1 /*
2 * Copyright (c) 1997, 2006, Oracle and/or its affiliates. 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24 */
25
26 /*
27 * (C) Copyright Taligent, Inc. 1996 - 1997, All Rights Reserved
28 * (C) Copyright IBM Corp. 1996 - 1998, All Rights Reserved
29 *
30 * The original version of this source code and documentation is
31 * copyrighted and owned by Taligent, Inc., a wholly-owned subsidiary
32 * of IBM. These materials are provided under terms of a License
33 * Agreement between Taligent and Sun. This technology is protected
34 * by multiple US and International patents.
35 *
36 * This notice and attribution to Taligent may not be removed.
37 * Taligent is a registered trademark of Taligent, Inc.
38 *
39 */
40
41 package java.awt.font;
42
43 import java.io.InvalidObjectException;
44 import java.text.AttributedCharacterIterator.Attribute;
45 import java.util.Map;
46 import java.util.HashMap;
47
48 /**
49 * The <code>TextAttribute</code> class defines attribute keys and
50 * attribute values used for text rendering.
51 * <p>
52 * <code>TextAttribute</code> instances are used as attribute keys to
53 * identify attributes in
54 * {@link java.awt.Font Font},
55 * {@link java.awt.font.TextLayout TextLayout},
56 * {@link java.text.AttributedCharacterIterator AttributedCharacterIterator},
57 * and other classes handling text attributes. Other constants defined
58 * in this class can be used as attribute values.
59 * <p>
60 * For each text attribute, the documentation provides:
61 * <UL>
62 * <LI>the type of its value,
63 * <LI>the relevant predefined constants, if any
64 * <LI>the default effect if the attribute is absent
65 * <LI>the valid values if there are limitations
66 * <LI>a description of the effect.
67 * </UL>
68 * <p>
69 * <H4>Values</H4>
70 * <UL>
71 * <LI>The values of attributes must always be immutable.
72 * <LI>Where value limitations are given, any value outside of that
73 * set is reserved for future use; the value will be treated as
74 * the default.
75 * <LI>The value <code>null</code> is treated the same as the
76 * default value and results in the default behavior.
77 * <li>If the value is not of the proper type, the attribute
78 * will be ignored.
79 * <li>The identity of the value does not matter, only the actual
80 * value. For example, <code>TextAttribute.WEIGHT_BOLD</code> and
81 * <code>new Float(2.0)</code>
82 * indicate the same <code>WEIGHT</code>.
83 * <li>Attribute values of type <code>Number</code> (used for
84 * <code>WEIGHT</code>, <code>WIDTH</code>, <code>POSTURE</code>,
85 * <code>SIZE</code>, <code>JUSTIFICATION</code>, and
86 * <code>TRACKING</code>) can vary along their natural range and are
87 * not restricted to the predefined constants.
88 * <code>Number.floatValue()</code> is used to get the actual value
89 * from the <code>Number</code>.
90 * <li>The values for <code>WEIGHT</code>, <code>WIDTH</code>, and
91 * <code>POSTURE</code> are interpolated by the system, which
92 * can select the 'nearest available' font or use other techniques to
93 * approximate the user's request.
94 *
95 * </UL>
96 *
97 * <h4>Summary of attributes</h4>
98 * <p>
99 * <font size="-1">
100 * <table align="center" border="0" cellspacing="0" cellpadding="2" width="%95"
101 * summary="Key, value type, principal constants, and default value
102 * behavior of all TextAttributes">
103 * <tr bgcolor="#ccccff">
104 * <th valign="TOP" align="CENTER">Key</th>
105 * <th valign="TOP" align="CENTER">Value Type</th>
106 * <th valign="TOP" align="CENTER">Principal Constants</th>
107 * <th valign="TOP" align="CENTER">Default Value</th>
108 * </tr>
109 * <tr>
110 * <td valign="TOP">{@link #FAMILY}</td>
111 * <td valign="TOP">String</td>
112 * <td valign="TOP">See Font {@link java.awt.Font#DIALOG DIALOG},
113 {@link java.awt.Font#DIALOG_INPUT DIALOG_INPUT},<br> {@link java.awt.Font#SERIF SERIF},
114 {@link java.awt.Font#SANS_SERIF SANS_SERIF}, and {@link java.awt.Font#MONOSPACED MONOSPACED}.
