Showing the changes to java/pkg/javax/swing/SpringLayout.java (1 of 18352 files). Show all
Unified · Split
| @@ -0,0 +1,1233 @@ | |||
| 1 | /* | ||
| 2 | * Copyright (c) 2001, 2008, 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 | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | package javax.swing; | ||
| 26 | |||
| 27 | import java.awt.Component; | ||
| 28 | import java.awt.Container; | ||
| 29 | import java.awt.Dimension; | ||
| 30 | import java.awt.FontMetrics; | ||
| 31 | import java.awt.Insets; | ||
| 32 | import java.awt.LayoutManager2; | ||
| 33 | import java.awt.Rectangle; | ||
| 34 | import java.util.*; | ||
| 35 | |||
| 36 | /** | ||
| 37 | * A <code>SpringLayout</code> lays out the children of its associated container | ||
| 38 | * according to a set of constraints. | ||
| 39 | * See <a href="http://java.sun.com/docs/books/tutorial/uiswing/layout/spring.html">How to Use SpringLayout</a> | ||
| 40 | * in <em>The Java Tutorial</em> for examples of using | ||
| 41 | * <code>SpringLayout</code>. | ||
| 42 | * | ||
| 43 | * <p> | ||
| 44 | * Each constraint, | ||
| 45 | * represented by a <code>Spring</code> object, | ||
| 46 | * controls the vertical or horizontal distance | ||
| 47 | * between two component edges. | ||
| 48 | * The edges can belong to | ||
| 49 | * any child of the container, | ||
| 50 | * or to the container itself. | ||
| 51 | * For example, | ||
| 52 | * the allowable width of a component | ||
| 53 | * can be expressed using a constraint | ||
| 54 | * that controls the distance between the west (left) and east (right) | ||
| 55 | * edges of the component. | ||
| 56 | * The allowable <em>y</em> coordinates for a component | ||
| 57 | * can be expressed by constraining the distance between | ||
| 58 | * the north (top) edge of the component | ||
| 59 | * and the north edge of its container. | ||
| 60 | * | ||
| 61 | * <P> | ||
| 62 | * Every child of a <code>SpringLayout</code>-controlled container, | ||
| 63 | * as well as the container itself, | ||
| 64 | * has exactly one set of constraints | ||
| 65 | * associated with it. | ||
| 66 | * These constraints are represented by | ||
| 67 | * a <code>SpringLayout.Constraints</code> object. | ||
| 68 | * By default, | ||
| 69 | * <code>SpringLayout</code> creates constraints | ||
| 70 | * that make their associated component | ||
| 71 | * have the minimum, preferred, and maximum sizes | ||
| 72 | * returned by the component's | ||
| 73 | * {@link java.awt.Component#getMinimumSize}, | ||
| 74 | * {@link java.awt.Component#getPreferredSize}, and | ||
| 75 | * {@link java.awt.Component#getMaximumSize} | ||
| 76 | * methods. The <em>x</em> and <em>y</em> positions are initially not | ||
| 77 | * constrained, so that until you constrain them the <code>Component</code> | ||
| 78 | * will be positioned at 0,0 relative to the <code>Insets</code> of the | ||
| 79 | * parent <code>Container</code>. | ||
| 80 | * | ||
| 81 | * <p> | ||
| 82 | * You can change | ||
| 83 | * a component's constraints in several ways. | ||
| 84 | * You can | ||
| 85 | * use one of the | ||
| 86 | * {@link #putConstraint putConstraint} | ||
| 87 | * methods | ||
| 88 | * to establish a spring | ||
| 89 | * linking the edges of two components within the same container. | ||
| 90 | * Or you can get the appropriate <code>SpringLayout.Constraints</code> | ||
| 91 | * object using | ||
| 92 | * {@link #getConstraints getConstraints} | ||
| 93 | * and then modify one or more of its springs. | ||
| 94 | * Or you can get the spring for a particular edge of a component | ||
| 95 | * using {@link #getConstraint getConstraint}, | ||
| 96 | * and modify it. | ||
| 97 | * You can also associate | ||
| 98 | * your own <code>SpringLayout.Constraints</code> object | ||
| 99 | * with a component by specifying the constraints object | ||
| 100 | * when you add the component to its container | ||
| 101 | * (using | ||
| 102 | * {@link Container#add(Component, Object)}). | ||
| 103 | * | ||
| 104 | * <p> | ||
| 105 | * The <code>Spring</code> object representing each constraint | ||
| 106 | * has a minimum, preferred, maximum, and current value. | ||
| 107 | * The current value of the spring | ||
| 108 | * is somewhere between the minimum and maximum values, | ||
| 109 | * according to the formula given in the | ||
| 110 | * {@link Spring#sum} method description. | ||
| 111 | * When the minimum, preferred, and maximum values are the same, | ||
| 112 | * the current value is always equal to them; | ||
| 113 | * this inflexible spring is called a <em>strut</em>. | ||
| 114 | * You can create struts using the factory method | ||
| 115 | * {@link Spring#constant(int)}. | ||
| 116 | * The <code>Spring</code> class also provides factory methods | ||
| 117 | * for creating other kinds of springs, | ||
| 118 | * including springs that depend on other springs. | ||
| 119 | * | ||
| 120 | * <p> | ||
| 121 | * In a <code>SpringLayout</code>, the position of each edge is dependent on | ||
| 122 | * the position of just one other edge. If a constraint is subsequently added | ||
| 123 | * to create a new binding for an edge, the previous binding is discarded | ||
| 124 | * and the edge remains dependent on a single edge. | ||
| 125 | * Springs should only be attached | ||
| 126 | * between edges of the container and its immediate children; the behavior | ||
| 127 | * of the <code>SpringLayout</code> when presented with constraints linking | ||
| 128 | * the edges of components from different containers (either internal or | ||
| 129 | * external) is undefined. | ||
| 130 | * | ||
| 131 | * <h3> | ||
| 132 | * SpringLayout vs. Other Layout Managers | ||
| 133 | * </h3> | ||
| 134 | * | ||
| 135 | * <blockquote> | ||
| 136 | * <hr> | ||
| 137 | * <strong>Note:</strong> | ||
| 138 | * Unlike many layout managers, | ||
| 139 | * <code>SpringLayout</code> doesn't automatically set the location of | ||
| 140 | * the components it manages. | ||
| 141 | * If you hand-code a GUI that uses <code>SpringLayout</code>, | ||
| 142 | * remember to initialize component locations by constraining the west/east | ||
| 143 | * and north/south locations. | ||
| 144 | * <p> | ||
| 145 | * Depending on the constraints you use, | ||
| 146 | * you may also need to set the size of the container explicitly. | ||
| 147 | * <hr> | ||
| 148 | * </blockquote> | ||
| 149 | * | ||
