001 /*
002 * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package javax.swing;
027
028 import java.awt.Font;
029 import java.awt.event.InputEvent;
030 import java.awt.event.KeyEvent;
031 import java.awt.Color;
032 import java.awt.Component;
033 import java.awt.SystemColor;
034 import java.awt.Toolkit;
035
036 import javax.swing.text.*;
037 import javax.swing.border.*;
038 import javax.swing.plaf.*;
039
040 import java.net.URL;
041 import sun.swing.SwingUtilities2;
042 import sun.swing.DefaultLayoutStyle;
043 import sun.swing.ImageIconUIResource;
044
045 import java.util.StringTokenizer;
046
047 /**
048 * {@code LookAndFeel}, as the name implies, encapsulates a look and
049 * feel. Beyond installing a look and feel most developers never need to
050 * interact directly with {@code LookAndFeel}. In general only developers
051 * creating a custom look and feel need to concern themselves with this class.
052 * <p>
053 * Swing is built upon the foundation that each {@code JComponent}
054 * subclass has an implementation of a specific {@code ComponentUI}
055 * subclass. The {@code ComponentUI} is often referred to as "the ui",
056 * "component ui", or "look and feel delegate". The {@code ComponentUI}
057 * subclass is responsible for providing the look and feel specific
058 * functionality of the component. For example, {@code JTree} requires
059 * an implementation of the {@code ComponentUI} subclass {@code
060 * TreeUI}. The implementation of the specific {@code
061 * ComponentUI} subclass is provided by the {@code LookAndFeel}. Each
062 * {@code JComponent} subclass identifies the {@code ComponentUI}
063 * subclass it requires by way of the {@code JComponent} method {@code
064 * getUIClassID}.
065 * <p>
066 * Each {@code LookAndFeel} implementation must provide
067 * an implementation of the appropriate {@code ComponentUI} subclass by
068 * specifying a value for each of Swing's ui class ids in the {@code
069 * UIDefaults} object returned from {@code getDefaults}. For example,
070 * {@code BasicLookAndFeel} uses {@code BasicTreeUI} as the concrete
071 * implementation for {@code TreeUI}. This is accomplished by {@code
072 * BasicLookAndFeel} providing the key-value pair {@code
073 * "TreeUI"-"javax.swing.plaf.basic.BasicTreeUI"}, in the
074 * {@code UIDefaults} returned from {@code getDefaults}. Refer to
075 * {@link UIDefaults#getUI(JComponent)} for defails on how the implementation
076 * of the {@code ComponentUI} subclass is obtained.
077 * <p>
078 * When a {@code LookAndFeel} is installed the {@code UIManager} does
079 * not check that an entry exists for all ui class ids. As such,
080 * random exceptions will occur if the current look and feel has not
081 * provided a value for a particular ui class id and an instance of
082 * the {@code JComponent} subclass is created.
083 *
084 * <h2>Recommendations for Look and Feels</h2>
085 *
086 * As noted in {@code UIManager} each {@code LookAndFeel} has the opportunity
087 * to provide a set of defaults that are layered in with developer and
088 * system defaults. Some of Swing's components require the look and feel
089 * to provide a specific set of defaults. These are documented in the
090 * classes that require the specific default.
091 *
092 * <h3><a name="#defaultRecommendation">ComponentUIs and defaults</a></h2>
093 *
094 * All {@code ComponentUIs} typically need to set various properties
095 * on the {@code JComponent} the {@code ComponentUI} is providing the
096 * look and feel for. This is typically done when the {@code
097 * ComponentUI} is installed on the {@code JComponent}. Setting a
098 * property should only be done if the developer has not set the
099 * property. For non-primitive values it is recommended that the
100 * {@code ComponentUI} only change the property on the {@code
101 * JComponent} if the current value is {@code null} or implements
102 * {@code UIResource}. If the current value is {@code null} or
103 * implements {@code UIResource} it indicates the property has not
104 * been set by the developer, and the ui is free to change it. For
105 * example, {@code BasicButtonUI.installDefaults} only changes the
106 * font on the {@code JButton} if the return value from {@code
107 * button.getFont()} is {@code null} or implements {@code
108 * UIResource}. On the other hand if {@code button.getFont()} returned
109 * a {@code non-null} value that did not implement {@code UIResource}
110 * then {@code BasicButtonUI.installDefaults} would not change the
111 * {@code JButton}'s font.
