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.awt.peer.ScrollbarPeer; |
| 28 | import java.awt.event.*; |
| 29 | import java.util.EventListener; |
| 30 | import java.io.ObjectOutputStream; |
| 31 | import java.io.ObjectInputStream; |
| 32 | import java.io.IOException; |
| 33 | import javax.accessibility.*; |
| 34 | |
| 35 | |
| 36 | /** |
| 37 | * The <code>Scrollbar</code> class embodies a scroll bar, a |
| 38 | * familiar user-interface object. A scroll bar provides a |
| 39 | * convenient means for allowing a user to select from a |
| 40 | * range of values. The following three vertical |
| 41 | * scroll bars could be used as slider controls to pick |
| 42 | * the red, green, and blue components of a color: |
| 43 | * <p> |
| 44 | * <img src="doc-files/Scrollbar-1.gif" alt="Image shows 3 vertical sliders, side-by-side." |
| 45 | * ALIGN=center HSPACE=10 VSPACE=7> |
| 46 | * <p> |
| 47 | * Each scroll bar in this example could be created with |
| 48 | * code similar to the following: |
| 49 | * <p> |
| 50 | * <hr><blockquote><pre> |
| 51 | * redSlider=new Scrollbar(Scrollbar.VERTICAL, 0, 1, 0, 255); |
| 52 | * add(redSlider); |
| 53 | * </pre></blockquote><hr> |
| 54 | * <p> |
| 55 | * Alternatively, a scroll bar can represent a range of values. For |
| 56 | * example, if a scroll bar is used for scrolling through text, the |
| 57 | * width of the "bubble" (also called the "thumb" or "scroll box") |
| 58 | * can be used to represent the amount of text that is visible. |
| 59 | * Here is an example of a scroll bar that represents a range: |
| 60 | * <p> |
| 61 | * <img src="doc-files/Scrollbar-2.gif" |
| 62 | * alt="Image shows horizontal slider with starting range of 0 and ending range of 300. The slider thumb is labeled 60." |
| 63 | * ALIGN=center HSPACE=10 VSPACE=7> |
| 64 | * <p> |
| 65 | * The value range represented by the bubble in this example |
| 66 | * is the <em>visible amount</em>. The horizontal scroll bar |
| 67 | * in this example could be created with code like the following: |
| 68 | * <p> |
| 69 | * <hr><blockquote><pre> |
| 70 | * ranger = new Scrollbar(Scrollbar.HORIZONTAL, 0, 60, 0, 300); |
| 71 | * add(ranger); |
| 72 | * </pre></blockquote><hr> |
| 73 | * <p> |
| 74 | * Note that the actual maximum value of the scroll bar is the |
| 75 | * <code>maximum</code> minus the <code>visible amount</code>. |
| 76 | * In the previous example, because the <code>maximum</code> is |
| 77 | * 300 and the <code>visible amount</code> is 60, the actual maximum |
| 78 | * value is 240. The range of the scrollbar track is 0 - 300. |
| 79 | * The left side of the bubble indicates the value of the |
| 80 | * scroll bar. |
| 81 | * <p> |
| 82 | * Normally, the user changes the value of the scroll bar by |
| 83 | * making a gesture with the mouse. For example, the user can |
| 84 | * drag the scroll bar's bubble up and down, or click in the |
| 85 | * scroll bar's unit increment or block increment areas. Keyboard |
| 86 | * gestures can also be mapped to the scroll bar. By convention, |
| 87 | * the <b>Page Up</b> and <b>Page Down</b> |
| 88 | * keys are equivalent to clicking in the scroll bar's block |
| 89 | * increment and block decrement areas. |
| 90 | * <p> |
| 91 | * When the user changes the value of the scroll bar, the scroll bar |
| 92 | * receives an instance of <code>AdjustmentEvent</code>. |
| 93 | * The scroll bar processes this event, passing it along to |
| 94 | * any registered listeners. |
| 95 | * <p> |
| 96 | * Any object that wishes to be notified of changes to the |
| 97 | * scroll bar's value should implement |
| 98 | * <code>AdjustmentListener</code>, an interface defined in |
| 99 | * the package <code>java.awt.event</code>. |
| 100 | * Listeners can be added and removed dynamically by calling |
| 101 | * the methods <code>addAdjustmentListener</code> and |
| 102 | * <code>removeAdjustmentListener</code>. |
| 103 | * <p> |
| 104 | * The <code>AdjustmentEvent</code> class defines five types |
| 105 | * of adjustment event, listed here: |
| 106 | * <p> |
| 107 | * <ul> |
| 108 | * <li><code>AdjustmentEvent.TRACK</code> is sent out when the |
| 109 | * user drags the scroll bar's bubble. |
| 110 | * <li><code>AdjustmentEvent.UNIT_INCREMENT</code> is sent out |
| 111 | * when the user clicks in the left arrow of a horizontal scroll |
| 112 | * bar, or the top arrow of a vertical scroll bar, or makes the |
| 113 | * equivalent gesture from the keyboard. |
| 114 | * <li><code>AdjustmentEvent.UNIT_DECREMENT</code> is sent out |
| 115 | * when the user clicks in the right arrow of a horizontal scroll |
| 116 | * bar, or the bottom arrow of a vertical scroll bar, or makes the |
| 117 | * equivalent gesture from the keyboard. |
| 118 | * <li><code>AdjustmentEvent.BLOCK_INCREMENT</code> is sent out |
| 119 | * when the user clicks in the track, to the left of the bubble |
| 120 | * on a horizontal scroll bar, or above the bubble on a vertical |
| 121 | * scroll bar. By convention, the <b>Page Up</b> |
| 122 | * key is equivalent, if the user is using a keyboard that |
| 123 | * defines a <b>Page Up</b> key. |
| 124 | * <li><code>AdjustmentEvent.BLOCK_DECREMENT</code> is sent out |
| 125 | * when the user clicks in the track, to the right of the bubble |
| 126 | * on a horizontal scroll bar, or below the bubble on a vertical |
| 127 | * scroll bar. By convention, the <b>Page Down</b> |
| 128 | * key is equivalent, if the user is using a keyboard that |
| 129 | * defines a <b>Page Down</b> key. |
| 130 | * </ul> |
| 131 | * <p> |
| 132 | * The JDK 1.0 event system is supported for backwards |
| 133 | * compatibility, but its use with newer versions of the platform is |
| 134 | * discouraged. The five types of adjustment events introduced |
| 135 | * with JDK 1.1 correspond to the five event types |
| 136 | * that are associated with scroll bars in previous platform versions. |
| 137 | * The following list gives the adjustment event type, |
| 138 | * and the corresponding JDK 1.0 event type it replaces. |
| 139 | * <p> |
| 140 | * <ul> |
| 141 | * <li><code>AdjustmentEvent.TRACK</code> replaces |
| 142 | * <code>Event.SCROLL_ABSOLUTE</code> |
| 143 | * <li><code>AdjustmentEvent.UNIT_INCREMENT</code> replaces |
| 144 | * <code>Event.SCROLL_LINE_UP</code> |
| 145 | * <li><code>AdjustmentEvent.UNIT_DECREMENT</code> replaces |
| 146 | * <code>Event.SCROLL_LINE_DOWN</code> |
| 147 | * <li><code>AdjustmentEvent.BLOCK_INCREMENT</code> replaces |
