J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1995-2006 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 | package java.awt; |
| 26 | |
| 27 | import java.io.ObjectInputStream; |
| 28 | import java.io.IOException; |
| 29 | |
| 30 | /** |
| 31 | * A flow layout arranges components in a directional flow, much |
| 32 | * like lines of text in a paragraph. The flow direction is |
| 33 | * determined by the container's <code>componentOrientation</code> |
| 34 | * property and may be one of two values: |
| 35 | * <ul> |
| 36 | * <li><code>ComponentOrientation.LEFT_TO_RIGHT</code> |
| 37 | * <li><code>ComponentOrientation.RIGHT_TO_LEFT</code> |
| 38 | * </ul> |
| 39 | * Flow layouts are typically used |
| 40 | * to arrange buttons in a panel. It arranges buttons |
| 41 | * horizontally until no more buttons fit on the same line. |
| 42 | * The line alignment is determined by the <code>align</code> |
| 43 | * property. The possible values are: |
| 44 | * <ul> |
| 45 | * <li>{@link #LEFT LEFT} |
| 46 | * <li>{@link #RIGHT RIGHT} |
| 47 | * <li>{@link #CENTER CENTER} |
| 48 | * <li>{@link #LEADING LEADING} |
| 49 | * <li>{@link #TRAILING TRAILING} |
| 50 | * </ul> |
| 51 | * <p> |
| 52 | * For example, the following picture shows an applet using the flow |
| 53 | * layout manager (its default layout manager) to position three buttons: |
| 54 | * <p> |
| 55 | * <img src="doc-files/FlowLayout-1.gif" |
| 56 | * ALT="Graphic of Layout for Three Buttons" |
| 57 | * ALIGN=center HSPACE=10 VSPACE=7> |
| 58 | * <p> |
| 59 | * Here is the code for this applet: |
| 60 | * <p> |
| 61 | * <hr><blockquote><pre> |
| 62 | * import java.awt.*; |
| 63 | * import java.applet.Applet; |
| 64 | * |
| 65 | * public class myButtons extends Applet { |
| 66 | * Button button1, button2, button3; |
| 67 | * public void init() { |
| 68 | * button1 = new Button("Ok"); |
| 69 | * button2 = new Button("Open"); |
| 70 | * button3 = new Button("Close"); |
| 71 | * add(button1); |
| 72 | * add(button2); |
| 73 | * add(button3); |
| 74 | * } |
| 75 | * } |
| 76 | * </pre></blockquote><hr> |
| 77 | * <p> |
| 78 | * A flow layout lets each component assume its natural (preferred) size. |
| 79 | * |
| 80 | * @author Arthur van Hoff |
| 81 | * @author Sami Shaio |
| 82 | * @since JDK1.0 |
| 83 | * @see ComponentOrientation |
| 84 | */ |
| 85 | public class FlowLayout implements LayoutManager, java.io.Serializable { |
| 86 | |
| 87 | /** |
| 88 | * This value indicates that each row of components |
| 89 | * should be left-justified. |
| 90 | */ |
| 91 | public static final int LEFT = 0; |
| 92 | |
| 93 | /** |
| 94 | * This value indicates that each row of components |
| 95 | * should be centered. |
| 96 | */ |
| 97 | public static final int CENTER = 1; |
| 98 | |
| 99 | /** |
| 100 | * This value indicates that each row of components |
| 101 | * should be right-justified. |
| 102 | */ |
| 103 | public static final int RIGHT = 2; |
| 104 | |
| 105 | /** |
| 106 | * This value indicates that each row of components |
| 107 | * should be justified to the leading edge of the container's |
| 108 | * orientation, for example, to the left in left-to-right orientations. |
| 109 | * |
| 110 | * @see java.awt.Component#getComponentOrientation |
| 111 | * @see java.awt.ComponentOrientation |
| 112 | * @since 1.2 |
| 113 | */ |
| 114 | public static final int LEADING = 3; |
| 115 | |
