J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1995-2005 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 | package java.awt; |
| 27 | |
| 28 | import java.awt.Graphics2D; |
| 29 | import java.awt.font.FontRenderContext; |
| 30 | import java.awt.font.LineMetrics; |
| 31 | import java.awt.geom.Rectangle2D; |
| 32 | import java.text.CharacterIterator; |
| 33 | |
| 34 | /** |
| 35 | * The <code>FontMetrics</code> class defines a font metrics object, which |
| 36 | * encapsulates information about the rendering of a particular font on a |
| 37 | * particular screen. |
| 38 | * <p> |
| 39 | * <b>Note to subclassers</b>: Since many of these methods form closed, |
| 40 | * mutually recursive loops, you must take care that you implement |
| 41 | * at least one of the methods in each such loop to prevent |
| 42 | * infinite recursion when your subclass is used. |
| 43 | * In particular, the following is the minimal suggested set of methods |
| 44 | * to override in order to ensure correctness and prevent infinite |
| 45 | * recursion (though other subsets are equally feasible): |
| 46 | * <ul> |
| 47 | * <li>{@link #getAscent()} |
| 48 | * <li>{@link #getLeading()} |
| 49 | * <li>{@link #getMaxAdvance()} |
| 50 | * <li>{@link #charWidth(char)} |
| 51 | * <li>{@link #charsWidth(char[], int, int)} |
| 52 | * </ul> |
| 53 | * <p> |
| 54 | * <img src="doc-files/FontMetrics-1.gif" alt="The letter 'p' showing its 'reference point'" border=15 align |
| 55 | * ALIGN=right HSPACE=10 VSPACE=7> |
| 56 | * Note that the implementations of these methods are |
| 57 | * inefficient, so they are usually overridden with more efficient |
| 58 | * toolkit-specific implementations. |
| 59 | * <p> |
| 60 | * When an application asks to place a character at the position |
| 61 | * (<i>x</i>, <i>y</i>), the character is placed so that its |
| 62 | * reference point (shown as the dot in the accompanying image) is |
| 63 | * put at that position. The reference point specifies a horizontal |
| 64 | * line called the <i>baseline</i> of the character. In normal |
| 65 | * printing, the baselines of characters should align. |
| 66 | * <p> |
| 67 | * In addition, every character in a font has an <i>ascent</i>, a |
| 68 | * <i>descent</i>, and an <i>advance width</i>. The ascent is the |
| 69 | * amount by which the character ascends above the baseline. The |
| 70 | * descent is the amount by which the character descends below the |
| 71 | * baseline. The advance width indicates the position at which AWT |
| 72 | * should place the next character. |
| 73 | * <p> |
| 74 | * An array of characters or a string can also have an ascent, a |
| 75 | * descent, and an advance width. The ascent of the array is the |
| 76 | * maximum ascent of any character in the array. The descent is the |
| 77 | * maximum descent of any character in the array. The advance width |
| 78 | * is the sum of the advance widths of each of the characters in the |
| 79 | * character array. The advance of a <code>String</code> is the |
| 80 | * distance along the baseline of the <code>String</code>. This |
| 81 | * distance is the width that should be used for centering or |
| 82 | * right-aligning the <code>String</code>. |
| 83 | * <p>Note that the advance of a <code>String</code> is not necessarily |
| 84 | * the sum of the advances of its characters measured in isolation |
| 85 | * because the width of a character can vary depending on its context. |
| 86 | * For example, in Arabic text, the shape of a character can change |
| 87 | * in order to connect to other characters. Also, in some scripts, |
| 88 | * certain character sequences can be represented by a single shape, |
| 89 | * called a <em>ligature</em>. Measuring characters individually does |
| 90 | * not account for these transformations. |
| 91 | * <p>Font metrics are baseline-relative, meaning that they are |
| 92 | * generally independent of the rotation applied to the font (modulo |
| 93 | * possible grid hinting effects). See {@link java.awt.Font Font}. |
| 94 | * |
| 95 | * @author Jim Graham |
