1/* 2 * Copyright (c) 2008, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24package com.sun.hotspot.igv.data; 25 26import java.util.ArrayList; 27import java.util.List; 28 29/** 30 * 31 * @author Thomas Wuerthinger 32 */ 33public abstract class Event<L> { 34 35 private List<L> listener; 36 private boolean fireEvents; 37 private boolean eventWasFired; 38 39 public Event() { 40 listener = new ArrayList<>(); 41 fireEvents = true; 42 } 43 44 public void addListener(L l) { 45 listener.add(l); 46 } 47 48 /** 49 * Remove listener 50 * @param l 51 */ 52 public void removeListener(final L l) { 53 listener.remove(l); 54 } 55 56 public void fire() { 57 if(fireEvents) { 58 List<L> tmpList = new ArrayList<>(listener); 59 for (L l : tmpList) { 60 fire(l); 61 } 62 } else { 63 eventWasFired = true; 64 } 65 } 66 67 public void beginAtomic() { 68 assert fireEvents : "endAtomic has to be called before another beginAtomic may be called"; 69 this.fireEvents = false; 70 this.eventWasFired = false; 71 } 72 73 public void endAtomic() { 74 assert !fireEvents : "beginAtomic has to be called first"; 75 this.fireEvents = true; 76 if(eventWasFired) { 77 fire(); 78 } 79 } 80 81 protected abstract void fire(L l); 82} 83