283 */ 284 private static native void initIDs(); 285 286 static { 287 /* ensure that the necessary native libraries are loaded */ 288 Toolkit.loadLibraries(); 289 if (!GraphicsEnvironment.isHeadless()) { 290 initIDs(); 291 } 292 } 293 294 /** 295 * Constructs a new vertical scroll bar. 296 * The default properties of the scroll bar are listed in 297 * the following table: 298 * 299 * <table class="striped"> 300 * <caption>Scrollbar default properties</caption> 301 * <thead> 302 * <tr> 303 * <th>Property</th> 304 * <th>Description</th> 305 * <th>Default Value</th> 306 * </tr> 307 * </thead> 308 * <tbody> 309 * <tr> 310 * <td>orientation</td> 311 * <td>indicates whether the scroll bar is vertical 312 * <br>or horizontal</td> 313 * <td>{@code Scrollbar.VERTICAL}</td> 314 * </tr> 315 * <tr> 316 * <td>value</td> 317 * <td>value which controls the location 318 * <br>of the scroll bar's bubble</td> 319 * <td>0</td> 320 * </tr> 321 * <tr> 322 * <td>visible amount</td> 323 * <td>visible amount of the scroll bar's range, 324 * <br>typically represented by the size of the 325 * <br>scroll bar's bubble</td> 326 * <td>10</td> 327 * </tr> 328 * <tr> 329 * <td>minimum</td> 330 * <td>minimum value of the scroll bar</td> 331 * <td>0</td> 332 * </tr> 333 * <tr> 334 * <td>maximum</td> 335 * <td>maximum value of the scroll bar</td> 336 * <td>100</td> 337 * </tr> 338 * <tr> 339 * <td>unit increment</td> 340 * <td>amount the value changes when the 341 * <br>Line Up or Line Down key is pressed, 342 * <br>or when the end arrows of the scrollbar 343 * <br>are clicked </td> 344 * <td>1</td> 345 * </tr> 346 * <tr> 347 * <td>block increment</td> 348 * <td>amount the value changes when the 349 * <br>Page Up or Page Down key is pressed, 350 * <br>or when the scrollbar track is clicked 351 * <br>on either side of the bubble </td> 352 * <td>10</td> 353 * </tr> 354 * </tbody> 355 * </table> 356 * 357 * @exception HeadlessException if GraphicsEnvironment.isHeadless() 358 * returns true. 359 * @see java.awt.GraphicsEnvironment#isHeadless 360 */ 361 public Scrollbar() throws HeadlessException { 362 this(VERTICAL, 0, 10, 0, 100); 363 } 364 365 /** 366 * Constructs a new scroll bar with the specified orientation. 367 * <p> 368 * The {@code orientation} argument must take one of the two 369 * values {@code Scrollbar.HORIZONTAL}, 370 * or {@code Scrollbar.VERTICAL}, 371 * indicating a horizontal or vertical scroll bar, respectively. 372 * 373 * @param orientation indicates the orientation of the scroll bar | 283 */ 284 private static native void initIDs(); 285 286 static { 287 /* ensure that the necessary native libraries are loaded */ 288 Toolkit.loadLibraries(); 289 if (!GraphicsEnvironment.isHeadless()) { 290 initIDs(); 291 } 292 } 293 294 /** 295 * Constructs a new vertical scroll bar. 296 * The default properties of the scroll bar are listed in 297 * the following table: 298 * 299 * <table class="striped"> 300 * <caption>Scrollbar default properties</caption> 301 * <thead> 302 * <tr> 303 * <th scope="col">Property 304 * <th scope="col">Description 305 * <th scope="col">Default Value 306 * </thead> 307 * <tbody> 308 * <tr> 309 * <th scope="row">orientation 310 * <td>indicates whether the scroll bar is vertical or horizontal 311 * <td>{@code Scrollbar.VERTICAL} 312 * <tr> 313 * <th scope="row">value 314 * <td>value which controls the location of the scroll bar's bubble 315 * <td>0 316 * <tr> 317 * <th scope="row">visible amount 318 * <td>visible amount of the scroll bar's range, typically represented 319 * by the size of the scroll bar's bubble 320 * <td>10 321 * <tr> 322 * <th scope="row">minimum 323 * <td>minimum value of the scroll bar 324 * <td>0 325 * <tr> 326 * <th scope="row">maximum 327 * <td>maximum value of the scroll bar 328 * <td>100 329 * <tr> 330 * <th scope="row">unit increment 331 * <td>amount the value changes when the Line Up or Line Down key is 332 * pressed, or when the end arrows of the scrollbar are clicked 333 * <td>1 334 * <tr> 335 * <th scope="row">block increment 336 * <td>amount the value changes when the Page Up or Page Down key is 337 * pressed, or when the scrollbar track is clicked<br>on either side of 338 * the bubble 339 * <td>10 340 * </tbody> 341 * </table> 342 * 343 * @exception HeadlessException if GraphicsEnvironment.isHeadless() 344 * returns true. 345 * @see java.awt.GraphicsEnvironment#isHeadless 346 */ 347 public Scrollbar() throws HeadlessException { 348 this(VERTICAL, 0, 10, 0, 100); 349 } 350 351 /** 352 * Constructs a new scroll bar with the specified orientation. 353 * <p> 354 * The {@code orientation} argument must take one of the two 355 * values {@code Scrollbar.HORIZONTAL}, 356 * or {@code Scrollbar.VERTICAL}, 357 * indicating a horizontal or vertical scroll bar, respectively. 358 * 359 * @param orientation indicates the orientation of the scroll bar |