| 116 | /** |
| 117 | * This value indicates that each row of components |
| 118 | * should be justified to the trailing edge of the container's |
| 119 | * orientation, for example, to the right in left-to-right orientations. |
| 120 | * |
| 121 | * @see java.awt.Component#getComponentOrientation |
| 122 | * @see java.awt.ComponentOrientation |
| 123 | * @since 1.2 |
| 124 | */ |
| 125 | public static final int TRAILING = 4; |
| 126 | |
| 127 | /** |
| 128 | * <code>align</code> is the property that determines |
| 129 | * how each row distributes empty space. |
| 130 | * It can be one of the following values: |
| 131 | * <ul> |
| 132 | * <code>LEFT</code> |
| 133 | * <code>RIGHT</code> |
| 134 | * <code>CENTER</code> |
| 135 | * </ul> |
| 136 | * |
| 137 | * @serial |
| 138 | * @see #getAlignment |
| 139 | * @see #setAlignment |
| 140 | */ |
| 141 | int align; // This is for 1.1 serialization compatibility |
| 142 | |
| 143 | /** |
| 144 | * <code>newAlign</code> is the property that determines |
| 145 | * how each row distributes empty space for the Java 2 platform, |
| 146 | * v1.2 and greater. |
| 147 | * It can be one of the following three values: |
| 148 | * <ul> |
| 149 | * <code>LEFT</code> |
| 150 | * <code>RIGHT</code> |
| 151 | * <code>CENTER</code> |
| 152 | * <code>LEADING</code> |
| 153 | * <code>TRAILING</code> |
| 154 | * </ul> |
| 155 | * |
| 156 | * @serial |
| 157 | * @since 1.2 |
| 158 | * @see #getAlignment |
| 159 | * @see #setAlignment |
| 160 | */ |
| 161 | int newAlign; // This is the one we actually use |
| 162 | |
| 163 | /** |
| 164 | * The flow layout manager allows a seperation of |
| 165 | * components with gaps. The horizontal gap will |
| 166 | * specify the space between components and between |
| 167 | * the components and the borders of the |
| 168 | * <code>Container</code>. |
| 169 | * |
| 170 | * @serial |
| 171 | * @see #getHgap() |
| 172 | * @see #setHgap(int) |
| 173 | */ |
| 174 | int hgap; |
| 175 | |
| 176 | /** |
| 177 | * The flow layout manager allows a seperation of |
| 178 | * components with gaps. The vertical gap will |
| 179 | * specify the space between rows and between the |
| 180 | * the rows and the borders of the <code>Container</code>. |
| 181 | * |
| 182 | * @serial |
| 183 | * @see #getHgap() |
| 184 | * @see #setHgap(int) |
| 185 | */ |
| 186 | int vgap; |
| 187 | |
| 188 | /** |
| 189 | * If true, components will be aligned on their baseline. |
| 190 | */ |
| 191 | private boolean alignOnBaseline; |
| 192 | |
| 193 | /* |
| 194 | * JDK 1.1 serialVersionUID |
| 195 | */ |
| 196 | private static final long serialVersionUID = -7262534875583282631L; |
| 197 | |
| 198 | /** |
| 199 | * Constructs a new <code>FlowLayout</code> with a centered alignment and a |
| 200 | * default 5-unit horizontal and vertical gap. |
| 201 | */ |
| 202 | public FlowLayout() { |
| 203 | this(CENTER, 5, 5); |
| 204 | } |
| 205 | |
| 206 | /** |
| 207 | * Constructs a new <code>FlowLayout</code> with the specified |
| 208 | * alignment and a default 5-unit horizontal and vertical gap. |
| 209 | * The value of the alignment argument must be one of |
| 210 | * <code>FlowLayout.LEFT</code>, <code>FlowLayout.RIGHT</code>, |
| 211 | * <code>FlowLayout.CENTER</code>, <code>FlowLayout.LEADING</code>, |
| 212 | * or <code>FlowLayout.TRAILING</code>. |
| 213 | * @param align the alignment value |
| 214 | */ |
