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| 1 | +/* | |
| 2 | + * Copyright (c) 2000, 2006, 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 java.awt; | |
| 26 | + | |
| 27 | +import java.awt.event.AdjustmentEvent; | |
| 28 | +import java.awt.event.AdjustmentListener; | |
| 29 | +import java.awt.peer.ScrollPanePeer; | |
| 30 | +import java.io.Serializable; | |
| 31 | + | |
| 32 | + | |
| 33 | +/** | |
| 34 | + * This class represents the state of a horizontal or vertical | |
| 35 | + * scrollbar of a <code>ScrollPane</code>. Objects of this class are | |
| 36 | + * returned by <code>ScrollPane</code> methods. | |
| 37 | + * | |
| 38 | + * @since 1.4 | |
| 39 | + */ | |
| 40 | +public class ScrollPaneAdjustable implements Adjustable, Serializable { | |
| 41 | + | |
| 42 | + /** | |
| 43 | + * The <code>ScrollPane</code> this object is a scrollbar of. | |
| 44 | + * @serial | |
| 45 | + */ | |
| 46 | + private ScrollPane sp; | |
| 47 | + | |
| 48 | + /** | |
| 49 | + * Orientation of this scrollbar. | |
| 50 | + * | |
| 51 | + * @serial | |
| 52 | + * @see #getOrientation | |
| 53 | + * @see java.awt.Adjustable#HORIZONTAL | |
| 54 | + * @see java.awt.Adjustable#VERTICAL | |
| 55 | + */ | |
| 56 | + private int orientation; | |
| 57 | + | |
| 58 | + /** | |
| 59 | + * The value of this scrollbar. | |
| 60 | + * <code>value</code> should be greater than <code>minimum</code> | |
| 61 | + * and less than <code>maximum</code> | |
| 62 | + * | |
| 63 | + * @serial | |
| 64 | + * @see #getValue | |
| 65 | + * @see #setValue | |
| 66 | + */ | |
| 67 | + private int value; | |
| 68 | + | |
| 69 | + /** | |
| 70 | + * The minimum value of this scrollbar. | |
| 71 | + * This value can only be set by the <code>ScrollPane</code>. | |
| 72 | + * <p> | |
| 73 | + * <strong>ATTN:</strong> In current implementation | |
| 74 | + * <code>minimum</code> is always <code>0</code>. This field can | |
| 75 | + * only be altered via <code>setSpan</code> method and | |
| 76 | + * <code>ScrollPane</code> always calls that method with | |
| 77 | + * <code>0</code> for the minimum. <code>getMinimum</code> method | |
| 78 | + * always returns <code>0</code> without checking this field. | |
| 79 | + * | |
| 80 | + * @serial | |
| 81 | + * @see #getMinimum | |
| 82 | + * @see #setSpan(int, int, int) | |
| 83 | + */ | |
| 84 | + private int minimum; | |
| 85 | + | |
| 86 | + /** | |
| 87 | + * The maximum value of this scrollbar. | |
| 88 | + * This value can only be set by the <code>ScrollPane</code>. | |
| 89 | + * | |
| 90 | + * @serial | |
| 91 | + * @see #getMaximum | |
| 92 | + * @see #setSpan(int, int, int) | |
| 93 | + */ | |
| 94 | + private int maximum; | |
| 95 | + | |
| 96 | + /** | |
| 97 | + * The size of the visible portion of this scrollbar. | |
| 98 | + * This value can only be set by the <code>ScrollPane</code>. | |
| 99 | + * | |
| 100 | + * @serial | |
| 101 | + * @see #getVisibleAmount | |
| 102 | + * @see #setSpan(int, int, int) | |
| 103 | + */ | |
| 104 | + private int visibleAmount; | |
| 105 | + | |
| 106 | + /** | |
| 107 | + * The adjusting status of the <code>Scrollbar</code>. | |
| 108 | + * True if the value is in the process of changing as a result of | |
| 109 | + * actions being taken by the user. | |
| 110 | + * | |
| 111 | + * @see #getValueIsAdjusting | |
| 112 | + * @see #setValueIsAdjusting | |