| 148 | * <code>Event.SCROLL_PAGE_UP</code> |
| 149 | * <li><code>AdjustmentEvent.BLOCK_DECREMENT</code> replaces |
| 150 | * <code>Event.SCROLL_PAGE_DOWN</code> |
| 151 | * </ul> |
| 152 | * <p> |
| 153 | * <b>Note</b>: We recommend using a <code>Scrollbar</code> |
| 154 | * for value selection only. If you want to implement |
| 155 | * a scrollable component inside a container, we recommend you use |
| 156 | * a {@link ScrollPane ScrollPane}. If you use a |
| 157 | * <code>Scrollbar</code> for this purpose, you are likely to |
| 158 | * encounter issues with painting, key handling, sizing and |
| 159 | * positioning. |
| 160 | * |
| 161 | * @author Sami Shaio |
| 162 | * @see java.awt.event.AdjustmentEvent |
| 163 | * @see java.awt.event.AdjustmentListener |
| 164 | * @since JDK1.0 |
| 165 | */ |
| 166 | public class Scrollbar extends Component implements Adjustable, Accessible { |
| 167 | |
| 168 | /** |
| 169 | * A constant that indicates a horizontal scroll bar. |
| 170 | */ |
| 171 | public static final int HORIZONTAL = 0; |
| 172 | |
| 173 | /** |
| 174 | * A constant that indicates a vertical scroll bar. |
| 175 | */ |
| 176 | public static final int VERTICAL = 1; |
| 177 | |
| 178 | /** |
| 179 | * The value of the <code>Scrollbar</code>. |
| 180 | * This property must be greater than or equal to <code>minimum</code> |
| 181 | * and less than or equal to |
| 182 | * <code>maximum - visibleAmount</code> |
| 183 | * |
| 184 | * @serial |
| 185 | * @see #getValue |
| 186 | * @see #setValue |
| 187 | */ |
| 188 | int value; |
| 189 | |
| 190 | /** |
| 191 | * The maximum value of the <code>Scrollbar</code>. |
| 192 | * This value must be greater than the <code>minimum</code> |
| 193 | * value.<br> |
| 194 | * |
| 195 | * @serial |
| 196 | * @see #getMaximum |
| 197 | * @see #setMaximum |
| 198 | */ |
| 199 | int maximum; |
| 200 | |
| 201 | /** |
| 202 | * The minimum value of the <code>Scrollbar</code>. |
| 203 | * This value must be less than the <code>maximum</code> |
| 204 | * value.<br> |
| 205 | * |
| 206 | * @serial |
| 207 | * @see #getMinimum |
| 208 | * @see #setMinimum |
| 209 | */ |
| 210 | int minimum; |
| 211 | |
| 212 | /** |
| 213 | * The size of the <code>Scrollbar</code>'s bubble. |
| 214 | * When a scroll bar is used to select a range of values, |
| 215 | * the visibleAmount represents the size of this range. |
| 216 | * This is visually indicated by the size of the bubble. |
| 217 | * |
| 218 | * @serial |
| 219 | * @see #getVisibleAmount |
| 220 | * @see #setVisibleAmount |
| 221 | */ |
| 222 | int visibleAmount; |
| 223 | |
| 224 | /** |
| 225 | * The <code>Scrollbar</code>'s orientation--being either horizontal |
| 226 | * or vertical. |
| 227 | * This value should be specified when the scrollbar is created.<BR> |
| 228 | * orientation can be either : <code>VERTICAL</code> or |
| 229 | * <code>HORIZONTAL</code> only. |
| 230 | * |
| 231 | * @serial |
| 232 | * @see #getOrientation |
| 233 | * @see #setOrientation |
| 234 | */ |
| 235 | int orientation; |
| 236 | |
| 237 | /** |
| 238 | * The amount by which the scrollbar value will change when going |
| 239 | * up or down by a line. |
| 240 | * This value must be greater than zero. |
| 241 | * |
| 242 | * @serial |
| 243 | * @see #getLineIncrement |
| 244 | * @see #setLineIncrement |
| 245 | */ |
| 246 | int lineIncrement = 1; |
| 247 | |
| 248 | /** |
| 249 | * The amount by which the scrollbar value will change when going |
| 250 | * up or down by a page. |
| 251 | * This value must be greater than zero. |
| 252 | * |
| 253 | * @serial |
| 254 | * @see #getPageIncrement |
| 255 | * @see #setPageIncrement |
| 256 | */ |
| 257 | int pageIncrement = 10; |
| 258 | |
| 259 | /** |
| 260 | * The adjusting status of the <code>Scrollbar</code>. |
| 261 | * True if the value is in the process of changing as a result of |
| 262 | * actions being taken by the user. |
| 263 | * |
| 264 | * @see #getValueIsAdjusting |
| 265 | * @see #setValueIsAdjusting |
| 266 | * @since 1.4 |
| 267 | */ |
| 268 | transient boolean isAdjusting; |
| 269 | |
| 270 | transient AdjustmentListener adjustmentListener; |
| 271 | |
| 272 | private static final String base = "scrollbar"; |
| 273 | private static int nameCounter = 0; |
| 274 | |
| 275 | /* |
| 276 | * JDK 1.1 serialVersionUID |
| 277 | */ |
| 278 | private static final long serialVersionUID = 8451667562882310543L; |
| 279 | |
| 280 | /** |
| 281 | * Initialize JNI field and method IDs. |
| 282 | */ |
| 283 | private static native void initIDs(); |
| 284 | |
| 285 | static { |
| 286 | /* ensure that the necessary native libraries are loaded */ |
| 287 | Toolkit.loadLibraries(); |
| 288 | if (!GraphicsEnvironment.isHeadless()) { |
| 289 | initIDs(); |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | /** |
| 294 | * Constructs a new vertical scroll bar. |
| 295 | * The default properties of the scroll bar are listed in |
| 296 | * the following table: |
| 297 | * <p> </p> |
| 298 | * <table border=1 summary="Scrollbar default properties"> |
| 299 | * <tr> |
| 300 | * <th>Property</th> |
| 301 | * <th>Description</th> |
| 302 | * <th>Default Value</th> |
| 303 | * </tr> |
| 304 | * <tr> |
| 305 | * <td>orientation</td> |
| 306 | * <td>indicates whether the scroll bar is vertical |
| 307 | * <br>or horizontal</td> |
| 308 | * <td><code>Scrollbar.VERTICAL</code></td> |
| 309 | * </tr> |
| 310 | * <tr> |
| 311 | * <td>value</td> |
| 312 | * <td>value which controls the location |
| 313 | * <br>of the scroll bar's bubble</td> |
| 314 | * <td>0</td> |
| 315 | * </tr> |
| 316 | * <tr> |
| 317 | * <td>visible amount</td> |
| 318 | * <td>visible amount of the scroll bar's range, |
| 319 | * <br>typically represented by the size of the |
| 320 | * <br>scroll bar's bubble</td> |
| 321 | * <td>10</td> |
| 322 | * </tr> |
| 323 | * <tr> |
| 324 | * <td>minimum</td> |
| 325 | * <td>minimum value of the scroll bar</td> |
| 326 | * <td>0</td> |
| 327 | * </tr> |
| 328 | * <tr> |
| 329 | * <td>maximum</td> |
| 330 | * <td>maximum value of the scroll bar</td> |
| 331 | * <td>100</td> |
| 332 | * </tr> |
| 333 | * <tr> |
| 334 | * <td>unit increment</td> |
| 335 | * <td>amount the value changes when the |
| 336 | * <br>Line Up or Line Down key is pressed, |
| 337 | * <br>or when the end arrows of the scrollbar |
| 338 | * <br>are clicked </td> |
| 339 | * <td>1</td> |
| 340 | * </tr> |
| 341 | * <tr> |
| 342 | * <td>block increment</td> |
| 343 | * <td>amount the value changes when the |