| 215 | public FlowLayout(int align) { |
| 216 | this(align, 5, 5); |
| 217 | } |
| 218 | |
| 219 | /** |
| 220 | * Creates a new flow layout manager with the indicated alignment |
| 221 | * and the indicated horizontal and vertical gaps. |
| 222 | * <p> |
| 223 | * The value of the alignment argument must be one of |
| 224 | * <code>FlowLayout.LEFT</code>, <code>FlowLayout.RIGHT</code>, |
| 225 | * <code>FlowLayout.CENTER</code>, <code>FlowLayout.LEADING</code>, |
| 226 | * or <code>FlowLayout.TRAILING</code>. |
| 227 | * @param align the alignment value |
| 228 | * @param hgap the horizontal gap between components |
| 229 | * and between the components and the |
| 230 | * borders of the <code>Container</code> |
| 231 | * @param vgap the vertical gap between components |
| 232 | * and between the components and the |
| 233 | * borders of the <code>Container</code> |
| 234 | */ |
| 235 | public FlowLayout(int align, int hgap, int vgap) { |
| 236 | this.hgap = hgap; |
| 237 | this.vgap = vgap; |
| 238 | setAlignment(align); |
| 239 | } |
| 240 | |
| 241 | /** |
| 242 | * Gets the alignment for this layout. |
| 243 | * Possible values are <code>FlowLayout.LEFT</code>, |
| 244 | * <code>FlowLayout.RIGHT</code>, <code>FlowLayout.CENTER</code>, |
| 245 | * <code>FlowLayout.LEADING</code>, |
| 246 | * or <code>FlowLayout.TRAILING</code>. |
| 247 | * @return the alignment value for this layout |
| 248 | * @see java.awt.FlowLayout#setAlignment |
| 249 | * @since JDK1.1 |
| 250 | */ |
| 251 | public int getAlignment() { |
| 252 | return newAlign; |
| 253 | } |
| 254 | |
| 255 | /** |
| 256 | * Sets the alignment for this layout. |
| 257 | * Possible values are |
| 258 | * <ul> |
| 259 | * <li><code>FlowLayout.LEFT</code> |
| 260 | * <li><code>FlowLayout.RIGHT</code> |
| 261 | * <li><code>FlowLayout.CENTER</code> |
| 262 | * <li><code>FlowLayout.LEADING</code> |
| 263 | * <li><code>FlowLayout.TRAILING</code> |
| 264 | * </ul> |
| 265 | * @param align one of the alignment values shown above |
| 266 | * @see #getAlignment() |
| 267 | * @since JDK1.1 |
| 268 | */ |
| 269 | public void setAlignment(int align) { |
| 270 | this.newAlign = align; |
| 271 | |
| 272 | // this.align is used only for serialization compatibility, |
| 273 | // so set it to a value compatible with the 1.1 version |
| 274 | // of the class |
| 275 | |
| 276 | switch (align) { |
| 277 | case LEADING: |
| 278 | this.align = LEFT; |
| 279 | break; |
| 280 | case TRAILING: |
| 281 | this.align = RIGHT; |
| 282 | break; |
| 283 | default: |
| 284 | this.align = align; |
| 285 | break; |
| 286 | } |
| 287 | } |
| 288 | |
| 289 | /** |
| 290 | * Gets the horizontal gap between components |
| 291 | * and between the components and the borders |
| 292 | * of the <code>Container</code> |
| 293 | * |
| 294 | * @return the horizontal gap between components |
| 295 | * and between the components and the borders |
| 296 | * of the <code>Container</code> |
| 297 | * @see java.awt.FlowLayout#setHgap |
| 298 | * @since JDK1.1 |
| 299 | */ |
| 300 | public int getHgap() { |
| 301 | return hgap; |
| 302 | } |
| 303 | |
| 304 | /** |
| 305 | * Sets the horizontal gap between components and |
| 306 | * between the components and the borders of the |
| 307 | * <code>Container</code>. |
| 308 | * |
| 309 | * @param hgap the horizontal gap between components |
| 310 | * and between the components and the borders |
