J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2004 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | |
| 27 | package javax.print.attribute; |
| 28 | |
| 29 | import java.io.Serializable; |
| 30 | |
| 31 | /** |
| 32 | * Class ResolutionSyntax is an abstract base class providing the common |
| 33 | * implementation of all attributes denoting a printer resolution. |
| 34 | * <P> |
| 35 | * A resolution attribute's value consists of two items, the cross feed |
| 36 | * direction resolution and the feed direction resolution. A resolution |
| 37 | * attribute may be constructed by supplying the two values and indicating the |
| 38 | * units in which the values are measured. Methods are provided to return a |
| 39 | * resolution attribute's values, indicating the units in which the values are |
| 40 | * to be returned. The two most common resolution units are dots per inch (dpi) |
| 41 | * and dots per centimeter (dpcm), and exported constants {@link #DPI |
| 42 | * <CODE>DPI</CODE>} and {@link #DPCM <CODE>DPCM</CODE>} are provided for |
| 43 | * indicating those units. |
| 44 | * <P> |
| 45 | * Once constructed, a resolution attribute's value is immutable. |
| 46 | * <P> |
| 47 | * <B>Design</B> |
| 48 | * <P> |
| 49 | * A resolution attribute's cross feed direction resolution and feed direction |
| 50 | * resolution values are stored internally using units of dots per 100 inches |
| 51 | * (dphi). Storing the values in dphi rather than, say, metric units allows |
| 52 | * precise integer arithmetic conversions between dpi and dphi and between dpcm |
| 53 | * and dphi: 1 dpi = 100 dphi, 1 dpcm = 254 dphi. Thus, the values can be stored |
| 54 | * into and retrieved back from a resolution attribute in either units with no |
| 55 | * loss of precision. This would not be guaranteed if a floating point |
| 56 | * representation were used. However, roundoff error will in general occur if a |
| 57 | * resolution attribute's values are created in one units and retrieved in |
| 58 | * different units; for example, 600 dpi will be rounded to 236 dpcm, whereas |
| 59 | * the true value (to five figures) is 236.22 dpcm. |
| 60 | * <P> |
| 61 | * Storing the values internally in common units of dphi lets two resolution |
| 62 | * attributes be compared without regard to the units in which they were |
| 63 | * created; for example, 300 dpcm will compare equal to 762 dpi, as they both |
| 64 | * are stored as 76200 dphi. In particular, a lookup service can |
| 65 | * match resolution attributes based on equality of their serialized |
| 66 | * representations regardless of the units in which they were created. Again, |
| 67 | * using integers for internal storage allows precise equality comparisons to be |
| 68 | * done, which would not be guaranteed if a floating point representation were |
| 69 | * used. |
| 70 | * <P> |
| 71 | * The exported constant {@link #DPI <CODE>DPI</CODE>} is actually the |
| 72 | * conversion factor by which to multiply a value in dpi to get the value in |
| 73 | * dphi. Likewise, the exported constant {@link #DPCM <CODE>DPCM</CODE>} is the |
| 74 | * conversion factor by which to multiply a value in dpcm to get the value in |
| 75 | * dphi. A client can specify a resolution value in units other than dpi or dpcm |
| 76 | * by supplying its own conversion factor. However, since the internal units of |
| 77 | * dphi was chosen with supporting only the external units of dpi and dpcm in |
| 78 | * mind, there is no guarantee that the conversion factor for the client's units |
| 79 | * will be an exact integer. If the conversion factor isn't an exact integer, |