| 344 | * <br>Page Up or Page Down key is pressed, |
| 345 | * <br>or when the scrollbar track is clicked |
| 346 | * <br>on either side of the bubble </td> |
| 347 | * <td>10</td> |
| 348 | * </tr> |
| 349 | * </table> |
| 350 | * |
| 351 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() |
| 352 | * returns true. |
| 353 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 354 | */ |
| 355 | public Scrollbar() throws HeadlessException { |
| 356 | this(VERTICAL, 0, 10, 0, 100); |
| 357 | } |
| 358 | |
| 359 | /** |
| 360 | * Constructs a new scroll bar with the specified orientation. |
| 361 | * <p> |
| 362 | * The <code>orientation</code> argument must take one of the two |
| 363 | * values <code>Scrollbar.HORIZONTAL</code>, |
| 364 | * or <code>Scrollbar.VERTICAL</code>, |
| 365 | * indicating a horizontal or vertical scroll bar, respectively. |
| 366 | * |
| 367 | * @param orientation indicates the orientation of the scroll bar |
| 368 | * @exception IllegalArgumentException when an illegal value for |
| 369 | * the <code>orientation</code> argument is supplied |
| 370 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() |
| 371 | * returns true. |
| 372 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 373 | */ |
| 374 | public Scrollbar(int orientation) throws HeadlessException { |
| 375 | this(orientation, 0, 10, 0, 100); |
| 376 | } |
| 377 | |
| 378 | /** |
| 379 | * Constructs a new scroll bar with the specified orientation, |
| 380 | * initial value, visible amount, and minimum and maximum values. |
| 381 | * <p> |
| 382 | * The <code>orientation</code> argument must take one of the two |
| 383 | * values <code>Scrollbar.HORIZONTAL</code>, |
| 384 | * or <code>Scrollbar.VERTICAL</code>, |
| 385 | * indicating a horizontal or vertical scroll bar, respectively. |
| 386 | * <p> |
| 387 | * The parameters supplied to this constructor are subject to the |
| 388 | * constraints described in {@link #setValues(int, int, int, int)}. |
| 389 | * |
| 390 | * @param orientation indicates the orientation of the scroll bar. |
| 391 | * @param value the initial value of the scroll bar |
| 392 | * @param visible the visible amount of the scroll bar, typically |
| 393 | * represented by the size of the bubble |
| 394 | * @param minimum the minimum value of the scroll bar |
| 395 | * @param maximum the maximum value of the scroll bar |
| 396 | * @exception IllegalArgumentException when an illegal value for |
| 397 | * the <code>orientation</code> argument is supplied |
| 398 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() |
| 399 | * returns true. |
| 400 | * @see #setValues |
| 401 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 402 | */ |
| 403 | public Scrollbar(int orientation, int value, int visible, int minimum, |
| 404 | int maximum) throws HeadlessException { |
| 405 | GraphicsEnvironment.checkHeadless(); |
| 406 | switch (orientation) { |
| 407 | case HORIZONTAL: |
| 408 | case VERTICAL: |
| 409 | this.orientation = orientation; |
| 410 | break; |
| 411 | default: |
| 412 | throw new IllegalArgumentException("illegal scrollbar orientation"); |
| 413 | } |
| 414 | setValues(value, visible, minimum, maximum); |
| 415 | } |
| 416 | |
| 417 | /** |
| 418 | * Constructs a name for this component. Called by <code>getName</code> |
| 419 | * when the name is <code>null</code>. |
| 420 | */ |
| 421 | String constructComponentName() { |
| 422 | synchronized (Scrollbar.class) { |
| 423 | return base + nameCounter++; |
| 424 | } |
| 425 | } |
| 426 | |
| 427 | /** |
| 428 | * Creates the <code>Scrollbar</code>'s peer. The peer allows you to modify |
| 429 | * the appearance of the <code>Scrollbar</code> without changing any of its |
| 430 | * functionality. |
| 431 | */ |
| 432 | public void addNotify() { |
| 433 | synchronized (getTreeLock()) { |
| 434 | if (peer == null) |
| 435 | peer = getToolkit().createScrollbar(this); |
| 436 | super.addNotify(); |
| 437 | } |
| 438 | } |
| 439 | |
| 440 | /** |
| 441 | * Returns the orientation of this scroll bar. |
| 442 | * |
| 443 | * @return the orientation of this scroll bar, either |
| 444 | * <code>Scrollbar.HORIZONTAL</code> or |
| 445 | * <code>Scrollbar.VERTICAL</code> |
| 446 | * @see java.awt.Scrollbar#setOrientation |
| 447 | */ |
| 448 | public int getOrientation() { |
| 449 | return orientation; |
| 450 | } |
| 451 | |
| 452 | /** |
| 453 | * Sets the orientation for this scroll bar. |
| 454 | * |
| 455 | * @param orientation the orientation of this scroll bar, either |
| 456 | * <code>Scrollbar.HORIZONTAL</code> or |
| 457 | * <code>Scrollbar.VERTICAL</code> |
| 458 | * @see java.awt.Scrollbar#getOrientation |
| 459 | * @exception IllegalArgumentException if the value supplied |
| 460 | * for <code>orientation</code> is not a |
| 461 | * legal value |
| 462 | * @since JDK1.1 |
| 463 | */ |
| 464 | public void setOrientation(int orientation) { |
| 465 | synchronized (getTreeLock()) { |
| 466 | if (orientation == this.orientation) { |
| 467 | return; |
| 468 | } |
| 469 | switch (orientation) { |
| 470 | case HORIZONTAL: |
| 471 | case VERTICAL: |
| 472 | this.orientation = orientation; |
| 473 | break; |
| 474 | default: |
| 475 | throw new IllegalArgumentException("illegal scrollbar orientation"); |
| 476 | } |
| 477 | /* Create a new peer with the specified orientation. */ |
| 478 | if (peer != null) { |
| 479 | removeNotify(); |
| 480 | addNotify(); |
| 481 | invalidate(); |
| 482 | } |
| 483 | } |
| 484 | if (accessibleContext != null) { |
| 485 | accessibleContext.firePropertyChange( |
| 486 | AccessibleContext.ACCESSIBLE_STATE_PROPERTY, |
| 487 | ((orientation == VERTICAL) |
| 488 | ? AccessibleState.HORIZONTAL : AccessibleState.VERTICAL), |
| 489 | ((orientation == VERTICAL) |
| 490 | ? AccessibleState.VERTICAL : AccessibleState.HORIZONTAL)); |
| 491 | } |
| 492 | } |
| 493 | |
| 494 | /** |
| 495 | * Gets the current value of this scroll bar. |
| 496 | * |
| 497 | * @return the current value of this scroll bar |
| 498 | * @see java.awt.Scrollbar#getMinimum |
| 499 | * @see java.awt.Scrollbar#getMaximum |
| 500 | */ |
| 501 | public int getValue() { |
| 502 | return value; |
| 503 | } |
| 504 | |
| 505 | /** |
| 506 | * Sets the value of this scroll bar to the specified value. |
| 507 | * <p> |
| 508 | * If the value supplied is less than the current <code>minimum</code> |
| 509 | * or greater than the current <code>maximum - visibleAmount</code>, |