112 * <p>
113 * For primitive values, such as {@code opaque}, the method {@code
114 * installProperty} should be invoked. {@code installProperty} only changes
115 * the correspoding property if the value has not been changed by the
116 * developer.
117 * <p>
118 * {@code ComponentUI} implementations should use the various install methods
119 * provided by this class as they handle the necessary checking and install
120 * the property using the recommended guidelines.
121 * <p>
122 * <h3><a name="exceptions"></a>Exceptions</h3>
123 *
124 * All of the install methods provided by {@code LookAndFeel} need to
125 * access the defaults if the value of the property being changed is
126 * {@code null} or a {@code UIResource}. For example, installing the
127 * font does the following:
128 * <pre>
129 * JComponent c;
130 * Font font = c.getFont();
131 * if (font == null || (font instanceof UIResource)) {
132 * c.setFont(UIManager.getFont("fontKey"));
133 * }
134 * </pre>
135 * If the font is {@code null} or a {@code UIResource}, the
136 * defaults table is queried with the key {@code fontKey}. All of
137 * {@code UIDefault's} get methods throw a {@code
138 * NullPointerException} if passed in {@code null}. As such, unless
139 * otherwise noted each of the various install methods of {@code
140 * LookAndFeel} throw a {@code NullPointerException} if the current
141 * value is {@code null} or a {@code UIResource} and the supplied
142 * defaults key is {@code null}. In addition, unless otherwise specified
143 * all of the {@code install} methods throw a {@code NullPointerException} if
144 * a {@code null} component is passed in.
145 *
146 * @version 1.50 05/05/07
147 * @author Tom Ball
148 * @author Hans Muller
149 */
150 public abstract class LookAndFeel {
151
152 /**
153 * Convenience method for setting a component's foreground
154 * and background color properties with values from the
155 * defaults. The properties are only set if the current
156 * value is either {@code null} or a {@code UIResource}.
157 *
158 * @param c component to set the colors on
159 * @param defaultBgName key for the background
160 * @param defaultFgName key for the foreground
161 *
162 * @see #installColorsAndFont
163 * @see UIManager#getColor
164 * @throws NullPointerException as described in
165 * <a href="#exceptions">exceptions</a>
166 */
167 public static void installColors(JComponent c,
168 String defaultBgName, String defaultFgName) {
169 Color bg = c.getBackground();
170 if (bg == null || bg instanceof UIResource) {
171 c.setBackground(UIManager.getColor(defaultBgName));
172 }
173
174 Color fg = c.getForeground();
175 if (fg == null || fg instanceof UIResource) {
176 c.setForeground(UIManager.getColor(defaultFgName));
177 }
178 }
179
180 /**
181 * Convenience method for setting a component's foreground,
182 * background and font properties with values from the
183 * defaults. The properties are only set if the current
184 * value is either {@code null} or a {@code UIResource}.
185 *
186 * @param c component set to the colors and font on
187 * @param defaultBgName key for the background
188 * @param defaultFgName key for the foreground
189 * @param defaultFontName key for the font
190 * @throws NullPointerException as described in
191 * <a href="#exceptions">exceptions</a>
192 *
193 * @see #installColors
194 * @see UIManager#getColor
195 * @see UIManager#getFont
196 */
197 public static void installColorsAndFont(JComponent c,
198 String defaultBgName, String defaultFgName,
199 String defaultFontName) {
200 Font f = c.getFont();
201 if (f == null || f instanceof UIResource) {
202 c.setFont(UIManager.getFont(defaultFontName));
203 }
204
205 installColors(c, defaultBgName, defaultFgName);
206 }
207
208 /**
209 * Convenience method for setting a component's border property with
210 * a value from the defaults. The border is only set if the border is
211 * {@code null} or an instance of {@code UIResource}.