| 311 | * of the <code>Container</code> |
| 312 | * @see java.awt.FlowLayout#getHgap |
| 313 | * @since JDK1.1 |
| 314 | */ |
| 315 | public void setHgap(int hgap) { |
| 316 | this.hgap = hgap; |
| 317 | } |
| 318 | |
| 319 | /** |
| 320 | * Gets the vertical gap between components and |
| 321 | * between the components and the borders of the |
| 322 | * <code>Container</code>. |
| 323 | * |
| 324 | * @return the vertical gap between components |
| 325 | * and between the components and the borders |
| 326 | * of the <code>Container</code> |
| 327 | * @see java.awt.FlowLayout#setVgap |
| 328 | * @since JDK1.1 |
| 329 | */ |
| 330 | public int getVgap() { |
| 331 | return vgap; |
| 332 | } |
| 333 | |
| 334 | /** |
| 335 | * Sets the vertical gap between components and between |
| 336 | * the components and the borders of the <code>Container</code>. |
| 337 | * |
| 338 | * @param vgap the vertical gap between components |
| 339 | * and between the components and the borders |
| 340 | * of the <code>Container</code> |
| 341 | * @see java.awt.FlowLayout#getVgap |
| 342 | * @since JDK1.1 |
| 343 | */ |
| 344 | public void setVgap(int vgap) { |
| 345 | this.vgap = vgap; |
| 346 | } |
| 347 | |
| 348 | /** |
| 349 | * Sets whether or not components should be vertically aligned along their |
| 350 | * baseline. Components that do not have a baseline will be centered. |
| 351 | * The default is false. |
| 352 | * |
| 353 | * @param alignOnBaseline whether or not components should be |
| 354 | * vertically aligned on their baseline |
| 355 | * @since 1.6 |
| 356 | */ |
| 357 | public void setAlignOnBaseline(boolean alignOnBaseline) { |
| 358 | this.alignOnBaseline = alignOnBaseline; |
| 359 | } |
| 360 | |
| 361 | /** |
| 362 | * Returns true if components are to be vertically aligned along |
| 363 | * their baseline. The default is false. |
| 364 | * |
| 365 | * @return true if components are to be vertically aligned along |
| 366 | * their baseline |
| 367 | * @since 1.6 |
| 368 | */ |
| 369 | public boolean getAlignOnBaseline() { |
| 370 | return alignOnBaseline; |
| 371 | } |
| 372 | |
| 373 | /** |
| 374 | * Adds the specified component to the layout. |
| 375 | * Not used by this class. |
| 376 | * @param name the name of the component |
| 377 | * @param comp the component to be added |
| 378 | */ |
| 379 | public void addLayoutComponent(String name, Component comp) { |
| 380 | } |
| 381 | |
| 382 | /** |
| 383 | * Removes the specified component from the layout. |
| 384 | * Not used by this class. |
| 385 | * @param comp the component to remove |
| 386 | * @see java.awt.Container#removeAll |
| 387 | */ |
| 388 | public void removeLayoutComponent(Component comp) { |
| 389 | } |
| 390 | |
| 391 | /** |
| 392 | * Returns the preferred dimensions for this layout given the |
| 393 | * <i>visible</i> components in the specified target container. |
| 394 | * |
| 395 | * @param target the container that needs to be laid out |
| 396 | * @return the preferred dimensions to lay out the |
| 397 | * subcomponents of the specified container |
| 398 | * @see Container |
| 399 | * @see #minimumLayoutSize |
| 400 | * @see java.awt.Container#getPreferredSize |
| 401 | */ |
| 402 | public Dimension preferredLayoutSize(Container target) { |
| 403 | synchronized (target.getTreeLock()) { |
| 404 | Dimension dim = new Dimension(0, 0); |
| 405 | int nmembers = target.getComponentCount(); |