| 510 | * then either <code>minimum</code> or <code>maximum - visibleAmount</code> |
| 511 | * is substituted, as appropriate. |
| 512 | * <p> |
| 513 | * Normally, a program should change a scroll bar's |
| 514 | * value only by calling <code>setValues</code>. |
| 515 | * The <code>setValues</code> method simultaneously |
| 516 | * and synchronously sets the minimum, maximum, visible amount, |
| 517 | * and value properties of a scroll bar, so that they are |
| 518 | * mutually consistent. |
| 519 | * <p> |
| 520 | * Calling this method does not fire an |
| 521 | * <code>AdjustmentEvent</code>. |
| 522 | * |
| 523 | * @param newValue the new value of the scroll bar |
| 524 | * @see java.awt.Scrollbar#setValues |
| 525 | * @see java.awt.Scrollbar#getValue |
| 526 | * @see java.awt.Scrollbar#getMinimum |
| 527 | * @see java.awt.Scrollbar#getMaximum |
| 528 | */ |
| 529 | public void setValue(int newValue) { |
| 530 | // Use setValues so that a consistent policy relating |
| 531 | // minimum, maximum, visible amount, and value is enforced. |
| 532 | setValues(newValue, visibleAmount, minimum, maximum); |
| 533 | } |
| 534 | |
| 535 | /** |
| 536 | * Gets the minimum value of this scroll bar. |
| 537 | * |
| 538 | * @return the minimum value of this scroll bar |
| 539 | * @see java.awt.Scrollbar#getValue |
| 540 | * @see java.awt.Scrollbar#getMaximum |
| 541 | */ |
| 542 | public int getMinimum() { |
| 543 | return minimum; |
| 544 | } |
| 545 | |
| 546 | /** |
| 547 | * Sets the minimum value of this scroll bar. |
| 548 | * <p> |
| 549 | * When <code>setMinimum</code> is called, the minimum value |
| 550 | * is changed, and other values (including the maximum, the |
| 551 | * visible amount, and the current scroll bar value) |
| 552 | * are changed to be consistent with the new minimum. |
| 553 | * <p> |
| 554 | * Normally, a program should change a scroll bar's minimum |
| 555 | * value only by calling <code>setValues</code>. |
| 556 | * The <code>setValues</code> method simultaneously |
| 557 | * and synchronously sets the minimum, maximum, visible amount, |
| 558 | * and value properties of a scroll bar, so that they are |
| 559 | * mutually consistent. |
| 560 | * <p> |
| 561 | * Note that setting the minimum value to <code>Integer.MAX_VALUE</code> |
| 562 | * will result in the new minimum value being set to |
| 563 | * <code>Integer.MAX_VALUE - 1</code>. |
| 564 | * |
| 565 | * @param newMinimum the new minimum value for this scroll bar |
| 566 | * @see java.awt.Scrollbar#setValues |
| 567 | * @see java.awt.Scrollbar#setMaximum |
| 568 | * @since JDK1.1 |
| 569 | */ |
| 570 | public void setMinimum(int newMinimum) { |
| 571 | // No checks are necessary in this method since minimum is |
| 572 | // the first variable checked in the setValues function. |
| 573 | |
| 574 | // Use setValues so that a consistent policy relating |
| 575 | // minimum, maximum, visible amount, and value is enforced. |
| 576 | setValues(value, visibleAmount, newMinimum, maximum); |
| 577 | } |
| 578 | |
| 579 | /** |
| 580 | * Gets the maximum value of this scroll bar. |
| 581 | * |
| 582 | * @return the maximum value of this scroll bar |
| 583 | * @see java.awt.Scrollbar#getValue |
| 584 | * @see java.awt.Scrollbar#getMinimum |
| 585 | */ |
| 586 | public int getMaximum() { |
| 587 | return maximum; |
| 588 | } |
| 589 | |
| 590 | /** |
| 591 | * Sets the maximum value of this scroll bar. |
| 592 | * <p> |
| 593 | * When <code>setMaximum</code> is called, the maximum value |
| 594 | * is changed, and other values (including the minimum, the |
| 595 | * visible amount, and the current scroll bar value) |
| 596 | * are changed to be consistent with the new maximum. |
| 597 | * <p> |
| 598 | * Normally, a program should change a scroll bar's maximum |
| 599 | * value only by calling <code>setValues</code>. |
| 600 | * The <code>setValues</code> method simultaneously |
| 601 | * and synchronously sets the minimum, maximum, visible amount, |
| 602 | * and value properties of a scroll bar, so that they are |
| 603 | * mutually consistent. |
| 604 | * <p> |
| 605 | * Note that setting the maximum value to <code>Integer.MIN_VALUE</code> |
| 606 | * will result in the new maximum value being set to |
| 607 | * <code>Integer.MIN_VALUE + 1</code>. |
| 608 | * |
| 609 | * @param newMaximum the new maximum value |
| 610 | * for this scroll bar |
| 611 | * @see java.awt.Scrollbar#setValues |
| 612 | * @see java.awt.Scrollbar#setMinimum |
| 613 | * @since JDK1.1 |
| 614 | */ |
| 615 | public void setMaximum(int newMaximum) { |
| 616 | // minimum is checked first in setValues, so we need to |
| 617 | // enforce minimum and maximum checks here. |
| 618 | if (newMaximum == Integer.MIN_VALUE) { |
| 619 | newMaximum = Integer.MIN_VALUE + 1; |
| 620 | } |
| 621 | |
| 622 | if (minimum >= newMaximum) { |
| 623 | minimum = newMaximum - 1; |
| 624 | } |
| 625 | |
| 626 | // Use setValues so that a consistent policy relating |
| 627 | // minimum, maximum, visible amount, and value is enforced. |
| 628 | setValues(value, visibleAmount, minimum, newMaximum); |
| 629 | } |
| 630 | |
| 631 | /** |
| 632 | * Gets the visible amount of this scroll bar. |
| 633 | * <p> |
| 634 | * When a scroll bar is used to select a range of values, |
| 635 | * the visible amount is used to represent the range of values |
| 636 | * that are currently visible. The size of the scroll bar's |
| 637 | * bubble (also called a thumb or scroll box), usually gives a |
| 638 | * visual representation of the relationship of the visible |
| 639 | * amount to the range of the scroll bar. |
| 640 | * <p> |
| 641 | * The scroll bar's bubble may not be displayed when it is not |
| 642 | * moveable (e.g. when it takes up the entire length of the |
| 643 | * scroll bar's track, or when the scroll bar is disabled). |
| 644 | * Whether the bubble is displayed or not will not affect |
| 645 | * the value returned by <code>getVisibleAmount</code>. |
| 646 | * |
| 647 | * @return the visible amount of this scroll bar |
| 648 | * @see java.awt.Scrollbar#setVisibleAmount |
| 649 | * @since JDK1.1 |
| 650 | */ |
| 651 | public int getVisibleAmount() { |
| 652 | return getVisible(); |
| 653 | } |
| 654 | |
| 655 | /** |
| 656 | * @deprecated As of JDK version 1.1, |
| 657 | * replaced by <code>getVisibleAmount()</code>. |
| 658 | */ |
| 659 | @Deprecated |
| 660 | public int getVisible() { |
| 661 | return visibleAmount; |
| 662 | } |
| 663 | |
| 664 | /** |
| 665 | * Sets the visible amount of this scroll bar. |