115 </td>
116 * <td valign="TOP">"Default" (use platform default)</td>
117 * </tr>
118 * <tr bgcolor="#eeeeff">
119 * <td valign="TOP">{@link #WEIGHT}</td>
120 * <td valign="TOP">Number</td>
121 * <td valign="TOP">WEIGHT_REGULAR, WEIGHT_BOLD</td>
122 * <td valign="TOP">WEIGHT_REGULAR</td>
123 * </tr>
124 * <tr>
125 * <td valign="TOP">{@link #WIDTH}</td>
126 * <td valign="TOP">Number</td>
127 * <td valign="TOP">WIDTH_CONDENSED, WIDTH_REGULAR,<br>WIDTH_EXTENDED</td>
128 * <td valign="TOP">WIDTH_REGULAR</td>
129 * </tr>
130 * <tr bgcolor="#eeeeff">
131 * <td valign="TOP">{@link #POSTURE}</td>
132 * <td valign="TOP">Number</td>
133 * <td valign="TOP">POSTURE_REGULAR, POSTURE_OBLIQUE</td>
134 * <td valign="TOP">POSTURE_REGULAR</td>
135 * </tr>
136 * <tr>
137 * <td valign="TOP">{@link #SIZE}</td>
138 * <td valign="TOP">Number</td>
139 * <td valign="TOP">none</td>
140 * <td valign="TOP">12.0</td>
141 * </tr>
142 * <tr bgcolor="#eeeeff">
143 * <td valign="TOP">{@link #TRANSFORM}</td>
144 * <td valign="TOP">{@link TransformAttribute}</td>
145 * <td valign="TOP">See TransformAttribute {@link TransformAttribute#IDENTITY IDENTITY}</td>
146 * <td valign="TOP">TransformAttribute.IDENTITY</td>
147 * </tr>
148 * <tr>
149 * <td valign="TOP">{@link #SUPERSCRIPT}</td>
150 * <td valign="TOP">Integer</td>
151 * <td valign="TOP">SUPERSCRIPT_SUPER, SUPERSCRIPT_SUB</td>
152 * <td valign="TOP">0 (use the standard glyphs and metrics)</td>
153 * </tr>
154 * <tr bgcolor="#eeeeff">
155 * <td valign="TOP">{@link #FONT}</td>
156 * <td valign="TOP">{@link java.awt.Font}</td>
157 * <td valign="TOP">none</td>
158 * <td valign="TOP">null (do not override font resolution)</td>
159 * </tr>
160 * <tr>
161 * <td valign="TOP">{@link #CHAR_REPLACEMENT}</td>
162 * <td valign="TOP">{@link GraphicAttribute}</td>
163 * <td valign="TOP">none</td>
164 * <td valign="TOP">null (draw text using font glyphs)</td>
165 * </tr>
166 * <tr bgcolor="#eeeeff">
167 * <td valign="TOP">{@link #FOREGROUND}</td>
168 * <td valign="TOP">{@link java.awt.Paint}</td>
169 * <td valign="TOP">none</td>
170 * <td valign="TOP">null (use current graphics paint)</td>
171 * </tr>
172 * <tr>
173 * <td valign="TOP">{@link #BACKGROUND}</td>
174 * <td valign="TOP">{@link java.awt.Paint}</td>
175 * <td valign="TOP">none</td>
176 * <td valign="TOP">null (do not render background)</td>
177 * </tr>
178 * <tr bgcolor="#eeeeff">
179 * <td valign="TOP">{@link #UNDERLINE}</td>
180 * <td valign="TOP">Integer</td>
181 * <td valign="TOP">UNDERLINE_ON</td>
182 * <td valign="TOP">-1 (do not render underline)</td>
183 * </tr>
184 * <tr>
185 * <td valign="TOP">{@link #STRIKETHROUGH}</td>
186 * <td valign="TOP">Boolean</td>
187 * <td valign="TOP">STRIKETHROUGH_ON</td>
188 * <td valign="TOP">false (do not render strikethrough)</td>
189 * </tr>
190 * <tr bgcolor="#eeeeff">
191 * <td valign="TOP">{@link #RUN_DIRECTION}</td>
192 * <td valign="TOP">Boolean</td>
193 * <td valign="TOP">RUN_DIRECTION_LTR<br>RUN_DIRECTION_RTL</td>
194 * <td valign="TOP">null (use {@link java.text.Bidi} standard default)</td>
195 * </tr>
196 * <tr>
197 * <td valign="TOP">{@link #BIDI_EMBEDDING}</td>
198 * <td valign="TOP">Integer</td>
199 * <td valign="TOP">none</td>
200 * <td valign="TOP">0 (use base line direction)</td>
201 * </tr>
202 * <tr bgcolor="#eeeeff">
203 * <td valign="TOP">{@link #JUSTIFICATION}</td>
204 * <td valign="TOP">Number</td>
205 * <td valign="TOP">JUSTIFICATION_FULL</td>
206 * <td valign="TOP">JUSTIFICATION_FULL</td>
207 * </tr>
208 * <tr>
209 * <td valign="TOP">{@link #INPUT_METHOD_HIGHLIGHT}</td>
210 * <td valign="TOP">{@link java.awt.im.InputMethodHighlight},<br>{@link java.text.Annotation}</td>
211 * <td valign="TOP">(see class)</td>
212 * <td valign="TOP">null (do not apply input highlighting)</td>
213 * </tr>
214 * <tr bgcolor="#eeeeff">
215 * <td valign="TOP">{@link #INPUT_METHOD_UNDERLINE}</td>
216 * <td valign="TOP">Integer</td>
217 * <td valign="TOP">UNDERLINE_LOW_ONE_PIXEL,<br>UNDERLINE_LOW_TWO_PIXEL</td>
218 * <td valign="TOP">-1 (do not render underline)</td>
219 * </tr>
220 * <tr>
221 * <td valign="TOP">{@link #SWAP_COLORS}</td>
222 * <td valign="TOP">Boolean</td>
223 * <td valign="TOP">SWAP_COLORS_ON</td>
224 * <td valign="TOP">false (do not swap colors)</td>
225 * </tr>
226 * <tr bgcolor="#eeeeff">
227 * <td valign="TOP">{@link #NUMERIC_SHAPING}</td>
228 * <td valign="TOP">{@link java.awt.font.NumericShaper}</td>
229 * <td valign="TOP">none</td>
230 * <td valign="TOP">null (do not shape digits)</td>
231 * </tr>
232 * <tr>
233 * <td valign="TOP">{@link #KERNING}</td>
234 * <td valign="TOP">Integer</td>
235 * <td valign="TOP">KERNING_ON</td>
236 * <td valign="TOP">0 (do not request kerning)</td>
237 * </tr>
238 * <tr bgcolor="#eeeeff">
239 * <td valign="TOP">{@link #LIGATURES}</td>
240 * <td valign="TOP">Integer</td>
241 * <td valign="TOP">LIGATURES_ON</td>
242 * <td valign="TOP">0 (do not form optional ligatures)</td>
243 * </tr>
244 * <tr>
245 * <td valign="TOP">{@link #TRACKING}</td>
246 * <td valign="TOP">Number</td>
247 * <td valign="TOP">TRACKING_LOOSE, TRACKING_TIGHT</td>
248 * <td valign="TOP">0 (do not add tracking)</td>
249 * </tr>
250 * </table>
251 * </font>
252 *
253 * @see java.awt.Font
254 * @see java.awt.font.TextLayout
255 * @see java.text.AttributedCharacterIterator
256 */
257 public final class TextAttribute extends Attribute {
258
259 // table of all instances in this class, used by readResolve
260 private static final Map instanceMap = new HashMap(29);
261
262 /**
263 * Constructs a <code>TextAttribute</code> with the specified name.