| 96 | * @see java.awt.Font |
| 97 | * @since JDK1.0 |
| 98 | */ |
| 99 | public abstract class FontMetrics implements java.io.Serializable { |
| 100 | |
| 101 | static { |
| 102 | /* ensure that the necessary native libraries are loaded */ |
| 103 | Toolkit.loadLibraries(); |
| 104 | if (!GraphicsEnvironment.isHeadless()) { |
| 105 | initIDs(); |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | private static final FontRenderContext |
| 110 | DEFAULT_FRC = new FontRenderContext(null, false, false); |
| 111 | |
| 112 | /** |
| 113 | * The actual {@link Font} from which the font metrics are |
| 114 | * created. |
| 115 | * This cannot be null. |
| 116 | * |
| 117 | * @serial |
| 118 | * @see #getFont() |
| 119 | */ |
| 120 | protected Font font; |
| 121 | |
| 122 | /* |
| 123 | * JDK 1.1 serialVersionUID |
| 124 | */ |
| 125 | private static final long serialVersionUID = 1681126225205050147L; |
| 126 | |
| 127 | /** |
| 128 | * Creates a new <code>FontMetrics</code> object for finding out |
| 129 | * height and width information about the specified <code>Font</code> |
| 130 | * and specific character glyphs in that <code>Font</code>. |
| 131 | * @param font the <code>Font</code> |
| 132 | * @see java.awt.Font |
| 133 | */ |
| 134 | protected FontMetrics(Font font) { |
| 135 | this.font = font; |
| 136 | } |
| 137 | |
| 138 | /** |
| 139 | * Gets the <code>Font</code> described by this |
| 140 | * <code>FontMetrics</code> object. |
| 141 | * @return the <code>Font</code> described by this |
| 142 | * <code>FontMetrics</code> object. |
| 143 | */ |
| 144 | public Font getFont() { |
| 145 | return font; |
| 146 | } |
| 147 | |
| 148 | /** |
| 149 | * Gets the <code>FontRenderContext</code> used by this |
| 150 | * <code>FontMetrics</code> object to measure text. |
| 151 | * <p> |
| 152 | * Note that methods in this class which take a <code>Graphics</code> |
| 153 | * parameter measure text using the <code>FontRenderContext</code> |
| 154 | * of that <code>Graphics</code> object, and not this |
| 155 | * <code>FontRenderContext</code> |
| 156 | * @return the <code>FontRenderContext</code> used by this |
| 157 | * <code>FontMetrics</code> object. |
| 158 | * @since 1.6 |
| 159 | */ |
| 160 | public FontRenderContext getFontRenderContext() { |
| 161 | return DEFAULT_FRC; |
| 162 | } |
| 163 | |
| 164 | /** |
| 165 | * Determines the <em>standard leading</em> of the |
| 166 | * <code>Font</code> described by this <code>FontMetrics</code> |
| 167 | * object. The standard leading, or |
| 168 | * interline spacing, is the logical amount of space to be reserved |
| 169 | * between the descent of one line of text and the ascent of the next |
| 170 | * line. The height metric is calculated to include this extra space. |
| 171 | * @return the standard leading of the <code>Font</code>. |
| 172 | * @see #getHeight() |
| 173 | * @see #getAscent() |
| 174 | * @see #getDescent() |
| 175 | */ |
| 176 | public int getLeading() { |
| 177 | return 0; |
| 178 | } |
| 179 | |
| 180 | /** |
| 181 | * Determines the <em>font ascent</em> of the <code>Font</code> |
| 182 | * described by this <code>FontMetrics</code> object. The font ascent |
| 183 | * is the distance from the font's baseline to the top of most |
| 184 | * alphanumeric characters. Some characters in the <code>Font</code> |
| 185 | * might extend above the font ascent line. |
| 186 | * @return the font ascent of the <code>Font</code>. |
| 187 | * @see #getMaxAscent() |
| 188 | */ |
| 189 | public int getAscent() { |
| 190 | return font.getSize(); |
| 191 | } |
| 192 | |
| 193 | /** |
| 194 | * Determines the <em>font descent</em> of the <code>Font</code> |
| 195 | * described by this |
| 196 | * <code>FontMetrics</code> object. The font descent is the distance |
| 197 | * from the font's baseline to the bottom of most alphanumeric |
| 198 | * characters with descenders. Some characters in the |
| 199 | * <code>Font</code> might extend |
| 200 | * below the font descent line. |
| 201 | * @return the font descent of the <code>Font</code>. |
| 202 | * @see #getMaxDescent() |