| 666 | * <p> |
| 667 | * When a scroll bar is used to select a range of values, |
| 668 | * the visible amount is used to represent the range of values |
| 669 | * that are currently visible. The size of the scroll bar's |
| 670 | * bubble (also called a thumb or scroll box), usually gives a |
| 671 | * visual representation of the relationship of the visible |
| 672 | * amount to the range of the scroll bar. |
| 673 | * <p> |
| 674 | * The scroll bar's bubble may not be displayed when it is not |
| 675 | * moveable (e.g. when it takes up the entire length of the |
| 676 | * scroll bar's track, or when the scroll bar is disabled). |
| 677 | * Whether the bubble is displayed or not will not affect |
| 678 | * the value returned by <code>getVisibleAmount</code>. |
| 679 | * <p> |
| 680 | * If the visible amount supplied is less than <code>one</code> |
| 681 | * or greater than the current <code>maximum - minimum</code>, |
| 682 | * then either <code>one</code> or <code>maximum - minimum</code> |
| 683 | * is substituted, as appropriate. |
| 684 | * <p> |
| 685 | * Normally, a program should change a scroll bar's |
| 686 | * value only by calling <code>setValues</code>. |
| 687 | * The <code>setValues</code> method simultaneously |
| 688 | * and synchronously sets the minimum, maximum, visible amount, |
| 689 | * and value properties of a scroll bar, so that they are |
| 690 | * mutually consistent. |
| 691 | * |
| 692 | * @param newAmount the new visible amount |
| 693 | * @see java.awt.Scrollbar#getVisibleAmount |
| 694 | * @see java.awt.Scrollbar#setValues |
| 695 | * @since JDK1.1 |
| 696 | */ |
| 697 | public void setVisibleAmount(int newAmount) { |
| 698 | // Use setValues so that a consistent policy relating |
| 699 | // minimum, maximum, visible amount, and value is enforced. |
| 700 | setValues(value, newAmount, minimum, maximum); |
| 701 | } |
| 702 | |
| 703 | /** |
| 704 | * Sets the unit increment for this scroll bar. |
| 705 | * <p> |
| 706 | * The unit increment is the value that is added or subtracted |
| 707 | * when the user activates the unit increment area of the |
| 708 | * scroll bar, generally through a mouse or keyboard gesture |
| 709 | * that the scroll bar receives as an adjustment event. |
| 710 | * The unit increment must be greater than zero. |
| 711 | * Attepts to set the unit increment to a value lower than 1 |
| 712 | * will result in a value of 1 being set. |
| 713 | * |
| 714 | * @param v the amount by which to increment or decrement |
| 715 | * the scroll bar's value |
| 716 | * @see java.awt.Scrollbar#getUnitIncrement |
| 717 | * @since JDK1.1 |
| 718 | */ |
| 719 | public void setUnitIncrement(int v) { |
| 720 | setLineIncrement(v); |
| 721 | } |
| 722 | |
| 723 | /** |
| 724 | * @deprecated As of JDK version 1.1, |
| 725 | * replaced by <code>setUnitIncrement(int)</code>. |
| 726 | */ |
| 727 | @Deprecated |
| 728 | public synchronized void setLineIncrement(int v) { |
| 729 | int tmp = (v < 1) ? 1 : v; |
| 730 | |
| 731 | if (lineIncrement == tmp) { |
| 732 | return; |
| 733 | } |
| 734 | lineIncrement = tmp; |
| 735 | |
| 736 | ScrollbarPeer peer = (ScrollbarPeer)this.peer; |
| 737 | if (peer != null) { |
| 738 | peer.setLineIncrement(lineIncrement); |
| 739 | } |
| 740 | } |
| 741 | |
| 742 | /** |
| 743 | * Gets the unit increment for this scrollbar. |
| 744 | * <p> |
| 745 | * The unit increment is the value that is added or subtracted |
| 746 | * when the user activates the unit increment area of the |
| 747 | * scroll bar, generally through a mouse or keyboard gesture |
| 748 | * that the scroll bar receives as an adjustment event. |
| 749 | * The unit increment must be greater than zero. |
| 750 | * |
| 751 | * @return the unit increment of this scroll bar |
| 752 | * @see java.awt.Scrollbar#setUnitIncrement |
| 753 | * @since JDK1.1 |
| 754 | */ |
| 755 | public int getUnitIncrement() { |
| 756 | return getLineIncrement(); |
| 757 | } |
| 758 | |
| 759 | /** |
| 760 | * @deprecated As of JDK version 1.1, |
| 761 | * replaced by <code>getUnitIncrement()</code>. |
| 762 | */ |
| 763 | @Deprecated |
| 764 | public int getLineIncrement() { |
| 765 | return lineIncrement; |
| 766 | } |
| 767 | |
| 768 | /** |
| 769 | * Sets the block increment for this scroll bar. |
| 770 | * <p> |
| 771 | * The block increment is the value that is added or subtracted |
| 772 | * when the user activates the block increment area of the |
| 773 | * scroll bar, generally through a mouse or keyboard gesture |
| 774 | * that the scroll bar receives as an adjustment event. |
| 775 | * The block increment must be greater than zero. |
| 776 | * Attepts to set the block increment to a value lower than 1 |
| 777 | * will result in a value of 1 being set. |
| 778 | * |
| 779 | * @param v the amount by which to increment or decrement |
| 780 | * the scroll bar's value |
| 781 | * @see java.awt.Scrollbar#getBlockIncrement |
| 782 | * @since JDK1.1 |
| 783 | */ |
| 784 | public void setBlockIncrement(int v) { |
| 785 | setPageIncrement(v); |
| 786 | } |
| 787 | |
| 788 | /** |
| 789 | * @deprecated As of JDK version 1.1, |
| 790 | * replaced by <code>setBlockIncrement()</code>. |
| 791 | */ |
| 792 | @Deprecated |
| 793 | public synchronized void setPageIncrement(int v) { |
| 794 | int tmp = (v < 1) ? 1 : v; |
| 795 | |
| 796 | if (pageIncrement == tmp) { |
| 797 | return; |
| 798 | } |
| 799 | pageIncrement = tmp; |
| 800 | |
| 801 | ScrollbarPeer peer = (ScrollbarPeer)this.peer; |
| 802 | if (peer != null) { |
| 803 | peer.setPageIncrement(pageIncrement); |
| 804 | } |
| 805 | } |
| 806 | |
| 807 | /** |
| 808 | * Gets the block increment of this scroll bar. |
| 809 | * <p> |
| 810 | * The block increment is the value that is added or subtracted |
| 811 | * when the user activates the block increment area of the |
| 812 | * scroll bar, generally through a mouse or keyboard gesture |
| 813 | * that the scroll bar receives as an adjustment event. |
| 814 | * The block increment must be greater than zero. |
| 815 | * |
| 816 | * @return the block increment of this scroll bar |
| 817 | * @see java.awt.Scrollbar#setBlockIncrement |
| 818 | * @since JDK1.1 |
| 819 | */ |
| 820 | public int getBlockIncrement() { |
| 821 | return getPageIncrement(); |
| 822 | } |
| 823 | |
| 824 | /** |
| 825 | * @deprecated As of JDK version 1.1, |
| 826 | * replaced by <code>getBlockIncrement()</code>. |
| 827 | */ |
| 828 | @Deprecated |
| 829 | public int getPageIncrement() { |