212 *
213 * @param c component to set the border on
214 * @param defaultBorderName key specifying the border
215 * @throws NullPointerException as described in
216 * <a href="#exceptions">exceptions</a>
217 */
218 public static void installBorder(JComponent c,
219 String defaultBorderName) {
220 Border b = c.getBorder();
221 if (b == null || b instanceof UIResource) {
222 c.setBorder(UIManager.getBorder(defaultBorderName));
223 }
224 }
225
226 /**
227 * Convenience method for uninstalling a border. If the border of
228 * the component is a {@code UIResource}, it is set to {@code
229 * null}.
230 *
231 * @param c component to uninstall the border on
232 * @throws NullPointerException if {@code c} is {@code null}
233 */
234 public static void uninstallBorder(JComponent c) {
235 if (c.getBorder() instanceof UIResource) {
236 c.setBorder(null);
237 }
238 }
239
240 /**
241 * Convenience method for installing a property with the specified name
242 * and value on a component if that property has not already been set
243 * by the developer. This method is intended to be used by
244 * ui delegate instances that need to specify a default value for a
245 * property of primitive type (boolean, int, ..), but do not wish
246 * to override a value set by the client. Since primitive property
247 * values cannot be wrapped with the {@code UIResource} marker, this method
248 * uses private state to determine whether the property has been set
249 * by the client.
250 *
251 * @throws IllegalArgumentException if the specified property is not
252 * one which can be set using this method
253 * @throws ClassCastException if the property value has not been set
254 * by the developer and the type does not match the property's type
255 * @throws NullPointerException if {@code c} is {@code null}, or the
256 * named property has not been set by the developer and
257 * {@code propertyValue} is {@code null}
258 * @param c target component to set the property on
259 * @param propertyName name of the property to set
260 * @param propertyValue value of the property
261 * @since 1.5
262 */
263 public static void installProperty(JComponent c,
264 String propertyName, Object propertyValue) {
265 // this is a special case because the JPasswordField's ancestor heirarchy
266 // includes a class outside of javax.swing, thus we cannot call setUIProperty
267 // directly.
268 if (c instanceof JPasswordField) {
269 if (!((JPasswordField) c).customSetUIProperty(propertyName,
270 propertyValue)) {
271 c.setUIProperty(propertyName, propertyValue);
272 }
273 } else {
274 c.setUIProperty(propertyName, propertyValue);
275 }
276 }
277
278 /**
279 * Convenience method for building an array of {@code
280 * KeyBindings}. While this method is not deprecated, developers
281 * should instead use {@code ActionMap} and {@code InputMap} for
282 * supplying key bindings.
283 * <p>
284 * This method returns an array of {@code KeyBindings}, one for each
285 * alternating {@code key-action} pair in {@code keyBindingList}.
286 * A {@code key} can either be a {@code String} in the format
287 * specified by the <code>KeyStroke.getKeyStroke</code> method, or
288 * a {@code KeyStroke}. The {@code action} part of the pair is a
289 * {@code String} that corresponds to the name of the {@code
290 * Action}.
291 * <p>
292 * The following example illustrates creating a {@code KeyBinding} array
293 * from six alternating {@code key-action} pairs:
294 * <pre>
295 * JTextComponent.KeyBinding[] multilineBindings = makeKeyBindings( new Object[] {
296 * "UP", DefaultEditorKit.upAction,
297 * "DOWN", DefaultEditorKit.downAction,
298 * "PAGE_UP", DefaultEditorKit.pageUpAction,
299 * "PAGE_DOWN", DefaultEditorKit.pageDownAction,
300 * "ENTER", DefaultEditorKit.insertBreakAction,
301 * "TAB", DefaultEditorKit.insertTabAction
302 * });
303 * </pre>
304 * If {@code keyBindingList's} length is odd, the last element is
305 * ignored.