| 113 | + * @since 1.4 | |
| 114 | + */ | |
| 115 | + private transient boolean isAdjusting; | |
| 116 | + | |
| 117 | + /** | |
| 118 | + * The amount by which the scrollbar value will change when going | |
| 119 | + * up or down by a line. | |
| 120 | + * This value should be a non negative integer. | |
| 121 | + * | |
| 122 | + * @serial | |
| 123 | + * @see #getUnitIncrement | |
| 124 | + * @see #setUnitIncrement | |
| 125 | + */ | |
| 126 | + private int unitIncrement = 1; | |
| 127 | + | |
| 128 | + /** | |
| 129 | + * The amount by which the scrollbar value will change when going | |
| 130 | + * up or down by a page. | |
| 131 | + * This value should be a non negative integer. | |
| 132 | + * | |
| 133 | + * @serial | |
| 134 | + * @see #getBlockIncrement | |
| 135 | + * @see #setBlockIncrement | |
| 136 | + */ | |
| 137 | + private int blockIncrement = 1; | |
| 138 | + | |
| 139 | + private AdjustmentListener adjustmentListener; | |
| 140 | + | |
| 141 | + /** | |
| 142 | + * Error message for <code>AWTError</code> reported when one of | |
| 143 | + * the public but unsupported methods is called. | |
| 144 | + */ | |
| 145 | + private static final String SCROLLPANE_ONLY = | |
| 146 | + "Can be set by scrollpane only"; | |
| 147 | + | |
| 148 | + | |
| 149 | + /** | |
| 150 | + * Initialize JNI field and method ids. | |
| 151 | + */ | |
| 152 | + private static native void initIDs(); | |
| 153 | + | |
| 154 | + static { | |
| 155 | + Toolkit.loadLibraries(); | |
| 156 | + if (!GraphicsEnvironment.isHeadless()) { | |
| 157 | + initIDs(); | |
| 158 | + } | |
| 159 | + } | |
| 160 | + | |
| 161 | + /** | |
| 162 | + * JDK 1.1 serialVersionUID. | |
| 163 | + */ | |
| 164 | + private static final long serialVersionUID = -3359745691033257079L; | |
| 165 | + | |
| 166 | + | |
| 167 | + /** | |
| 168 | + * Constructs a new object to represent specified scrollabar | |
| 169 | + * of the specified <code>ScrollPane</code>. | |
| 170 | + * Only ScrollPane creates instances of this class. | |
| 171 | + * @param sp <code>ScrollPane</code> | |
| 172 | + * @param l <code>AdjustmentListener</code> to add upon creation. | |
| 173 | + * @param orientation specifies which scrollbar this object represents, | |
| 174 | + * can be either <code>Adjustable.HORIZONTAL</code> | |
| 175 | + * or <code>Adjustable.VERTICAL</code>. | |
| 176 | + */ | |
| 177 | + ScrollPaneAdjustable(ScrollPane sp, AdjustmentListener l, int orientation) { | |
| 178 | + this.sp = sp; | |
| 179 | + this.orientation = orientation; | |
| 180 | + addAdjustmentListener(l); | |
| 181 | + } | |
| 182 | + | |
| 183 | + /** | |
| 184 | + * This is called by the scrollpane itself to update the | |
| 185 | + * <code>minimum</code>, <code>maximum</code> and | |
| 186 | + * <code>visible</code> values. The scrollpane is the only one | |
| 187 | + * that should be changing these since it is the source of these | |
| 188 | + * values. | |
| 189 | + */ | |
| 190 | + void setSpan(int min, int max, int visible) { | |
| 191 | + // adjust the values to be reasonable | |
| 192 | + minimum = min; | |
| 193 | + maximum = Math.max(max, minimum + 1); | |
| 194 | + visibleAmount = Math.min(visible, maximum - minimum); | |
| 195 | + visibleAmount = Math.max(visibleAmount, 1); | |
| 196 | + blockIncrement = Math.max((int)(visible * .90), 1); | |
| 197 | + setValue(value); | |
