ImageConsumerQueue.java

/*
 * Copyright (c) 1997, 2002, 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
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package sun.awt.image;

import java.awt.image.ImageConsumer;

class ImageConsumerQueue {
    ImageConsumerQueue next;

    ImageConsumer consumer;
    boolean interested;

    Object securityContext;
    boolean secure;

    static ImageConsumerQueue removeConsumer(ImageConsumerQueue cqbase,
					     ImageConsumer ic,
					     boolean stillinterested)
    {
	ImageConsumerQueue cqprev = null;
	for (ImageConsumerQueue cq = cqbase; cq != null; cq = cq.next) {
	    if (cq.consumer == ic) {
		if (cqprev == null) {
		    cqbase = cq.next;
		} else {
		    cqprev.next = cq.next;
		}
		cq.interested = stillinterested;
		break;
	    }
	    cqprev = cq;
	}
	return cqbase;
    }

    static boolean isConsumer(ImageConsumerQueue cqbase, ImageConsumer ic) {
	for (ImageConsumerQueue cq = cqbase; cq != null; cq = cq.next) {
	    if (cq.consumer == ic) {
		return true;
	    }
	}
	return false;
    }

    ImageConsumerQueue(InputStreamImageSource src, ImageConsumer ic) {
	consumer = ic;
	interested = true;
	// ImageReps do their own security at access time.
	if (ic instanceof ImageRepresentation) {
	    ImageRepresentation ir = (ImageRepresentation) ic;
	    if (ir.image.source != src) {
		throw new SecurityException("ImageRep added to wrong image source");
	    }
	    secure = true;
	} else {
            SecurityManager security = System.getSecurityManager();
            if (security != null) {
                securityContext = security.getSecurityContext();
            } else {
                securityContext = null;
            }
	}
    }

    public String toString() {
	return ("[" + consumer +
		", " + (interested ? "" : "not ") + "interested" +
		(securityContext != null ? ", " + securityContext : "") +
		"]");
    }
}