J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | |
| 27 | package javax.swing; |
| 28 | |
| 29 | import java.awt.*; |
| 30 | import java.awt.event.*; |
| 31 | import java.beans.ConstructorProperties; |
| 32 | import java.util.Locale; |
| 33 | import java.io.Serializable; |
| 34 | import javax.accessibility.*; |
| 35 | |
| 36 | /** |
| 37 | * A lightweight container |
| 38 | * that uses a BoxLayout object as its layout manager. |
| 39 | * Box provides several class methods |
| 40 | * that are useful for containers using BoxLayout -- |
| 41 | * even non-Box containers. |
| 42 | * |
| 43 | * <p> |
| 44 | * The <code>Box</code> class can create several kinds |
| 45 | * of invisible components |
| 46 | * that affect layout: |
| 47 | * glue, struts, and rigid areas. |
| 48 | * If all the components your <code>Box</code> contains |
| 49 | * have a fixed size, |
| 50 | * you might want to use a glue component |
| 51 | * (returned by <code>createGlue</code>) |
| 52 | * to control the components' positions. |
| 53 | * If you need a fixed amount of space between two components, |
| 54 | * try using a strut |
| 55 | * (<code>createHorizontalStrut</code> or <code>createVerticalStrut</code>). |
| 56 | * If you need an invisible component |
| 57 | * that always takes up the same amount of space, |
| 58 | * get it by invoking <code>createRigidArea</code>. |
| 59 | * <p> |
| 60 | * If you are implementing a <code>BoxLayout</code> you |
| 61 | * can find further information and examples in |
| 62 | * <a |
| 63 | href="http://java.sun.com/docs/books/tutorial/uiswing/layout/box.html">How to Use BoxLayout</a>, |
| 64 | * a section in <em>The Java Tutorial.</em> |
| 65 | * <p> |
| 66 | * <strong>Warning:</strong> |
| 67 | * Serialized objects of this class will not be compatible with |
| 68 | * future Swing releases. The current serialization support is |
| 69 | * appropriate for short term storage or RMI between applications running |
| 70 | * the same version of Swing. As of 1.4, support for long term storage |
| 71 | * of all JavaBeans<sup><font size="-2">TM</font></sup> |
| 72 | * has been added to the <code>java.beans</code> package. |
| 73 | * Please see {@link java.beans.XMLEncoder}. |
| 74 | * |
| 75 | * @see BoxLayout |
| 76 | * |
| 77 | * @author Timothy Prinzing |
| 78 | */ |
| 79 | public class Box extends JComponent implements Accessible { |
| 80 | |
| 81 | /** |
| 82 | * Creates a <code>Box</code> that displays its components |
| 83 | * along the the specified axis. |
| 84 | * |
| 85 | * @param axis can be {@link BoxLayout#X_AXIS}, |
| 86 | * {@link BoxLayout#Y_AXIS}, |
| 87 | * {@link BoxLayout#LINE_AXIS} or |
| 88 | * {@link BoxLayout#PAGE_AXIS}. |
| 89 | * @throws AWTError if the <code>axis</code> is invalid |
| 90 | * @see #createHorizontalBox |
| 91 | * @see #createVerticalBox |
| 92 | */ |
| 93 | public Box(int axis) { |
| 94 | super(); |
| 95 | super.setLayout(new BoxLayout(this, axis)); |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Creates a <code>Box</code> that displays its components |
| 100 | * from left to right. If you want a <code>Box</code> that |
| 101 | * respects the component orientation you should create the |
| 102 | * <code>Box</code> using the constructor and pass in |
| 103 | * <code>BoxLayout.LINE_AXIS</code>, eg: |
| 104 | * <pre> |
| 105 | * Box lineBox = new Box(BoxLayout.LINE_AXIS); |
| 106 | * </pre> |
| 107 | * |
| 108 | * @return the box |
| 109 | */ |
| 110 | public static Box createHorizontalBox() { |
| 111 | return new Box(BoxLayout.X_AXIS); |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * Creates a <code>Box</code> that displays its components |
| 116 | * from top to bottom. If you want a <code>Box</code> that |
| 117 | * respects the component orientation you should create the |
| 118 | * <code>Box</code> using the constructor and pass in |
| 119 | * <code>BoxLayout.PAGE_AXIS</code>, eg: |
| 120 | * <pre> |
| 121 | * Box lineBox = new Box(BoxLayout.PAGE_AXIS); |
| 122 | * </pre> |
| 123 | * |