306 * <p>
307 * Supplying a {@code null} value for either the {@code key} or
308 * {@code action} part of the {@code key-action} pair results in
309 * creating a {@code KeyBinding} with the corresponding value
310 * {@code null}. As other parts of Swing's expect {@code non-null} values
311 * in a {@code KeyBinding}, you should avoid supplying {@code null} as
312 * either the {@code key} or {@code action} part of the {@code key-action}
313 * pair.
314 *
315 * @param keyBindingList an array of {@code key-action} pairs
316 * @return an array of {@code KeyBindings}
317 * @throws NullPointerException if {@code keyBindingList} is {@code null}
318 * @throws ClassCastException if the {@code key} part of the pair is
319 * not a {@code KeyStroke} or {@code String}, or the
320 * {@code action} part of the pair is not a {@code String}
321 * @see ActionMap
322 * @see InputMap
323 * @see KeyStroke#getKeyStroke
324 */
325 public static JTextComponent.KeyBinding[] makeKeyBindings(
326 Object[] keyBindingList) {
327 JTextComponent.KeyBinding[] rv = new JTextComponent.KeyBinding[keyBindingList.length / 2];
328
329 for (int i = 0; i < keyBindingList.length; i += 2) {
330 KeyStroke keystroke = (keyBindingList[i] instanceof KeyStroke) ? (KeyStroke) keyBindingList[i]
331 : KeyStroke
332 .getKeyStroke((String) keyBindingList[i]);
333 String action = (String) keyBindingList[i + 1];
334 rv[i / 2] = new JTextComponent.KeyBinding(keystroke, action);
335 }
336
337 return rv;
338 }
339
340 /**
341 * Creates a {@code InputMapUIResource} from <code>keys</code>. This is
342 * a convenience method for creating a new {@code InputMapUIResource},
343 * invoking {@code loadKeyBindings(map, keys)}, and returning the
344 * {@code InputMapUIResource}.
345 *
346 * @param keys alternating pairs of {@code keystroke-action key}
347 * pairs as described in {@link #loadKeyBindings}
348 * @return newly created and populated {@code InputMapUIResource}
349 * @see #loadKeyBindings
350 *
351 * @since 1.3
352 */
353 public static InputMap makeInputMap(Object[] keys) {
354 InputMap retMap = new InputMapUIResource();
355 loadKeyBindings(retMap, keys);
356 return retMap;
357 }
358
359 /**
360 * Creates a {@code ComponentInputMapUIResource} from
361 * <code>keys</code>. This is a convenience method for creating a
362 * new {@code ComponentInputMapUIResource}, invoking {@code
363 * loadKeyBindings(map, keys)}, and returning the {@code
364 * ComponentInputMapUIResource}.
365 *
366 * @param c component to create the {@code ComponentInputMapUIResource}
367 * with
368 * @param keys alternating pairs of {@code keystroke-action key}
369 * pairs as described in {@link #loadKeyBindings}
370 * @return newly created and populated {@code InputMapUIResource}
371 * @throws IllegalArgumentException if {@code c} is {@code null}
372 *
373 * @see #loadKeyBindings
374 * @see ComponentInputMapUIResource
375 *
376 * @since 1.3
377 */
378 public static ComponentInputMap makeComponentInputMap(JComponent c,
379 Object[] keys) {
380 ComponentInputMap retMap = new ComponentInputMapUIResource(c);
381 loadKeyBindings(retMap, keys);
382 return retMap;
383 }
384
385 /**
386 * Populates an {@code InputMap} with the specified bindings.
387 * The bindings are supplied as a list of alternating
388 * {@code keystroke-action key} pairs. The {@code keystroke} is either
389 * an instance of {@code KeyStroke}, or a {@code String}
390 * that identifies the {@code KeyStroke} for the binding. Refer
391 * to {@code KeyStroke.getKeyStroke(String)} for the specific
392 * format. The {@code action key} part of the pair is the key
393 * registered in the {@code InputMap} for the {@code KeyStroke}.