| 80 | * resolution values in the client's units won't be stored precisely. |
| 81 | * <P> |
| 82 | * |
| 83 | * @author David Mendenhall |
| 84 | * @author Alan Kaminsky |
| 85 | */ |
| 86 | public abstract class ResolutionSyntax implements Serializable, Cloneable { |
| 87 | |
| 88 | private static final long serialVersionUID = 2706743076526672017L; |
| 89 | |
| 90 | /** |
| 91 | * Cross feed direction resolution in units of dots per 100 inches (dphi). |
| 92 | * @serial |
| 93 | */ |
| 94 | private int crossFeedResolution; |
| 95 | |
| 96 | /** |
| 97 | * Feed direction resolution in units of dots per 100 inches (dphi). |
| 98 | * @serial |
| 99 | */ |
| 100 | private int feedResolution; |
| 101 | |
| 102 | /** |
| 103 | * Value to indicate units of dots per inch (dpi). It is actually the |
| 104 | * conversion factor by which to multiply dpi to yield dphi (100). |
| 105 | */ |
| 106 | public static final int DPI = 100; |
| 107 | |
| 108 | /** |
| 109 | * Value to indicate units of dots per centimeter (dpcm). It is actually |
| 110 | * the conversion factor by which to multiply dpcm to yield dphi (254). |
| 111 | */ |
| 112 | public static final int DPCM = 254; |
| 113 | |
| 114 | |
| 115 | /** |
| 116 | * Construct a new resolution attribute from the given items. |
| 117 | * |
| 118 | * @param crossFeedResolution |
| 119 | * Cross feed direction resolution. |
| 120 | * @param feedResolution |
| 121 | * Feed direction resolution. |
| 122 | * @param units |
| 123 | * Unit conversion factor, e.g. {@link #DPI <CODE>DPI</CODE>} or |
| 124 | * {@link #DPCM <CODE>DPCM</CODE>}. |
| 125 | * |
| 126 | * @exception IllegalArgumentException |
| 127 | * (unchecked exception) Thrown if <CODE>crossFeedResolution</CODE> < |
| 128 | * 1 or <CODE>feedResolution</CODE> < 1 or <CODE>units</CODE> < 1. |
| 129 | */ |
| 130 | public ResolutionSyntax(int crossFeedResolution, int feedResolution, |
| 131 | int units) { |
| 132 | |
| 133 | if (crossFeedResolution < 1) { |
| 134 | throw new IllegalArgumentException("crossFeedResolution is < 1"); |
| 135 | } |
| 136 | if (feedResolution < 1) { |
| 137 | throw new IllegalArgumentException("feedResolution is < 1"); |
| 138 | } |
| 139 | if (units < 1) { |
| 140 | throw new IllegalArgumentException("units is < 1"); |
| 141 | } |
| 142 | |
| 143 | this.crossFeedResolution = crossFeedResolution * units; |
| 144 | this.feedResolution = feedResolution * units; |
| 145 | } |
| 146 | |
| 147 | /** |
| 148 | * Convert a value from dphi to some other units. The result is rounded to |
| 149 | * the nearest integer. |
| 150 | * |
| 151 | * @param dphi |
| 152 | * Value (dphi) to convert. |
| 153 | * @param units |
| 154 | * Unit conversion factor, e.g. {@link #DPI <CODE>DPI</CODE>} or |
| 155 | * {@link #DPCM <CODE>DPCM</CODE>}. |
| 156 | * |
| 157 | * @return The value of <CODE>dphi</CODE> converted to the desired units. |
| 158 | * |
| 159 | * @exception IllegalArgumentException |
| 160 | * (unchecked exception) Thrown if <CODE>units</CODE> < 1. |
| 161 | */ |
| 162 | private static int convertFromDphi(int dphi, int units) { |
| 163 | if (units < 1) { |
| 164 | throw new IllegalArgumentException(": units is < 1"); |
| 165 | } |
| 166 | int round = units / 2; |
| 167 | return (dphi + round) / units; |
| 168 | } |
| 169 | |
| 170 | /** |
| 171 | * Get this resolution attribute's resolution values in the given units. |
| 172 | * The values are rounded to the nearest integer. |
| 173 | * |
| 174 | * @param units |
| 175 | * Unit conversion factor, e.g. {@link #DPI <CODE>DPI</CODE>} or |
| 176 | * {@link #DPCM <CODE>DPCM</CODE>}. |
