1 /* 2 * Copyright (c) 2011, 2012, 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 26 package com.sun.tools.javac.api; 27 28 import java.util.Arrays; 29 import java.util.Collection; 30 31 import com.sun.source.util.TaskEvent; 32 import com.sun.source.util.TaskListener; 33 import com.sun.tools.javac.code.DeferredCompletionFailureHandler; 34 import com.sun.tools.javac.code.DeferredCompletionFailureHandler.Handler; 35 import com.sun.tools.javac.util.Context; 36 import com.sun.tools.javac.util.DefinedBy; 37 import com.sun.tools.javac.util.DefinedBy.Api; 38 39 /** 40 * A collection of currently registered {@link TaskListener}s. Events passed to this TaskListener 41 * will be forwarded to all the registered TaskListeners. 42 * 43 * <p><b>This is NOT part of any supported API. 44 * If you write code that depends on this, you do so at your own risk. 45 * This code and its internal interfaces are subject to change or 46 * deletion without notice.</b> 47 */ 48 public class MultiTaskListener implements TaskListener { 49 /** The context key for the MultiTaskListener. */ 50 public static final Context.Key<MultiTaskListener> taskListenerKey = new Context.Key<>(); 51 52 /** Empty array of task listeners */ 53 private static final TaskListener[] EMPTY_LISTENERS = new TaskListener[0]; 54 55 private final DeferredCompletionFailureHandler dcfh; 56 57 /** Get the MultiTaskListener instance for this context. */ 58 public static MultiTaskListener instance(Context context) { 59 MultiTaskListener instance = context.get(taskListenerKey); 60 if (instance == null) 61 instance = new MultiTaskListener(context); 62 return instance; 63 } 64 65 protected MultiTaskListener(Context context) { 66 context.put(taskListenerKey, this); 67 ccw = ClientCodeWrapper.instance(context); 68 dcfh = DeferredCompletionFailureHandler.instance(context); 69 } 70 71 /** 72 * The current set of registered listeners. 73 * This is a mutable reference to an immutable array. 74 */ 75 TaskListener[] listeners = EMPTY_LISTENERS; 76 77 ClientCodeWrapper ccw; 78 79 public Collection<TaskListener> getTaskListeners() { 80 return Arrays.asList(listeners); 81 } 82 83 public boolean isEmpty() { 84 return listeners == EMPTY_LISTENERS; 85 } 86 87 public void add(TaskListener listener) { 88 for (TaskListener l: listeners) { 89 if (ccw.unwrap(l) == listener) 90 throw new IllegalStateException(); 91 } 92 listeners = Arrays.copyOf(listeners, listeners.length + 1); 93 listeners[listeners.length - 1] = ccw.wrap(listener); 94 } 95 96 public void remove(TaskListener listener) { 97 for (int i = 0; i < listeners.length; i++) { 98 if (ccw.unwrap(listeners[i]) == listener) { 99 if (listeners.length == 1) { 100 listeners = EMPTY_LISTENERS; 101 } else { 102 TaskListener[] newListeners = new TaskListener[listeners.length - 1]; 103 System.arraycopy(listeners, 0, newListeners, 0, i); 104 System.arraycopy(listeners, i + 1, newListeners, i, newListeners.length - i); 105 listeners = newListeners; 106 } 107 break; 108 } 109 } 110 } 111 112 @Override @DefinedBy(Api.COMPILER_TREE) 113 public void started(TaskEvent e) { 114 Handler prevDeferredHandler = dcfh.setHandler(dcfh.userCodeHandler); 115 try { 116 // guard against listeners being updated by a listener 117 TaskListener[] ll = this.listeners; 118 for (TaskListener l: ll) 119 l.started(e); 120 } finally { 121 dcfh.setHandler(prevDeferredHandler); 122 } 123 } 124 125 @Override @DefinedBy(Api.COMPILER_TREE) 126 public void finished(TaskEvent e) { 127 Handler prevDeferredHandler = dcfh.setHandler(dcfh.userCodeHandler); 128 try { 129 // guard against listeners being updated by a listener 130 TaskListener[] ll = this.listeners; 131 for (TaskListener l: ll) 132 l.finished(e); 133 } finally { 134 dcfh.setHandler(prevDeferredHandler); 135 } 136 } 137 138 @Override 139 public String toString() { 140 return Arrays.toString(listeners); 141 } 142 143 public void clear() { 144 listeners = EMPTY_LISTENERS; 145 } 146 }