| 406 | boolean firstVisibleComponent = true; |
| 407 | boolean useBaseline = getAlignOnBaseline(); |
| 408 | int maxAscent = 0; |
| 409 | int maxDescent = 0; |
| 410 | |
| 411 | for (int i = 0 ; i < nmembers ; i++) { |
| 412 | Component m = target.getComponent(i); |
| 413 | if (m.isVisible()) { |
| 414 | Dimension d = m.getPreferredSize(); |
| 415 | dim.height = Math.max(dim.height, d.height); |
| 416 | if (firstVisibleComponent) { |
| 417 | firstVisibleComponent = false; |
| 418 | } else { |
| 419 | dim.width += hgap; |
| 420 | } |
| 421 | dim.width += d.width; |
| 422 | if (useBaseline) { |
| 423 | int baseline = m.getBaseline(d.width, d.height); |
| 424 | if (baseline >= 0) { |
| 425 | maxAscent = Math.max(maxAscent, baseline); |
| 426 | maxDescent = Math.max(maxDescent, d.height - baseline); |
| 427 | } |
| 428 | } |
| 429 | } |
| 430 | } |
| 431 | if (useBaseline) { |
| 432 | dim.height = Math.max(maxAscent + maxDescent, dim.height); |
| 433 | } |
| 434 | Insets insets = target.getInsets(); |
| 435 | dim.width += insets.left + insets.right + hgap*2; |
| 436 | dim.height += insets.top + insets.bottom + vgap*2; |
| 437 | return dim; |
| 438 | } |
| 439 | } |
| 440 | |
| 441 | /** |
| 442 | * Returns the minimum dimensions needed to layout the <i>visible</i> |
| 443 | * components contained in the specified target container. |
| 444 | * @param target the container that needs to be laid out |
| 445 | * @return the minimum dimensions to lay out the |
| 446 | * subcomponents of the specified container |
| 447 | * @see #preferredLayoutSize |
| 448 | * @see java.awt.Container |
| 449 | * @see java.awt.Container#doLayout |
| 450 | */ |
| 451 | public Dimension minimumLayoutSize(Container target) { |
| 452 | synchronized (target.getTreeLock()) { |
| 453 | boolean useBaseline = getAlignOnBaseline(); |
| 454 | Dimension dim = new Dimension(0, 0); |
| 455 | int nmembers = target.getComponentCount(); |
| 456 | int maxAscent = 0; |
| 457 | int maxDescent = 0; |
| 458 | boolean firstVisibleComponent = true; |
| 459 | |
| 460 | for (int i = 0 ; i < nmembers ; i++) { |
| 461 | Component m = target.getComponent(i); |
| 462 | if (m.visible) { |
| 463 | Dimension d = m.getMinimumSize(); |
| 464 | dim.height = Math.max(dim.height, d.height); |
| 465 | if (firstVisibleComponent) { |
| 466 | firstVisibleComponent = false; |
| 467 | } else { |
| 468 | dim.width += hgap; |
| 469 | } |
| 470 | dim.width += d.width; |
| 471 | if (useBaseline) { |
| 472 | int baseline = m.getBaseline(d.width, d.height); |
| 473 | if (baseline >= 0) { |
| 474 | maxAscent = Math.max(maxAscent, baseline); |
| 475 | maxDescent = Math.max(maxDescent, |
| 476 | dim.height - baseline); |
| 477 | } |
| 478 | } |
| 479 | } |
| 480 | } |
| 481 | |
| 482 | if (useBaseline) { |
| 483 | dim.height = Math.max(maxAscent + maxDescent, dim.height); |
| 484 | } |
| 485 | |
| 486 | Insets insets = target.getInsets(); |
| 487 | dim.width += insets.left + insets.right + hgap*2; |
| 488 | dim.height += insets.top + insets.bottom + vgap*2; |
| 489 | return dim; |
| 490 | |
| 491 | |
| 492 | |
| 493 | |
| 494 | |
| 495 | } |
| 496 | } |
| 497 | |
| 498 | /** |
| 499 | * Centers the elements in the specified row, if there is any slack. |
| 500 | * @param target the component which needs to be moved |
| 501 | * @param x the x coordinate |
| 502 | * @param y the y coordinate |
