/*
* Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
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*/
package com.sun.tools.javac.api;
import java.util.Arrays;
import java.util.Collection;
import com.sun.source.util.TaskEvent;
import com.sun.source.util.TaskListener;
import com.sun.tools.javac.code.DeferredCompletionFailureHandler;
import com.sun.tools.javac.code.DeferredCompletionFailureHandler.Handler;
import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.DefinedBy;
import com.sun.tools.javac.util.DefinedBy.Api;
/**
* A collection of currently registered {@link TaskListener}s. Events passed to this TaskListener
* will be forwarded to all the registered TaskListeners.
*
* <p><b>This is NOT part of any supported API.
* If you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.</b>
*/
public class MultiTaskListener implements TaskListener {
/** The context key for the MultiTaskListener. */
public static final Context.Key<MultiTaskListener> taskListenerKey = new Context.Key<>();
/** Empty array of task listeners */
private static final TaskListener[] EMPTY_LISTENERS = new TaskListener[0];
private final DeferredCompletionFailureHandler dcfh;
/** Get the MultiTaskListener instance for this context. */
public static MultiTaskListener instance(Context context) {
MultiTaskListener instance = context.get(taskListenerKey);
if (instance == null)
instance = new MultiTaskListener(context);
return instance;
}
protected MultiTaskListener(Context context) {
context.put(taskListenerKey, this);
ccw = ClientCodeWrapper.instance(context);
dcfh = DeferredCompletionFailureHandler.instance(context);
}
/**
* The current set of registered listeners.
* This is a mutable reference to an immutable array.
*/
TaskListener[] listeners = EMPTY_LISTENERS;
ClientCodeWrapper ccw;
public Collection<TaskListener> getTaskListeners() {
return Arrays.asList(listeners);
}
public boolean isEmpty() {
return listeners == EMPTY_LISTENERS;
}
public void add(TaskListener listener) {
for (TaskListener l: listeners) {
if (ccw.unwrap(l) == listener)
throw new IllegalStateException();
}
listeners = Arrays.copyOf(listeners, listeners.length + 1);
listeners[listeners.length - 1] = ccw.wrap(listener);
}
public void remove(TaskListener listener) {
for (int i = 0; i < listeners.length; i++) {
if (ccw.unwrap(listeners[i]) == listener) {
if (listeners.length == 1) {
listeners = EMPTY_LISTENERS;
} else {
TaskListener[] newListeners = new TaskListener[listeners.length - 1];
System.arraycopy(listeners, 0, newListeners, 0, i);
System.arraycopy(listeners, i + 1, newListeners, i, newListeners.length - i);
listeners = newListeners;
}
break;
}
}
}
@Override @DefinedBy(Api.COMPILER_TREE)
public void started(TaskEvent e) {
Handler prevDeferredHandler = dcfh.setHandler(dcfh.userCodeHandler);
try {
// guard against listeners being updated by a listener
TaskListener[] ll = this.listeners;
for (TaskListener l: ll)
l.started(e);
} finally {
dcfh.setHandler(prevDeferredHandler);
}
}
@Override @DefinedBy(Api.COMPILER_TREE)
/**代码未完, 请加载全部代码(NowJava.com).**/