264 * @param name the attribute name to assign to this
265 * <code>TextAttribute</code>
266 */
267 protected TextAttribute(String name) {
268 super(name);
269 if (this.getClass() == TextAttribute.class) {
270 instanceMap.put(name, this);
271 }
272 }
273
274 /**
275 * Resolves instances being deserialized to the predefined constants.
276 */
277 protected Object readResolve() throws InvalidObjectException {
278 if (this.getClass() != TextAttribute.class) {
279 throw new InvalidObjectException(
280 "subclass didn't correctly implement readResolve");
281 }
282
283 TextAttribute instance = (TextAttribute) instanceMap.get(getName());
284 if (instance != null) {
285 return instance;
286 } else {
287 throw new InvalidObjectException("unknown attribute name");
288 }
289 }
290
291 // Serialization compatibility with Java 2 platform v1.2.
292 // 1.2 will throw an InvalidObjectException if ever asked to
293 // deserialize INPUT_METHOD_UNDERLINE.
294 // This shouldn't happen in real life.
295 static final long serialVersionUID = 7744112784117861702L;
296
297 //
298 // For use with Font.
299 //
300
301 /**
302 * Attribute key for the font name. Values are instances of
303 * <b><code>String</code></b>. The default value is
304 * <code>"Default"</code>, which causes the platform default font
305 * family to be used.
306 *
307 * <p> The <code>Font</code> class defines constants for the logical
308 * font names
309 * {@link java.awt.Font#DIALOG DIALOG},
310 * {@link java.awt.Font#DIALOG_INPUT DIALOG_INPUT},
311 * {@link java.awt.Font#SANS_SERIF SANS_SERIF},
312 * {@link java.awt.Font#SERIF SERIF}, and
313 * {@link java.awt.Font#MONOSPACED MONOSPACED}.
314 *
315 * <p>This defines the value passed as <code>name</code> to the
316 * <code>Font</code> constructor. Both logical and physical
317 * font names are allowed. If a font with the requested name
318 * is not found, the default font is used.
319 *
320 * <p><em>Note:</em> This attribute is unfortunately misnamed, as
321 * it specifies the face name and not just the family. Thus
322 * values such as "Lucida Sans Bold" will select that face if it
323 * exists. Note, though, that if the requested face does not
324 * exist, the default will be used with <em>regular</em> weight.
325 * The "Bold" in the name is part of the face name, not a separate
326 * request that the font's weight be bold.</p>
327 */
328 public static final TextAttribute FAMILY =
329 new TextAttribute("family");
330
331 /**
332 * Attribute key for the weight of a font. Values are instances
333 * of <b><code>Number</code></b>. The default value is
334 * <code>WEIGHT_REGULAR</code>.
335 *
336 * <p>Several constant values are provided, see {@link
337 * #WEIGHT_EXTRA_LIGHT}, {@link #WEIGHT_LIGHT}, {@link
338 * #WEIGHT_DEMILIGHT}, {@link #WEIGHT_REGULAR}, {@link
339 * #WEIGHT_SEMIBOLD}, {@link #WEIGHT_MEDIUM}, {@link
340 * #WEIGHT_DEMIBOLD}, {@link #WEIGHT_BOLD}, {@link #WEIGHT_HEAVY},
341 * {@link #WEIGHT_EXTRABOLD}, and {@link #WEIGHT_ULTRABOLD}. The
342 * value <code>WEIGHT_BOLD</code> corresponds to the
343 * style value <code>Font.BOLD</code> as passed to the
344 * <code>Font</code> constructor.
345 *
346 * <p>The value is roughly the ratio of the stem width to that of
347 * the regular weight.
348 *
349 * <p>The system can interpolate the provided value.
350 */
351 public static final TextAttribute WEIGHT =
352 new TextAttribute("weight");
353
354 /**
355 * The lightest predefined weight.
356 * @see #WEIGHT
357 */
358 public static final Float WEIGHT_EXTRA_LIGHT =
359 Float.valueOf(0.5f);
360
361 /**
362 * The standard light weight.
363 * @see #WEIGHT
364 */
365 public static final Float WEIGHT_LIGHT =
366 Float.valueOf(0.75f);
367
368 /**
369 * An intermediate weight between <code>WEIGHT_LIGHT</code> and
370 * <code>WEIGHT_STANDARD</code>.
371 * @see #WEIGHT
372 */
373 public static final Float WEIGHT_DEMILIGHT =
374 Float.valueOf(0.875f);
375
376 /**
377 * The standard weight. This is the default value for <code>WEIGHT</code>.
