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	/*
	* Copyright (c) 2000, 2013, 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
	* questions.
	*/


	package javax.print.attribute;

	import java.io.Serializable;

	/**
	* Class ResolutionSyntax is an abstract base class providing the common
	* implementation of all attributes denoting a printer resolution.
	* <P>
	* A resolution attribute's value consists of two items, the cross feed
	* direction resolution and the feed direction resolution. A resolution
	* attribute may be constructed by supplying the two values and indicating the
	* units in which the values are measured. Methods are provided to return a
	* resolution attribute's values, indicating the units in which the values are
	* to be returned. The two most common resolution units are dots per inch (dpi)
	* and dots per centimeter (dpcm), and exported constants {@link #DPI
	* DPI} and {@link #DPCM DPCM} are provided for
	* indicating those units.
	* <P>
	* Once constructed, a resolution attribute's value is immutable.
	* <P>
	* <B>Design</B>
	* <P>
	* A resolution attribute's cross feed direction resolution and feed direction
	* resolution values are stored internally using units of dots per 100 inches
	* (dphi). Storing the values in dphi rather than, say, metric units allows
	* precise integer arithmetic conversions between dpi and dphi and between dpcm
	* and dphi: 1 dpi = 100 dphi, 1 dpcm = 254 dphi. Thus, the values can be stored
	* into and retrieved back from a resolution attribute in either units with no
	* loss of precision. This would not be guaranteed if a floating point
	* representation were used. However, roundoff error will in general occur if a
	* resolution attribute's values are created in one units and retrieved in
	* different units; for example, 600 dpi will be rounded to 236 dpcm, whereas
	* the true value (to five figures) is 236.22 dpcm.
	* <P>
	* Storing the values internally in common units of dphi lets two resolution
	* attributes be compared without regard to the units in which they were
	* created; for example, 300 dpcm will compare equal to 762 dpi, as they both
	* are stored as 76200 dphi. In particular, a lookup service can
	* match resolution attributes based on equality of their serialized
	* representations regardless of the units in which they were created. Again,
	* using integers for internal storage allows precise equality comparisons to be
	* done, which would not be guaranteed if a floating point representation were
	* used.
	* <P>
	* The exported constant {@link #DPI DPI} is actually the
	* conversion factor by which to multiply a value in dpi to get the value in
	* dphi. Likewise, the exported constant {@link #DPCM DPCM} is the
	* conversion factor by which to multiply a value in dpcm to get the value in
	* dphi. A client can specify a resolution value in units other than dpi or dpcm
	* by supplying its own conversion factor. However, since the internal units of
	* dphi was chosen with supporting only the external units of dpi and dpcm in
	* mind, there is no guarantee that the conversion factor for the client's units
	* will be an exact integer. If the conversion factor isn't an exact integer,
	* resolution values in the client's units won't be stored precisely.
	* <P>
	*
	* @author David Mendenhall
	* @author Alan Kaminsky
	*/
	public abstract class ResolutionSyntax implements Serializable, Cloneable {

	private static final long serialVersionUID = 2706743076526672017L;

	/**
	* Cross feed direction resolution in units of dots per 100 inches (dphi).
	* @serial
	*/
	private int crossFeedResolution;

	/**
	* Feed direction resolution in units of dots per 100 inches (dphi).
	* @serial
	*/
	private int feedResolution;

	/**
	* Value to indicate units of dots per inch (dpi). It is actually the
	* conversion factor by which to multiply dpi to yield dphi (100).
	*/
	public static final int DPI = 100;

	/**
	* Value to indicate units of dots per centimeter (dpcm). It is actually
	* the conversion factor by which to multiply dpcm to yield dphi (254).
	*/
	public static final int DPCM = 254;