| 124 | * @return the box |
| 125 | */ |
| 126 | public static Box createVerticalBox() { |
| 127 | return new Box(BoxLayout.Y_AXIS); |
| 128 | } |
| 129 | |
| 130 | /** |
| 131 | * Creates an invisible component that's always the specified size. |
| 132 | * <!-- WHEN WOULD YOU USE THIS AS OPPOSED TO A STRUT? --> |
| 133 | * |
| 134 | * @param d the dimensions of the invisible component |
| 135 | * @return the component |
| 136 | * @see #createGlue |
| 137 | * @see #createHorizontalStrut |
| 138 | * @see #createVerticalStrut |
| 139 | */ |
| 140 | public static Component createRigidArea(Dimension d) { |
| 141 | return new Filler(d, d, d); |
| 142 | } |
| 143 | |
| 144 | /** |
| 145 | * Creates an invisible, fixed-width component. |
| 146 | * In a horizontal box, |
| 147 | * you typically use this method |
| 148 | * to force a certain amount of space between two components. |
| 149 | * In a vertical box, |
| 150 | * you might use this method |
| 151 | * to force the box to be at least the specified width. |
| 152 | * The invisible component has no height |
| 153 | * unless excess space is available, |
| 154 | * in which case it takes its share of available space, |
| 155 | * just like any other component that has no maximum height. |
| 156 | * |
| 157 | * @param width the width of the invisible component, in pixels >= 0 |
| 158 | * @return the component |
| 159 | * @see #createVerticalStrut |
| 160 | * @see #createGlue |
| 161 | * @see #createRigidArea |
| 162 | */ |
| 163 | public static Component createHorizontalStrut(int width) { |
| 164 | return new Filler(new Dimension(width,0), new Dimension(width,0), |
| 165 | new Dimension(width, Short.MAX_VALUE)); |
| 166 | } |
| 167 | |
| 168 | /** |
| 169 | * Creates an invisible, fixed-height component. |
| 170 | * In a vertical box, |
| 171 | * you typically use this method |
| 172 | * to force a certain amount of space between two components. |
| 173 | * In a horizontal box, |
| 174 | * you might use this method |
| 175 | * to force the box to be at least the specified height. |
| 176 | * The invisible component has no width |
| 177 | * unless excess space is available, |
| 178 | * in which case it takes its share of available space, |
| 179 | * just like any other component that has no maximum width. |
| 180 | * |
| 181 | * @param height the height of the invisible component, in pixels >= 0 |
| 182 | * @return the component |
| 183 | * @see #createHorizontalStrut |
| 184 | * @see #createGlue |
| 185 | * @see #createRigidArea |
| 186 | */ |
| 187 | public static Component createVerticalStrut(int height) { |
| 188 | return new Filler(new Dimension(0,height), new Dimension(0,height), |
| 189 | new Dimension(Short.MAX_VALUE, height)); |
| 190 | } |
| 191 | |
| 192 | /** |
| 193 | * Creates an invisible "glue" component |
| 194 | * that can be useful in a Box |
| 195 | * whose visible components have a maximum width |
| 196 | * (for a horizontal box) |
| 197 | * or height (for a vertical box). |
| 198 | * You can think of the glue component |
| 199 | * as being a gooey substance |
| 200 | * that expands as much as necessary |
| 201 | * to fill the space between its neighboring components. |
| 202 | * |
| 203 | * <p> |
| 204 | * |
| 205 | * For example, suppose you have |
| 206 | * a horizontal box that contains two fixed-size components. |
| 207 | * If the box gets extra space, |
| 208 | * the fixed-size components won't become larger, |
| 209 | * so where does the extra space go? |
| 210 | * Without glue, |
| 211 | * the extra space goes to the right of the second component. |
| 212 | * If you put glue between the fixed-size components, |
| 213 | * then the extra space goes there. |
| 214 | * If you put glue before the first fixed-size component, |
| 215 | * the extra space goes there, |
| 216 | * and the fixed-size components are shoved against the right |
| 217 | * edge of the box. |
| 218 | * If you put glue before the first fixed-size component |
| 219 | * and after the second fixed-size component, |
