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package javax.print.attribute;

/**
 * Interface AttributeSet specifies the interface for a set of printing
 * attributes. A printing attribute is an object whose class implements
 * interface {@link Attribute Attribute}.
 * <P>
 * An attribute set contains a group of <I>attribute values,</I>
 * where duplicate values are not allowed in the set.
 * Furthermore, each value in an attribute set is
 * a member of some <I>category,</I> and at most one value in any particular
 * category is allowed in the set. For an attribute set, the values are {@link
 * Attribute Attribute} objects, and the categories are {@link java.lang.Class
 * Class} objects. An attribute's category is the class (or interface) at the
 * root of the class hierarchy for that kind of attribute. Note that an
 * attribute object's category may be a superclass of the attribute object's
 * class rather than the attribute object's class itself. An attribute
 * object's
 * category is determined by calling the {@link Attribute#getCategory()
 * getCategory()} method defined in interface {@link Attribute
 * Attribute}.
 * <P>
 * The interfaces of an AttributeSet resemble those of the Java Collections
 * API's java.util.Map interface, but is more restrictive in the types
 * it will accept, and combines keys and values into an Attribute.
 * <P>
 * Attribute sets are used in several places in the Print Service API. In
 * each context, only certain kinds of attributes are allowed to appear in the
 * attribute set, as determined by the tagging interfaces which the attribute
 * class implements -- {@link DocAttribute DocAttribute}, {@link
 * PrintRequestAttribute PrintRequestAttribute}, {@link PrintJobAttribute
 * PrintJobAttribute}, and {@link PrintServiceAttribute
 * PrintServiceAttribute}.
 * There are four specializations of an attribute set that are restricted to
 * contain just one of the four kinds of attribute -- {@link DocAttributeSet
 * DocAttributeSet}, {@link PrintRequestAttributeSet
 * PrintRequestAttributeSet},
 * {@link PrintJobAttributeSet PrintJobAttributeSet}, and {@link
 * PrintServiceAttributeSet PrintServiceAttributeSet}, respectively. Note that
 * many attribute classes implement more than one tagging interface and so may
 * appear in more than one context.
 * <UL>
 * <LI>
 * A {@link DocAttributeSet DocAttributeSet}, containing {@link DocAttribute
 * DocAttribute}s, specifies the characteristics of an individual doc and the
 * print job settings to be applied to an individual doc.
 * <P>
 * <LI>
 * A {@link PrintRequestAttributeSet PrintRequestAttributeSet}, containing
 * {@link PrintRequestAttribute PrintRequestAttribute}s, specifies the
 * settings
 * to be applied to a whole print job and to all the docs in the print job.
 * <P>
 * <LI>
 * A {@link PrintJobAttributeSet PrintJobAttributeSet}, containing {@link
 * PrintJobAttribute PrintJobAttribute}s, reports the status of a print job.
 * <P>
 * <LI>
 * A {@link PrintServiceAttributeSet PrintServiceAttributeSet}, containing
 * {@link PrintServiceAttribute PrintServiceAttribute}s, reports the status of
 * a Print Service instance.
 * </UL>
 * <P>
 * In some contexts, the client is only allowed to examine an attribute set's
 * contents but not change them (the set is read-only). In other places, the
 * client is allowed both to examine and to change an attribute set's contents
 * (the set is read-write). For a read-only attribute set, calling a mutating
 * operation throws an UnmodifiableSetException.
 * <P>
 * The Print Service API provides one implementation of interface
 * AttributeSet, class {@link HashAttributeSet HashAttributeSet}.
 * A client can use class {@link
 * HashAttributeSet HashAttributeSet} or provide its own implementation of
 * interface AttributeSet. The Print Service API also provides
 * implementations of interface AttributeSet's subinterfaces -- classes {@link
 * HashDocAttributeSet HashDocAttributeSet},
 * {@link HashPrintRequestAttributeSet
 * HashPrintRequestAttributeSet}, {@link HashPrintJobAttributeSet
 * HashPrintJobAttributeSet}, and {@link HashPrintServiceAttributeSet
 * HashPrintServiceAttributeSet}.
 * <P>
 *
 * @author Alan Kaminsky
 */
public interface AttributeSet {


 /**
 * Returns the attribute value which this attribute set contains in the
 * given attribute category. Returns <tt>null</tt> if this attribute set
 * does not contain any attribute value in the given attribute category.
 *
 * @param category Attribute category whose associated attribute value
 * is to be returned. It must be a
 * {@link java.lang.Class Class}
 * that implements interface {@link Attribute
 * Attribute}.
 *
 * @return The attribute value in the given attribute category contained
 * in this attribute set, or <tt>null</tt> if this attribute set
 * does not contain any attribute value in the given attribute
 * category.
 *
 * @throws NullPointerException
 * (unchecked exception) Thrown if the <CODE>category</CODE> is null.
 * @throws ClassCastException
 * (unchecked exception) Thrown if the <CODE>category</CODE> is not a
 * {@link java.lang.Class Class} that implements interface {@link
 * Attribute Attribute}.
 */
 public Attribute get(Class<?> category);