| 830 | return pageIncrement; |
| 831 | } |
| 832 | |
| 833 | /** |
| 834 | * Sets the values of four properties for this scroll bar: |
| 835 | * <code>value</code>, <code>visibleAmount</code>, |
| 836 | * <code>minimum</code>, and <code>maximum</code>. |
| 837 | * If the values supplied for these properties are inconsistent |
| 838 | * or incorrect, they will be changed to ensure consistency. |
| 839 | * <p> |
| 840 | * This method simultaneously and synchronously sets the values |
| 841 | * of four scroll bar properties, assuring that the values of |
| 842 | * these properties are mutually consistent. It enforces the |
| 843 | * following constraints: |
| 844 | * <code>maximum</code> must be greater than <code>minimum</code>, |
| 845 | * <code>maximum - minimum</code> must not be greater |
| 846 | * than <code>Integer.MAX_VALUE</code>, |
| 847 | * <code>visibleAmount</code> must be greater than zero. |
| 848 | * <code>visibleAmount</code> must not be greater than |
| 849 | * <code>maximum - minimum</code>, |
| 850 | * <code>value</code> must not be less than <code>minimum</code>, |
| 851 | * and <code>value</code> must not be greater than |
| 852 | * <code>maximum - visibleAmount</code> |
| 853 | * <p> |
| 854 | * Calling this method does not fire an |
| 855 | * <code>AdjustmentEvent</code>. |
| 856 | * |
| 857 | * @param value is the position in the current window |
| 858 | * @param visible is the visible amount of the scroll bar |
| 859 | * @param minimum is the minimum value of the scroll bar |
| 860 | * @param maximum is the maximum value of the scroll bar |
| 861 | * @see #setMinimum |
| 862 | * @see #setMaximum |
| 863 | * @see #setVisibleAmount |
| 864 | * @see #setValue |
| 865 | */ |
| 866 | public void setValues(int value, int visible, int minimum, int maximum) { |
| 867 | int oldValue; |
| 868 | synchronized (this) { |
| 869 | if (minimum == Integer.MAX_VALUE) { |
| 870 | minimum = Integer.MAX_VALUE - 1; |
| 871 | } |
| 872 | if (maximum <= minimum) { |
| 873 | maximum = minimum + 1; |
| 874 | } |
| 875 | |
| 876 | long maxMinusMin = (long) maximum - (long) minimum; |
| 877 | if (maxMinusMin > Integer.MAX_VALUE) { |
| 878 | maxMinusMin = Integer.MAX_VALUE; |
| 879 | maximum = minimum + (int) maxMinusMin; |
| 880 | } |
| 881 | if (visible > (int) maxMinusMin) { |
| 882 | visible = (int) maxMinusMin; |
| 883 | } |
| 884 | if (visible < 1) { |
| 885 | visible = 1; |
| 886 | } |
| 887 | |
| 888 | if (value < minimum) { |
| 889 | value = minimum; |
| 890 | } |
| 891 | if (value > maximum - visible) { |
| 892 | value = maximum - visible; |
| 893 | } |
| 894 | |
| 895 | oldValue = this.value; |
| 896 | this.value = value; |
| 897 | this.visibleAmount = visible; |
| 898 | this.minimum = minimum; |
| 899 | this.maximum = maximum; |
| 900 | ScrollbarPeer peer = (ScrollbarPeer)this.peer; |
| 901 | if (peer != null) { |
| 902 | peer.setValues(value, visibleAmount, minimum, maximum); |
| 903 | } |
| 904 | } |
| 905 | |
| 906 | if ((oldValue != value) && (accessibleContext != null)) { |
| 907 | accessibleContext.firePropertyChange( |
| 908 | AccessibleContext.ACCESSIBLE_VALUE_PROPERTY, |
| 909 | Integer.valueOf(oldValue), |
| 910 | Integer.valueOf(value)); |
| 911 | } |
| 912 | } |
| 913 | |
| 914 | /** |
| 915 | * Returns true if the value is in the process of changing as a |
| 916 | * result of actions being taken by the user. |
| 917 | * |
| 918 | * @return the value of the <code>valueIsAdjusting</code> property |
| 919 | * @see #setValueIsAdjusting |
| 920 | * @since 1.4 |
| 921 | */ |
| 922 | public boolean getValueIsAdjusting() { |
| 923 | return isAdjusting; |
| 924 | } |
| 925 | |
| 926 | /** |
| 927 | * Sets the <code>valueIsAdjusting</code> property. |
| 928 | * |
| 929 | * @param b new adjustment-in-progress status |
| 930 | * @see #getValueIsAdjusting |
| 931 | * @since 1.4 |
| 932 | */ |
| 933 | public void setValueIsAdjusting(boolean b) { |
| 934 | boolean oldValue; |
| 935 | |
| 936 | synchronized (this) { |
| 937 | oldValue = isAdjusting; |
| 938 | isAdjusting = b; |
| 939 | } |
| 940 | |
| 941 | if ((oldValue != b) && (accessibleContext != null)) { |
| 942 | accessibleContext.firePropertyChange( |
| 943 | AccessibleContext.ACCESSIBLE_STATE_PROPERTY, |
| 944 | ((oldValue) ? AccessibleState.BUSY : null), |
| 945 | ((b) ? AccessibleState.BUSY : null)); |
| 946 | } |
| 947 | } |
| 948 | |
| 949 | |
| 950 | |
| 951 | /** |
| 952 | * Adds the specified adjustment listener to receive instances of |
| 953 | * <code>AdjustmentEvent</code> from this scroll bar. |
| 954 | * If l is <code>null</code>, no exception is thrown and no |
| 955 | * action is performed. |
| 956 | * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" |
| 957 | * >AWT Threading Issues</a> for details on AWT's threading model. |
| 958 | * |
| 959 | * @param l the adjustment listener |
| 960 | * @see #removeAdjustmentListener |
| 961 | * @see #getAdjustmentListeners |
| 962 | * @see java.awt.event.AdjustmentEvent |
| 963 | * @see java.awt.event.AdjustmentListener |
| 964 | * @since JDK1.1 |
| 965 | */ |
| 966 | public synchronized void addAdjustmentListener(AdjustmentListener l) { |
| 967 | if (l == null) { |
| 968 | return; |
| 969 | } |
| 970 | adjustmentListener = AWTEventMulticaster.add(adjustmentListener, l); |
| 971 | newEventsOnly = true; |
| 972 | } |
| 973 | |
| 974 | /** |
| 975 | * Removes the specified adjustment listener so that it no longer |
| 976 | * receives instances of <code>AdjustmentEvent</code> from this scroll bar. |
| 977 | * If l is <code>null</code>, no exception is thrown and no action |
| 978 | * is performed. |
| 979 | * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" |
| 980 | * >AWT Threading Issues</a> for details on AWT's threading model. |
| 981 | * |
| 982 | * @param l the adjustment listener |
| 983 | * @see #addAdjustmentListener |
| 984 | * @see #getAdjustmentListeners |
| 985 | * @see java.awt.event.AdjustmentEvent |
| 986 | * @see java.awt.event.AdjustmentListener |
| 987 | * @since JDK1.1 |
| 988 | */ |
| 989 | public synchronized void removeAdjustmentListener(AdjustmentListener l) { |
| 990 | if (l == null) { |
| 991 | return; |
| 992 | } |
| 993 | adjustmentListener = AWTEventMulticaster.remove(adjustmentListener, l); |
| 994 | } |
| 995 | |
| 996 | /** |
| 997 | * Returns an array of all the adjustment listeners |
| 998 | * registered on this scrollbar. |
| 999 | * |
| 1000 | * @return all of this scrollbar's <code>AdjustmentListener</code>s |