| 503 | * @param width the width dimensions |
| 504 | * @param height the height dimensions |
| 505 | * @param rowStart the beginning of the row |
| 506 | * @param rowEnd the the ending of the row |
| 507 | * @param useBaseline Whether or not to align on baseline. |
| 508 | * @param ascent Ascent for the components. This is only valid if |
| 509 | * useBaseline is true. |
| 510 | * @param descent Ascent for the components. This is only valid if |
| 511 | * useBaseline is true. |
| 512 | * @return actual row height |
| 513 | */ |
| 514 | private int moveComponents(Container target, int x, int y, int width, int height, |
| 515 | int rowStart, int rowEnd, boolean ltr, |
| 516 | boolean useBaseline, int[] ascent, |
| 517 | int[] descent) { |
| 518 | switch (newAlign) { |
| 519 | case LEFT: |
| 520 | x += ltr ? 0 : width; |
| 521 | break; |
| 522 | case CENTER: |
| 523 | x += width / 2; |
| 524 | break; |
| 525 | case RIGHT: |
| 526 | x += ltr ? width : 0; |
| 527 | break; |
| 528 | case LEADING: |
| 529 | break; |
| 530 | case TRAILING: |
| 531 | x += width; |
| 532 | break; |
| 533 | } |
| 534 | int maxAscent = 0; |
| 535 | int nonbaselineHeight = 0; |
| 536 | int baselineOffset = 0; |
| 537 | if (useBaseline) { |
| 538 | int maxDescent = 0; |
| 539 | for (int i = rowStart ; i < rowEnd ; i++) { |
| 540 | Component m = target.getComponent(i); |
| 541 | if (m.visible) { |
| 542 | if (ascent[i] >= 0) { |
| 543 | maxAscent = Math.max(maxAscent, ascent[i]); |
| 544 | maxDescent = Math.max(maxDescent, descent[i]); |
| 545 | } |
| 546 | else { |
| 547 | nonbaselineHeight = Math.max(m.getHeight(), |
| 548 | nonbaselineHeight); |
| 549 | } |
| 550 | } |
| 551 | } |
| 552 | height = Math.max(maxAscent + maxDescent, nonbaselineHeight); |
| 553 | baselineOffset = (height - maxAscent - maxDescent) / 2; |
| 554 | } |
| 555 | for (int i = rowStart ; i < rowEnd ; i++) { |
| 556 | Component m = target.getComponent(i); |
| 557 | if (m.isVisible()) { |
| 558 | int cy; |
| 559 | if (useBaseline && ascent[i] >= 0) { |
| 560 | cy = y + baselineOffset + maxAscent - ascent[i]; |
| 561 | } |
| 562 | else { |
| 563 | cy = y + (height - m.height) / 2; |
| 564 | } |
| 565 | if (ltr) { |
| 566 | m.setLocation(x, cy); |
| 567 | } else { |
| 568 | m.setLocation(target.width - x - m.width, cy); |
| 569 | } |
| 570 | x += m.width + hgap; |
| 571 | } |
| 572 | } |
| 573 | return height; |
| 574 | } |
| 575 | |
| 576 | /** |
| 577 | * Lays out the container. This method lets each |
| 578 | * <i>visible</i> component take |
| 579 | * its preferred size by reshaping the components in the |
| 580 | * target container in order to satisfy the alignment of |
| 581 | * this <code>FlowLayout</code> object. |
| 582 | * |
| 583 | * @param target the specified component being laid out |
| 584 | * @see Container |
| 585 | * @see java.awt.Container#doLayout |
| 586 | */ |
| 587 | public void layoutContainer(Container target) { |
| 588 | synchronized (target.getTreeLock()) { |
| 589 | Insets insets = target.getInsets(); |
| 590 | int maxwidth = target.width - (insets.left + insets.right + hgap*2); |
| 591 | int nmembers = target.getComponentCount(); |
| 592 | int x = 0, y = insets.top + vgap; |
| 593 | int rowh = 0, start = 0; |
| 594 | |
| 595 | boolean ltr = target.getComponentOrientation().isLeftToRight(); |
| 596 | |
| 597 | boolean useBaseline = getAlignOnBaseline(); |
| 598 | int[] ascent = null; |