| 150 | * <p> | ||
| 151 | * Despite the simplicity of <code>SpringLayout</code>, | ||
| 152 | * it can emulate the behavior of most other layout managers. | ||
| 153 | * For some features, | ||
| 154 | * such as the line breaking provided by <code>FlowLayout</code>, | ||
| 155 | * you'll need to | ||
| 156 | * create a special-purpose subclass of the <code>Spring</code> class. | ||
| 157 | * | ||
| 158 | * <p> | ||
| 159 | * <code>SpringLayout</code> also provides a way to solve | ||
| 160 | * many of the difficult layout | ||
| 161 | * problems that cannot be solved by nesting combinations | ||
| 162 | * of <code>Box</code>es. That said, <code>SpringLayout</code> honors the | ||
| 163 | * <code>LayoutManager2</code> contract correctly and so can be nested with | ||
| 164 | * other layout managers -- a technique that can be preferable to | ||
| 165 | * creating the constraints implied by the other layout managers. | ||
| 166 | * <p> | ||
| 167 | * The asymptotic complexity of the layout operation of a <code>SpringLayout</code> | ||
| 168 | * is linear in the number of constraints (and/or components). | ||
| 169 | * <p> | ||
| 170 | * <strong>Warning:</strong> | ||
| 171 | * Serialized objects of this class will not be compatible with | ||
| 172 | * future Swing releases. The current serialization support is | ||
| 173 | * appropriate for short term storage or RMI between applications running | ||
| 174 | * the same version of Swing. As of 1.4, support for long term storage | ||
| 175 | * of all JavaBeans<sup><font size="-2">TM</font></sup> | ||
| 176 | * has been added to the <code>java.beans</code> package. | ||
| 177 | * Please see {@link java.beans.XMLEncoder}. | ||
| 178 | * | ||
| 179 | * @see Spring | ||
| 180 | * @see SpringLayout.Constraints | ||
| 181 | * | ||
| 182 | * @author Philip Milne | ||
| 183 | * @author Scott Violet | ||
| 184 | * @author Joe Winchester | ||
| 185 | * @since 1.4 | ||
| 186 | */ | ||
| 187 | public class SpringLayout implements LayoutManager2 { | ||
| 188 | private Map<Component, Constraints> componentConstraints = new HashMap<Component, Constraints>(); | ||
| 189 | |||
| 190 | private Spring cyclicReference = Spring.constant(Spring.UNSET); | ||
| 191 | private Set<Spring> cyclicSprings; | ||
| 192 | private Set<Spring> acyclicSprings; | ||
| 193 | |||
| 194 | |||
| 195 | /** | ||
| 196 | * Specifies the top edge of a component's bounding rectangle. | ||
| 197 | */ | ||
| 198 | public static final String NORTH = "North"; | ||
| 199 | |||
| 200 | /** | ||
| 201 | * Specifies the bottom edge of a component's bounding rectangle. | ||
| 202 | */ | ||
| 203 | public static final String SOUTH = "South"; | ||
| 204 | |||
| 205 | /** | ||
| 206 | * Specifies the right edge of a component's bounding rectangle. | ||
| 207 | */ | ||
| 208 | public static final String EAST = "East"; | ||
| 209 | |||
| 210 | /** | ||
| 211 | * Specifies the left edge of a component's bounding rectangle. | ||
| 212 | */ | ||
| 213 | public static final String WEST = "West"; | ||
| 214 | |||
| 215 | /** | ||
| 216 | * Specifies the horizontal center of a component's bounding rectangle. | ||
| 217 | * | ||
| 218 | * @since 1.6 | ||
| 219 | */ | ||
| 220 | public static final String HORIZONTAL_CENTER = "HorizontalCenter"; | ||
| 221 | |||
| 222 | /** | ||
| 223 | * Specifies the vertical center of a component's bounding rectangle. | ||
| 224 | * | ||
| 225 | * @since 1.6 | ||
| 226 | */ | ||
| 227 | public static final String VERTICAL_CENTER = "VerticalCenter"; | ||
| 228 | |||
| 229 | /** | ||
| 230 | * Specifies the baseline of a component. | ||
| 231 | * | ||
| 232 | * @since 1.6 | ||
| 233 | */ | ||
| 234 | public static final String BASELINE = "Baseline"; | ||
| 235 | |||
| 236 | /** | ||
| 237 | * Specifies the width of a component's bounding rectangle. | ||
| 238 | * | ||
| 239 | * @since 1.6 | ||
| 240 | */ | ||
| 241 | public static final String WIDTH = "Width"; | ||
| 242 | |||
| 243 | /** | ||
| 244 | * Specifies the height of a component's bounding rectangle. | ||
| 245 | * | ||
| 246 | * @since 1.6 | ||
| 247 | */ | ||
| 248 | public static final String HEIGHT = "Height"; | ||
| 249 | |||
| 250 | private static String[] ALL_HORIZONTAL = {WEST, WIDTH, EAST, HORIZONTAL_CENTER}; | ||
| 251 | |||
| 252 | private static String[] ALL_VERTICAL = {NORTH, HEIGHT, SOUTH, VERTICAL_CENTER, BASELINE}; | ||
| 253 | |||
| 254 | /** | ||
| 255 | * A <code>Constraints</code> object holds the | ||
| 256 | * constraints that govern the way a component's size and position | ||
| 257 | * change in a container controlled by a <code>SpringLayout</code>. | ||
| 258 | * A <code>Constraints</code> object is | ||
| 259 | * like a <code>Rectangle</code>, in that it | ||
| 260 | * has <code>x</code>, <code>y</code>, | ||
| 261 | * <code>width</code>, and <code>height</code> properties. | ||
| 262 | * In the <code>Constraints</code> object, however, | ||
| 263 | * these properties have | ||
| 264 | * <code>Spring</code> values instead of integers. | ||
| 265 | * In addition, | ||
| 266 | * a <code>Constraints</code> object | ||
| 267 | * can be manipulated as four edges | ||
| 268 | * -- north, south, east, and west -- | ||
| 269 | * using the <code>constraint</code> property. | ||
| 270 | * | ||
| 271 | * <p> | ||
| 272 | * The following formulas are always true | ||
| 273 | * for a <code>Constraints</code> object (here WEST and <code>x</code> are synonyms, as are and NORTH and <code>y</code>): | ||
| 274 | * | ||
| 275 | * <pre> | ||
| 276 | * EAST = WEST + WIDTH | ||
| 277 | * SOUTH = NORTH + HEIGHT | ||
| 278 | * HORIZONTAL_CENTER = WEST + WIDTH/2 | ||
| 279 | * VERTICAL_CENTER = NORTH + HEIGHT/2 | ||
| 280 | * ABSOLUTE_BASELINE = NORTH + RELATIVE_BASELINE* | ||
| 281 | * </pre> | ||
| 282 | * <p> | ||
| 283 | * For example, if you have specified the WIDTH and WEST (X) location | ||
| 284 | * the EAST is calculated as WEST + WIDTH. If you instead specified | ||
| 285 | * the WIDTH and EAST locations the WEST (X) location is then calculated | ||
| 286 | * as EAST - WIDTH. | ||
| 287 | * <p> | ||
| 288 | * [RELATIVE_BASELINE is a private constraint that is set automatically when | ||
| 289 | * the SpringLayout.Constraints(Component) constuctor is called or when | ||
| 290 | * a constraints object is registered with a SpringLayout object.] | ||
| 291 | * <p> | ||
| 292 | * <b>Note</b>: In this document, | ||