378 * @see #WEIGHT
379 */
380 public static final Float WEIGHT_REGULAR =
381 Float.valueOf(1.0f);
382
383 /**
384 * A moderately heavier weight than <code>WEIGHT_REGULAR</code>.
385 * @see #WEIGHT
386 */
387 public static final Float WEIGHT_SEMIBOLD =
388 Float.valueOf(1.25f);
389
390 /**
391 * An intermediate weight between <code>WEIGHT_REGULAR</code> and
392 * <code>WEIGHT_BOLD</code>.
393 * @see #WEIGHT
394 */
395 public static final Float WEIGHT_MEDIUM =
396 Float.valueOf(1.5f);
397
398 /**
399 * A moderately lighter weight than <code>WEIGHT_BOLD</code>.
400 * @see #WEIGHT
401 */
402 public static final Float WEIGHT_DEMIBOLD =
403 Float.valueOf(1.75f);
404
405 /**
406 * The standard bold weight.
407 * @see #WEIGHT
408 */
409 public static final Float WEIGHT_BOLD =
410 Float.valueOf(2.0f);
411
412 /**
413 * A moderately heavier weight than <code>WEIGHT_BOLD</code>.
414 * @see #WEIGHT
415 */
416 public static final Float WEIGHT_HEAVY =
417 Float.valueOf(2.25f);
418
419 /**
420 * An extra heavy weight.
421 * @see #WEIGHT
422 */
423 public static final Float WEIGHT_EXTRABOLD =
424 Float.valueOf(2.5f);
425
426 /**
427 * The heaviest predefined weight.
428 * @see #WEIGHT
429 */
430 public static final Float WEIGHT_ULTRABOLD =
431 Float.valueOf(2.75f);
432
433 /**
434 * Attribute key for the width of a font. Values are instances of
435 * <b><code>Number</code></b>. The default value is
436 * <code>WIDTH_REGULAR</code>.
437 *
438 * <p>Several constant values are provided, see {@link
439 * #WIDTH_CONDENSED}, {@link #WIDTH_SEMI_CONDENSED}, {@link
440 * #WIDTH_REGULAR}, {@link #WIDTH_SEMI_EXTENDED}, {@link
441 * #WIDTH_EXTENDED}.
442 *
443 * <p>The value is roughly the ratio of the advance width to that
444 * of the regular width.
445 *
446 * <p>The system can interpolate the provided value.
447 */
448 public static final TextAttribute WIDTH =
449 new TextAttribute("width");
450
451 /**
452 * The most condensed predefined width.
453 * @see #WIDTH
454 */
455 public static final Float WIDTH_CONDENSED =
456 Float.valueOf(0.75f);
457
458 /**
459 * A moderately condensed width.
460 * @see #WIDTH
461 */
462 public static final Float WIDTH_SEMI_CONDENSED =
463 Float.valueOf(0.875f);
464
465 /**
466 * The standard width. This is the default value for
467 * <code>WIDTH</code>.
468 * @see #WIDTH
469 */
470 public static final Float WIDTH_REGULAR =
471 Float.valueOf(1.0f);
472
473 /**
474 * A moderately extended width.
475 * @see #WIDTH
476 */
477 public static final Float WIDTH_SEMI_EXTENDED =
478 Float.valueOf(1.25f);
479
480 /**
481 * The most extended predefined width.
482 * @see #WIDTH
483 */
484 public static final Float WIDTH_EXTENDED =
485 Float.valueOf(1.5f);
486
487 /**
488 * Attribute key for the posture of a font. Values are instances
489 * of <b><code>Number</code></b>. The default value is
490 * <code>POSTURE_REGULAR</code>.
491 *
492 * <p>Two constant values are provided, {@link #POSTURE_REGULAR}
493 * and {@link #POSTURE_OBLIQUE}. The value
494 * <code>POSTURE_OBLIQUE</code> corresponds to the style value
495 * <code>Font.ITALIC</code> as passed to the <code>Font</code>
496 * constructor.
497 *
498 * <p>The value is roughly the slope of the stems of the font,
499 * expressed as the run over the rise. Positive values lean right.
500 *
501 * <p>The system can interpolate the provided value.
502 *
503 * <p>This will affect the font's italic angle as returned by
504 * <code>Font.getItalicAngle</code>.
505 *
506 * @see java.awt.Font#getItalicAngle()
507 */
508 public static final TextAttribute POSTURE =
509 new TextAttribute("posture");
510
511 /**
512 * The standard posture, upright. This is the default value for
513 * <code>POSTURE</code>.
514 * @see #POSTURE
515 */
516 public static final Float POSTURE_REGULAR =
517 Float.valueOf(0.0f);
518
519 /**
520 * The standard italic posture.
521 * @see #POSTURE
522 */
523 public static final Float POSTURE_OBLIQUE =
524 Float.valueOf(0.20f);
525
526 /**
527 * Attribute key for the font size. Values are instances of
528 * <b><code>Number</code></b>. The default value is 12pt.
529 *
530 * <p>This corresponds to the <code>size</code> parameter to the
531 * <code>Font</code> constructor.
532 *
533 * <p>Very large or small sizes will impact rendering performance,
534 * and the rendering system might not render text at these sizes.
535 * Negative sizes are illegal and result in the default size.
536 *
537 * <p>Note that the appearance and metrics of a 12pt font with a
538 * 2x transform might be different than that of a 24 point font
539 * with no transform.