| 177 | * |
| 178 | * @return A two-element array with the cross feed direction resolution |
| 179 | * at index 0 and the feed direction resolution at index 1. |
| 180 | * |
| 181 | * @exception IllegalArgumentException |
| 182 | * (unchecked exception) Thrown if <CODE>units</CODE> < 1. |
| 183 | */ |
| 184 | public int[] getResolution(int units) { |
| 185 | return new int[] { getCrossFeedResolution(units), |
| 186 | getFeedResolution(units) |
| 187 | }; |
| 188 | } |
| 189 | |
| 190 | /** |
| 191 | * Returns this resolution attribute's cross feed direction resolution in |
| 192 | * the given units. The value is rounded to the nearest integer. |
| 193 | * |
| 194 | * @param units |
| 195 | * Unit conversion factor, e.g. {@link #DPI <CODE>DPI</CODE>} or |
| 196 | * {@link #DPCM <CODE>DPCM</CODE>}. |
| 197 | * |
| 198 | * @return Cross feed direction resolution. |
| 199 | * |
| 200 | * @exception IllegalArgumentException |
| 201 | * (unchecked exception) Thrown if <CODE>units</CODE> < 1. |
| 202 | */ |
| 203 | public int getCrossFeedResolution(int units) { |
| 204 | return convertFromDphi (crossFeedResolution, units); |
| 205 | } |
| 206 | |
| 207 | /** |
| 208 | * Returns this resolution attribute's feed direction resolution in the |
| 209 | * given units. The value is rounded to the nearest integer. |
| 210 | * |
| 211 | * @param units |
| 212 | * Unit conversion factor, e.g. {@link #DPI <CODE>DPI</CODE>} or {@link |
| 213 | * #DPCM <CODE>DPCM</CODE>}. |
| 214 | * |
| 215 | * @return Feed direction resolution. |
| 216 | * |
| 217 | * @exception IllegalArgumentException |
| 218 | * (unchecked exception) Thrown if <CODE>units</CODE> < 1. |
| 219 | */ |
| 220 | public int getFeedResolution(int units) { |
| 221 | return convertFromDphi (feedResolution, units); |
| 222 | } |
| 223 | |
| 224 | /** |
| 225 | * Returns a string version of this resolution attribute in the given units. |
| 226 | * The string takes the form <CODE>"<I>C</I>x<I>F</I> <I>U</I>"</CODE>, |
| 227 | * where <I>C</I> is the cross feed direction resolution, <I>F</I> is the |
| 228 | * feed direction resolution, and <I>U</I> is the units name. The values are |
| 229 | * rounded to the nearest integer. |
| 230 | * |
| 231 | * @param units |
| 232 | * Unit conversion factor, e.g. {@link #DPI <CODE>DPI</CODE>} or {@link |
| 233 | * #DPCM <CODE>DPCM</CODE>}. |
| 234 | * @param unitsName |
| 235 | * Units name string, e.g. <CODE>"dpi"</CODE> or <CODE>"dpcm"</CODE>. If |
| 236 | * null, no units name is appended to the result. |
| 237 | * |
| 238 | * @return String version of this resolution attribute. |
| 239 | * |
| 240 | * @exception IllegalArgumentException |
| 241 | * (unchecked exception) Thrown if <CODE>units</CODE> < 1. |
| 242 | */ |
| 243 | public String toString(int units, String unitsName) { |
| 244 | StringBuffer result = new StringBuffer(); |
| 245 | result.append(getCrossFeedResolution (units)); |
| 246 | result.append('x'); |
| 247 | result.append(getFeedResolution (units)); |
| 248 | if (unitsName != null) { |
| 249 | result.append (' '); |
| 250 | result.append (unitsName); |
| 251 | } |
| 252 | return result.toString(); |
| 253 | } |
| 254 | |
| 255 | |
| 256 | /** |
| 257 | * Determine whether this resolution attribute's value is less than or |
| 258 | * equal to the given resolution attribute's value. This is true if all |
| 259 | * of the following conditions are true: |
| 260 | * <UL> |
| 261 | * <LI> |
| 262 | * This attribute's cross feed direction resolution is less than or equal to |
| 263 | * the <CODE>other</CODE> attribute's cross feed direction resolution. |