394 * <p>
395 * The following illustrates loading an {@code InputMap} with two
396 * {@code key-action} pairs:
397 * <pre>
398 * LookAndFeel.loadKeyBindings(inputMap, new Object[] {
399 * "control X", "cut",
400 * "control V", "paste"
401 * });
402 * </pre>
403 * <p>
404 * Supplying a {@code null} list of bindings ({@code keys}) does not
405 * change {@code retMap} in any way.
406 * <p>
407 * Specifying a {@code null} {@code action key} results in
408 * removing the {@code keystroke's} entry from the {@code InputMap}.
409 * A {@code null} {@code keystroke} is ignored.
410 *
411 * @param retMap {@code InputMap} to add the {@code key-action}
412 * pairs to
413 * @param keys bindings to add to {@code retMap}
414 * @throws NullPointerException if {@code keys} is
415 * {@code non-null}, not empty, and {@code retMap} is
416 * {@code null}
417 *
418 * @see KeyStroke#getKeyStroke(String)
419 * @see InputMap
420 *
421 * @since 1.3
422 */
423 public static void loadKeyBindings(InputMap retMap, Object[] keys) {
424 if (keys != null) {
425 for (int counter = 0, maxCounter = keys.length; counter < maxCounter; counter++) {
426 Object keyStrokeO = keys[counter++];
427 KeyStroke ks = (keyStrokeO instanceof KeyStroke) ? (KeyStroke) keyStrokeO
428 : KeyStroke.getKeyStroke((String) keyStrokeO);
429 retMap.put(ks, keys[counter]);
430 }
431 }
432 }
433
434 /**
435 * Creates and returns a {@code UIDefault.LazyValue} that loads an
436 * image. The returned value is an implementation of {@code
437 * UIDefaults.LazyValue}. When {@code createValue} is invoked on
438 * the returned object, the image is loaded. If the image is {@code
439 * non-null}, it is then wrapped in an {@code Icon} that implements {@code
440 * UIResource}. The image is loaded using {@code
441 * Class.getResourceAsStream(gifFile)}.
442 * <p>
443 * This method does not check the arguments in any way. It is
444 * strongly recommended that {@code non-null} values are supplied else
445 * exceptions may occur when {@code createValue} is invoked on the
446 * returned object.
447 *
448 * @param baseClass {@code Class} used to load the resource
449 * @param gifFile path to the image to load
450 * @return a {@code UIDefaults.LazyValue}; when resolved the
451 * {@code LazyValue} loads the specified image
452 * @see UIDefaults.LazyValue
453 * @see Icon
454 * @see Class#getResourceAsStream(String)
455 */
456 public static Object makeIcon(final Class<?> baseClass,
457 final String gifFile) {
458 return SwingUtilities2.makeIcon(baseClass, baseClass, gifFile);
459 }
460
461 /**
462 * Returns the <code>LayoutStyle</code> for this look
463 * and feel. This never returns {@code null}.
464 * <p>
465 * You generally don't use the <code>LayoutStyle</code> from
466 * the look and feel, instead use the <code>LayoutStyle</code>
467 * method <code>getInstance</code>.
468 *
469 * @see LayoutStyle#getInstance
470 * @return the <code>LayoutStyle</code> for this look and feel
471 * @since 1.6
472 */
473 public LayoutStyle getLayoutStyle() {
474 return DefaultLayoutStyle.getInstance();
475 }
476
477 /**
478 * Invoked when the user attempts an invalid operation,
479 * such as pasting into an uneditable <code>JTextField</code>
480 * that has focus. The default implementation beeps. Subclasses
481 * that wish different behavior should override this and provide
482 * the additional feedback.
483 *
484 * @param component the <code>Component</code> the error occurred in,
485 * may be <code>null</code>
486 * indicating the error condition is not directly
487 * associated with a <code>Component</code>
488 * @since 1.4
489 */
490 public void provideErrorFeedback(Component component) {
491 Toolkit toolkit = null;
492 if (component != null) {
493 toolkit = component.getToolkit();
494 } else {
495 toolkit = Toolkit.getDefaultToolkit();
496 }
497 toolkit.beep();
498 } // provideErrorFeedback()
499
500 /**
501 * Returns the value of the specified system desktop property by
502 * invoking <code>Toolkit.getDefaultToolkit().getDesktopProperty()</code>.