540 */
541 public static final TextAttribute SIZE =
542 new TextAttribute("size");
543
544 /**
545 * Attribute key for the transform of a font. Values are
546 * instances of <b><code>TransformAttribute</code></b>. The
547 * default value is <code>TransformAttribute.IDENTITY</code>.
548 *
549 * <p>The <code>TransformAttribute</code> class defines the
550 * constant {@link TransformAttribute#IDENTITY IDENTITY}.
551 *
552 * <p>This corresponds to the transform passed to
553 * <code>Font.deriveFont(AffineTransform)</code>. Since that
554 * transform is mutable and <code>TextAttribute</code> values must
555 * not be, the <code>TransformAttribute</code> wrapper class is
556 * used.
557 *
558 * <p>The primary intent is to support scaling and skewing, though
559 * other effects are possible.</p>
560 *
561 * <p>Some transforms will cause the baseline to be rotated and/or
562 * shifted. The text and the baseline are transformed together so
563 * that the text follows the new baseline. For example, with text
564 * on a horizontal baseline, the new baseline follows the
565 * direction of the unit x vector passed through the
566 * transform. Text metrics are measured against this new baseline.
567 * So, for example, with other things being equal, text rendered
568 * with a rotated TRANSFORM and an unrotated TRANSFORM will measure as
569 * having the same ascent, descent, and advance.</p>
570 *
571 * <p>In styled text, the baselines for each such run are aligned
572 * one after the other to potentially create a non-linear baseline
573 * for the entire run of text. For more information, see {@link
574 * TextLayout#getLayoutPath}.</p>
575 *
576 * @see TransformAttribute
577 * @see java.awt.geom.AffineTransform
578 */
579 public static final TextAttribute TRANSFORM =
580 new TextAttribute("transform");
581
582 /**
583 * Attribute key for superscripting and subscripting. Values are
584 * instances of <b><code>Integer</code></b>. The default value is
585 * 0, which means that no superscript or subscript is used.
586 *
587 * <p>Two constant values are provided, see {@link
588 * #SUPERSCRIPT_SUPER} and {@link #SUPERSCRIPT_SUB}. These have
589 * the values 1 and -1 respectively. Values of
590 * greater magnitude define greater levels of superscript or
591 * subscripting, for example, 2 corresponds to super-superscript,
592 * 3 to super-super-superscript, and similarly for negative values
593 * and subscript, up to a level of 7 (or -7). Values beyond this
594 * range are reserved; behavior is platform-dependent.
595 *
596 * <p><code>SUPERSCRIPT</code> can
597 * impact the ascent and descent of a font. The ascent
598 * and descent can never become negative, however.
599 */
600 public static final TextAttribute SUPERSCRIPT =
601 new TextAttribute("superscript");
602
603 /**
604 * Standard superscript.
605 * @see #SUPERSCRIPT
606 */
607 public static final Integer SUPERSCRIPT_SUPER =
608 Integer.valueOf(1);
609
610 /**
611 * Standard subscript.
612 * @see #SUPERSCRIPT
613 */
614 public static final Integer SUPERSCRIPT_SUB =
615 Integer.valueOf(-1);
616
617 /**
618 * Attribute key used to provide the font to use to render text.
619 * Values are instances of {@link java.awt.Font}. The default
620 * value is null, indicating that normal resolution of a
621 * <code>Font</code> from attributes should be performed.
622 *
623 * <p><code>TextLayout</code> and
624 * <code>AttributedCharacterIterator</code> work in terms of
625 * <code>Maps</code> of <code>TextAttributes</code>. Normally,
626 * all the attributes are examined and used to select and
627 * configure a <code>Font</code> instance. If a <code>FONT</code>
628 * attribute is present, though, its associated <code>Font</code>
629 * will be used. This provides a way for users to override the
630 * resolution of font attributes into a <code>Font</code>, or
631 * force use of a particular <code>Font</code> instance. This
632 * also allows users to specify subclasses of <code>Font</code> in
633 * cases where a <code>Font</code> can be subclassed.
634 *
635 * <p><code>FONT</code> is used for special situations where
636 * clients already have a <code>Font</code> instance but still
637 * need to use <code>Map</code>-based APIs. Typically, there will
638 * be no other attributes in the <code>Map</code> except the
639 * <code>FONT</code> attribute. With <code>Map</code>-based APIs
640 * the common case is to specify all attributes individually, so
641 * <code>FONT</code> is not needed or desireable.
642 *
643 * <p>However, if both <code>FONT</code> and other attributes are
644 * present in the <code>Map</code>, the rendering system will
645 * merge the attributes defined in the <code>Font</code> with the
646 * additional attributes. This merging process classifies
647 * <code>TextAttributes</code> into two groups. One group, the
648 * 'primary' group, is considered fundamental to the selection and
649 * metric behavior of a font. These attributes are
650 * <code>FAMILY</code>, <code>WEIGHT</code>, <code>WIDTH</code>,
651 * <code>POSTURE</code>, <code>SIZE</code>,
652 * <code>TRANSFORM</code>, <code>SUPERSCRIPT</code>, and
653 * <code>TRACKING</code>. The other group, the 'secondary' group,
654 * consists of all other defined attributes, with the exception of
655 * <code>FONT</code> itself.
656 *
657 * <p>To generate the new <code>Map</code>, first the
658 * <code>Font</code> is obtained from the <code>FONT</code>
659 * attribute, and <em>all</em> of its attributes extracted into a
660 * new <code>Map</code>. Then only the <em>secondary</em>
661 * attributes from the original <code>Map</code> are added to
662 * those in the new <code>Map</code>. Thus the values of primary
663 * attributes come solely from the <code>Font</code>, and the
664 * values of secondary attributes originate with the
665 * <code>Font</code> but can be overridden by other values in the
666 * <code>Map</code>.
