1 /*
2 * Copyright (c) 2008, 2017, 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
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7 * published by the Free Software Foundation. Oracle designates this
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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 *
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24 */
25
26 package com.sun.awt;
27
28 import java.awt.*;
29
30 import javax.swing.JRootPane;
31
32 import sun.awt.AWTAccessor;
33 import sun.awt.SunToolkit;
34
35 /**
36 * A collection of utility methods for AWT.
37 *
38 * The functionality provided by the static methods of the class includes:
39 * <ul>
40 * <li>Setting shapes on top-level windows
41 * <li>Setting a constant alpha value for each pixel of a top-level window
42 * <li>Making a window non-opaque, after that it paints only explicitly
43 * painted pixels on the screen, with arbitrary alpha values for every pixel.
44 * <li>Setting a 'mixing-cutout' shape for a component.
45 * </ul>
46 * <p>
47 * A "top-level window" is an instance of the {@code Window} class (or its
48 * descendant, such as {@code JFrame}).
49 * <p>
50 * Some of the mentioned features may not be supported by the native platform.
51 * To determine whether a particular feature is supported, the user must use
52 * the {@code isTranslucencySupported()} method of the class passing a desired
53 * translucency kind (a member of the {@code Translucency} enum) as an
54 * argument.
55 * <p>
56 * The per-pixel alpha feature also requires the user to create her/his
57 * windows using a translucency-capable graphics configuration.
58 * The {@code isTranslucencyCapable()} method must
59 * be used to verify whether any given GraphicsConfiguration supports
60 * the translucency effects.
61 * <p>
62 * <b>WARNING</b>: This class is an implementation detail and only meant
63 * for limited use outside of the core platform. This API may change
64 * drastically between update release, and it may even be
65 * removed or be moved in some other package(s)/class(es).
66 */
67 public final class AWTUtilities {
68
69 /**
70 * The AWTUtilities class should not be instantiated
71 */
72 private AWTUtilities() {
73 }
74
75 /** Kinds of translucency supported by the underlying system.
76 * @see #isTranslucencySupported
77 */
78 public static enum Translucency {
79 /**
80 * Represents support in the underlying system for windows each pixel
81 * of which is guaranteed to be either completely opaque, with
82 * an alpha value of 1.0, or completely transparent, with an alpha
83 * value of 0.0.
84 */
85 PERPIXEL_TRANSPARENT,
86
87 /**
88 * Represents support in the underlying system for windows all of
89 * the pixels of which have the same alpha value between or including
90 * 0.0 and 1.0.
91 */
92 TRANSLUCENT,
93
94 /**
95 * Represents support in the underlying system for windows that
96 * contain or might contain pixels with arbitrary alpha values
97 * between and including 0.0 and 1.0.
98 */
99 PERPIXEL_TRANSLUCENT;
100 }
101
102
103 /**
104 * Returns whether the given level of translucency is supported by
105 * the underlying system.
106 *
107 * Note that this method may sometimes return the value
108 * indicating that the particular level is supported, but
109 * the native windowing system may still not support the
110 * given level of translucency (due to the bugs in
111 * the windowing system).
112 *
113 * @param translucencyKind a kind of translucency support
114 * (either PERPIXEL_TRANSPARENT,
115 * TRANSLUCENT, or PERPIXEL_TRANSLUCENT)
116 * @return whether the given translucency kind is supported
117 */
118 public static boolean isTranslucencySupported(Translucency translucencyKind) {
119 switch (translucencyKind) {
120 case PERPIXEL_TRANSPARENT:
121 return isWindowShapingSupported();
122 case TRANSLUCENT:
123 return isWindowOpacitySupported();
124 case PERPIXEL_TRANSLUCENT:
125 return isWindowTranslucencySupported();
126 }
127 return false;
128 }
129
130
131 /**
132 * Returns whether the windowing system supports changing the opacity
133 * value of top-level windows.
134 * Note that this method may sometimes return true, but the native
135 * windowing system may still not support the concept of
136 * translucency (due to the bugs in the windowing system).
137 */
138 private static boolean isWindowOpacitySupported() {
139 Toolkit curToolkit = Toolkit.getDefaultToolkit();
140 if (!(curToolkit instanceof SunToolkit)) {
141 return false;
142 }
143 return ((SunToolkit)curToolkit).isWindowOpacitySupported();
144 }
145
146 /**
147 * Set the opacity of the window. The opacity is at the range [0..1].
148 * Note that setting the opacity level of 0 may or may not disable
149 * the mouse event handling on this window. This is
150 * a platform-dependent behavior.
151 *
152 * In order for this method to enable the translucency effect,
153 * the isTranslucencySupported() method should indicate that the
154 * TRANSLUCENT level of translucency is supported.