| 203 | */ |
| 204 | public int getDescent() { |
| 205 | return 0; |
| 206 | } |
| 207 | |
| 208 | /** |
| 209 | * Gets the standard height of a line of text in this font. This |
| 210 | * is the distance between the baseline of adjacent lines of text. |
| 211 | * It is the sum of the leading + ascent + descent. Due to rounding |
| 212 | * this may not be the same as getAscent() + getDescent() + getLeading(). |
| 213 | * There is no guarantee that lines of text spaced at this distance are |
| 214 | * disjoint; such lines may overlap if some characters overshoot |
| 215 | * either the standard ascent or the standard descent metric. |
| 216 | * @return the standard height of the font. |
| 217 | * @see #getLeading() |
| 218 | * @see #getAscent() |
| 219 | * @see #getDescent() |
| 220 | */ |
| 221 | public int getHeight() { |
| 222 | return getLeading() + getAscent() + getDescent(); |
| 223 | } |
| 224 | |
| 225 | /** |
| 226 | * Determines the maximum ascent of the <code>Font</code> |
| 227 | * described by this <code>FontMetrics</code> object. No character |
| 228 | * extends further above the font's baseline than this height. |
| 229 | * @return the maximum ascent of any character in the |
| 230 | * <code>Font</code>. |
| 231 | * @see #getAscent() |
| 232 | */ |
| 233 | public int getMaxAscent() { |
| 234 | return getAscent(); |
| 235 | } |
| 236 | |
| 237 | /** |
| 238 | * Determines the maximum descent of the <code>Font</code> |
| 239 | * described by this <code>FontMetrics</code> object. No character |
| 240 | * extends further below the font's baseline than this height. |
| 241 | * @return the maximum descent of any character in the |
| 242 | * <code>Font</code>. |
| 243 | * @see #getDescent() |
| 244 | */ |
| 245 | public int getMaxDescent() { |
| 246 | return getDescent(); |
| 247 | } |
| 248 | |
| 249 | /** |
| 250 | * For backward compatibility only. |
| 251 | * @return the maximum descent of any character in the |
| 252 | * <code>Font</code>. |
| 253 | * @see #getMaxDescent() |
| 254 | * @deprecated As of JDK version 1.1.1, |
| 255 | * replaced by <code>getMaxDescent()</code>. |
| 256 | */ |
| 257 | @Deprecated |
| 258 | public int getMaxDecent() { |
| 259 | return getMaxDescent(); |
| 260 | } |
| 261 | |
| 262 | /** |
| 263 | * Gets the maximum advance width of any character in this |
| 264 | * <code>Font</code>. The advance is the |
| 265 | * distance from the leftmost point to the rightmost point on the |
| 266 | * string's baseline. The advance of a <code>String</code> is |
| 267 | * not necessarily the sum of the advances of its characters. |
| 268 | * @return the maximum advance width of any character |
| 269 | * in the <code>Font</code>, or <code>-1</code> if the |
| 270 | * maximum advance width is not known. |
| 271 | */ |
| 272 | public int getMaxAdvance() { |
| 273 | return -1; |
| 274 | } |
| 275 | |
| 276 | /** |
| 277 | * Returns the advance width of the specified character in this |
| 278 | * <code>Font</code>. The advance is the |
| 279 | * distance from the leftmost point to the rightmost point on the |
| 280 | * character's baseline. Note that the advance of a |
| 281 | * <code>String</code> is not necessarily the sum of the advances |
| 282 | * of its characters. |
| 283 | * |
| 284 | * <p>This method doesn't validate the specified character to be a |
| 285 | * valid Unicode code point. The caller must validate the |
| 286 | * character value using {@link |
| 287 | * java.lang.Character#isValidCodePoint(int) |
| 288 | * Character.isValidCodePoint} if necessary. |
| 289 | * |
| 290 | * @param codePoint the character (Unicode code point) to be measured |
| 291 | * @return the advance width of the specified character |
| 292 | * in the <code>Font</code> described by this |
| 293 | * <code>FontMetrics</code> object. |
| 294 | * @see #charsWidth(char[], int, int) |
| 295 | * @see #stringWidth(String) |
| 296 | */ |
| 297 | public int charWidth(int codePoint) { |
| 298 | if (!Character.isValidCodePoint(codePoint)) { |
| 299 | codePoint = 0xffff; // substitute missing glyph width |