667 *
668 * <p><em>Note:</em><code>Font's</code> <code>Map</code>-based
669 * constructor and <code>deriveFont</code> methods do not process
670 * the <code>FONT</code> attribute, as these are used to create
671 * new <code>Font</code> objects. Instead, {@link
672 * java.awt.Font#getFont(Map) Font.getFont(Map)} should be used to
673 * handle the <code>FONT</code> attribute.
674 *
675 * @see java.awt.Font
676 */
677 public static final TextAttribute FONT =
678 new TextAttribute("font");
679
680 /**
681 * Attribute key for a user-defined glyph to display in lieu
682 * of the font's standard glyph for a character. Values are
683 * intances of GraphicAttribute. The default value is null,
684 * indicating that the standard glyphs provided by the font
685 * should be used.
686 *
687 * <p>This attribute is used to reserve space for a graphic or
688 * other component embedded in a line of text. It is required for
689 * correct positioning of 'inline' components within a line when
690 * bidirectional reordering (see {@link java.text.Bidi}) is
691 * performed. Each character (Unicode code point) will be
692 * rendered using the provided GraphicAttribute. Typically, the
693 * characters to which this attribute is applied should be
694 * <code>\uFFFC</code>.
695 *
696 * <p>The GraphicAttribute determines the logical and visual
697 * bounds of the text; the actual Font values are ignored.
698 *
699 * @see GraphicAttribute
700 */
701 public static final TextAttribute CHAR_REPLACEMENT =
702 new TextAttribute("char_replacement");
703
704 //
705 // Adornments added to text.
706 //
707
708 /**
709 * Attribute key for the paint used to render the text. Values are
710 * instances of <b><code>Paint</code></b>. The default value is
711 * null, indicating that the <code>Paint</code> set on the
712 * <code>Graphics2D</code> at the time of rendering is used.
713 *
714 * <p>Glyphs will be rendered using this
715 * <code>Paint</code> regardless of the <code>Paint</code> value
716 * set on the <code>Graphics</code> (but see {@link #SWAP_COLORS}).
717 *
718 * @see java.awt.Paint
719 * @see #SWAP_COLORS
720 */
721 public static final TextAttribute FOREGROUND =
722 new TextAttribute("foreground");
723
724 /**
725 * Attribute key for the paint used to render the background of
726 * the text. Values are instances of <b><code>Paint</code></b>.
727 * The default value is null, indicating that the background
728 * should not be rendered.
729 *
730 * <p>The logical bounds of the text will be filled using this
731 * <code>Paint</code>, and then the text will be rendered on top
732 * of it (but see {@link #SWAP_COLORS}).
733 *
734 * <p>The visual bounds of the text is extended to include the
735 * logical bounds, if necessary. The outline is not affected.
736 *
737 * @see java.awt.Paint
738 * @see #SWAP_COLORS
739 */
740 public static final TextAttribute BACKGROUND =
741 new TextAttribute("background");
742
743 /**
744 * Attribute key for underline. Values are instances of
745 * <b><code>Integer</code></b>. The default value is -1, which
746 * means no underline.
747 *
748 * <p>The constant value {@link #UNDERLINE_ON} is provided.
749 *
750 * <p>The underline affects both the visual bounds and the outline
751 * of the text.
752 */
753 public static final TextAttribute UNDERLINE =
754 new TextAttribute("underline");
755
756 /**
757 * Standard underline.
758 *
759 * @see #UNDERLINE
760 */
761 public static final Integer UNDERLINE_ON =
762 Integer.valueOf(0);
763
764 /**
765 * Attribute key for strikethrough. Values are instances of
766 * <b><code>Boolean</code></b>. The default value is
767 * <code>false</code>, which means no strikethrough.
768 *
769 * <p>The constant value {@link #STRIKETHROUGH_ON} is provided.
770 *
771 * <p>The strikethrough affects both the visual bounds and the
772 * outline of the text.
773 */
774 public static final TextAttribute STRIKETHROUGH =
775 new TextAttribute("strikethrough");
776
777 /**
778 * A single strikethrough.
779 *
780 * @see #STRIKETHROUGH
781 */
782 public static final Boolean STRIKETHROUGH_ON =
783 Boolean.TRUE;
784
785 //
786 // Attributes use to control layout of text on a line.
787 //
788
789 /**
790 * Attribute key for the run direction of the line. Values are
791 * instances of <b><code>Boolean</code></b>. The default value is
792 * null, which indicates that the standard Bidi algorithm for
793 * determining run direction should be used with the value {@link
794 * java.text.Bidi#DIRECTION_DEFAULT_LEFT_TO_RIGHT}.
795 *
796 * <p>The constants {@link #RUN_DIRECTION_RTL} and {@link
797 * #RUN_DIRECTION_LTR} are provided.
798 *
799 * <p>This determines the value passed to the {@link
800 * java.text.Bidi} constructor to select the primary direction of
801 * the text in the paragraph.
802 *
803 * <p><em>Note:</em> This attribute should have the same value for
804 * all the text in a paragraph, otherwise the behavior is
805 * undetermined.
806 *
807 * @see java.text.Bidi
808 */
809 public static final TextAttribute RUN_DIRECTION =
810 new TextAttribute("run_direction");
811
812 /**
813 * Left-to-right run direction.