| 264 | * <LI> |
| 265 | * This attribute's feed direction resolution is less than or equal to the |
| 266 | * <CODE>other</CODE> attribute's feed direction resolution. |
| 267 | * </UL> |
| 268 | * |
| 269 | * @param other Resolution attribute to compare with. |
| 270 | * |
| 271 | * @return True if this resolution attribute is less than or equal to the |
| 272 | * <CODE>other</CODE> resolution attribute, false otherwise. |
| 273 | * |
| 274 | * @exception NullPointerException |
| 275 | * (unchecked exception) Thrown if <CODE>other</CODE> is null. |
| 276 | */ |
| 277 | public boolean lessThanOrEquals(ResolutionSyntax other) { |
| 278 | return (this.crossFeedResolution <= other.crossFeedResolution && |
| 279 | this.feedResolution <= other.feedResolution); |
| 280 | } |
| 281 | |
| 282 | |
| 283 | /** |
| 284 | * Returns whether this resolution attribute is equivalent to the passed in |
| 285 | * object. To be equivalent, all of the following conditions must be true: |
| 286 | * <OL TYPE=1> |
| 287 | * <LI> |
| 288 | * <CODE>object</CODE> is not null. |
| 289 | * <LI> |
| 290 | * <CODE>object</CODE> is an instance of class ResolutionSyntax. |
| 291 | * <LI> |
| 292 | * This attribute's cross feed direction resolution is equal to |
| 293 | * <CODE>object</CODE>'s cross feed direction resolution. |
| 294 | * <LI> |
| 295 | * This attribute's feed direction resolution is equal to |
| 296 | * <CODE>object</CODE>'s feed direction resolution. |
| 297 | * </OL> |
| 298 | * |
| 299 | * @param object Object to compare to. |
| 300 | * |
| 301 | * @return True if <CODE>object</CODE> is equivalent to this resolution |
| 302 | * attribute, false otherwise. |
| 303 | */ |
| 304 | public boolean equals(Object object) { |
| 305 | |
| 306 | return(object != null && |
| 307 | object instanceof ResolutionSyntax && |
| 308 | this.crossFeedResolution == |
| 309 | ((ResolutionSyntax) object).crossFeedResolution && |
| 310 | this.feedResolution == |
| 311 | ((ResolutionSyntax) object).feedResolution); |
| 312 | } |
| 313 | |
| 314 | /** |
| 315 | * Returns a hash code value for this resolution attribute. |
| 316 | */ |
| 317 | public int hashCode() { |
| 318 | return(((crossFeedResolution & 0x0000FFFF)) | |
| 319 | ((feedResolution & 0x0000FFFF) << 16)); |
| 320 | } |
| 321 | |
| 322 | /** |
| 323 | * Returns a string version of this resolution attribute. The string takes |
| 324 | * the form <CODE>"<I>C</I>x<I>F</I> dphi"</CODE>, where <I>C</I> is the |
| 325 | * cross feed direction resolution and <I>F</I> is the feed direction |
| 326 | * resolution. The values are reported in the internal units of dphi. |
| 327 | */ |
| 328 | public String toString() { |
| 329 | StringBuffer result = new StringBuffer(); |
| 330 | result.append(crossFeedResolution); |
| 331 | result.append('x'); |
| 332 | result.append(feedResolution); |
| 333 | result.append(" dphi"); |
| 334 | return result.toString(); |
| 335 | } |
| 336 | |
| 337 | |
| 338 | /** |
| 339 | * Returns this resolution attribute's cross feed direction resolution in |
| 340 | * units of dphi. (For use in a subclass.) |
| 341 | * |
| 342 | * @return Cross feed direction resolution. |
| 343 | */ |
| 344 | protected int getCrossFeedResolutionDphi() { |
| 345 | return crossFeedResolution; |
| 346 | } |
| 347 | |
| 348 | /** |
| 349 | * Returns this resolution attribute's feed direction resolution in units |
| 350 | * of dphi. (For use in a subclass.) |
| 351 | * |
| 352 | * @return Feed direction resolution. |
| 353 | */ |
| 354 | protected int getFeedResolutionDphi() { |
| 355 | return feedResolution; |
| 356 | } |
| 357 | |
| 358 | } |