jdk/src/share/classes/javax/print/attribute/standard/PrinterStateReasons.java

/*
 * Copyright 2000-2006 Sun Microsystems, Inc.  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.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
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package javax.print.attribute.standard;

import java.util.AbstractSet;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.HashMap;
import java.util.Set;

import javax.print.attribute.Attribute;
import javax.print.attribute.PrintServiceAttribute;

/**
 * Class PrinterStateReasons is a printing attribute class, a set of
 * enumeration values, that provides additional information about the
 * printer's current state, i.e., information that augments the value of the
 * printer's {@link PrinterState PrinterState} attribute.
 * <P>
 * Instances of {@link PrinterStateReason PrinterStateReason} do not appear in
 *  a Print Service's attribute set directly. Rather, a PrinterStateReasons
 * attribute appears in the Print Service's attribute set. The
 * PrinterStateReasons attribute contains zero, one, or more than one {@link
 * PrinterStateReason PrinterStateReason} objects which pertain to the Print
 * Service's status, and each {@link PrinterStateReason PrinterStateReason}
 * object is associated with a {@link Severity Severity} level of REPORT
 *  (least severe), WARNING, or ERROR (most severe). The printer adds a {@link
 * PrinterStateReason PrinterStateReason} object to the Print Service's
 * PrinterStateReasons attribute when the corresponding condition becomes true
 * of the printer, and the printer removes the {@link PrinterStateReason
 * PrinterStateReason} object again when the corresponding condition becomes
 * false, regardless of whether the Print Service's overall
 * {@link PrinterState PrinterState} also changed.
 * <P>
 * Class PrinterStateReasons inherits its implementation from class {@link
 * java.util.HashMap java.util.HashMap}. Each entry in the map consists of a
 * {@link PrinterStateReason PrinterStateReason} object (key) mapping to a
 * {@link Severity Severity} object (value):
 * <P>
 * Unlike most printing attributes which are immutable once constructed, class
 * PrinterStateReasons is designed to be mutable; you can add {@link
 * PrinterStateReason PrinterStateReason} objects to an existing
 * PrinterStateReasons object and remove them again. However, like class
 *  {@link java.util.HashMap java.util.HashMap}, class PrinterStateReasons is
 * bot multiple thread safe. If a PrinterStateReasons object will be used by
 * multiple threads, be sure to synchronize its operations (e.g., using a
 * synchronized map view obtained from class {@link java.util.Collections
 * java.util.Collections}).
 * <P>
 * <B>IPP Compatibility:</B> The string values returned by each individual
 * {@link PrinterStateReason PrinterStateReason} object's and the associated
 * {@link Severity Severity} object's <CODE>toString()</CODE> methods,
 * concatenated
 * together with a hyphen (<CODE>"-"</CODE>) in between, gives the IPP keyword
 * value. The category name returned by <CODE>getName()</CODE> gives the IPP
 * attribute name.
 * <P>
 *
 * @author  Alan Kaminsky
 */
public final class PrinterStateReasons
    extends HashMap<PrinterStateReason,Severity>
    implements PrintServiceAttribute
{

    private static final long serialVersionUID = -3731791085163619457L;

    /**
     * Construct a new, empty printer state reasons attribute; the underlying
     * hash map has the default initial capacity and load factor.
     */
    public PrinterStateReasons() {
        super();
    }

    /**
     * super a new, empty printer state reasons attribute; the underlying
     * hash map has the given initial capacity and the default load factor.
     *
     * @param  initialCapacity  Initial capacity.
     *
     * @throws IllegalArgumentException if the initial capacity is less
     *     than zero.
     */
    public PrinterStateReasons(int initialCapacity) {
        super (initialCapacity);
    }

    /**
     * Construct a new, empty printer state reasons attribute; the underlying
     * hash map has the given initial capacity and load factor.
     *
     * @param  initialCapacity  Initial capacity.
     * @param  loadFactor       Load factor.
     *
     * @throws IllegalArgumentException if the initial capacity is less
     *     than zero.
     */
    public PrinterStateReasons(int initialCapacity, float loadFactor) {
        super (initialCapacity, loadFactor);
    }

    /**
     * Construct a new printer state reasons attribute that contains the same
     * {@link PrinterStateReason PrinterStateReason}-to-{@link Severity
     * Severity} mappings as the given map. The underlying hash map's initial
     * capacity and load factor are as specified in the superclass constructor
     * {@link java.util.HashMap#HashMap(java.util.Map)
     * <CODE>HashMap(Map)</CODE>}.
     *
     * @param  map  Map to copy.
     *
     * @exception  NullPointerException
     *     (unchecked exception) Thrown if <CODE>map</CODE> is null or if any
     *     key or value in <CODE>map</CODE> is null.
     * @throws  ClassCastException
     *     (unchecked exception) Thrown if any key in <CODE>map</CODE> is not
     *   an instance of class {@link PrinterStateReason PrinterStateReason} or
     *     if any value in <CODE>map</CODE> is not an instance of class
     *     {@link Severity Severity}.
     */
    public PrinterStateReasons(Map<PrinterStateReason,Severity> map) {
        this();
        for (Map.Entry<PrinterStateReason,Severity> e : map.entrySet())
            put(e.getKey(), e.getValue());
    }

