001 /* ResolutionSyntax.java --
002 Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
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007 it under the terms of the GNU General Public License as published by
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009 any later version.
010
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013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
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019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
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025
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027 permission to link this library with independent modules to produce an
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035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038 package javax.print.attribute;
039
040 import java.io.Serializable;
041
042 /**
043 * <code>ResolutionSyntax</code> is the abstract base class of all attribute
044 * classes which provide a resolution as value (e.g. printer resolution).
045 * <p>
046 * A <code>ResolutionSyntax</code> instance consists of two integer values
047 * describing the resolution in feed and cross feed direction. The units of
048 * the given values is determined by two defined constants:
049 * <ul>
050 * <li>DPCM - dots per centimeter</li>
051 * <li>DPI - dots per inch</li>
052 * </ul>
053 * </p>
054 * <p>
055 * A resolutions attribute is constructed by two values for the resolution and
056 * one of the two constants defining the actual units of the given values.
057 * </p>
058 * <p>
059 * There are different methods provided to return the resolution values in
060 * either of the both units and to compare if a resolution is less than or
061 * equal to a given other resolution attribute.
062 * </p>
063 * <p>
064 * <b>Internal storage:</b><br>
065 * The resolutions are stored internally as dots per 100 inches (dphi). The
066 * values of the provided constants for dots per inch (value 100) and dots
067 * per centimeter (value 254) are used as conversion factors to the internal
068 * storage units. To get the internal dphi values a multiplication of a given
069 * resolution value with its units constant value is needed. Retrieving the
070 * resolution for specific units is done by dividing the internal stored
071 * value through the units constant value. Clients are therefore able to
072 * provide their own resolution units by supplying other conversion factors.
073 * Subclasses of <code>ResolutionSyntax</code> have access to the internal
074 * resolution values through the protected methods
075 * {@link #getCrossFeedResolutionDphi()} and {@link #getFeedResolutionDphi()}.
076 * </p>
077 *
078 * @author Michael Koch (konqueror@gmx.de)
079 */
080 public abstract class ResolutionSyntax
081 implements Cloneable, Serializable
082 {
083 private static final long serialVersionUID = 2706743076526672017L;
084
085 /**
086 * Constant for units of dots per centimeter.
087 */
088 public static final int DPCM = 254;
089
090 /**
091 * Constant for units of dots per inch
092 */
093 public static final int DPI = 100;
094
095 private int crossFeedResolution;
096 private int feedResolution;
097
098 /**
099 * Creates a <code>ResolutionSyntax</code> object with the given arguments.
100 *
101 * @param crossFeedResolution the cross feed resolution
102 * @param feedResolution the feed resolution
103 * @param units the unit to use (e.g. {@link #DPCM} or {@link #DPI})
104 *
105 * @exception IllegalArgumentException if preconditions fail
106 */
107 public ResolutionSyntax(int crossFeedResolution, int feedResolution,
108 int units)
109 {
110 if (crossFeedResolution < 1
111 || feedResolution < 1
112 || units < 1)
113 throw new IllegalArgumentException("no argument may be less than 1");
114
115 this.crossFeedResolution = crossFeedResolution * units;
116 this.feedResolution = feedResolution * units;
117 }
118
119 /**
120 * Tests if the given object is equal to this object.
121 *
122 * @param obj the object to test
123 *
124 * @return <code>true</code> if both objects are equal,
125 * <code>false</code> otherwise.
126 */
127 public boolean equals(Object obj)
128 {
129 if(! (obj instanceof ResolutionSyntax))
130 return false;
131
132 ResolutionSyntax tmp = (ResolutionSyntax) obj;
133
134 return (crossFeedResolution == tmp.getCrossFeedResolutionDphi()
135 && feedResolution == tmp.getFeedResolutionDphi());
136 }
137
138 /**
139 * Returns the cross feed resolution for the given units.
140 *
141 * @param units the unit to use (e.g. {@link #DPCM} or {@link #DPI})
142 * @return The resolution for the given units.
143 *
144 * @exception IllegalArgumentException if units < 1
145 */
146 public int getCrossFeedResolution(int units)
147 {
148 if (units < 1)
149 throw new IllegalArgumentException("units may not be less then 1");
150
151 return crossFeedResolution / units;
152 }
153
154 /**
155 * Returns the raw cross feed resolution in dots per 100 inches.
156 *
157 * @return The raw resolution.
158 */
159 protected int getCrossFeedResolutionDphi()
160 {
161 return crossFeedResolution;
162 }
163
164 /**
165 * Returns the feed resolution for the given units.
166 *
167 * @param units the unit to use (e.g. {@link #DPCM} or {@link #DPI})
168 * @return The resolution for the given units.
169 *
170 * @exception IllegalArgumentException if units < 1
171 */
172 public int getFeedResolution(int units)
173 {
174 if (units < 1)
175 throw new IllegalArgumentException("units may not be less then 1");
176
177 return feedResolution / units;
178 }
179
180 /**
181 * Returns the raw feed resolution in dots per 100 inches.
182 *
183 * @return The raw resolution.
184 */
185 protected int getFeedResolutionDphi()
186 {
187 return feedResolution;
188 }
189
190 /**
191 * Returns the resolution as two field array. Index 0 is the cross feed
192 * resolution, index 1 the feed resolution.
193 *
194 * @param units the units to use
195 *
196 * @return The array with the resolutions.
197 */
198 public int[] getResolution(int units)
199 {
200 int[] resolution = new int[2];
201 resolution[0] = getCrossFeedResolution(units);
202 resolution[1] = getFeedResolution(units);
203 return resolution;
204 }
205
206 /**
207 * Returns the hashcode for this object.
208 *
209 * @return The hashcode.
210 */
211 public int hashCode()
212 {
213 return crossFeedResolution + feedResolution;
214 }
215
216 /**
217 * Checks if the given resolution attribute is a lower or equal
218 * to this resolution object.
219 *
220 * @param other the resolution to check against
221 *
222 * @return <code>true</code> if other resolution attribute describes
223 * a lower or equal resolution, <code>false</code> otherwise.
224 */
225 public boolean lessThanOrEquals(ResolutionSyntax other)
226 {
227 if (other == null)
228 throw new NullPointerException("other may not be null");
229
230 return (crossFeedResolution <= other.getCrossFeedResolutionDphi()
231 && feedResolution <= other.getFeedResolutionDphi());
232 }
233
234 /**
235 * Returns the string representation for this object.
236 * <p>
237 * The returned string is in the form "CxF dphi" with C standing
238 * for the cross feed and F for the feed direction resolution.
239 * Units used are dots per 100 inches (dphi).
240 * </p>
241 * @return The string representation.
242 */
243 public String toString()
244 {
245 return toString(1, "dphi");
246 }
247
248 /**
249 * Returns the string representation for this object.
250 * <p>
251 * The returned string is in the form "CxF U" with C standing
252 * for the cross feed and F for the feed direction resolution.
253 * U denotes the units name if one is supplied.
254 * </p>
255 *
256 * @param units the units to use
257 * @param unitsName the name of the units. If <code>null</code>
258 * it is ommitted from the string representation.
259 *
260 * @return The string representation.
261 */
262 public String toString(int units, String unitsName)
263 {
264 if (unitsName == null)
265 return getCrossFeedResolution(units) + "x" + getFeedResolution(units);
266
267 return ("" + getCrossFeedResolution(units)
268 + "x" + getFeedResolution(units)
269 + " " + unitsName);
270 }
271 }