 /**
 * Adds the specified attribute to this attribute set if it is not
 * already present, first removing any existing value in the same
 * attribute category as the specified attribute value.
 *
 * @param attribute Attribute value to be added to this attribute set.
 *
 * @return <tt>true</tt> if this attribute set changed as a result of the
 * call, i.e., the given attribute value was not already a member
 * of this attribute set.
 *
 * @throws NullPointerException
 * (unchecked exception) Thrown if the <CODE>attribute</CODE> is null.
 * @throws UnmodifiableSetException
 * (unchecked exception) Thrown if this attribute set does not support
 * the <CODE>add()</CODE> operation.
 */
 public boolean add(Attribute attribute);


 /**
 * Removes any attribute for this category from this attribute set if
 * present. If <CODE>category</CODE> is null, then
 * <CODE>remove()</CODE> does nothing and returns <tt>false</tt>.
 *
 * @param category Attribute category to be removed from this
 * attribute set.
 *
 * @return <tt>true</tt> if this attribute set changed as a result of the
 * call, i.e., the given attribute value had been a member of this
 * attribute set.
 *
 * @throws UnmodifiableSetException
 * (unchecked exception) Thrown if this attribute set does not support
 * the <CODE>remove()</CODE> operation.
 */
 public boolean remove(Class<?> category);

 /**
 * Removes the specified attribute from this attribute set if
 * present. If <CODE>attribute</CODE> is null, then
 * <CODE>remove()</CODE> does nothing and returns <tt>false</tt>.
 *
 * @param attribute Attribute value to be removed from this attribute set.
 *
 * @return <tt>true</tt> if this attribute set changed as a result of the
 * call, i.e., the given attribute value had been a member of this
 * attribute set.
 *
 * @throws UnmodifiableSetException
 * (unchecked exception) Thrown if this attribute set does not support
 * the <CODE>remove()</CODE> operation.
 */
 public boolean remove(Attribute attribute);

 /**
 * Returns <tt>true</tt> if this attribute set contains an
 * attribute for the specified category.
 *
 * @param category whose presence in this attribute set is
 * to be tested.
 *
 * @return <tt>true</tt> if this attribute set contains an attribute
 * value for the specified category.
 */
 public boolean containsKey(Class<?> category);

 /**
 * Returns <tt>true</tt> if this attribute set contains the given
 * attribute value.
 *
 * @param attribute Attribute value whose presence in this
 * attribute set is to be tested.
 *
 * @return <tt>true</tt> if this attribute set contains the given
 * attribute value.
 */
 public boolean containsValue(Attribute attribute);

 /**
 * Adds all of the elements in the specified set to this attribute.
 * The outcome is the same as if the =
 * {@link #add(Attribute) add(Attribute)}
 * operation had been applied to this attribute set successively with each
 * element from the specified set.
 * The behavior of the <CODE>addAll(AttributeSet)</CODE>
 * operation is unspecified if the specified set is modified while
 * the operation is in progress.
 * <P>
 * If the <CODE>addAll(AttributeSet)</CODE> operation throws an exception,
 * the effect on this attribute set's state is implementation dependent;
 * elements from the specified set before the point of the exception may
 * or may not have been added to this attribute set.
 *
 * @param attributes whose elements are to be added to this attribute
 * set.
 *
 * @return <tt>true</tt> if this attribute set changed as a result of the
 * call.
 *
 * @throws UnmodifiableSetException
 * (Unchecked exception) Thrown if this attribute set does not support
 * the <tt>addAll(AttributeSet)</tt> method.
 * @throws NullPointerException
 * (Unchecked exception) Thrown if some element in the specified
 * set is null.
 *
 * @see #add(Attribute)
 */
 public boolean addAll(AttributeSet attributes);

 /**
 * Returns the number of attributes in this attribute set. If this
 * attribute set contains more than <tt>Integer.MAX_VALUE</tt> elements,
 * returns <tt>Integer.MAX_VALUE</tt>.
 *
 * @return The number of attributes in this attribute set.
 */
 public int size();

 /**
 * Returns an array of the attributes contained in this set.
 * @return the Attributes contained in this set as an array, zero length
 * if the AttributeSet is empty.
 */
 public Attribute[] toArray();


 /**
 * Removes all attributes from this attribute set.
 *
 * @throws UnmodifiableSetException
 * (unchecked exception) Thrown if this attribute set does not support
 * the <CODE>clear()</CODE> operation.
 */
 public void clear();

 /**
 * Returns true if this attribute set contains no attributes.
 *
 * @return true if this attribute set contains no attributes.
 */
 public boolean isEmpty();

 /**
 * Compares the specified object with this attribute set for equality.
 * Returns <tt>true</tt> if the given object is also an attribute set and
 * the two attribute sets contain the same attribute category-attribute
 * value mappings. This ensures that the
 * <tt>equals()</tt> method works properly across different
 * implementations of the AttributeSet interface.
 *
 * @param object to be compared for equality with this attribute set.
 *
 * @return <tt>true</tt> if the specified object is equal to this
 * attribute set.
 */
 public boolean equals(Object object);

 /**
 * Returns the hash code value for this attribute set. The hash code of an
 * attribute set is defined to be the sum of the hash codes of each entry
 * in the AttributeSet.
 * This ensures that <tt>t1.equals(t2)</tt> implies that
 * <tt>t1.hashCode()==t2.hashCode()</tt> for any two attribute sets
 * <tt>t1</tt> and <tt>t2</tt>, as required by the general contract of
 * {@link java.lang.Object#hashCode() Object.hashCode()}.
 *
 * @return The hash code value for this attribute set.
 */
 public int hashCode();

}