    /**
     * Adds the given printer state reason to this printer state reasons
     * attribute, associating it with the given severity level. If this
     * printer state reasons attribute previously contained a mapping for the
     * given printer state reason, the old value is replaced.
     *
     * @param  reason    Printer state reason. This must be an instance of
     *                    class {@link PrinterStateReason PrinterStateReason}.
     * @param  severity  Severity of the printer state reason. This must be
     *                      an instance of class {@link Severity Severity}.
     *
     * @return  Previous severity associated with the given printer state
     *          reason, or <tt>null</tt> if the given printer state reason was
     *          not present.
     *
     * @throws  NullPointerException
     *     (unchecked exception) Thrown if <CODE>reason</CODE> is null or
     *     <CODE>severity</CODE> is null.
     * @throws  ClassCastException
     *     (unchecked exception) Thrown if <CODE>reason</CODE> is not an
     *   instance of class {@link PrinterStateReason PrinterStateReason} or if
     *     <CODE>severity</CODE> is not an instance of class {@link Severity
     *     Severity}.
     * @since 1.5
     */
    public Severity put(PrinterStateReason reason, Severity severity) {
        if (reason == null) {
            throw new NullPointerException("reason is null");
        }
        if (severity == null) {
            throw new NullPointerException("severity is null");
        }
        return super.put((PrinterStateReason) reason,
                         (Severity) severity);
    }

    /**
     * Get the printing attribute class which is to be used as the "category"
     * for this printing attribute value.
     * <P>
     * For class PrinterStateReasons, the
     * category is class PrinterStateReasons itself.
     *
     * @return  Printing attribute class (category), an instance of class
     *          {@link java.lang.Class java.lang.Class}.
     */
    public final Class<? extends Attribute> getCategory() {
        return PrinterStateReasons.class;
    }

    /**
     * Get the name of the category of which this attribute value is an
     * instance.
     * <P>
     * For class PrinterStateReasons, the
     * category name is <CODE>"printer-state-reasons"</CODE>.
     *
     * @return  Attribute category name.
     */
    public final String getName() {
        return "printer-state-reasons";
    }

    /**
     * Obtain an unmodifiable set view of the individual printer state reason
     * attributes at the given severity level in this PrinterStateReasons
     * attribute. Each element in the set view is a {@link PrinterStateReason
     * PrinterStateReason} object. The only elements in the set view are the
     * {@link PrinterStateReason PrinterStateReason} objects that map to the
     * given severity value. The set view is backed by this
     * PrinterStateReasons attribute, so changes to this PrinterStateReasons
     * attribute are reflected  in the set view.
     * The set view does not support element insertion or
     * removal. The set view's iterator does not support element removal.
     *
     * @param  severity  Severity level.
     *
     * @return  Set view of the individual {@link PrinterStateReason
     *          PrinterStateReason} attributes at the given {@link Severity
     *          Severity} level.
     *
     * @exception  NullPointerException
     *     (unchecked exception) Thrown if <CODE>severity</CODE> is null.
     */
    public Set<PrinterStateReason> printerStateReasonSet(Severity severity) {
        if (severity == null) {
            throw new NullPointerException("severity is null");
        }
        return new PrinterStateReasonSet (severity, entrySet());
    }

    private class PrinterStateReasonSet
        extends AbstractSet<PrinterStateReason>
    {
        private Severity mySeverity;
        private Set myEntrySet;

        public PrinterStateReasonSet(Severity severity, Set entrySet) {
            mySeverity = severity;
            myEntrySet = entrySet;
        }

        public int size() {
            int result = 0;
            Iterator iter = iterator();
            while (iter.hasNext()) {
                iter.next();
                ++ result;
            }
            return result;
        }

        public Iterator iterator() {
            return new PrinterStateReasonSetIterator(mySeverity,
                                                     myEntrySet.iterator());
        }
    }

    private class PrinterStateReasonSetIterator implements Iterator {
        private Severity mySeverity;
        private Iterator myIterator;
        private Map.Entry myEntry;

        public PrinterStateReasonSetIterator(Severity severity,
                                             Iterator iterator) {
            mySeverity = severity;
            myIterator = iterator;
            goToNext();
        }

        private void goToNext() {
            myEntry = null;
            while (myEntry == null && myIterator.hasNext()) {
                myEntry = (Map.Entry) myIterator.next();
                if ((Severity) myEntry.getValue() != mySeverity) {
                    myEntry = null;
                }
            }
        }

        public boolean hasNext() {
            return myEntry != null;
        }

        public Object next() {
            if (myEntry == null) {
                throw new NoSuchElementException();
            }
            Object result = myEntry.getKey();
            goToNext();
            return result;
        }

        public void remove() {
            throw new UnsupportedOperationException();
        }
    }

}