| 1001 | * or an empty array if no adjustment |
| 1002 | * listeners are currently registered |
| 1003 | * @see #addAdjustmentListener |
| 1004 | * @see #removeAdjustmentListener |
| 1005 | * @see java.awt.event.AdjustmentEvent |
| 1006 | * @see java.awt.event.AdjustmentListener |
| 1007 | * @since 1.4 |
| 1008 | */ |
| 1009 | public synchronized AdjustmentListener[] getAdjustmentListeners() { |
| 1010 | return (AdjustmentListener[])(getListeners(AdjustmentListener.class)); |
| 1011 | } |
| 1012 | |
| 1013 | /** |
| 1014 | * Returns an array of all the objects currently registered |
| 1015 | * as <code><em>Foo</em>Listener</code>s |
| 1016 | * upon this <code>Scrollbar</code>. |
| 1017 | * <code><em>Foo</em>Listener</code>s are registered using the |
| 1018 | * <code>add<em>Foo</em>Listener</code> method. |
| 1019 | * <p> |
| 1020 | * You can specify the <code>listenerType</code> argument |
| 1021 | * with a class literal, such as |
| 1022 | * <code><em>Foo</em>Listener.class</code>. |
| 1023 | * For example, you can query a |
| 1024 | * <code>Scrollbar</code> <code>c</code> |
| 1025 | * for its mouse listeners with the following code: |
| 1026 | * |
| 1027 | * <pre>MouseListener[] mls = (MouseListener[])(c.getListeners(MouseListener.class));</pre> |
| 1028 | * |
| 1029 | * If no such listeners exist, this method returns an empty array. |
| 1030 | * |
| 1031 | * @param listenerType the type of listeners requested; this parameter |
| 1032 | * should specify an interface that descends from |
| 1033 | * <code>java.util.EventListener</code> |
| 1034 | * @return an array of all objects registered as |
| 1035 | * <code><em>Foo</em>Listener</code>s on this component, |
| 1036 | * or an empty array if no such listeners have been added |
| 1037 | * @exception ClassCastException if <code>listenerType</code> |
| 1038 | * doesn't specify a class or interface that implements |
| 1039 | * <code>java.util.EventListener</code> |
| 1040 | * |
| 1041 | * @since 1.3 |
| 1042 | */ |
| 1043 | public <T extends EventListener> T[] getListeners(Class<T> listenerType) { |
| 1044 | EventListener l = null; |
| 1045 | if (listenerType == AdjustmentListener.class) { |
| 1046 | l = adjustmentListener; |
| 1047 | } else { |
| 1048 | return super.getListeners(listenerType); |
| 1049 | } |
| 1050 | return AWTEventMulticaster.getListeners(l, listenerType); |
| 1051 | } |
| 1052 | |
| 1053 | // REMIND: remove when filtering is done at lower level |
| 1054 | boolean eventEnabled(AWTEvent e) { |
| 1055 | if (e.id == AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED) { |
| 1056 | if ((eventMask & AWTEvent.ADJUSTMENT_EVENT_MASK) != 0 || |
| 1057 | adjustmentListener != null) { |
| 1058 | return true; |
| 1059 | } |
| 1060 | return false; |
| 1061 | } |
| 1062 | return super.eventEnabled(e); |
| 1063 | } |
| 1064 | |
| 1065 | /** |
| 1066 | * Processes events on this scroll bar. If the event is an |
| 1067 | * instance of <code>AdjustmentEvent</code>, it invokes the |
| 1068 | * <code>processAdjustmentEvent</code> method. |
| 1069 | * Otherwise, it invokes its superclass's |
| 1070 | * <code>processEvent</code> method. |
| 1071 | * <p>Note that if the event parameter is <code>null</code> |
| 1072 | * the behavior is unspecified and may result in an |
| 1073 | * exception. |
| 1074 | * |
| 1075 | * @param e the event |
| 1076 | * @see java.awt.event.AdjustmentEvent |
| 1077 | * @see java.awt.Scrollbar#processAdjustmentEvent |
| 1078 | * @since JDK1.1 |
| 1079 | */ |
| 1080 | protected void processEvent(AWTEvent e) { |
| 1081 | if (e instanceof AdjustmentEvent) { |
| 1082 | processAdjustmentEvent((AdjustmentEvent)e); |
| 1083 | return; |
| 1084 | } |
| 1085 | super.processEvent(e); |
| 1086 | } |
| 1087 | |
| 1088 | /** |
| 1089 | * Processes adjustment events occurring on this |
| 1090 | * scrollbar by dispatching them to any registered |
| 1091 | * <code>AdjustmentListener</code> objects. |
| 1092 | * <p> |
| 1093 | * This method is not called unless adjustment events are |
| 1094 | * enabled for this component. Adjustment events are enabled |
| 1095 | * when one of the following occurs: |
| 1096 | * <p><ul> |
| 1097 | * <li>An <code>AdjustmentListener</code> object is registered |
| 1098 | * via <code>addAdjustmentListener</code>. |
| 1099 | * <li>Adjustment events are enabled via <code>enableEvents</code>. |
| 1100 | * </ul><p> |
| 1101 | * <p>Note that if the event parameter is <code>null</code> |
| 1102 | * the behavior is unspecified and may result in an |
| 1103 | * exception. |
| 1104 | * |
| 1105 | * @param e the adjustment event |
| 1106 | * @see java.awt.event.AdjustmentEvent |
| 1107 | * @see java.awt.event.AdjustmentListener |
| 1108 | * @see java.awt.Scrollbar#addAdjustmentListener |
| 1109 | * @see java.awt.Component#enableEvents |
| 1110 | * @since JDK1.1 |
| 1111 | */ |
| 1112 | protected void processAdjustmentEvent(AdjustmentEvent e) { |
| 1113 | AdjustmentListener listener = adjustmentListener; |
| 1114 | if (listener != null) { |
| 1115 | listener.adjustmentValueChanged(e); |
| 1116 | } |
| 1117 | } |
| 1118 | |
| 1119 | /** |
| 1120 | * Returns a string representing the state of this <code>Scrollbar</code>. |
| 1121 | * This method is intended to be used only for debugging purposes, and the |
| 1122 | * content and format of the returned string may vary between |
| 1123 | * implementations. The returned string may be empty but may not be |
| 1124 | * <code>null</code>. |
| 1125 | * |
| 1126 | * @return the parameter string of this scroll bar |
| 1127 | */ |
| 1128 | protected String paramString() { |
| 1129 | return super.paramString() + |
| 1130 | ",val=" + value + |
| 1131 | ",vis=" + visibleAmount + |
| 1132 | ",min=" + minimum + |
| 1133 | ",max=" + maximum + |
| 1134 | ((orientation == VERTICAL) ? ",vert" : ",horz") + |
| 1135 | ",isAdjusting=" + isAdjusting; |
| 1136 | } |
| 1137 | |
| 1138 | |
| 1139 | /* Serialization support. |
| 1140 | */ |
| 1141 | |
| 1142 | /** |
| 1143 | * The scroll bar's serialized Data Version. |
| 1144 | * |
| 1145 | * @serial |
| 1146 | */ |
| 1147 | private int scrollbarSerializedDataVersion = 1; |
| 1148 | |
| 1149 | /** |
| 1150 | * Writes default serializable fields to stream. Writes |
| 1151 | * a list of serializable <code>AdjustmentListeners</code> |
| 1152 | * as optional data. The non-serializable listeners are |
| 1153 | * detected and no attempt is made to serialize them. |
| 1154 | * |
| 1155 | * @param s the <code>ObjectOutputStream</code> to write |