| 599 | int[] descent = null; |
| 600 | |
| 601 | if (useBaseline) { |
| 602 | ascent = new int[nmembers]; |
| 603 | descent = new int[nmembers]; |
| 604 | } |
| 605 | |
| 606 | for (int i = 0 ; i < nmembers ; i++) { |
| 607 | Component m = target.getComponent(i); |
| 608 | if (m.isVisible()) { |
| 609 | Dimension d = m.getPreferredSize(); |
| 610 | m.setSize(d.width, d.height); |
| 611 | |
| 612 | if (useBaseline) { |
| 613 | int baseline = m.getBaseline(d.width, d.height); |
| 614 | if (baseline >= 0) { |
| 615 | ascent[i] = baseline; |
| 616 | descent[i] = d.height - baseline; |
| 617 | } |
| 618 | else { |
| 619 | ascent[i] = -1; |
| 620 | } |
| 621 | } |
| 622 | if ((x == 0) || ((x + d.width) <= maxwidth)) { |
| 623 | if (x > 0) { |
| 624 | x += hgap; |
| 625 | } |
| 626 | x += d.width; |
| 627 | rowh = Math.max(rowh, d.height); |
| 628 | } else { |
| 629 | rowh = moveComponents(target, insets.left + hgap, y, |
| 630 | maxwidth - x, rowh, start, i, ltr, |
| 631 | useBaseline, ascent, descent); |
| 632 | x = d.width; |
| 633 | y += vgap + rowh; |
| 634 | rowh = d.height; |
| 635 | start = i; |
| 636 | } |
| 637 | } |
| 638 | } |
| 639 | moveComponents(target, insets.left + hgap, y, maxwidth - x, rowh, |
| 640 | start, nmembers, ltr, useBaseline, ascent, descent); |
| 641 | } |
| 642 | } |
| 643 | |
| 644 | // |
| 645 | // the internal serial version which says which version was written |
| 646 | // - 0 (default) for versions before the Java 2 platform, v1.2 |
| 647 | // - 1 for version >= Java 2 platform v1.2, which includes "newAlign" field |
| 648 | // |
| 649 | private static final int currentSerialVersion = 1; |
| 650 | /** |
| 651 | * This represent the <code>currentSerialVersion</code> |
| 652 | * which is bein used. It will be one of two values : |
| 653 | * <code>0</code> versions before Java 2 platform v1.2.. |
| 654 | * <code>1</code> versions after Java 2 platform v1.2.. |
| 655 | * |
| 656 | * @serial |
| 657 | * @since 1.2 |
| 658 | */ |
| 659 | private int serialVersionOnStream = currentSerialVersion; |
| 660 | |
| 661 | /** |
| 662 | * Reads this object out of a serialization stream, handling |
| 663 | * objects written by older versions of the class that didn't contain all |
| 664 | * of the fields we use now.. |
| 665 | */ |
| 666 | private void readObject(ObjectInputStream stream) |
| 667 | throws IOException, ClassNotFoundException |
| 668 | { |
| 669 | stream.defaultReadObject(); |
| 670 | |
| 671 | if (serialVersionOnStream < 1) { |
| 672 | // "newAlign" field wasn't present, so use the old "align" field. |
| 673 | setAlignment(this.align); |
| 674 | } |
| 675 | serialVersionOnStream = currentSerialVersion; |
| 676 | } |
| 677 | |
| 678 | /** |
| 679 | * Returns a string representation of this <code>FlowLayout</code> |
| 680 | * object and its values. |
| 681 | * @return a string representation of this layout |
| 682 | */ |
| 683 | public String toString() { |
| 684 | String str = ""; |
| 685 | switch (align) { |
| 686 | case LEFT: str = ",align=left"; break; |
| 687 | case CENTER: str = ",align=center"; break; |
| 688 | case RIGHT: str = ",align=right"; break; |
| 689 | case LEADING: str = ",align=leading"; break; |
| 690 | case TRAILING: str = ",align=trailing"; break; |
| 691 | } |
| 692 | return getClass().getName() + "[hgap=" + hgap + ",vgap=" + vgap + str + "]"; |
| 693 | } |
| 694 | |
| 695 | |
| 696 | } |