1/* 2 * Copyright (c) 2000, 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package sun.print; 27 28import java.util.Vector; 29 30import javax.print.PrintService; 31import javax.print.attribute.PrintServiceAttributeSet; 32import javax.print.attribute.HashPrintServiceAttributeSet; 33import javax.print.event.PrintServiceAttributeEvent; 34import javax.print.event.PrintServiceAttributeListener; 35 36/* 37 * A utility class usable by all print services for managing listeners 38 * The services create an instance and delegate the listener callback 39 * management to this class. The ServiceNotifier calls back to the service 40 * to obtain the state of the attributes and notifies the listeners of 41 * any changes. 42 */ 43class ServiceNotifier extends Thread { 44 45 private PrintService service; 46 private Vector<PrintServiceAttributeListener> listeners; 47 private boolean stop = false; 48 private PrintServiceAttributeSet lastSet; 49 50 /* 51 * If adding any other constructors, always call the 5-args 52 * super-class constructor passing "false" for inherit-locals. 53 */ 54 ServiceNotifier(PrintService service) { 55 super(null, null, service.getName() + " notifier", 0, false); 56 this.service = service; 57 listeners = new Vector<>(); 58 try { 59 setPriority(Thread.NORM_PRIORITY-1); 60 setDaemon(true); 61 start(); 62 } catch (SecurityException e) { 63 } 64 } 65 66 void addListener(PrintServiceAttributeListener listener) { 67 synchronized (this) { 68 if (listener == null || listeners == null) { 69 return; 70 } 71 listeners.add(listener); 72 } 73 } 74 75 void removeListener(PrintServiceAttributeListener listener) { 76 synchronized (this) { 77 if (listener == null || listeners == null) { 78 return; 79 } 80 listeners.remove(listener); 81 } 82 } 83 84 boolean isEmpty() { 85 return (listeners == null || listeners.isEmpty()); 86 } 87 88 void stopNotifier() { 89 stop = true; 90 } 91 92 /* If a service submits a job it may call this method which may prompt 93 * immediate notification of listeners. 94 */ 95 void wake() { 96 try { 97 interrupt(); 98 } catch (SecurityException e) { 99 } 100 } 101 102 /* A heuristic is used to calculate sleep time. 103 * 10 times the time taken to loop through all the listeners, with 104 * a minimum of 15 seconds. Ensures this won't take more than 10% 105 * of available time. 106 */ 107 public void run() { 108 109 long minSleepTime = 15000; 110 long sleepTime = 2000; 111 HashPrintServiceAttributeSet attrs; 112 PrintServiceAttributeEvent attrEvent; 113 PrintServiceAttributeListener listener; 114 PrintServiceAttributeSet psa; 115 116 while (!stop) { 117 try { 118 Thread.sleep(sleepTime); 119 } catch (InterruptedException e) { 120 } 121 synchronized (this) { 122 if (listeners == null) { 123 continue; 124 } 125 long startTime = System.currentTimeMillis(); 126 if (listeners != null) { 127 if (service instanceof AttributeUpdater) { 128 psa = 129 ((AttributeUpdater)service).getUpdatedAttributes(); 130 } else { 131 psa = service.getAttributes(); 132 } 133 if (psa != null && !psa.isEmpty()) { 134 for (int i = 0; i < listeners.size() ; i++) { 135 listener = listeners.elementAt(i); 136 attrs = 137 new HashPrintServiceAttributeSet(psa); 138 attrEvent = 139 new PrintServiceAttributeEvent(service, attrs); 140 listener.attributeUpdate(attrEvent); 141 } 142 } 143 } 144 sleepTime = (System.currentTimeMillis()-startTime)*10; 145 if (sleepTime < minSleepTime) { 146 sleepTime = minSleepTime; 147 } 148 } 149 } 150 } 151 152} 153