandListener.class, "itemExpand", ExpandEvent.class); /** * Callback method for when an item has been expanded. * * @param event * the expand event */ public void itemExpand(ExpandEvent<T> event); } }