| 293 | * operators represent methods | ||
| 294 | * in the <code>Spring</code> class. | ||
| 295 | * For example, "a + b" is equal to | ||
| 296 | * <code>Spring.sum(a, b)</code>, | ||
| 297 | * and "a - b" is equal to | ||
| 298 | * <code>Spring.sum(a, Spring.minus(b))</code>. | ||
| 299 | * See the | ||
| 300 | * {@link Spring <code>Spring</code> API documentation} | ||
| 301 | * for further details | ||
| 302 | * of spring arithmetic. | ||
| 303 | * | ||
| 304 | * <p> | ||
| 305 | * | ||
| 306 | * Because a <code>Constraints</code> object's properties -- | ||
| 307 | * representing its edges, size, and location -- can all be set | ||
| 308 | * independently and yet are interrelated, | ||
| 309 | * a <code>Constraints</code> object can become <em>over-constrained</em>. | ||
| 310 | * For example, if the <code>WEST</code>, <code>WIDTH</code> and | ||
| 311 | * <code>EAST</code> edges are all set, steps must be taken to ensure that | ||
| 312 | * the first of the formulas above holds. To do this, the | ||
| 313 | * <code>Constraints</code> | ||
| 314 | * object throws away the <em>least recently set</em> | ||
| 315 | * constraint so as to make the formulas hold. | ||
| 316 | * @since 1.4 | ||
| 317 | */ | ||
| 318 | public static class Constraints { | ||
| 319 | private Spring x; | ||
| 320 | private Spring y; | ||
| 321 | private Spring width; | ||
| 322 | private Spring height; | ||
| 323 | private Spring east; | ||
| 324 | private Spring south; | ||
| 325 | private Spring horizontalCenter; | ||
| 326 | private Spring verticalCenter; | ||
| 327 | private Spring baseline; | ||
| 328 | |||
| 329 | private List<String> horizontalHistory = new ArrayList<String>(2); | ||
| 330 | private List<String> verticalHistory = new ArrayList<String>(2); | ||
| 331 | |||
| 332 | // Used for baseline calculations | ||
| 333 | private Component c; | ||
| 334 | |||
| 335 | /** | ||
| 336 | * Creates an empty <code>Constraints</code> object. | ||
| 337 | */ | ||
| 338 | public Constraints() { | ||
| 339 | } | ||
| 340 | |||
| 341 | /** | ||
| 342 | * Creates a <code>Constraints</code> object with the | ||
| 343 | * specified values for its | ||
| 344 | * <code>x</code> and <code>y</code> properties. | ||
| 345 | * The <code>height</code> and <code>width</code> springs | ||
| 346 | * have <code>null</code> values. | ||
| 347 | * | ||
| 348 | * @param x the spring controlling the component's <em>x</em> value | ||
| 349 | * @param y the spring controlling the component's <em>y</em> value | ||
| 350 | */ | ||
| 351 | public Constraints(Spring x, Spring y) { | ||
| 352 | setX(x); | ||
| 353 | setY(y); | ||
| 354 | } | ||
| 355 | |||
| 356 | /** | ||
| 357 | * Creates a <code>Constraints</code> object with the | ||
| 358 | * specified values for its | ||
| 359 | * <code>x</code>, <code>y</code>, <code>width</code>, | ||
| 360 | * and <code>height</code> properties. | ||
| 361 | * Note: If the <code>SpringLayout</code> class | ||
| 362 | * encounters <code>null</code> values in the | ||
| 363 | * <code>Constraints</code> object of a given component, | ||
| 364 | * it replaces them with suitable defaults. | ||
| 365 | * | ||
| 366 | * @param x the spring value for the <code>x</code> property | ||
| 367 | * @param y the spring value for the <code>y</code> property | ||
| 368 | * @param width the spring value for the <code>width</code> property | ||
| 369 | * @param height the spring value for the <code>height</code> property | ||
| 370 | */ | ||
| 371 | public Constraints(Spring x, Spring y, Spring width, Spring height) { | ||
| 372 | setX(x); | ||
| 373 | setY(y); | ||
| 374 | setWidth(width); | ||
| 375 | setHeight(height); | ||
| 376 | } | ||
| 377 | |||
| 378 | /** | ||
| 379 | * Creates a <code>Constraints</code> object with | ||
| 380 | * suitable <code>x</code>, <code>y</code>, <code>width</code> and | ||
| 381 | * <code>height</code> springs for component, <code>c</code>. | ||
| 382 | * The <code>x</code> and <code>y</code> springs are constant | ||
| 383 | * springs initialised with the component's location at | ||
| 384 | * the time this method is called. The <code>width</code> and | ||
| 385 | * <code>height</code> springs are special springs, created by | ||
| 386 | * the <code>Spring.width()</code> and <code>Spring.height()</code> | ||
| 387 | * methods, which track the size characteristics of the component | ||
| 388 | * when they change. | ||
| 389 | * | ||
| 390 | * @param c the component whose characteristics will be reflected by this Constraints object | ||
| 391 | * @throws NullPointerException if <code>c</code> is null. | ||
| 392 | * @since 1.5 | ||
| 393 | */ | ||
| 394 | public Constraints(Component c) { | ||
| 395 | this.c = c; | ||
| 396 | setX(Spring.constant(c.getX())); | ||
| 397 | setY(Spring.constant(c.getY())); | ||
| 398 | setWidth(Spring.width(c)); | ||
| 399 | setHeight(Spring.height(c)); | ||
| 400 | } | ||
| 401 | |||
| 402 | private void pushConstraint(String name, Spring value, boolean horizontal) { | ||
| 403 | boolean valid = true; | ||
| 404 | List<String> history = horizontal ? horizontalHistory : | ||
| 405 | verticalHistory; | ||
| 406 | if (history.contains(name)) { | ||
| 407 | history.remove(name); | ||
| 408 | valid = false; | ||
| 409 | } else if (history.size() == 2 && value != null) { | ||
| 410 | history.remove(0); | ||
| 411 | valid = false; | ||
| 412 | } | ||
| 413 | if (value != null) { | ||
| 414 | history.add(name); | ||
| 415 | } | ||
| 416 | if (!valid) { | ||
| 417 | String[] all = horizontal ? ALL_HORIZONTAL : ALL_VERTICAL; | ||
| 418 | for (String s : all) { | ||
| 419 | if (!history.contains(s)) { | ||
| 420 | setConstraint(s, null); | ||
| 421 | } | ||
| 422 | } | ||
| 423 | } | ||
| 424 | } | ||
| 425 | |||
| 426 | private Spring sum(Spring s1, Spring s2) { | ||
| 427 | return (s1 == null || s2 == null) ? null : Spring.sum(s1, s2); | ||
| 428 | } | ||
| 429 | |||
| 430 | private Spring difference(Spring s1, Spring s2) { | ||
| 431 | return (s1 == null || s2 == null) ? null : Spring.difference(s1, s2); | ||
| 432 | } | ||
| 433 | |||
| 434 | private Spring scale(Spring s, float factor) { | ||
| 435 | return (s == null) ? null : Spring.scale(s, factor); | ||
| 436 | } | ||
| 437 | |||
| 438 | private int getBaselineFromHeight(int height) { | ||
| 439 | if (height < 0) { | ||
| 440 | // Bad Scott, Bad Scott! | ||
