001/*
002 * #%L
003 * GwtMaterial
004 * %%
005 * Copyright (C) 2015 - 2017 GwtMaterialDesign
006 * %%
007 * Licensed under the Apache License, Version 2.0 (the "License");
008 * you may not use this file except in compliance with the License.
009 * You may obtain a copy of the License at
010 * 
011 *      http://www.apache.org/licenses/LICENSE-2.0
012 * 
013 * Unless required by applicable law or agreed to in writing, software
014 * distributed under the License is distributed on an "AS IS" BASIS,
015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016 * See the License for the specific language governing permissions and
017 * limitations under the License.
018 * #L%
019 */
020package gwt.material.design.client.base.helper;
021
022import com.google.gwt.event.logical.shared.AttachEvent;
023import com.google.gwt.event.logical.shared.HasAttachHandlers;
024import com.google.gwt.event.shared.HandlerRegistration;
025
026/**
027 * Replaced with {@link gwt.material.design.client.events.HandlerRegistry}
028 */
029public final class EventHelper {
030
031    public static void onAttachOnce(HasAttachHandlers has, AttachEvent.Handler handler) {
032        HandlerRegistration[] reg = new HandlerRegistration[1];
033        reg[0] = has.addAttachHandler(event -> {
034            if(event.isAttached()) {
035                handler.onAttachOrDetach(event);
036
037                if (reg[0] != null) {
038                    reg[0].removeHandler();
039                }
040            }
041        });
042    }
043}