	/**
	* Construct a new resolution attribute from the given items.
	*
	* @param crossFeedResolution
	* Cross feed direction resolution.
	* @param feedResolution
	* Feed direction resolution.
	* @param units
	* Unit conversion factor, e.g. {@link #DPI DPI} or
	* {@link #DPCM DPCM}.
	*
	* @exception IllegalArgumentException
	* (unchecked exception) Thrown if {@code crossFeedResolution < 1}
	* or {@code feedResolution < 1} or {@code units < 1}.
	*/
	public ResolutionSyntax(int crossFeedResolution, int feedResolution,
	int units) {

	if (crossFeedResolution < 1) {
	throw new IllegalArgumentException("crossFeedResolution is < 1");
	}
	if (feedResolution < 1) {
	throw new IllegalArgumentException("feedResolution is < 1");
	}
	if (units < 1) {
	throw new IllegalArgumentException("units is < 1");
	}

	this.crossFeedResolution = crossFeedResolution * units;
	this.feedResolution = feedResolution * units;
	}

	/**
	* Convert a value from dphi to some other units. The result is rounded to
	* the nearest integer.
	*
	* @param dphi
	* Value (dphi) to convert.
	* @param units
	* Unit conversion factor, e.g. {@link #DPI <CODE>DPI</CODE>} or
	* {@link #DPCM <CODE>DPCM</CODE>}.
	*
	* @return The value of <CODE>dphi</CODE> converted to the desired units.
	*
	* @exception IllegalArgumentException
	* (unchecked exception) Thrown if <CODE>units</CODE> < 1.
	*/
	private static int convertFromDphi(int dphi, int units) {
	if (units < 1) {
	throw new IllegalArgumentException(": units is < 1");
	}
	int round = units / 2;
	return (dphi + round) / units;
	}

	/**
	* Get this resolution attribute's resolution values in the given units.
	* The values are rounded to the nearest integer.
	*
	* @param units
	* Unit conversion factor, e.g. {@link #DPI DPI} or
	* {@link #DPCM DPCM}.
	*
	* @return A two-element array with the cross feed direction resolution
	* at index 0 and the feed direction resolution at index 1.
	*
	* @exception IllegalArgumentException
	* (unchecked exception) Thrown if {@code units < 1}.
	*/
	public int[] getResolution(int units) {
	return new int[] { getCrossFeedResolution(units),
	getFeedResolution(units)
	};
	}

	/**
	* Returns this resolution attribute's cross feed direction resolution in
	* the given units. The value is rounded to the nearest integer.
	*
	* @param units
	* Unit conversion factor, e.g. {@link #DPI DPI} or
	* {@link #DPCM DPCM}.
	*
	* @return Cross feed direction resolution.
	*
	* @exception IllegalArgumentException
	* (unchecked exception) Thrown if {@code units < 1}.
	*/
	public int getCrossFeedResolution(int units) {
	return convertFromDphi (crossFeedResolution, units);
	}

	/**
	* Returns this resolution attribute's feed direction resolution in the
	* given units. The value is rounded to the nearest integer.
	*
	* @param units
	* Unit conversion factor, e.g. {@link #DPI DPI} or {@link
	* #DPCM DPCM}.
	*
	* @return Feed direction resolution.
	*
	* @exception IllegalArgumentException
	* (unchecked exception) Thrown if {@code units < 1}.
	*/
	public int getFeedResolution(int units) {
	return convertFromDphi (feedResolution, units);
	}

	/**
	* Returns a string version of this resolution attribute in the given units.
	* The string takes the form <CODE>"<I>C</I>x<I>F</I> <I>U</I>"</CODE>,
	* where <I>C</I> is the cross feed direction resolution, <I>F</I> is the
	* feed direction resolution, and <I>U</I> is the units name. The values are
	* rounded to the nearest integer.
	*
	* @param units
	* Unit conversion factor, e.g. {@link #DPI CODE>DPI} or {@link
	* #DPCM DPCM}.
	* @param unitsName
	* Units name string, e.g. <CODE>"dpi"</CODE> or <CODE>"dpcm"</CODE>. If
	* null, no units name is appended to the result.
	*
	* @return String version of this resolution attribute.
	*
	* @exception IllegalArgumentException
	* (unchecked exception) Thrown if {@code units < 1}.
	*/
	public String toString(int units, String unitsName) {
	StringBuffer result = new StringBuffer();
	result.append(getCrossFeedResolution (units));
	result.append('x');
	result.append(getFeedResolution (units));
	if (unitsName != null) {
	result.append (' ');
	result.append (unitsName);
	}
	return result.toString();
	}