| 441 | return -c.getBaseline(c.getPreferredSize().width, | ||
| 442 | -height); | ||
| 443 | } | ||
| 444 | return c.getBaseline(c.getPreferredSize().width, height); | ||
| 445 | } | ||
| 446 | |||
| 447 | private int getHeightFromBaseLine(int baseline) { | ||
| 448 | Dimension prefSize = c.getPreferredSize(); | ||
| 449 | int prefHeight = prefSize.height; | ||
| 450 | int prefBaseline = c.getBaseline(prefSize.width, prefHeight); | ||
| 451 | if (prefBaseline == baseline) { | ||
| 452 | // If prefBaseline < 0, then no baseline, assume preferred | ||
| 453 | // height. | ||
| 454 | // If prefBaseline == baseline, then specified baseline | ||
| 455 | // matches preferred baseline, return preferred height | ||
| 456 | return prefHeight; | ||
| 457 | } | ||
| 458 | // Valid baseline | ||
| 459 | switch(c.getBaselineResizeBehavior()) { | ||
| 460 | case CONSTANT_DESCENT: | ||
| 461 | return prefHeight + (baseline - prefBaseline); | ||
| 462 | case CENTER_OFFSET: | ||
| 463 | return prefHeight + 2 * (baseline - prefBaseline); | ||
| 464 | case CONSTANT_ASCENT: | ||
| 465 | // Component baseline and specified baseline will NEVER | ||
| 466 | // match, fall through to default | ||
| 467 | default: // OTHER | ||
| 468 | // No way to map from baseline to height. | ||
| 469 | } | ||
| 470 | return Integer.MIN_VALUE; | ||
| 471 | } | ||
| 472 | |||
| 473 | private Spring heightToRelativeBaseline(Spring s) { | ||
| 474 | return new Spring.SpringMap(s) { | ||
| 475 | protected int map(int i) { | ||
| 476 | return getBaselineFromHeight(i); | ||
| 477 | } | ||
| 478 | |||
| 479 | protected int inv(int i) { | ||
| 480 | return getHeightFromBaseLine(i); | ||
| 481 | } | ||
| 482 | }; | ||
| 483 | } | ||
| 484 | |||
| 485 | private Spring relativeBaselineToHeight(Spring s) { | ||
| 486 | return new Spring.SpringMap(s) { | ||
| 487 | protected int map(int i) { | ||
| 488 | return getHeightFromBaseLine(i); | ||
| 489 | } | ||
| 490 | |||
| 491 | protected int inv(int i) { | ||
| 492 | return getBaselineFromHeight(i); | ||
| 493 | } | ||
| 494 | }; | ||
| 495 | } | ||
| 496 | |||
| 497 | private boolean defined(List history, String s1, String s2) { | ||
| 498 | return history.contains(s1) && history.contains(s2); | ||
| 499 | } | ||
| 500 | |||
| 501 | /** | ||
| 502 | * Sets the <code>x</code> property, | ||
| 503 | * which controls the <code>x</code> value | ||
| 504 | * of a component's location. | ||
| 505 | * | ||
| 506 | * @param x the spring controlling the <code>x</code> value | ||
| 507 | * of a component's location | ||
| 508 | * | ||
| 509 | * @see #getX | ||
| 510 | * @see SpringLayout.Constraints | ||
| 511 | */ | ||
| 512 | public void setX(Spring x) { | ||
| 513 | this.x = x; | ||
| 514 | pushConstraint(WEST, x, true); | ||
| 515 | } | ||
| 516 | |||
| 517 | /** | ||
| 518 | * Returns the value of the <code>x</code> property. | ||
| 519 | * | ||
| 520 | * @return the spring controlling the <code>x</code> value | ||
| 521 | * of a component's location | ||
| 522 | * | ||
| 523 | * @see #setX | ||
| 524 | * @see SpringLayout.Constraints | ||
| 525 | */ | ||
| 526 | public Spring getX() { | ||
| 527 | if (x == null) { | ||
| 528 | if (defined(horizontalHistory, EAST, WIDTH)) { | ||
| 529 | x = difference(east, width); | ||
| 530 | } else if (defined(horizontalHistory, HORIZONTAL_CENTER, WIDTH)) { | ||
| 531 | x = difference(horizontalCenter, scale(width, 0.5f)); | ||
| 532 | } else if (defined(horizontalHistory, HORIZONTAL_CENTER, EAST)) { | ||
| 533 | x = difference(scale(horizontalCenter, 2f), east); | ||
| 534 | } | ||
| 535 | } | ||
| 536 | return x; | ||
| 537 | } | ||
| 538 | |||
| 539 | /** | ||
| 540 | * Sets the <code>y</code> property, | ||
| 541 | * which controls the <code>y</code> value | ||
| 542 | * of a component's location. | ||
| 543 | * | ||
| 544 | * @param y the spring controlling the <code>y</code> value | ||
| 545 | * of a component's location | ||
| 546 | * | ||
| 547 | * @see #getY | ||
| 548 | * @see SpringLayout.Constraints | ||
| 549 | */ | ||
| 550 | public void setY(Spring y) { | ||
| 551 | this.y = y; | ||
| 552 | pushConstraint(NORTH, y, false); | ||
| 553 | } | ||
| 554 | |||
| 555 | /** | ||
| 556 | * Returns the value of the <code>y</code> property. | ||
| 557 | * | ||
| 558 | * @return the spring controlling the <code>y</code> value | ||
| 559 | * of a component's location | ||
| 560 | * | ||
| 561 | * @see #setY | ||
| 562 | * @see SpringLayout.Constraints | ||
| 563 | */ | ||
| 564 | public Spring getY() { | ||
| 565 | if (y == null) { | ||
| 566 | if (defined(verticalHistory, SOUTH, HEIGHT)) { | ||
| 567 | y = difference(south, height); | ||
| 568 | } else if (defined(verticalHistory, VERTICAL_CENTER, HEIGHT)) { | ||
| 569 | y = difference(verticalCenter, scale(height, 0.5f)); | ||
| 570 | } else if (defined(verticalHistory, VERTICAL_CENTER, SOUTH)) { | ||
| 571 | y = difference(scale(verticalCenter, 2f), south); | ||
| 572 | } else if (defined(verticalHistory, BASELINE, HEIGHT)) { | ||
| 573 | y = difference(baseline, heightToRelativeBaseline(height)); | ||
| 574 | } else if (defined(verticalHistory, BASELINE, SOUTH)) { | ||
| 575 | y = scale(difference(baseline, heightToRelativeBaseline(south)), 2f); | ||
| 576 | /* | ||
| 577 | } else if (defined(verticalHistory, BASELINE, VERTICAL_CENTER)) { | ||
| 578 | y = scale(difference(baseline, heightToRelativeBaseline(scale(verticalCenter, 2))), 1f/(1-2*0.5f)); | ||
| 579 | */ | ||
| 580 | } | ||
| 581 | } | ||
| 582 | return y; | ||
| 583 | } | ||
| 584 | |||
| 585 | /** | ||
| 586 | * Sets the <code>width</code> property, | ||
| 587 | * which controls the width of a component. | ||
| 588 | * | ||
| 589 | * @param width the spring controlling the width of this | ||
| 590 | * <code>Constraints</code> object | ||
| 591 | * | ||
| 592 | * @see #getWidth | ||
| 593 | * @see SpringLayout.Constraints | ||
| 594 | */ | ||
| 595 | public void setWidth(Spring width) { | ||
| 596 | this.width = width; | ||
| 597 | pushConstraint(WIDTH, width, true); | ||
| 598 | } | ||
| 599 | |||
| 600 | /** | ||
| 601 | * Returns the value of the <code>width</code> property. | ||
| 602 | * | ||
| 603 | * @return the spring controlling the width of a component | ||
| 604 | * | ||
| 605 | * @see #setWidth | ||
| 606 | * @see SpringLayout.Constraints | ||
| 607 | */ | ||
| 608 | public Spring getWidth() { | ||
| 609 | if (width == null) { | ||
