J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2001 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package sun.print; |
| 27 | |
| 28 | import java.util.Vector; |
| 29 | |
| 30 | import javax.print.PrintService; |
| 31 | import javax.print.attribute.PrintServiceAttributeSet; |
| 32 | import javax.print.attribute.HashPrintServiceAttributeSet; |
| 33 | import javax.print.event.PrintServiceAttributeEvent; |
| 34 | import 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 | */ |
| 43 | class ServiceNotifier extends Thread { |
| 44 | |
| 45 | private PrintService service; |
| 46 | private Vector listeners; |
| 47 | private boolean stop = false; |
| 48 | private PrintServiceAttributeSet lastSet; |
| 49 | |
| 50 | ServiceNotifier(PrintService service) { |
| 51 | super(service.getName() + " notifier"); |
| 52 | this.service = service; |
| 53 | listeners = new Vector(); |
| 54 | try { |
| 55 | setPriority(Thread.NORM_PRIORITY-1); |
| 56 | setDaemon(true); |
| 57 | start(); |
| 58 | } catch (SecurityException e) { |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | void addListener(PrintServiceAttributeListener listener) { |
| 63 | synchronized (this) { |
| 64 | if (listener == null || listeners == null) { |
| 65 | return; |
| 66 | } |
| 67 | listeners.add(listener); |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | void removeListener(PrintServiceAttributeListener listener) { |
| 72 | synchronized (this) { |
| 73 | if (listener == null || listeners == null) { |
| 74 | return; |
| 75 | } |
| 76 | listeners.remove(listener); |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | boolean isEmpty() { |
| 81 | return (listeners == null || listeners.isEmpty()); |
| 82 | } |
| 83 | |
| 84 | void stopNotifier() { |
| 85 | stop = true; |
| 86 | } |
| 87 | |
| 88 | /* If a service submits a job it may call this method which may prompt |
| 89 | * immediate notification of listeners. |
| 90 | */ |
| 91 | void wake() { |
| 92 | try { |
| 93 | interrupt(); |
| 94 | } catch (SecurityException e) { |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | /* A heuristic is used to calculate sleep time. |
| 99 | * 10 times the time taken to loop through all the listeners, with |
| 100 | * a minimum of 15 seconds. Ensures this won't take more than 10% |
| 101 | * of available time. |
| 102 | */ |
| 103 | public void run() { |
| 104 | |
| 105 | long minSleepTime = 15000; |
| 106 | long sleepTime = 2000; |
| 107 | HashPrintServiceAttributeSet attrs; |
| 108 | PrintServiceAttributeEvent attrEvent; |
| 109 | PrintServiceAttributeListener listener; |
| 110 | PrintServiceAttributeSet psa; |
| 111 | |
| 112 | while (!stop) { |
| 113 | try { |
| 114 | Thread.sleep(sleepTime); |
| 115 | } catch (InterruptedException e) { |
| 116 | } |
| 117 | synchronized (this) { |
| 118 | if (listeners == null) { |
| 119 | continue; |
| 120 | } |
| 121 | long startTime = System.currentTimeMillis(); |
| 122 | if (listeners != null) { |
| 123 | if (service instanceof AttributeUpdater) { |
| 124 | psa = |
| 125 | ((AttributeUpdater)service).getUpdatedAttributes(); |
| 126 | } else { |
| 127 | psa = service.getAttributes(); |
| 128 | } |
| 129 | if (psa != null && !psa.isEmpty()) { |
| 130 | for (int i = 0; i < listeners.size() ; i++) { |
| 131 | listener = (PrintServiceAttributeListener) |
| 132 | listeners.elementAt(i); |
| 133 | attrs = |
| 134 | new HashPrintServiceAttributeSet(psa); |
| 135 | attrEvent = |
| 136 | new PrintServiceAttributeEvent(service, attrs); |
| 137 | listener.attributeUpdate(attrEvent); |
| 138 | } |
| 139 | } |
| 140 | } |
| 141 | sleepTime = (System.currentTimeMillis()-startTime)*10; |
| 142 | if (sleepTime < minSleepTime) { |
| 143 | sleepTime = minSleepTime; |
| 144 | } |
| 145 | } |
| 146 | } |
| 147 | } |
| 148 | |
| 149 | } |