| 198 | + } | |
| 199 | + | |
| 200 | + /** | |
| 201 | + * Returns the orientation of this scrollbar. | |
| 202 | + * @return the orientation of this scrollbar, either | |
| 203 | + * <code>Adjustable.HORIZONTAL</code> or | |
| 204 | + * <code>Adjustable.VERTICAL</code> | |
| 205 | + */ | |
| 206 | + public int getOrientation() { | |
| 207 | + return orientation; | |
| 208 | + } | |
| 209 | + | |
| 210 | + /** | |
| 211 | + * This method should <strong>NOT</strong> be called by user code. | |
| 212 | + * This method is public for this class to properly implement | |
| 213 | + * <code>Adjustable</code> interface. | |
| 214 | + * | |
| 215 | + * @throws <code>AWTError</code> Always throws an error when called. | |
| 216 | + */ | |
| 217 | + public void setMinimum(int min) { | |
| 218 | + throw new AWTError(SCROLLPANE_ONLY); | |
| 219 | + } | |
| 220 | + | |
| 221 | + public int getMinimum() { | |
| 222 | + // XXX: This relies on setSpan always being called with 0 for | |
| 223 | + // the minimum (which is currently true). | |
| 224 | + return 0; | |
| 225 | + } | |
| 226 | + | |
| 227 | + /** | |
| 228 | + * This method should <strong>NOT</strong> be called by user code. | |
| 229 | + * This method is public for this class to properly implement | |
| 230 | + * <code>Adjustable</code> interface. | |
| 231 | + * | |
| 232 | + * @throws <code>AWTError</code> Always throws an error when called. | |
| 233 | + */ | |
| 234 | + public void setMaximum(int max) { | |
| 235 | + throw new AWTError(SCROLLPANE_ONLY); | |
| 236 | + } | |
| 237 | + | |
| 238 | + public int getMaximum() { | |
| 239 | + return maximum; | |
| 240 | + } | |
| 241 | + | |
| 242 | + public synchronized void setUnitIncrement(int u) { | |
| 243 | + if (u != unitIncrement) { | |
| 244 | + unitIncrement = u; | |
| 245 | + if (sp.peer != null) { | |
| 246 | + ScrollPanePeer peer = (ScrollPanePeer) sp.peer; | |
| 247 | + peer.setUnitIncrement(this, u); | |
| 248 | + } | |
| 249 | + } | |
| 250 | + } | |
| 251 | + | |
| 252 | + public int getUnitIncrement() { | |
| 253 | + return unitIncrement; | |
| 254 | + } | |
| 255 | + | |
| 256 | + public synchronized void setBlockIncrement(int b) { | |
| 257 | + blockIncrement = b; | |
| 258 | + } | |
| 259 | + | |
| 260 | + public int getBlockIncrement() { | |
| 261 | + return blockIncrement; | |
| 262 | + } | |
| 263 | + | |
| 264 | + /** | |
| 265 | + * This method should <strong>NOT</strong> be called by user code. | |
| 266 | + * This method is public for this class to properly implement | |
| 267 | + * <code>Adjustable</code> interface. | |
| 268 | + * | |
| 269 | + * @throws <code>AWTError</code> Always throws an error when called. | |
| 270 | + */ | |
| 271 | + public void setVisibleAmount(int v) { | |
| 272 | + throw new AWTError(SCROLLPANE_ONLY); | |
| 273 | + } | |
| 274 | + | |
| 275 | + public int getVisibleAmount() { | |
| 276 | + return visibleAmount; | |
| 277 | + } | |
| 278 | + | |
| 279 | + | |
| 280 | + /** | |
| 281 | + * Sets the <code>valueIsAdjusting</code> property. | |
| 282 | + * | |
| 283 | + * @param b new adjustment-in-progress status | |
| 284 | + * @see #getValueIsAdjusting | |
| 285 | + * @since 1.4 | |
| 286 | + */ | |
| 287 | + public void setValueIsAdjusting(boolean b) { | |
| 288 | + if (isAdjusting != b) { | |
| 289 | + isAdjusting = b; | |
| 290 | + AdjustmentEvent e = | |