| 1156 | * @serialData <code>null</code> terminated sequence of 0 |
| 1157 | * or more pairs; the pair consists of a <code>String</code> |
| 1158 | * and an <code>Object</code>; the <code>String</code> indicates |
| 1159 | * the type of object and is one of the following: |
| 1160 | * <code>adjustmentListenerK</code> indicating an |
| 1161 | * <code>AdjustmentListener</code> object |
| 1162 | * |
| 1163 | * @see AWTEventMulticaster#save(ObjectOutputStream, String, EventListener) |
| 1164 | * @see java.awt.Component#adjustmentListenerK |
| 1165 | * @see #readObject(ObjectInputStream) |
| 1166 | */ |
| 1167 | private void writeObject(ObjectOutputStream s) |
| 1168 | throws IOException |
| 1169 | { |
| 1170 | s.defaultWriteObject(); |
| 1171 | |
| 1172 | AWTEventMulticaster.save(s, adjustmentListenerK, adjustmentListener); |
| 1173 | s.writeObject(null); |
| 1174 | } |
| 1175 | |
| 1176 | /** |
| 1177 | * Reads the <code>ObjectInputStream</code> and if |
| 1178 | * it isn't <code>null</code> adds a listener to |
| 1179 | * receive adjustment events fired by the |
| 1180 | * <code>Scrollbar</code>. |
| 1181 | * Unrecognized keys or values will be ignored. |
| 1182 | * |
| 1183 | * @param s the <code>ObjectInputStream</code> to read |
| 1184 | * @exception HeadlessException if |
| 1185 | * <code>GraphicsEnvironment.isHeadless</code> returns |
| 1186 | * <code>true</code> |
| 1187 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 1188 | * @see #writeObject(ObjectOutputStream) |
| 1189 | */ |
| 1190 | private void readObject(ObjectInputStream s) |
| 1191 | throws ClassNotFoundException, IOException, HeadlessException |
| 1192 | { |
| 1193 | GraphicsEnvironment.checkHeadless(); |
| 1194 | s.defaultReadObject(); |
| 1195 | |
| 1196 | Object keyOrNull; |
| 1197 | while(null != (keyOrNull = s.readObject())) { |
| 1198 | String key = ((String)keyOrNull).intern(); |
| 1199 | |
| 1200 | if (adjustmentListenerK == key) |
| 1201 | addAdjustmentListener((AdjustmentListener)(s.readObject())); |
| 1202 | |
| 1203 | else // skip value for unrecognized key |
| 1204 | s.readObject(); |
| 1205 | } |
| 1206 | } |
| 1207 | |
| 1208 | |
| 1209 | ///////////////// |
| 1210 | // Accessibility support |
| 1211 | //////////////// |
| 1212 | |
| 1213 | /** |
| 1214 | * Gets the <code>AccessibleContext</code> associated with this |
| 1215 | * <code>Scrollbar</code>. For scrollbars, the |
| 1216 | * <code>AccessibleContext</code> takes the form of an |
| 1217 | * <code>AccessibleAWTScrollBar</code>. A new |
| 1218 | * <code>AccessibleAWTScrollBar</code> instance is created if necessary. |
| 1219 | * |
| 1220 | * @return an <code>AccessibleAWTScrollBar</code> that serves as the |
| 1221 | * <code>AccessibleContext</code> of this <code>ScrollBar</code> |
| 1222 | * @since 1.3 |
| 1223 | */ |
| 1224 | public AccessibleContext getAccessibleContext() { |
| 1225 | if (accessibleContext == null) { |
| 1226 | accessibleContext = new AccessibleAWTScrollBar(); |
| 1227 | } |
| 1228 | return accessibleContext; |
| 1229 | } |
| 1230 | |
| 1231 | /** |
| 1232 | * This class implements accessibility support for the |
| 1233 | * <code>Scrollbar</code> class. It provides an implementation of |
| 1234 | * the Java Accessibility API appropriate to scrollbar |
| 1235 | * user-interface elements. |
| 1236 | * @since 1.3 |
| 1237 | */ |
| 1238 | protected class AccessibleAWTScrollBar extends AccessibleAWTComponent |
| 1239 | implements AccessibleValue |
| 1240 | { |
| 1241 | /* |
| 1242 | * JDK 1.3 serialVersionUID |
| 1243 | */ |
| 1244 | private static final long serialVersionUID = -344337268523697807L; |
| 1245 | |
| 1246 | /** |
| 1247 | * Get the state set of this object. |
| 1248 | * |
| 1249 | * @return an instance of <code>AccessibleState</code> |
| 1250 | * containing the current state of the object |
| 1251 | * @see AccessibleState |
| 1252 | */ |
| 1253 | public AccessibleStateSet getAccessibleStateSet() { |
| 1254 | AccessibleStateSet states = super.getAccessibleStateSet(); |
| 1255 | if (getValueIsAdjusting()) { |
| 1256 | states.add(AccessibleState.BUSY); |
| 1257 | } |
| 1258 | if (getOrientation() == VERTICAL) { |
| 1259 | states.add(AccessibleState.VERTICAL); |
| 1260 | } else { |
| 1261 | states.add(AccessibleState.HORIZONTAL); |
| 1262 | } |
| 1263 | return states; |
| 1264 | } |
| 1265 | |
| 1266 | /** |
| 1267 | * Get the role of this object. |
| 1268 | * |
| 1269 | * @return an instance of <code>AccessibleRole</code> |
| 1270 | * describing the role of the object |
| 1271 | */ |
| 1272 | public AccessibleRole getAccessibleRole() { |
| 1273 | return AccessibleRole.SCROLL_BAR; |
| 1274 | } |
| 1275 | |
| 1276 | /** |
| 1277 | * Get the <code>AccessibleValue</code> associated with this |
| 1278 | * object. In the implementation of the Java Accessibility |
| 1279 | * API for this class, return this object, which is |
| 1280 | * responsible for implementing the |
| 1281 | * <code>AccessibleValue</code> interface on behalf of itself. |
| 1282 | * |
| 1283 | * @return this object |
| 1284 | */ |
| 1285 | public AccessibleValue getAccessibleValue() { |
| 1286 | return this; |
| 1287 | } |
| 1288 | |
| 1289 | /** |
| 1290 | * Get the accessible value of this object. |
| 1291 | * |
| 1292 | * @return The current value of this object. |
| 1293 | */ |
| 1294 | public Number getCurrentAccessibleValue() { |
| 1295 | return Integer.valueOf(getValue()); |
| 1296 | } |
| 1297 | |
| 1298 | /** |
| 1299 | * Set the value of this object as a Number. |
| 1300 | * |
| 1301 | * @return True if the value was set. |
| 1302 | */ |
| 1303 | public boolean setCurrentAccessibleValue(Number n) { |
| 1304 | if (n instanceof Integer) { |
| 1305 | setValue(n.intValue()); |
| 1306 | return true; |
| 1307 | } else { |
| 1308 | return false; |
| 1309 | } |
| 1310 | } |
| 1311 | |
| 1312 | /** |
| 1313 | * Get the minimum accessible value of this object. |
| 1314 | * |
| 1315 | * @return The minimum value of this object. |
| 1316 | */ |
| 1317 | public Number getMinimumAccessibleValue() { |
| 1318 | return Integer.valueOf(getMinimum()); |
| 1319 | } |
| 1320 | |
| 1321 | /** |
| 1322 | * Get the maximum accessible value of this object. |
| 1323 | * |
| 1324 | * @return The maximum value of this object. |
| 1325 | */ |
| 1326 | public Number getMaximumAccessibleValue() { |
| 1327 | return Integer.valueOf(getMaximum()); |
| 1328 | } |
| 1329 | |
| 1330 | } // AccessibleAWTScrollBar |
| 1331 | |
| 1332 | } |