| 300 | } |
| 301 | |
| 302 | if (codePoint < 256) { |
| 303 | return getWidths()[codePoint]; |
| 304 | } else { |
| 305 | char[] buffer = new char[2]; |
| 306 | int len = Character.toChars(codePoint, buffer, 0); |
| 307 | return charsWidth(buffer, 0, len); |
| 308 | } |
| 309 | } |
| 310 | |
| 311 | /** |
| 312 | * Returns the advance width of the specified character in this |
| 313 | * <code>Font</code>. The advance is the |
| 314 | * distance from the leftmost point to the rightmost point on the |
| 315 | * character's baseline. Note that the advance of a |
| 316 | * <code>String</code> is not necessarily the sum of the advances |
| 317 | * of its characters. |
| 318 | * |
| 319 | * <p><b>Note:</b> This method cannot handle <a |
| 320 | * href="../lang/Character.html#supplementary"> supplementary |
| 321 | * characters</a>. To support all Unicode characters, including |
| 322 | * supplementary characters, use the {@link #charWidth(int)} method. |
| 323 | * |
| 324 | * @param ch the character to be measured |
| 325 | * @return the advance width of the specified character |
| 326 | * in the <code>Font</code> described by this |
| 327 | * <code>FontMetrics</code> object. |
| 328 | * @see #charsWidth(char[], int, int) |
| 329 | * @see #stringWidth(String) |
| 330 | */ |
| 331 | public int charWidth(char ch) { |
| 332 | if (ch < 256) { |
| 333 | return getWidths()[ch]; |
| 334 | } |
| 335 | char data[] = {ch}; |
| 336 | return charsWidth(data, 0, 1); |
| 337 | } |
| 338 | |
| 339 | /** |
| 340 | * Returns the total advance width for showing the specified |
| 341 | * <code>String</code> in this <code>Font</code>. The advance |
| 342 | * is the distance from the leftmost point to the rightmost point |
| 343 | * on the string's baseline. |
| 344 | * <p> |
| 345 | * Note that the advance of a <code>String</code> is |
| 346 | * not necessarily the sum of the advances of its characters. |
| 347 | * @param str the <code>String</code> to be measured |
| 348 | * @return the advance width of the specified <code>String</code> |
| 349 | * in the <code>Font</code> described by this |
| 350 | * <code>FontMetrics</code>. |
| 351 | * @throws NullPointerException if str is null. |
| 352 | * @see #bytesWidth(byte[], int, int) |
| 353 | * @see #charsWidth(char[], int, int) |
| 354 | * @see #getStringBounds(String, Graphics) |
| 355 | */ |
| 356 | public int stringWidth(String str) { |
| 357 | int len = str.length(); |
| 358 | char data[] = new char[len]; |
| 359 | str.getChars(0, len, data, 0); |
| 360 | return charsWidth(data, 0, len); |
| 361 | } |
| 362 | |
| 363 | /** |
| 364 | * Returns the total advance width for showing the specified array |
| 365 | * of characters in this <code>Font</code>. The advance is the |
| 366 | * distance from the leftmost point to the rightmost point on the |
| 367 | * string's baseline. The advance of a <code>String</code> |
| 368 | * is not necessarily the sum of the advances of its characters. |
| 369 | * This is equivalent to measuring a <code>String</code> of the |
| 370 | * characters in the specified range. |
| 371 | * @param data the array of characters to be measured |
| 372 | * @param off the start offset of the characters in the array |
| 373 | * @param len the number of characters to be measured from the array |
| 374 | * @return the advance width of the subarray of the specified |
| 375 | * <code>char</code> array in the font described by |
| 376 | * this <code>FontMetrics</code> object. |
| 377 | * @throws NullPointerException if <code>data</code> is null. |
| 378 | * @throws IndexOutOfBoundsException if the <code>off</code> |
| 379 | * and <code>len</code> arguments index characters outside |
| 380 | * the bounds of the <code>data</code> array. |
| 381 | * @see #charWidth(int) |
| 382 | * @see #charWidth(char) |
| 383 | * @see #bytesWidth(byte[], int, int) |
| 384 | * @see #stringWidth(String) |
| 385 | */ |
| 386 | public int charsWidth(char data[], int off, int len) { |
| 387 | return stringWidth(new String(data, off, len)); |
| 388 | } |
| 389 | |