814 * @see #RUN_DIRECTION
815 */
816 public static final Boolean RUN_DIRECTION_LTR =
817 Boolean.FALSE;
818
819 /**
820 * Right-to-left run direction.
821 * @see #RUN_DIRECTION
822 */
823 public static final Boolean RUN_DIRECTION_RTL =
824 Boolean.TRUE;
825
826 /**
827 * Attribute key for the embedding level of the text. Values are
828 * instances of <b><code>Integer</code></b>. The default value is
829 * <code>null</code>, indicating that the the Bidirectional
830 * algorithm should run without explicit embeddings.
831 *
832 * <p>Positive values 1 through 61 are <em>embedding</em> levels,
833 * negative values -1 through -61 are <em>override</em> levels.
834 * The value 0 means that the base line direction is used. These
835 * levels are passed in the embedding levels array to the {@link
836 * java.text.Bidi} constructor.
837 *
838 * <p><em>Note:</em> When this attribute is present anywhere in
839 * a paragraph, then any Unicode bidi control characters (RLO,
840 * LRO, RLE, LRE, and PDF) in the paragraph are
841 * disregarded, and runs of text where this attribute is not
842 * present are treated as though it were present and had the value
843 * 0.
844 *
845 * @see java.text.Bidi
846 */
847 public static final TextAttribute BIDI_EMBEDDING =
848 new TextAttribute("bidi_embedding");
849
850 /**
851 * Attribute key for the justification of a paragraph. Values are
852 * instances of <b><code>Number</code></b>. The default value is
853 * 1, indicating that justification should use the full width
854 * provided. Values are pinned to the range [0..1].
855 *
856 * <p>The constants {@link #JUSTIFICATION_FULL} and {@link
857 * #JUSTIFICATION_NONE} are provided.
858 *
859 * <p>Specifies the fraction of the extra space to use when
860 * justification is requested on a <code>TextLayout</code>. For
861 * example, if the line is 50 points wide and it is requested to
862 * justify to 70 points, a value of 0.75 will pad to use
863 * three-quarters of the remaining space, or 15 points, so that
864 * the resulting line will be 65 points in length.
865 *
866 * <p><em>Note:</em> This should have the same value for all the
867 * text in a paragraph, otherwise the behavior is undetermined.
868 *
869 * @see TextLayout#getJustifiedLayout
870 */
871 public static final TextAttribute JUSTIFICATION =
872 new TextAttribute("justification");
873
874 /**
875 * Justify the line to the full requested width. This is the
876 * default value for <code>JUSTIFICATION</code>.
877 * @see #JUSTIFICATION
878 */
879 public static final Float JUSTIFICATION_FULL =
880 Float.valueOf(1.0f);
881
882 /**
883 * Do not allow the line to be justified.
884 * @see #JUSTIFICATION
885 */
886 public static final Float JUSTIFICATION_NONE =
887 Float.valueOf(0.0f);
888
889 //
890 // For use by input method.
891 //
892
893 /**
894 * Attribute key for input method highlight styles.
895 *
896 * <p>Values are instances of {@link
897 * java.awt.im.InputMethodHighlight} or {@link
898 * java.text.Annotation}. The default value is <code>null</code>,
899 * which means that input method styles should not be applied
900 * before rendering.
901 *
902 * <p>If adjacent runs of text with the same
903 * <code>InputMethodHighlight</code> need to be rendered
904 * separately, the <code>InputMethodHighlights</code> should be
905 * wrapped in <code>Annotation</code> instances.
906 *
907 * <p>Input method highlights are used while text is being
908 * composed by an input method. Text editing components should
909 * retain them even if they generally only deal with unstyled
910 * text, and make them available to the drawing routines.
911 *
912 * @see java.awt.Font
913 * @see java.awt.im.InputMethodHighlight
914 * @see java.text.Annotation
915 */
916 public static final TextAttribute INPUT_METHOD_HIGHLIGHT =
917 new TextAttribute("input method highlight");
918
919 /**
920 * Attribute key for input method underlines. Values
921 * are instances of <b><code>Integer</code></b>. The default
922 * value is <code>-1</code>, which means no underline.
923 *
924 * <p>Several constant values are provided, see {@link
925 * #UNDERLINE_LOW_ONE_PIXEL}, {@link #UNDERLINE_LOW_TWO_PIXEL},
926 * {@link #UNDERLINE_LOW_DOTTED}, {@link #UNDERLINE_LOW_GRAY}, and
927 * {@link #UNDERLINE_LOW_DASHED}.
928 *
929 * <p>This may be used in conjunction with {@link #UNDERLINE} if
930 * desired. The primary purpose is for use by input methods.
931 * Other use of these underlines for simple ornamentation might
932 * confuse users.
933 *
934 * <p>The input method underline affects both the visual bounds and
935 * the outline of the text.
936 *
937 * @since 1.3
938 */
939 public static final TextAttribute INPUT_METHOD_UNDERLINE =
940 new TextAttribute("input method underline");
941
942 /**
943 * Single pixel solid low underline.
944 * @see #INPUT_METHOD_UNDERLINE
945 * @since 1.3
946 */
947 public static final Integer UNDERLINE_LOW_ONE_PIXEL =
948 Integer.valueOf(1);
949
950 /**
951 * Double pixel solid low underline.
952 * @see #INPUT_METHOD_UNDERLINE
953 * @since 1.3
954 */
955 public static final Integer UNDERLINE_LOW_TWO_PIXEL =
956 Integer.valueOf(2);
957
958 /**
959 * Single pixel dotted low underline.