| 610 | if (horizontalHistory.contains(EAST)) { | ||
| 611 | width = difference(east, getX()); | ||
| 612 | } else if (horizontalHistory.contains(HORIZONTAL_CENTER)) { | ||
| 613 | width = scale(difference(horizontalCenter, getX()), 2f); | ||
| 614 | } | ||
| 615 | } | ||
| 616 | return width; | ||
| 617 | } | ||
| 618 | |||
| 619 | /** | ||
| 620 | * Sets the <code>height</code> property, | ||
| 621 | * which controls the height of a component. | ||
| 622 | * | ||
| 623 | * @param height the spring controlling the height of this <code>Constraints</code> | ||
| 624 | * object | ||
| 625 | * | ||
| 626 | * @see #getHeight | ||
| 627 | * @see SpringLayout.Constraints | ||
| 628 | */ | ||
| 629 | public void setHeight(Spring height) { | ||
| 630 | this.height = height; | ||
| 631 | pushConstraint(HEIGHT, height, false); | ||
| 632 | } | ||
| 633 | |||
| 634 | /** | ||
| 635 | * Returns the value of the <code>height</code> property. | ||
| 636 | * | ||
| 637 | * @return the spring controlling the height of a component | ||
| 638 | * | ||
| 639 | * @see #setHeight | ||
| 640 | * @see SpringLayout.Constraints | ||
| 641 | */ | ||
| 642 | public Spring getHeight() { | ||
| 643 | if (height == null) { | ||
| 644 | if (verticalHistory.contains(SOUTH)) { | ||
| 645 | height = difference(south, getY()); | ||
| 646 | } else if (verticalHistory.contains(VERTICAL_CENTER)) { | ||
| 647 | height = scale(difference(verticalCenter, getY()), 2f); | ||
| 648 | } else if (verticalHistory.contains(BASELINE)) { | ||
| 649 | height = relativeBaselineToHeight(difference(baseline, getY())); | ||
| 650 | } | ||
| 651 | } | ||
| 652 | return height; | ||
| 653 | } | ||
| 654 | |||
| 655 | private void setEast(Spring east) { | ||
| 656 | this.east = east; | ||
| 657 | pushConstraint(EAST, east, true); | ||
| 658 | } | ||
| 659 | |||
| 660 | private Spring getEast() { | ||
| 661 | if (east == null) { | ||
| 662 | east = sum(getX(), getWidth()); | ||
| 663 | } | ||
| 664 | return east; | ||
| 665 | } | ||
| 666 | |||
| 667 | private void setSouth(Spring south) { | ||
| 668 | this.south = south; | ||
| 669 | pushConstraint(SOUTH, south, false); | ||
| 670 | } | ||
| 671 | |||
| 672 | private Spring getSouth() { | ||
| 673 | if (south == null) { | ||
| 674 | south = sum(getY(), getHeight()); | ||
| 675 | } | ||
| 676 | return south; | ||
| 677 | } | ||
| 678 | |||
| 679 | private Spring getHorizontalCenter() { | ||
| 680 | if (horizontalCenter == null) { | ||
| 681 | horizontalCenter = sum(getX(), scale(getWidth(), 0.5f)); | ||
| 682 | } | ||
| 683 | return horizontalCenter; | ||
| 684 | } | ||
| 685 | |||
| 686 | private void setHorizontalCenter(Spring horizontalCenter) { | ||
| 687 | this.horizontalCenter = horizontalCenter; | ||
| 688 | pushConstraint(HORIZONTAL_CENTER, horizontalCenter, true); | ||
| 689 | } | ||
| 690 | |||
| 691 | private Spring getVerticalCenter() { | ||
| 692 | if (verticalCenter == null) { | ||
| 693 | verticalCenter = sum(getY(), scale(getHeight(), 0.5f)); | ||
| 694 | } | ||
| 695 | return verticalCenter; | ||
| 696 | } | ||
| 697 | |||
| 698 | private void setVerticalCenter(Spring verticalCenter) { | ||
| 699 | this.verticalCenter = verticalCenter; | ||
| 700 | pushConstraint(VERTICAL_CENTER, verticalCenter, false); | ||
| 701 | } | ||
| 702 | |||
| 703 | private Spring getBaseline() { | ||
| 704 | if (baseline == null) { | ||
| 705 | baseline = sum(getY(), heightToRelativeBaseline(getHeight())); | ||
| 706 | } | ||
| 707 | return baseline; | ||
| 708 | } | ||
| 709 | |||
| 710 | private void setBaseline(Spring baseline) { | ||
| 711 | this.baseline = baseline; | ||
| 712 | pushConstraint(BASELINE, baseline, false); | ||
| 713 | } | ||
| 714 | |||
| 715 | /** | ||
| 716 | * Sets the spring controlling the specified edge. | ||
| 717 | * The edge must have one of the following values: | ||
| 718 | * <code>SpringLayout.NORTH</code>, | ||
| 719 | * <code>SpringLayout.SOUTH</code>, | ||
| 720 | * <code>SpringLayout.EAST</code>, | ||
| 721 | * <code>SpringLayout.WEST</code>, | ||
| 722 | * <code>SpringLayout.HORIZONTAL_CENTER</code>, | ||
| 723 | * <code>SpringLayout.VERTICAL_CENTER</code>, | ||
| 724 | * <code>SpringLayout.BASELINE</code>, | ||
| 725 | * <code>SpringLayout.WIDTH</code> or | ||
| 726 | * <code>SpringLayout.HEIGHT</code>. | ||
| 727 | * For any other <code>String</code> value passed as the edge, | ||
| 728 | * no action is taken. For a <code>null</code> edge, a | ||
| 729 | * <code>NullPointerException</code> is thrown. | ||
| 730 | * <p/> | ||
| 731 | * <b>Note:</b> This method can affect {@code x} and {@code y} values | ||
| 732 | * previously set for this {@code Constraints}. | ||
| 733 | * | ||
| 734 | * @param edgeName the edge to be set | ||
| 735 | * @param s the spring controlling the specified edge | ||
| 736 | * | ||
| 737 | * @throws NullPointerException if <code>edgeName</code> is <code>null</code> | ||
| 738 | * | ||
| 739 | * @see #getConstraint | ||
| 740 | * @see #NORTH | ||
| 741 | * @see #SOUTH | ||
| 742 | * @see #EAST | ||
| 743 | * @see #WEST | ||
| 744 | * @see #HORIZONTAL_CENTER | ||
| 745 | * @see #VERTICAL_CENTER | ||
| 746 | * @see #BASELINE | ||
| 747 | * @see #WIDTH | ||
| 748 | * @see #HEIGHT | ||
| 749 | * @see SpringLayout.Constraints | ||
| 750 | */ | ||
| 751 | public void setConstraint(String edgeName, Spring s) { | ||
| 752 | edgeName = edgeName.intern(); | ||
| 753 | if (edgeName == WEST) { | ||
| 754 | setX(s); | ||
| 755 | } else if (edgeName == NORTH) { | ||
| 756 | setY(s); | ||
| 757 | } else if (edgeName == EAST) { | ||
| 758 | setEast(s); | ||
| 759 | } else if (edgeName == SOUTH) { | ||
| 760 | setSouth(s); | ||
| 761 | } else if (edgeName == HORIZONTAL_CENTER) { | ||
| 762 | setHorizontalCenter(s); | ||
| 763 | } else if (edgeName == WIDTH) { | ||
| 764 | setWidth(s); | ||
| 765 | } else if (edgeName == HEIGHT) { | ||
| 766 | setHeight(s); | ||
| 767 | } else if (edgeName == VERTICAL_CENTER) { | ||
| 768 | setVerticalCenter(s); | ||
| 769 | } else if (edgeName == BASELINE) { | ||
| 770 | setBaseline(s); | ||
| 771 | } | ||
| 772 | } | ||
| 773 | |||
| 774 | /** | ||
| 775 | * Returns the value of the specified edge, which may be | ||
| 776 | * a derived value, or even <code>null</code>. | ||
| 777 | * The edge must have one of the following values: | ||
| 778 | * <code>SpringLayout.NORTH</code>, | ||
| 779 | * <code>SpringLayout.SOUTH</code>, | ||