| 291 | + new AdjustmentEvent(this, | |
| 292 | + AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED, | |
| 293 | + AdjustmentEvent.TRACK, value, b); | |
| 294 | + adjustmentListener.adjustmentValueChanged(e); | |
| 295 | + } | |
| 296 | + } | |
| 297 | + | |
| 298 | + /** | |
| 299 | + * Returns true if the value is in the process of changing as a | |
| 300 | + * result of actions being taken by the user. | |
| 301 | + * | |
| 302 | + * @return the value of the <code>valueIsAdjusting</code> property | |
| 303 | + * @see #setValueIsAdjusting | |
| 304 | + */ | |
| 305 | + public boolean getValueIsAdjusting() { | |
| 306 | + return isAdjusting; | |
| 307 | + } | |
| 308 | + | |
| 309 | + /** | |
| 310 | + * Sets the value of this scrollbar to the specified value. | |
| 311 | + * <p> | |
| 312 | + * If the value supplied is less than the current minimum or | |
| 313 | + * greater than the current maximum, then one of those values is | |
| 314 | + * substituted, as appropriate. | |
| 315 | + * | |
| 316 | + * @param v the new value of the scrollbar | |
| 317 | + */ | |
| 318 | + public void setValue(int v) { | |
| 319 | + setTypedValue(v, AdjustmentEvent.TRACK); | |
| 320 | + } | |
| 321 | + | |
| 322 | + /** | |
| 323 | + * Sets the value of this scrollbar to the specified value. | |
| 324 | + * <p> | |
| 325 | + * If the value supplied is less than the current minimum or | |
| 326 | + * greater than the current maximum, then one of those values is | |
| 327 | + * substituted, as appropriate. Also, creates and dispatches | |
| 328 | + * the AdjustementEvent with specified type and value. | |
| 329 | + * | |
| 330 | + * @param v the new value of the scrollbar | |
| 331 | + * @param type the type of the scrolling operation occured | |
| 332 | + */ | |
| 333 | + private void setTypedValue(int v, int type) { | |
| 334 | + v = Math.max(v, minimum); | |
| 335 | + v = Math.min(v, maximum - visibleAmount); | |
| 336 | + | |
| 337 | + if (v != value) { | |
| 338 | + value = v; | |
| 339 | + // Synchronously notify the listeners so that they are | |
| 340 | + // guaranteed to be up-to-date with the Adjustable before | |
| 341 | + // it is mutated again. | |
| 342 | + AdjustmentEvent e = | |
| 343 | + new AdjustmentEvent(this, | |
| 344 | + AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED, | |
| 345 | + type, value, isAdjusting); | |
| 346 | + adjustmentListener.adjustmentValueChanged(e); | |
| 347 | + } | |
| 348 | + } | |
| 349 | + | |
| 350 | + public int getValue() { | |
| 351 | + return value; | |
| 352 | + } | |
| 353 | + | |
| 354 | + /** | |
| 355 | + * Adds the specified adjustment listener to receive adjustment | |
| 356 | + * events from this <code>ScrollPaneAdjustable</code>. | |
| 357 | + * If <code>l</code> is <code>null</code>, no exception is thrown | |
| 358 | + * and no action is performed. | |
| 359 | + * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" | |
| 360 | + * >AWT Threading Issues</a> for details on AWT's threading model. | |
| 361 | + * | |
| 362 | + * @param l the adjustment listener. | |
| 363 | + * @see #removeAdjustmentListener | |
| 364 | + * @see #getAdjustmentListeners | |
| 365 | + * @see java.awt.event.AdjustmentListener | |
| 366 | + * @see java.awt.event.AdjustmentEvent | |
| 367 | + */ | |
| 368 | + public synchronized void addAdjustmentListener(AdjustmentListener l) { | |