| 390 | /** |
| 391 | * Returns the total advance width for showing the specified array |
| 392 | * of bytes in this <code>Font</code>. The advance is the |
| 393 | * distance from the leftmost point to the rightmost point on the |
| 394 | * string's baseline. The advance of a <code>String</code> |
| 395 | * is not necessarily the sum of the advances of its characters. |
| 396 | * This is equivalent to measuring a <code>String</code> of the |
| 397 | * characters in the specified range. |
| 398 | * @param data the array of bytes to be measured |
| 399 | * @param off the start offset of the bytes in the array |
| 400 | * @param len the number of bytes to be measured from the array |
| 401 | * @return the advance width of the subarray of the specified |
| 402 | * <code>byte</code> array in the <code>Font</code> |
| 403 | * described by |
| 404 | * this <code>FontMetrics</code> object. |
| 405 | * @throws NullPointerException if <code>data</code> is null. |
| 406 | * @throws IndexOutOfBoundsException if the <code>off</code> |
| 407 | * and <code>len</code> arguments index bytes outside |
| 408 | * the bounds of the <code>data</code> array. |
| 409 | * @see #charsWidth(char[], int, int) |
| 410 | * @see #stringWidth(String) |
| 411 | */ |
| 412 | public int bytesWidth(byte data[], int off, int len) { |
| 413 | return stringWidth(new String(data, 0, off, len)); |
| 414 | } |
| 415 | |
| 416 | /** |
| 417 | * Gets the advance widths of the first 256 characters in the |
| 418 | * <code>Font</code>. The advance is the |
| 419 | * distance from the leftmost point to the rightmost point on the |
| 420 | * character's baseline. Note that the advance of a |
| 421 | * <code>String</code> is not necessarily the sum of the advances |
| 422 | * of its characters. |
| 423 | * @return an array storing the advance widths of the |
| 424 | * characters in the <code>Font</code> |
| 425 | * described by this <code>FontMetrics</code> object. |
| 426 | */ |
| 427 | public int[] getWidths() { |
| 428 | int widths[] = new int[256]; |
| 429 | for (char ch = 0 ; ch < 256 ; ch++) { |
| 430 | widths[ch] = charWidth(ch); |
| 431 | } |
| 432 | return widths; |
| 433 | } |
| 434 | |
| 435 | /** |
| 436 | * Checks to see if the <code>Font</code> has uniform line metrics. A |
| 437 | * composite font may consist of several different fonts to cover |
| 438 | * various character sets. In such cases, the |
| 439 | * <code>FontLineMetrics</code> objects are not uniform. |
| 440 | * Different fonts may have a different ascent, descent, metrics and |
| 441 | * so on. This information is sometimes necessary for line |
| 442 | * measuring and line breaking. |
| 443 | * @return <code>true</code> if the font has uniform line metrics; |
| 444 | * <code>false</code> otherwise. |
| 445 | * @see java.awt.Font#hasUniformLineMetrics() |
| 446 | */ |
| 447 | public boolean hasUniformLineMetrics() { |
| 448 | return font.hasUniformLineMetrics(); |
| 449 | } |
| 450 | |
| 451 | /** |
| 452 | * Returns the {@link LineMetrics} object for the specified |
| 453 | * <code>String</code> in the specified {@link Graphics} context. |
| 454 | * @param str the specified <code>String</code> |
| 455 | * @param context the specified <code>Graphics</code> context |
| 456 | * @return a <code>LineMetrics</code> object created with the |
| 457 | * specified <code>String</code> and <code>Graphics</code> context. |
| 458 | * @see java.awt.Font#getLineMetrics(String, FontRenderContext) |
| 459 | */ |
| 460 | public LineMetrics getLineMetrics( String str, Graphics context) { |
| 461 | return font.getLineMetrics(str, myFRC(context)); |
| 462 | } |
| 463 | |
| 464 | /** |
| 465 | * Returns the {@link LineMetrics} object for the specified |
| 466 | * <code>String</code> in the specified {@link Graphics} context. |
| 467 | * @param str the specified <code>String</code> |
| 468 | * @param beginIndex the initial offset of <code>str</code> |
| 469 | * @param limit the end offset of <code>str</code> |
| 470 | * @param context the specified <code>Graphics</code> context |