| 780 | * <code>SpringLayout.EAST</code>, | ||
| 781 | * <code>SpringLayout.WEST</code>, | ||
| 782 | * <code>SpringLayout.HORIZONTAL_CENTER</code>, | ||
| 783 | * <code>SpringLayout.VERTICAL_CENTER</code>, | ||
| 784 | * <code>SpringLayout.BASELINE</code>, | ||
| 785 | * <code>SpringLayout.WIDTH</code> or | ||
| 786 | * <code>SpringLayout.HEIGHT</code>. | ||
| 787 | * For any other <code>String</code> value passed as the edge, | ||
| 788 | * <code>null</code> will be returned. Throws | ||
| 789 | * <code>NullPointerException</code> for a <code>null</code> edge. | ||
| 790 | * | ||
| 791 | * @param edgeName the edge whose value | ||
| 792 | * is to be returned | ||
| 793 | * | ||
| 794 | * @return the spring controlling the specified edge, may be <code>null</code> | ||
| 795 | * | ||
| 796 | * @throws NullPointerException if <code>edgeName</code> is <code>null</code> | ||
| 797 | * | ||
| 798 | * @see #setConstraint | ||
| 799 | * @see #NORTH | ||
| 800 | * @see #SOUTH | ||
| 801 | * @see #EAST | ||
| 802 | * @see #WEST | ||
| 803 | * @see #HORIZONTAL_CENTER | ||
| 804 | * @see #VERTICAL_CENTER | ||
| 805 | * @see #BASELINE | ||
| 806 | * @see #WIDTH | ||
| 807 | * @see #HEIGHT | ||
| 808 | * @see SpringLayout.Constraints | ||
| 809 | */ | ||
| 810 | public Spring getConstraint(String edgeName) { | ||
| 811 | edgeName = edgeName.intern(); | ||
| 812 | return (edgeName == WEST) ? getX() : | ||
| 813 | (edgeName == NORTH) ? getY() : | ||
| 814 | (edgeName == EAST) ? getEast() : | ||
| 815 | (edgeName == SOUTH) ? getSouth() : | ||
| 816 | (edgeName == WIDTH) ? getWidth() : | ||
| 817 | (edgeName == HEIGHT) ? getHeight() : | ||
| 818 | (edgeName == HORIZONTAL_CENTER) ? getHorizontalCenter() : | ||
| 819 | (edgeName == VERTICAL_CENTER) ? getVerticalCenter() : | ||
| 820 | (edgeName == BASELINE) ? getBaseline() : | ||
| 821 | null; | ||
| 822 | } | ||
| 823 | |||
| 824 | /*pp*/ void reset() { | ||
| 825 | Spring[] allSprings = {x, y, width, height, east, south, | ||
| 826 | horizontalCenter, verticalCenter, baseline}; | ||
| 827 | for (Spring s : allSprings) { | ||
| 828 | if (s != null) { | ||
| 829 | s.setValue(Spring.UNSET); | ||
| 830 | } | ||
| 831 | } | ||
| 832 | } | ||
| 833 | } | ||
| 834 | |||
| 835 | private static class SpringProxy extends Spring { | ||
| 836 | private String edgeName; | ||
| 837 | private Component c; | ||
| 838 | private SpringLayout l; | ||
| 839 | |||
| 840 | public SpringProxy(String edgeName, Component c, SpringLayout l) { | ||
| 841 | this.edgeName = edgeName; | ||
| 842 | this.c = c; | ||
| 843 | this.l = l; | ||
| 844 | } | ||
| 845 | |||
| 846 | private Spring getConstraint() { | ||
| 847 | return l.getConstraints(c).getConstraint(edgeName); | ||
| 848 | } | ||
| 849 | |||
| 850 | public int getMinimumValue() { | ||
| 851 | return getConstraint().getMinimumValue(); | ||
| 852 | } | ||
| 853 | |||
| 854 | public int getPreferredValue() { | ||
| 855 | return getConstraint().getPreferredValue(); | ||
| 856 | } | ||
| 857 | |||
| 858 | public int getMaximumValue() { | ||
| 859 | return getConstraint().getMaximumValue(); | ||
| 860 | } | ||
| 861 | |||
| 862 | public int getValue() { | ||
| 863 | return getConstraint().getValue(); | ||
| 864 | } | ||
| 865 | |||
| 866 | public void setValue(int size) { | ||
| 867 | getConstraint().setValue(size); | ||
| 868 | } | ||
| 869 | |||
| 870 | /*pp*/ boolean isCyclic(SpringLayout l) { | ||
| 871 | return l.isCyclic(getConstraint()); | ||
| 872 | } | ||
| 873 | |||
| 874 | public String toString() { | ||
| 875 | return "SpringProxy for " + edgeName + " edge of " + c.getName() + "."; | ||
| 876 | } | ||
| 877 | } | ||
| 878 | |||
| 879 | /** | ||
| 880 | * Constructs a new <code>SpringLayout</code>. | ||
| 881 | */ | ||
| 882 | public SpringLayout() {} | ||
| 883 | |||
| 884 | private void resetCyclicStatuses() { | ||
| 885 | cyclicSprings = new HashSet<Spring>(); | ||
| 886 | acyclicSprings = new HashSet<Spring>(); | ||
| 887 | } | ||
| 888 | |||
| 889 | private void setParent(Container p) { | ||
| 890 | resetCyclicStatuses(); | ||
| 891 | Constraints pc = getConstraints(p); | ||
| 892 | |||
| 893 | pc.setX(Spring.constant(0)); | ||
| 894 | pc.setY(Spring.constant(0)); | ||
| 895 | // The applyDefaults() method automatically adds width and | ||
| 896 | // height springs that delegate their calculations to the | ||
| 897 | // getMinimumSize(), getPreferredSize() and getMaximumSize() | ||
| 898 | // methods of the relevant component. In the case of the | ||
| 899 | // parent this will cause an infinite loop since these | ||
| 900 | // methods, in turn, delegate their calculations to the | ||
| 901 | // layout manager. Check for this case and replace the | ||
| 902 | // the springs that would cause this problem with a | ||
| 903 | // constant springs that supply default values. | ||
| 904 | Spring width = pc.getWidth(); | ||
| 905 | if (width instanceof Spring.WidthSpring && ((Spring.WidthSpring)width).c == p) { | ||
| 906 | pc.setWidth(Spring.constant(0, 0, Integer.MAX_VALUE)); | ||
| 907 | } | ||
| 908 | Spring height = pc.getHeight(); | ||
| 909 | if (height instanceof Spring.HeightSpring && ((Spring.HeightSpring)height).c == p) { | ||
| 910 | pc.setHeight(Spring.constant(0, 0, Integer.MAX_VALUE)); | ||
| 911 | } | ||
| 912 | } | ||
| 913 | |||
| 914 | /*pp*/ boolean isCyclic(Spring s) { | ||
| 915 | if (s == null) { | ||
| 916 | return false; | ||
| 917 | } | ||
| 918 | if (cyclicSprings.contains(s)) { | ||
| 919 | return true; | ||
| 920 | } | ||
| 921 | if (acyclicSprings.contains(s)) { | ||
| 922 | return false; | ||
| 923 | } | ||
| 924 | cyclicSprings.add(s); | ||
| 925 | boolean result = s.isCyclic(this); | ||
| 926 | if (!result) { | ||
| 927 | acyclicSprings.add(s); | ||
| 928 | cyclicSprings.remove(s); | ||
| 929 | } | ||
| 930 | else { | ||
| 931 | System.err.println(s + " is cyclic. "); | ||
| 932 | } | ||
| 933 | return result; | ||
| 934 | } | ||
| 935 | |||
| 936 | private Spring abandonCycles(Spring s) { | ||
| 937 | return isCyclic(s) ? cyclicReference : s; | ||
| 938 | } | ||
| 939 | |||
| 940 | // LayoutManager methods. | ||
| 941 | |||
| 942 | /** | ||
| 943 | * Has no effect, | ||
| 944 | * since this layout manager does not | ||
| 945 | * use a per-component string. | ||
| 946 | */ | ||
| 947 | public void addLayoutComponent(String name, Component c) {} | ||
| 948 | |||