| 369 | + if (l == null) { | |
| 370 | + return; | |
| 371 | + } | |
| 372 | + adjustmentListener = AWTEventMulticaster.add(adjustmentListener, l); | |
| 373 | + } | |
| 374 | + | |
| 375 | + /** | |
| 376 | + * Removes the specified adjustment listener so that it no longer | |
| 377 | + * receives adjustment events from this <code>ScrollPaneAdjustable</code>. | |
| 378 | + * If <code>l</code> is <code>null</code>, no exception is thrown | |
| 379 | + * and no action is performed. | |
| 380 | + * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" | |
| 381 | + * >AWT Threading Issues</a> for details on AWT's threading model. | |
| 382 | + * | |
| 383 | + * @param l the adjustment listener. | |
| 384 | + * @see #addAdjustmentListener | |
| 385 | + * @see #getAdjustmentListeners | |
| 386 | + * @see java.awt.event.AdjustmentListener | |
| 387 | + * @see java.awt.event.AdjustmentEvent | |
| 388 | + * @since JDK1.1 | |
| 389 | + */ | |
| 390 | + public synchronized void removeAdjustmentListener(AdjustmentListener l){ | |
| 391 | + if (l == null) { | |
| 392 | + return; | |
| 393 | + } | |
| 394 | + adjustmentListener = AWTEventMulticaster.remove(adjustmentListener, l); | |
| 395 | + } | |
| 396 | + | |
| 397 | + /** | |
| 398 | + * Returns an array of all the adjustment listeners | |
| 399 | + * registered on this <code>ScrollPaneAdjustable</code>. | |
| 400 | + * | |
| 401 | + * @return all of this <code>ScrollPaneAdjustable</code>'s | |
| 402 | + * <code>AdjustmentListener</code>s | |
| 403 | + * or an empty array if no adjustment | |
| 404 | + * listeners are currently registered | |
| 405 | + * | |
| 406 | + * @see #addAdjustmentListener | |
| 407 | + * @see #removeAdjustmentListener | |
| 408 | + * @see java.awt.event.AdjustmentListener | |
| 409 | + * @see java.awt.event.AdjustmentEvent | |
| 410 | + * @since 1.4 | |
| 411 | + */ | |
| 412 | + public synchronized AdjustmentListener[] getAdjustmentListeners() { | |
| 413 | + return (AdjustmentListener[])(AWTEventMulticaster.getListeners( | |
| 414 | + adjustmentListener, | |
| 415 | + AdjustmentListener.class)); | |
| 416 | + } | |
| 417 | + | |
| 418 | + /** | |
| 419 | + * Returns a string representation of this scrollbar and its values. | |
| 420 | + * @return a string representation of this scrollbar. | |
| 421 | + */ | |
| 422 | + public String toString() { | |
| 423 | + return getClass().getName() + "[" + paramString() + "]"; | |
| 424 | + } | |
| 425 | + | |
| 426 | + /** | |
| 427 | + * Returns a string representing the state of this scrollbar. | |
| 428 | + * This method is intended to be used only for debugging purposes, | |
| 429 | + * and the content and format of the returned string may vary | |
| 430 | + * between implementations. The returned string may be empty but | |
| 431 | + * may not be <code>null</code>. | |
| 432 | + * | |
| 433 | + * @return the parameter string of this scrollbar. | |
| 434 | + */ | |
| 435 | + public String paramString() { | |
| 436 | + return ((orientation == Adjustable.VERTICAL ? "vertical," | |
| 437 | + :"horizontal,") | |
| 438 | + + "[0.."+maximum+"]" | |
| 439 | + + ",val=" + value | |
| 440 | + + ",vis=" + visibleAmount | |
| 441 | + + ",unit=" + unitIncrement | |
| 442 | + + ",block=" + blockIncrement | |
| 443 | + + ",isAdjusting=" + isAdjusting); | |
| 444 | + } | |
| 445 | +} | |