503 * If the value of the specified property is {@code null},
504 * {@code fallbackValue} is returned.
505 *
506 * @param systemPropertyName the name of the system desktop property being queried
507 * @param fallbackValue the object to be returned as the value if the system value is null
508 * @return the current value of the desktop property
509 *
510 * @see java.awt.Toolkit#getDesktopProperty
511 *
512 * @since 1.4
513 */
514 public static Object getDesktopPropertyValue(
515 String systemPropertyName, Object fallbackValue) {
516 Object value = Toolkit.getDefaultToolkit().getDesktopProperty(
517 systemPropertyName);
518 if (value == null) {
519 return fallbackValue;
520 } else if (value instanceof Color) {
521 return new ColorUIResource((Color) value);
522 } else if (value instanceof Font) {
523 return new FontUIResource((Font) value);
524 }
525 return value;
526 }
527
528 /**
529 * Returns an <code>Icon</code> with a disabled appearance.
530 * This method is used to generate a disabled <code>Icon</code> when
531 * one has not been specified. For example, if you create a
532 * <code>JButton</code> and only specify an <code>Icon</code> via
533 * <code>setIcon</code> this method will be called to generate the
534 * disabled <code>Icon</code>. If {@code null} is passed as
535 * <code>icon</code> this method returns {@code null}.
536 * <p>
537 * Some look and feels might not render the disabled {@code Icon}, in which
538 * case they will ignore this.
539 *
540 * @param component {@code JComponent} that will display the {@code Icon},
541 * may be {@code null}
542 * @param icon {@code Icon} to generate the disabled icon from
543 * @return disabled {@code Icon}, or {@code null} if a suitable
544 * {@code Icon} can not be generated
545 * @since 1.5
546 */
547 public Icon getDisabledIcon(JComponent component, Icon icon) {
548 if (icon instanceof ImageIcon) {
549 return new ImageIconUIResource(GrayFilter
550 .createDisabledImage(((ImageIcon) icon).getImage()));
551 }
552 return null;
553 }
554
555 /**
556 * Returns an <code>Icon</code> for use by disabled
557 * components that are also selected. This method is used to generate an
558 * <code>Icon</code> for components that are in both the disabled and
559 * selected states but do not have a specific <code>Icon</code> for this
560 * state. For example, if you create a <code>JButton</code> and only
561 * specify an <code>Icon</code> via <code>setIcon</code> this method
562 * will be called to generate the disabled and selected
563 * <code>Icon</code>. If {@code null} is passed as <code>icon</code> this
564 * methods returns {@code null}.
565 * <p>
566 * Some look and feels might not render the disabled and selected
567 * {@code Icon}, in which case they will ignore this.
568 *
569 * @param component {@code JComponent} that will display the {@code Icon},
570 * may be {@code null}
571 * @param icon {@code Icon} to generate disabled and selected icon from
572 * @return disabled and selected icon, or {@code null} if a suitable
573 * {@code Icon} can not be generated.
574 * @since 1.5
575 */
576 public Icon getDisabledSelectedIcon(JComponent component, Icon icon) {
577 return getDisabledIcon(component, icon);
578 }
579
580 /**
581 * Return a short string that identifies this look and feel, e.g.
582 * "CDE/Motif". This string should be appropriate for a menu item.
583 * Distinct look and feels should have different names, e.g.
584 * a subclass of MotifLookAndFeel that changes the way a few components
585 * are rendered should be called "CDE/Motif My Way"; something
586 * that would be useful to a user trying to select a L&F from a list
587 * of names.
588 *
589 * @return short identifier for the look and feel
590 */
591 public abstract String getName();
592
593 /**
594 * Return a string that identifies this look and feel. This string
595 * will be used by applications/services that want to recognize
596 * well known look and feel implementations. Presently
597 * the well known names are "Motif", "Windows", "Mac", "Metal". Note
598 * that a LookAndFeel derived from a well known superclass
599 * that doesn't make any fundamental changes to the look or feel
600 * shouldn't override this method.