| 949 | /** | ||
| 950 | * Removes the constraints associated with the specified component. | ||
| 951 | * | ||
| 952 | * @param c the component being removed from the container | ||
| 953 | */ | ||
| 954 | public void removeLayoutComponent(Component c) { | ||
| 955 | componentConstraints.remove(c); | ||
| 956 | } | ||
| 957 | |||
| 958 | private static Dimension addInsets(int width, int height, Container p) { | ||
| 959 | Insets i = p.getInsets(); | ||
| 960 | return new Dimension(width + i.left + i.right, height + i.top + i.bottom); | ||
| 961 | } | ||
| 962 | |||
| 963 | public Dimension minimumLayoutSize(Container parent) { | ||
| 964 | setParent(parent); | ||
| 965 | Constraints pc = getConstraints(parent); | ||
| 966 | return addInsets(abandonCycles(pc.getWidth()).getMinimumValue(), | ||
| 967 | abandonCycles(pc.getHeight()).getMinimumValue(), | ||
| 968 | parent); | ||
| 969 | } | ||
| 970 | |||
| 971 | public Dimension preferredLayoutSize(Container parent) { | ||
| 972 | setParent(parent); | ||
| 973 | Constraints pc = getConstraints(parent); | ||
| 974 | return addInsets(abandonCycles(pc.getWidth()).getPreferredValue(), | ||
| 975 | abandonCycles(pc.getHeight()).getPreferredValue(), | ||
| 976 | parent); | ||
| 977 | } | ||
| 978 | |||
| 979 | // LayoutManager2 methods. | ||
| 980 | |||
| 981 | public Dimension maximumLayoutSize(Container parent) { | ||
| 982 | setParent(parent); | ||
| 983 | Constraints pc = getConstraints(parent); | ||
| 984 | return addInsets(abandonCycles(pc.getWidth()).getMaximumValue(), | ||
| 985 | abandonCycles(pc.getHeight()).getMaximumValue(), | ||
| 986 | parent); | ||
| 987 | } | ||
| 988 | |||
| 989 | /** | ||
| 990 | * If <code>constraints</code> is an instance of | ||
| 991 | * <code>SpringLayout.Constraints</code>, | ||
| 992 | * associates the constraints with the specified component. | ||
| 993 | * <p> | ||
| 994 | * @param component the component being added | ||
| 995 | * @param constraints the component's constraints | ||
| 996 | * | ||
| 997 | * @see SpringLayout.Constraints | ||
| 998 | */ | ||
| 999 | public void addLayoutComponent(Component component, Object constraints) { | ||
| 1000 | if (constraints instanceof Constraints) { | ||
| 1001 | putConstraints(component, (Constraints)constraints); | ||
| 1002 | } | ||
| 1003 | } | ||
| 1004 | |||
| 1005 | /** | ||
| 1006 | * Returns 0.5f (centered). | ||
| 1007 | */ | ||
| 1008 | public float getLayoutAlignmentX(Container p) { | ||
| 1009 | return 0.5f; | ||
| 1010 | } | ||
| 1011 | |||
| 1012 | /** | ||
| 1013 | * Returns 0.5f (centered). | ||
| 1014 | */ | ||
| 1015 | public float getLayoutAlignmentY(Container p) { | ||
| 1016 | return 0.5f; | ||
| 1017 | } | ||
| 1018 | |||
| 1019 | public void invalidateLayout(Container p) {} | ||
| 1020 | |||
| 1021 | // End of LayoutManger2 methods | ||
| 1022 | |||
| 1023 | /** | ||
| 1024 | * Links edge <code>e1</code> of component <code>c1</code> to | ||
| 1025 | * edge <code>e2</code> of component <code>c2</code>, | ||
| 1026 | * with a fixed distance between the edges. This | ||
| 1027 | * constraint will cause the assignment | ||
| 1028 | * <pre> | ||
| 1029 | * value(e1, c1) = value(e2, c2) + pad</pre> | ||
| 1030 | * to take place during all subsequent layout operations. | ||
| 1031 | * <p> | ||
| 1032 | * @param e1 the edge of the dependent | ||
| 1033 | * @param c1 the component of the dependent | ||
| 1034 | * @param pad the fixed distance between dependent and anchor | ||
| 1035 | * @param e2 the edge of the anchor | ||
| 1036 | * @param c2 the component of the anchor | ||
| 1037 | * | ||
| 1038 | * @see #putConstraint(String, Component, Spring, String, Component) | ||
| 1039 | */ | ||
| 1040 | public void putConstraint(String e1, Component c1, int pad, String e2, Component c2) { | ||
| 1041 | putConstraint(e1, c1, Spring.constant(pad), e2, c2); | ||
| 1042 | } | ||
| 1043 | |||
| 1044 | /** | ||
| 1045 | * Links edge <code>e1</code> of component <code>c1</code> to | ||
| 1046 | * edge <code>e2</code> of component <code>c2</code>. As edge | ||
| 1047 | * <code>(e2, c2)</code> changes value, edge <code>(e1, c1)</code> will | ||
| 1048 | * be calculated by taking the (spring) sum of <code>(e2, c2)</code> | ||
| 1049 | * and <code>s</code>. | ||
| 1050 | * Each edge must have one of the following values: | ||
| 1051 | * <code>SpringLayout.NORTH</code>, | ||
| 1052 | * <code>SpringLayout.SOUTH</code>, | ||
| 1053 | * <code>SpringLayout.EAST</code>, | ||
| 1054 | * <code>SpringLayout.WEST</code>, | ||
| 1055 | * <code>SpringLayout.VERTICAL_CENTER</code>, | ||
| 1056 | * <code>SpringLayout.HORIZONTAL_CENTER</code> or | ||
| 1057 | * <code>SpringLayout.BASELINE</code>. | ||
| 1058 | * <p> | ||
| 1059 | * @param e1 the edge of the dependent | ||
| 1060 | * @param c1 the component of the dependent | ||
| 1061 | * @param s the spring linking dependent and anchor | ||
| 1062 | * @param e2 the edge of the anchor | ||
| 1063 | * @param c2 the component of the anchor | ||
| 1064 | * | ||
| 1065 | * @see #putConstraint(String, Component, int, String, Component) | ||
| 1066 | * @see #NORTH | ||
| 1067 | * @see #SOUTH | ||
| 1068 | * @see #EAST | ||
| 1069 | * @see #WEST | ||
| 1070 | * @see #VERTICAL_CENTER | ||
| 1071 | * @see #HORIZONTAL_CENTER | ||
| 1072 | * @see #BASELINE | ||
| 1073 | */ | ||
| 1074 | public void putConstraint(String e1, Component c1, Spring s, String e2, Component c2) { | ||
| 1075 | putConstraint(e1, c1, Spring.sum(s, getConstraint(e2, c2))); | ||
| 1076 | } | ||
| 1077 | |||
| 1078 | private void putConstraint(String e, Component c, Spring s) { | ||
| 1079 | if (s != null) { | ||
| 1080 | getConstraints(c).setConstraint(e, s); | ||
| 1081 | } | ||
| 1082 | } | ||
| 1083 | |||
| 1084 | private Constraints applyDefaults(Component c, Constraints constraints) { | ||
| 1085 | if (constraints == null) { | ||
| 1086 | constraints = new Constraints(); | ||
| 1087 | } | ||
| 1088 | if (constraints.c == null) { | ||
| 1089 | constraints.c = c; | ||
| 1090 | } | ||
| 1091 | if (constraints.horizontalHistory.size() < 2) { | ||
| 1092 | applyDefaults(constraints, WEST, Spring.constant(0), WIDTH, | ||
| 1093 | Spring.width(c), constraints.horizontalHistory); | ||
| 1094 | } | ||
| 1095 | if (constraints.verticalHistory.size() < 2) { | ||
| 1096 | applyDefaults(constraints, NORTH, Spring.constant(0), HEIGHT, | ||