| 220 | * the fixed-size components are centered in the box. |
| 221 | * |
| 222 | * <p> |
| 223 | * |
| 224 | * To use glue, |
| 225 | * call <code>Box.createGlue</code> |
| 226 | * and add the returned component to a container. |
| 227 | * The glue component has no minimum or preferred size, |
| 228 | * so it takes no space unless excess space is available. |
| 229 | * If excess space is available, |
| 230 | * then the glue component takes its share of available |
| 231 | * horizontal or vertical space, |
| 232 | * just like any other component that has no maximum width or height. |
| 233 | * |
| 234 | * @return the component |
| 235 | */ |
| 236 | public static Component createGlue() { |
| 237 | return new Filler(new Dimension(0,0), new Dimension(0,0), |
| 238 | new Dimension(Short.MAX_VALUE, Short.MAX_VALUE)); |
| 239 | } |
| 240 | |
| 241 | /** |
| 242 | * Creates a horizontal glue component. |
| 243 | * |
| 244 | * @return the component |
| 245 | */ |
| 246 | public static Component createHorizontalGlue() { |
| 247 | return new Filler(new Dimension(0,0), new Dimension(0,0), |
| 248 | new Dimension(Short.MAX_VALUE, 0)); |
| 249 | } |
| 250 | |
| 251 | /** |
| 252 | * Creates a vertical glue component. |
| 253 | * |
| 254 | * @return the component |
| 255 | */ |
| 256 | public static Component createVerticalGlue() { |
| 257 | return new Filler(new Dimension(0,0), new Dimension(0,0), |
| 258 | new Dimension(0, Short.MAX_VALUE)); |
| 259 | } |
| 260 | |
| 261 | /** |
| 262 | * Throws an AWTError, since a Box can use only a BoxLayout. |
| 263 | * |
| 264 | * @param l the layout manager to use |
| 265 | */ |
| 266 | public void setLayout(LayoutManager l) { |
| 267 | throw new AWTError("Illegal request"); |
| 268 | } |
| 269 | |
| 270 | /** |
| 271 | * Paints this <code>Box</code>. If this <code>Box</code> has a UI this |
| 272 | * method invokes super's implementation, otherwise if this |
| 273 | * <code>Box</code> is opaque the <code>Graphics</code> is filled |
| 274 | * using the background. |
| 275 | * |
| 276 | * @param g the <code>Graphics</code> to paint to |
| 277 | * @throws NullPointerException if <code>g</code> is null |
| 278 | * @since 1.6 |
| 279 | */ |
| 280 | protected void paintComponent(Graphics g) { |
| 281 | if (ui != null) { |
| 282 | // On the off chance some one created a UI, honor it |
| 283 | super.paintComponent(g); |
| 284 | } else if (isOpaque()) { |
| 285 | g.setColor(getBackground()); |
| 286 | g.fillRect(0, 0, getWidth(), getHeight()); |
| 287 | } |
| 288 | } |
| 289 | |
| 290 | |
| 291 | /** |
| 292 | * An implementation of a lightweight component that participates in |
| 293 | * layout but has no view. |
| 294 | * <p> |
| 295 | * <strong>Warning:</strong> |
| 296 | * Serialized objects of this class will not be compatible with |
| 297 | * future Swing releases. The current serialization support is |
| 298 | * appropriate for short term storage or RMI between applications running |
| 299 | * the same version of Swing. As of 1.4, support for long term storage |
| 300 | * of all JavaBeans<sup><font size="-2">TM</font></sup> |
| 301 | * has been added to the <code>java.beans</code> package. |
| 302 | * Please see {@link java.beans.XMLEncoder}. |
| 303 | */ |
| 304 | public static class Filler extends JComponent implements Accessible { |
| 305 | |
| 306 | /** |
| 307 | * Constructor to create shape with the given size ranges. |
| 308 | * |
| 309 | * @param min Minimum size |
| 310 | * @param pref Preferred size |
| 311 | * @param max Maximum size |
| 312 | */ |
| 313 | @ConstructorProperties({"minimumSize", "preferredSize", "maximumSize"}) |
| 314 | public Filler(Dimension min, Dimension pref, Dimension max) { |
| 315 | setMinimumSize(min); |
| 316 | setPreferredSize(pref); |
| 317 | setMaximumSize(max); |
| 318 | } |
| 319 | |
| 320 | /** |
| 321 | * Change the size requests for this shape. An invalidate() is |
| 322 | * propagated upward as a result so that layout will eventually |
| 323 | * happen with using the new sizes. |
| 324 | * |