	/**
	* Determine whether this resolution attribute's value is less than or
	* equal to the given resolution attribute's value. This is true if all
	* of the following conditions are true:
	* <UL>
	* <LI>
	* This attribute's cross feed direction resolution is less than or equal to
	* the <CODE>other</CODE> attribute's cross feed direction resolution.
	* <LI>
	* This attribute's feed direction resolution is less than or equal to the
	* <CODE>other</CODE> attribute's feed direction resolution.
	* </UL>
	*
	* @param other Resolution attribute to compare with.
	*
	* @return True if this resolution attribute is less than or equal to the
	* <CODE>other</CODE> resolution attribute, false otherwise.
	*
	* @exception NullPointerException
	* (unchecked exception) Thrown if <CODE>other</CODE> is null.
	*/
	public boolean lessThanOrEquals(ResolutionSyntax other) {
	return (this.crossFeedResolution <= other.crossFeedResolution &&
	this.feedResolution <= other.feedResolution);
	}


	/**
	* Returns whether this resolution attribute is equivalent to the passed in
	* object. To be equivalent, all of the following conditions must be true:
	* <OL TYPE=1>
	* <LI>
	* <CODE>object</CODE> is not null.
	* <LI>
	* <CODE>object</CODE> is an instance of class ResolutionSyntax.
	* <LI>
	* This attribute's cross feed direction resolution is equal to
	* <CODE>object</CODE>'s cross feed direction resolution.
	* <LI>
	* This attribute's feed direction resolution is equal to
	* <CODE>object</CODE>'s feed direction resolution.
	* </OL>
	*
	* @param object Object to compare to.
	*
	* @return True if <CODE>object</CODE> is equivalent to this resolution
	* attribute, false otherwise.
	*/
	public boolean equals(Object object) {

	return(object != null &&
	object instanceof ResolutionSyntax &&
	this.crossFeedResolution ==
	((ResolutionSyntax) object).crossFeedResolution &&
	this.feedResolution ==
	((ResolutionSyntax) object).feedResolution);
	}

	/**
	* Returns a hash code value for this resolution attribute.
	*/
	public int hashCode() {
	return(((crossFeedResolution & 0x0000FFFF)) \|
	((feedResolution & 0x0000FFFF) << 16));
	}

	/**
	* Returns a string version of this resolution attribute. The string takes
	* the form <CODE>"<I>C</I>x<I>F</I> dphi"</CODE>, where <I>C</I> is the
	* cross feed direction resolution and <I>F</I> is the feed direction
	* resolution. The values are reported in the internal units of dphi.
	*/
	public String toString() {
	StringBuffer result = new StringBuffer();
	result.append(crossFeedResolution);
	result.append('x');
	result.append(feedResolution);
	result.append(" dphi");
	return result.toString();
	}


	/**
	* Returns this resolution attribute's cross feed direction resolution in
	* units of dphi. (For use in a subclass.)
	*
	* @return Cross feed direction resolution.
	*/
	protected int getCrossFeedResolutionDphi() {
	return crossFeedResolution;
	}

	/**
	* Returns this resolution attribute's feed direction resolution in units
	* of dphi. (For use in a subclass.)
	*
	* @return Feed direction resolution.
	*/
	protected int getFeedResolutionDphi() {
	return feedResolution;
	}

	}

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