601 *
602 * @return identifier for the look and feel
603 */
604 public abstract String getID();
605
606 /**
607 * Return a one line description of this look and feel implementation,
608 * e.g. "The CDE/Motif Look and Feel". This string is intended for
609 * the user, e.g. in the title of a window or in a ToolTip message.
610 *
611 * @return short description for the look and feel
612 */
613 public abstract String getDescription();
614
615 /**
616 * Returns {@code true} if the <code>LookAndFeel</code> returned
617 * <code>RootPaneUI</code> instances support providing {@code Window}
618 * decorations in a <code>JRootPane</code>.
619 * <p>
620 * The default implementation returns {@code false}, subclasses that
621 * support {@code Window} decorations should override this and return
622 * {@code true}.
623 *
624 * @return {@code true} if the {@code RootPaneUI} instances created by
625 * this look and feel support client side decorations
626 * @see JDialog#setDefaultLookAndFeelDecorated
627 * @see JFrame#setDefaultLookAndFeelDecorated
628 * @see JRootPane#setWindowDecorationStyle
629 * @since 1.4
630 */
631 public boolean getSupportsWindowDecorations() {
632 return false;
633 }
634
635 /**
636 * If the underlying platform has a "native" look and feel, and
637 * this is an implementation of it, return {@code true}. For
638 * example, when the underlying platform is Solaris running CDE
639 * a CDE/Motif look and feel implementation would return {@code
640 * true}.
641 *
642 * @return {@code true} if this look and feel represents the underlying
643 * platform look and feel
644 */
645 public abstract boolean isNativeLookAndFeel();
646
647 /**
648 * Return {@code true} if the underlying platform supports and or permits
649 * this look and feel. This method returns {@code false} if the look
650 * and feel depends on special resources or legal agreements that
651 * aren't defined for the current platform.
652 *
653 *
654 * @return {@code true} if this is a supported look and feel
655 * @see UIManager#setLookAndFeel
656 */
657 public abstract boolean isSupportedLookAndFeel();
658
659 /**
660 * Initializes the look and feel. While this method is public,
661 * it should only be invoked by the {@code UIManager} when a
662 * look and feel is installed as the current look and feel. This
663 * method is invoked before the {@code UIManager} invokes
664 * {@code getDefaults}. This method is intended to perform any
665 * initialization for the look and feel. Subclasses
666 * should do any one-time setup they need here, rather than
667 * in a static initializer, because look and feel class objects
668 * may be loaded just to discover that {@code isSupportedLookAndFeel()}
669 * returns {@code false}.
670 *
671 * @see #uninitialize
672 * @see UIManager#setLookAndFeel
673 */
674 public void initialize() {
675 }
676
677 /**
678 * Uninitializes the look and feel. While this method is public,
679 * it should only be invoked by the {@code UIManager} when
680 * the look and feel is uninstalled. For example,
681 * {@code UIManager.setLookAndFeel} invokes this when the look and
682 * feel is changed.
683 * <p>
684 * Subclasses may choose to free up some resources here.
685 *
686 * @see #initialize
687 * @see UIManager#setLookAndFeel
688 */
689 public void uninitialize() {
690 }
691
692 /**
693 * Returns the look and feel defaults. While this method is public,
694 * it should only be invoked by the {@code UIManager} when the
695 * look and feel is set as the current look and feel and after
696 * {@code initialize} has been invoked.
697 *
698 * @return the look and feel defaults
699 * @see #initialize
700 * @see #uninitialize
701 * @see UIManager#setLookAndFeel
702 */
703 public UIDefaults getDefaults() {
704 return null;
705 }
706
707 /**
708 * Returns a string that displays and identifies this
709 * object's properties.
710 *
711 * @return a String representation of this object
712 */
713 public String toString() {
714 return "[" + getDescription() + " - " + getClass().getName()
715 + "]";
716 }
717 }
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