960 * @see #INPUT_METHOD_UNDERLINE
961 * @since 1.3
962 */
963 public static final Integer UNDERLINE_LOW_DOTTED =
964 Integer.valueOf(3);
965
966 /**
967 * Double pixel gray low underline.
968 * @see #INPUT_METHOD_UNDERLINE
969 * @since 1.3
970 */
971 public static final Integer UNDERLINE_LOW_GRAY =
972 Integer.valueOf(4);
973
974 /**
975 * Single pixel dashed low underline.
976 * @see #INPUT_METHOD_UNDERLINE
977 * @since 1.3
978 */
979 public static final Integer UNDERLINE_LOW_DASHED =
980 Integer.valueOf(5);
981
982 /**
983 * Attribute key for swapping foreground and background
984 * <code>Paints</code>. Values are instances of
985 * <b><code>Boolean</code></b>. The default value is
986 * <code>false</code>, which means do not swap colors.
987 *
988 * <p>The constant value {@link #SWAP_COLORS_ON} is defined.
989 *
990 * <p>If the {@link #FOREGROUND} attribute is set, its
991 * <code>Paint</code> will be used as the background, otherwise
992 * the <code>Paint</code> currently on the <code>Graphics</code>
993 * will be used. If the {@link #BACKGROUND} attribute is set, its
994 * <code>Paint</code> will be used as the foreground, otherwise
995 * the system will find a contrasting color to the
996 * (resolved) background so that the text will be visible.
997 *
998 * @see #FOREGROUND
999 * @see #BACKGROUND
1000 */
1001 public static final TextAttribute SWAP_COLORS =
1002 new TextAttribute("swap_colors");
1003
1004 /**
1005 * Swap foreground and background.
1006 * @see #SWAP_COLORS
1007 * @since 1.3
1008 */
1009 public static final Boolean SWAP_COLORS_ON =
1010 Boolean.TRUE;
1011
1012 /**
1013 * Attribute key for converting ASCII decimal digits to other
1014 * decimal ranges. Values are instances of {@link NumericShaper}.
1015 * The default is <code>null</code>, which means do not perform
1016 * numeric shaping.
1017 *
1018 * <p>When a numeric shaper is defined, the text is first
1019 * processed by the shaper before any other analysis of the text
1020 * is performed.
1021 *
1022 * <p><em>Note:</em> This should have the same value for all the
1023 * text in the paragraph, otherwise the behavior is undetermined.
1024 *
1025 * @see NumericShaper
1026 * @since 1.4
1027 */
1028 public static final TextAttribute NUMERIC_SHAPING =
1029 new TextAttribute("numeric_shaping");
1030
1031 /**
1032 * Attribute key to request kerning. Values are instances of
1033 * <b><code>Integer</code></b>. The default value is
1034 * <code>0</code>, which does not request kerning.
1035 *
1036 * <p>The constant value {@link #KERNING_ON} is provided.
1037 *
1038 * <p>The default advances of single characters are not
1039 * appropriate for some character sequences, for example "To" or
1040 * "AWAY". Without kerning the adjacent characters appear to be
1041 * separated by too much space. Kerning causes selected sequences
1042 * of characters to be spaced differently for a more pleasing
1043 * visual appearance.
1044 *
1045 * @since 1.6
1046 */
1047 public static final TextAttribute KERNING =
1048 new TextAttribute("kerning");
1049
1050 /**
1051 * Request standard kerning.
1052 * @see #KERNING
1053 * @since 1.6
1054 */
1055 public static final Integer KERNING_ON =
1056 Integer.valueOf(1);
1057
1058
1059 /**
1060 * Attribute key for enabling optional ligatures. Values are
1061 * instances of <b><code>Integer</code></b>. The default value is
1062 * <code>0</code>, which means do not use optional ligatures.
1063 *
1064 * <p>The constant value {@link #LIGATURES_ON} is defined.
1065 *
1066 * <p>Ligatures required by the writing system are always enabled.
1067 *
1068 * @since 1.6
1069 */
1070 public static final TextAttribute LIGATURES =
1071 new TextAttribute("ligatures");
1072
1073 /**
1074 * Request standard optional ligatures.
1075 * @see #LIGATURES
1076 * @since 1.6
1077 */
1078 public static final Integer LIGATURES_ON =
1079 Integer.valueOf(1);
1080
1081 /**
1082 * Attribute key to control tracking. Values are instances of
1083 * <b><code>Number</code></b>. The default value is
1084 * <code>0</code>, which means no additional tracking.
1085 *
1086 * <p>The constant values {@link #TRACKING_TIGHT} and {@link
1087 * #TRACKING_LOOSE} are provided.
1088 *
1089 * <p>The tracking value is multiplied by the font point size and
1090 * passed through the font transform to determine an additional
1091 * amount to add to the advance of each glyph cluster. Positive
1092 * tracking values will inhibit formation of optional ligatures.
1093 * Tracking values are typically between <code>-0.1</code> and
1094 * <code>0.3</code>; values outside this range are generally not
1095 * desireable.
1096 *
1097 * @since 1.6
1098 */
1099 public static final TextAttribute TRACKING =
1100 new TextAttribute("tracking");
1101
1102 /**
1103 * Perform tight tracking.
1104 * @see #TRACKING
1105 * @since 1.6
1106 */
1107 public static final Float TRACKING_TIGHT =
1108 Float.valueOf(-.04f);
1109
1110 /**
1111 * Perform loose tracking.
1112 * @see #TRACKING
1113 * @since 1.6
1114 */
1115 public static final Float TRACKING_LOOSE =
1116 Float.valueOf(.04f);
1117 }