| 471 | * @return a <code>LineMetrics</code> object created with the |
| 472 | * specified <code>String</code> and <code>Graphics</code> context. |
| 473 | * @see java.awt.Font#getLineMetrics(String, int, int, FontRenderContext) |
| 474 | */ |
| 475 | public LineMetrics getLineMetrics( String str, |
| 476 | int beginIndex, int limit, |
| 477 | Graphics context) { |
| 478 | return font.getLineMetrics(str, beginIndex, limit, myFRC(context)); |
| 479 | } |
| 480 | |
| 481 | /** |
| 482 | * Returns the {@link LineMetrics} object for the specified |
| 483 | * character array in the specified {@link Graphics} context. |
| 484 | * @param chars the specified character array |
| 485 | * @param beginIndex the initial offset of <code>chars</code> |
| 486 | * @param limit the end offset of <code>chars</code> |
| 487 | * @param context the specified <code>Graphics</code> context |
| 488 | * @return a <code>LineMetrics</code> object created with the |
| 489 | * specified character array and <code>Graphics</code> context. |
| 490 | * @see java.awt.Font#getLineMetrics(char[], int, int, FontRenderContext) |
| 491 | */ |
| 492 | public LineMetrics getLineMetrics(char [] chars, |
| 493 | int beginIndex, int limit, |
| 494 | Graphics context) { |
| 495 | return font.getLineMetrics( |
| 496 | chars, beginIndex, limit, myFRC(context)); |
| 497 | } |
| 498 | |
| 499 | /** |
| 500 | * Returns the {@link LineMetrics} object for the specified |
| 501 | * {@link CharacterIterator} in the specified {@link Graphics} |
| 502 | * context. |
| 503 | * @param ci the specified <code>CharacterIterator</code> |
| 504 | * @param beginIndex the initial offset in <code>ci</code> |
| 505 | * @param limit the end index of <code>ci</code> |
| 506 | * @param context the specified <code>Graphics</code> context |
| 507 | * @return a <code>LineMetrics</code> object created with the |
| 508 | * specified arguments. |
| 509 | * @see java.awt.Font#getLineMetrics(CharacterIterator, int, int, FontRenderContext) |
| 510 | */ |
| 511 | public LineMetrics getLineMetrics(CharacterIterator ci, |
| 512 | int beginIndex, int limit, |
| 513 | Graphics context) { |
| 514 | return font.getLineMetrics(ci, beginIndex, limit, myFRC(context)); |
| 515 | } |
| 516 | |
| 517 | /** |
| 518 | * Returns the bounds of the specified <code>String</code> in the |
| 519 | * specified <code>Graphics</code> context. The bounds is used |
| 520 | * to layout the <code>String</code>. |
| 521 | * <p>Note: The returned bounds is in baseline-relative coordinates |
| 522 | * (see {@link java.awt.FontMetrics class notes}). |
| 523 | * @param str the specified <code>String</code> |
| 524 | * @param context the specified <code>Graphics</code> context |
| 525 | * @return a {@link Rectangle2D} that is the bounding box of the |
| 526 | * specified <code>String</code> in the specified |
| 527 | * <code>Graphics</code> context. |
| 528 | * @see java.awt.Font#getStringBounds(String, FontRenderContext) |
| 529 | */ |
| 530 | public Rectangle2D getStringBounds( String str, Graphics context) { |
| 531 | return font.getStringBounds(str, myFRC(context)); |
| 532 | } |
| 533 | |
| 534 | /** |
| 535 | * Returns the bounds of the specified <code>String</code> in the |
| 536 | * specified <code>Graphics</code> context. The bounds is used |
| 537 | * to layout the <code>String</code>. |
| 538 | * <p>Note: The returned bounds is in baseline-relative coordinates |
| 539 | * (see {@link java.awt.FontMetrics class notes}). |
| 540 | * @param str the specified <code>String</code> |
| 541 | * @param beginIndex the offset of the beginning of <code>str</code> |
| 542 | * @param limit the end offset of <code>str</code> |
| 543 | * @param context the specified <code>Graphics</code> context |
| 544 | * @return a <code>Rectangle2D</code> that is the bounding box of the |
| 545 | * specified <code>String</code> in the specified |
| 546 | * <code>Graphics</code> context. |
| 547 | * @see java.awt.Font#getStringBounds(String, int, int, FontRenderContext) |
| 548 | */ |
| 549 | public Rectangle2D getStringBounds( String str, |