| 325 | * @param min Value to return for getMinimumSize |
| 326 | * @param pref Value to return for getPreferredSize |
| 327 | * @param max Value to return for getMaximumSize |
| 328 | */ |
| 329 | public void changeShape(Dimension min, Dimension pref, Dimension max) { |
| 330 | setMinimumSize(min); |
| 331 | setPreferredSize(pref); |
| 332 | setMaximumSize(max); |
| 333 | revalidate(); |
| 334 | } |
| 335 | |
| 336 | // ---- Component methods ------------------------------------------ |
| 337 | |
| 338 | /** |
| 339 | * Paints this <code>Filler</code>. If this |
| 340 | * <code>Filler</code> has a UI this method invokes super's |
| 341 | * implementation, otherwise if this <code>Filler</code> is |
| 342 | * opaque the <code>Graphics</code> is filled using the |
| 343 | * background. |
| 344 | * |
| 345 | * @param g the <code>Graphics</code> to paint to |
| 346 | * @throws NullPointerException if <code>g</code> is null |
| 347 | * @since 1.6 |
| 348 | */ |
| 349 | protected void paintComponent(Graphics g) { |
| 350 | if (ui != null) { |
| 351 | // On the off chance some one created a UI, honor it |
| 352 | super.paintComponent(g); |
| 353 | } else if (isOpaque()) { |
| 354 | g.setColor(getBackground()); |
| 355 | g.fillRect(0, 0, getWidth(), getHeight()); |
| 356 | } |
| 357 | } |
| 358 | |
| 359 | ///////////////// |
| 360 | // Accessibility support for Box$Filler |
| 361 | //////////////// |
| 362 | |
| 363 | /** |
| 364 | * Gets the AccessibleContext associated with this Box.Filler. |
| 365 | * For box fillers, the AccessibleContext takes the form of an |
| 366 | * AccessibleBoxFiller. |
| 367 | * A new AccessibleAWTBoxFiller instance is created if necessary. |
| 368 | * |
| 369 | * @return an AccessibleBoxFiller that serves as the |
| 370 | * AccessibleContext of this Box.Filler. |
| 371 | */ |
| 372 | public AccessibleContext getAccessibleContext() { |
| 373 | if (accessibleContext == null) { |
| 374 | accessibleContext = new AccessibleBoxFiller(); |
| 375 | } |
| 376 | return accessibleContext; |
| 377 | } |
| 378 | |
| 379 | /** |
| 380 | * This class implements accessibility support for the |
| 381 | * <code>Box.Filler</code> class. |
| 382 | */ |
| 383 | protected class AccessibleBoxFiller extends AccessibleAWTComponent { |
| 384 | // AccessibleContext methods |
| 385 | // |
| 386 | /** |
| 387 | * Gets the role of this object. |
| 388 | * |
| 389 | * @return an instance of AccessibleRole describing the role of |
| 390 | * the object (AccessibleRole.FILLER) |
| 391 | * @see AccessibleRole |
| 392 | */ |
| 393 | public AccessibleRole getAccessibleRole() { |
| 394 | return AccessibleRole.FILLER; |
| 395 | } |
| 396 | } |
| 397 | } |
| 398 | |
| 399 | ///////////////// |
| 400 | // Accessibility support for Box |
| 401 | //////////////// |
| 402 | |
| 403 | /** |
| 404 | * Gets the AccessibleContext associated with this Box. |
| 405 | * For boxes, the AccessibleContext takes the form of an |
| 406 | * AccessibleBox. |
| 407 | * A new AccessibleAWTBox instance is created if necessary. |
| 408 | * |
| 409 | * @return an AccessibleBox that serves as the |
| 410 | * AccessibleContext of this Box |
| 411 | */ |
| 412 | public AccessibleContext getAccessibleContext() { |
| 413 | if (accessibleContext == null) { |
| 414 | accessibleContext = new AccessibleBox(); |
| 415 | } |
| 416 | return accessibleContext; |
| 417 | } |
| 418 | |
| 419 | /** |
| 420 | * This class implements accessibility support for the |
| 421 | * <code>Box</code> class. |
| 422 | */ |
| 423 | protected class AccessibleBox extends AccessibleAWTContainer { |
| 424 | // AccessibleContext methods |
| 425 | // |
| 426 | /** |
| 427 | * Gets the role of this object. |
| 428 | * |
| 429 | * @return an instance of AccessibleRole describing the role of the |
| 430 | * object (AccessibleRole.FILLER) |
| 431 | * @see AccessibleRole |
| 432 | */ |
| 433 | public AccessibleRole getAccessibleRole() { |
| 434 | return AccessibleRole.FILLER; |
| 435 | } |
| 436 | } // inner class AccessibleBox |
| 437 | } |