| 1097 | Spring.height(c), constraints.verticalHistory); | ||
| 1098 | } | ||
| 1099 | return constraints; | ||
| 1100 | } | ||
| 1101 | |||
| 1102 | private void applyDefaults(Constraints constraints, String name1, | ||
| 1103 | Spring spring1, String name2, Spring spring2, | ||
| 1104 | List<String> history) { | ||
| 1105 | if (history.size() == 0) { | ||
| 1106 | constraints.setConstraint(name1, spring1); | ||
| 1107 | constraints.setConstraint(name2, spring2); | ||
| 1108 | } else { | ||
| 1109 | // At this point there must be exactly one constraint defined already. | ||
| 1110 | // Check width/height first. | ||
| 1111 | if (constraints.getConstraint(name2) == null) { | ||
| 1112 | constraints.setConstraint(name2, spring2); | ||
| 1113 | } else { | ||
| 1114 | // If width/height is already defined, install a default for x/y. | ||
| 1115 | constraints.setConstraint(name1, spring1); | ||
| 1116 | } | ||
| 1117 | // Either way, leave the user's constraint topmost on the stack. | ||
| 1118 | Collections.rotate(history, 1); | ||
| 1119 | } | ||
| 1120 | } | ||
| 1121 | |||
| 1122 | private void putConstraints(Component component, Constraints constraints) { | ||
| 1123 | componentConstraints.put(component, applyDefaults(component, constraints)); | ||
| 1124 | } | ||
| 1125 | |||
| 1126 | /** | ||
| 1127 | * Returns the constraints for the specified component. | ||
| 1128 | * Note that, | ||
| 1129 | * unlike the <code>GridBagLayout</code> | ||
| 1130 | * <code>getConstraints</code> method, | ||
| 1131 | * this method does not clone constraints. | ||
| 1132 | * If no constraints | ||
| 1133 | * have been associated with this component, | ||
| 1134 | * this method | ||
| 1135 | * returns a default constraints object positioned at | ||
| 1136 | * 0,0 relative to the parent's Insets and its width/height | ||
| 1137 | * constrained to the minimum, maximum, and preferred sizes of the | ||
| 1138 | * component. The size characteristics | ||
| 1139 | * are not frozen at the time this method is called; | ||
| 1140 | * instead this method returns a constraints object | ||
| 1141 | * whose characteristics track the characteristics | ||
| 1142 | * of the component as they change. | ||
| 1143 | * | ||
| 1144 | * @param c the component whose constraints will be returned | ||
| 1145 | * | ||
| 1146 | * @return the constraints for the specified component | ||
| 1147 | */ | ||
| 1148 | public Constraints getConstraints(Component c) { | ||
| 1149 | Constraints result = componentConstraints.get(c); | ||
| 1150 | if (result == null) { | ||
| 1151 | if (c instanceof javax.swing.JComponent) { | ||
| 1152 | Object cp = ((javax.swing.JComponent)c).getClientProperty(SpringLayout.class); | ||
| 1153 | if (cp instanceof Constraints) { | ||
| 1154 | return applyDefaults(c, (Constraints)cp); | ||
| 1155 | } | ||
| 1156 | } | ||
| 1157 | result = new Constraints(); | ||
| 1158 | putConstraints(c, result); | ||
| 1159 | } | ||
| 1160 | return result; | ||
| 1161 | } | ||
| 1162 | |||
| 1163 | /** | ||
| 1164 | * Returns the spring controlling the distance between | ||
| 1165 | * the specified edge of | ||
| 1166 | * the component and the top or left edge of its parent. This | ||
| 1167 | * method, instead of returning the current binding for the | ||
| 1168 | * edge, returns a proxy that tracks the characteristics | ||
| 1169 | * of the edge even if the edge is subsequently rebound. | ||
| 1170 | * Proxies are intended to be used in builder envonments | ||
| 1171 | * where it is useful to allow the user to define the | ||
| 1172 | * constraints for a layout in any order. Proxies do, however, | ||
| 1173 | * provide the means to create cyclic dependencies amongst | ||
| 1174 | * the constraints of a layout. Such cycles are detected | ||
| 1175 | * internally by <code>SpringLayout</code> so that | ||
| 1176 | * the layout operation always terminates. | ||
| 1177 | * | ||
| 1178 | * @param edgeName must be one of | ||
| 1179 | * <code>SpringLayout.NORTH</code>, | ||
| 1180 | * <code>SpringLayout.SOUTH</code>, | ||
| 1181 | * <code>SpringLayout.EAST</code>, | ||
| 1182 | * <code>SpringLayout.WEST</code>, | ||
| 1183 | * <code>SpringLayout.VERTICAL_CENTER</code>, | ||
| 1184 | * <code>SpringLayout.HORIZONTAL_CENTER</code> or | ||
| 1185 | * <code>SpringLayout.BASELINE</code> | ||
| 1186 | * @param c the component whose edge spring is desired | ||
| 1187 | * | ||
| 1188 | * @return a proxy for the spring controlling the distance between the | ||
| 1189 | * specified edge and the top or left edge of its parent | ||
| 1190 | * | ||
| 1191 | * @see #NORTH | ||
| 1192 | * @see #SOUTH | ||
| 1193 | * @see #EAST | ||
| 1194 | * @see #WEST | ||
| 1195 | * @see #VERTICAL_CENTER | ||
| 1196 | * @see #HORIZONTAL_CENTER | ||
| 1197 | * @see #BASELINE | ||
| 1198 | */ | ||
| 1199 | public Spring getConstraint(String edgeName, Component c) { | ||
| 1200 | // The interning here is unnecessary; it was added for efficiency. | ||
| 1201 | edgeName = edgeName.intern(); | ||
| 1202 | return new SpringProxy(edgeName, c, this); | ||
| 1203 | } | ||
| 1204 | |||
| 1205 | public void layoutContainer(Container parent) { | ||
| 1206 | setParent(parent); | ||
| 1207 | |||
| 1208 | int n = parent.getComponentCount(); | ||
| 1209 | getConstraints(parent).reset(); | ||
| 1210 | for (int i = 0 ; i < n ; i++) { | ||
| 1211 | getConstraints(parent.getComponent(i)).reset(); | ||
| 1212 | } | ||
| 1213 | |||
| 1214 | Insets insets = parent.getInsets(); | ||
| 1215 | Constraints pc = getConstraints(parent); | ||
| 1216 | abandonCycles(pc.getX()).setValue(0); | ||
| 1217 | abandonCycles(pc.getY()).setValue(0); | ||
| 1218 | abandonCycles(pc.getWidth()).setValue(parent.getWidth() - | ||
| 1219 | insets.left - insets.right); | ||
| 1220 | abandonCycles(pc.getHeight()).setValue(parent.getHeight() - | ||
| 1221 | insets.top - insets.bottom); | ||
| 1222 | |||
| 1223 | for (int i = 0 ; i < n ; i++) { | ||
| 1224 | Component c = parent.getComponent(i); | ||
| 1225 | Constraints cc = getConstraints(c); | ||
| 1226 | int x = abandonCycles(cc.getX()).getValue(); | ||
| 1227 | int y = abandonCycles(cc.getY()).getValue(); | ||
| 1228 | int width = abandonCycles(cc.getWidth()).getValue(); | ||
| 1229 | int height = abandonCycles(cc.getHeight()).getValue(); | ||
| 1230 | c.setBounds(insets.left + x, insets.top + y, width, height); | ||
| 1231 | } | ||
| 1232 | } | ||
| 1233 | } | ||