| 550 | int beginIndex, int limit, |
| 551 | Graphics context) { |
| 552 | return font.getStringBounds(str, beginIndex, limit, |
| 553 | myFRC(context)); |
| 554 | } |
| 555 | |
| 556 | /** |
| 557 | * Returns the bounds of the specified array of characters |
| 558 | * in the specified <code>Graphics</code> context. |
| 559 | * The bounds is used to layout the <code>String</code> |
| 560 | * created with the specified array of characters, |
| 561 | * <code>beginIndex</code> and <code>limit</code>. |
| 562 | * <p>Note: The returned bounds is in baseline-relative coordinates |
| 563 | * (see {@link java.awt.FontMetrics class notes}). |
| 564 | * @param chars an array of characters |
| 565 | * @param beginIndex the initial offset of the array of |
| 566 | * characters |
| 567 | * @param limit the end offset of the array of characters |
| 568 | * @param context the specified <code>Graphics</code> context |
| 569 | * @return a <code>Rectangle2D</code> that is the bounding box of the |
| 570 | * specified character array in the specified |
| 571 | * <code>Graphics</code> context. |
| 572 | * @see java.awt.Font#getStringBounds(char[], int, int, FontRenderContext) |
| 573 | */ |
| 574 | public Rectangle2D getStringBounds( char [] chars, |
| 575 | int beginIndex, int limit, |
| 576 | Graphics context) { |
| 577 | return font.getStringBounds(chars, beginIndex, limit, |
| 578 | myFRC(context)); |
| 579 | } |
| 580 | |
| 581 | /** |
| 582 | * Returns the bounds of the characters indexed in the specified |
| 583 | * <code>CharacterIterator</code> in the |
| 584 | * specified <code>Graphics</code> context. |
| 585 | * <p>Note: The returned bounds is in baseline-relative coordinates |
| 586 | * (see {@link java.awt.FontMetrics class notes}). |
| 587 | * @param ci the specified <code>CharacterIterator</code> |
| 588 | * @param beginIndex the initial offset in <code>ci</code> |
| 589 | * @param limit the end index of <code>ci</code> |
| 590 | * @param context the specified <code>Graphics</code> context |
| 591 | * @return a <code>Rectangle2D</code> that is the bounding box of the |
| 592 | * characters indexed in the specified <code>CharacterIterator</code> |
| 593 | * in the specified <code>Graphics</code> context. |
| 594 | * @see java.awt.Font#getStringBounds(CharacterIterator, int, int, FontRenderContext) |
| 595 | */ |
| 596 | public Rectangle2D getStringBounds(CharacterIterator ci, |
| 597 | int beginIndex, int limit, |
| 598 | Graphics context) { |
| 599 | return font.getStringBounds(ci, beginIndex, limit, |
| 600 | myFRC(context)); |
| 601 | } |
| 602 | |
| 603 | /** |
| 604 | * Returns the bounds for the character with the maximum bounds |
| 605 | * in the specified <code>Graphics</code> context. |
| 606 | * @param context the specified <code>Graphics</code> context |
| 607 | * @return a <code>Rectangle2D</code> that is the |
| 608 | * bounding box for the character with the maximum bounds. |
| 609 | * @see java.awt.Font#getMaxCharBounds(FontRenderContext) |
| 610 | */ |
| 611 | public Rectangle2D getMaxCharBounds(Graphics context) { |
| 612 | return font.getMaxCharBounds(myFRC(context)); |
| 613 | } |
| 614 | |
| 615 | private FontRenderContext myFRC(Graphics context) { |
| 616 | if (context instanceof Graphics2D) { |
| 617 | return ((Graphics2D)context).getFontRenderContext(); |
| 618 | } |
| 619 | return DEFAULT_FRC; |
| 620 | } |
| 621 | |
| 622 | |
| 623 | /** |
| 624 | * Returns a representation of this <code>FontMetrics</code> |
| 625 | * object's values as a <code>String</code>. |
| 626 | * @return a <code>String</code> representation of this |
| 627 | * <code>FontMetrics</code> object. |
| 628 | * @since JDK1.0. |
| 629 | */ |
| 630 | public String toString() { |
| 631 | return getClass().getName() + |
| 632 | "[font=" + getFont() + |
| 633 | "ascent=" + getAscent() + |
| 634 | ", descent=" + getDescent() + |
| 635 | ", height=" + getHeight() + "]"; |
| 636 | } |
| 637 | |
| 638 | /** |
| 639 | * Initialize JNI field and method IDs |
| 640 | */ |
| 641 | private static native void initIDs(); |
| 642 | } |