155 *
156 * <p>Also note that the window must not be in the full-screen mode
157 * when setting the opacity value < 1.0f. Otherwise
158 * the IllegalArgumentException is thrown.
159 *
160 * @param window the window to set the opacity level to
161 * @param opacity the opacity level to set to the window
162 * @throws NullPointerException if the window argument is null
163 * @throws IllegalArgumentException if the opacity is out of
164 * the range [0..1]
165 * @throws IllegalArgumentException if the window is in full screen mode,
166 * and the opacity is less than 1.0f
167 * @throws UnsupportedOperationException if the TRANSLUCENT translucency
168 * kind is not supported
169 */
170 public static void setWindowOpacity(Window window, float opacity) {
171 if (window == null) {
172 throw new NullPointerException(
173 "The window argument should not be null.");
174 }
175
176 AWTAccessor.getWindowAccessor().setOpacity(window, opacity);
177 }
178
179 /**
180 * Get the opacity of the window. If the opacity has not
181 * yet being set, this method returns 1.0.
182 *
183 * @param window the window to get the opacity level from
184 * @throws NullPointerException if the window argument is null
185 */
186 public static float getWindowOpacity(Window window) {
187 if (window == null) {
188 throw new NullPointerException(
189 "The window argument should not be null.");
190 }
191
192 return AWTAccessor.getWindowAccessor().getOpacity(window);
193 }
194
195 /**
196 * Returns whether the windowing system supports changing the shape
197 * of top-level windows.
198 * Note that this method may sometimes return true, but the native
199 * windowing system may still not support the concept of
200 * shaping (due to the bugs in the windowing system).
201 */
202 public static boolean isWindowShapingSupported() {
203 Toolkit curToolkit = Toolkit.getDefaultToolkit();
204 if (!(curToolkit instanceof SunToolkit)) {
205 return false;
206 }
207 return ((SunToolkit)curToolkit).isWindowShapingSupported();
208 }
209
210 /**
211 * Returns an object that implements the Shape interface and represents
212 * the shape previously set with the call to the setWindowShape() method.
213 * If no shape has been set yet, or the shape has been reset to null,
214 * this method returns null.
215 *
216 * @param window the window to get the shape from
217 * @return the current shape of the window
218 * @throws NullPointerException if the window argument is null
219 */
220 public static Shape getWindowShape(Window window) {
221 if (window == null) {
222 throw new NullPointerException(
223 "The window argument should not be null.");
224 }
225 return AWTAccessor.getWindowAccessor().getShape(window);
226 }
227
228 /**
229 * Sets a shape for the given window.
230 * If the shape argument is null, this methods restores
231 * the default shape making the window rectangular.
232 * <p>Note that in order to set a shape, the window must be undecorated.
233 * If the window is decorated, this method ignores the {@code shape}
234 * argument and resets the shape to null.
235 * <p>Also note that the window must not be in the full-screen mode
236 * when setting a non-null shape. Otherwise the IllegalArgumentException
237 * is thrown.
238 * <p>Depending on the platform, the method may return without
239 * effecting the shape of the window if the window has a non-null warning
240 * string ({@link Window#getWarningString()}). In this case the passed
241 * shape object is ignored.
242 *
243 * @param window the window to set the shape to
244 * @param shape the shape to set to the window
245 * @throws NullPointerException if the window argument is null
246 * @throws IllegalArgumentException if the window is in full screen mode,
247 * and the shape is not null
248 * @throws UnsupportedOperationException if the PERPIXEL_TRANSPARENT
249 * translucency kind is not supported
250 */
251 public static void setWindowShape(Window window, Shape shape) {
252 if (window == null) {
253 throw new NullPointerException(
254 "The window argument should not be null.");
255 }
256 AWTAccessor.getWindowAccessor().setShape(window, shape);
257 }
258
259 private static boolean isWindowTranslucencySupported() {
260 /*
261 * Per-pixel alpha is supported if all the conditions are TRUE:
262 * 1. The toolkit is a sort of SunToolkit
263 * 2. The toolkit supports translucency in general
264 * (isWindowTranslucencySupported())
265 * 3. There's at least one translucency-capable
266 * GraphicsConfiguration
267 */
268
269 Toolkit curToolkit = Toolkit.getDefaultToolkit();
270 if (!(curToolkit instanceof SunToolkit)) {
271 return false;
272 }
273
274 if (!((SunToolkit)curToolkit).isWindowTranslucencySupported()) {
275 return false;
276 }
277
278 GraphicsEnvironment env =
279 GraphicsEnvironment.getLocalGraphicsEnvironment();
280
281 // If the default GC supports translucency return true.
282 // It is important to optimize the verification this way,
283 // see CR 6661196 for more details.
284 if (isTranslucencyCapable(env.getDefaultScreenDevice()
285 .getDefaultConfiguration()))
286 {
287 return true;
288 }
289
290 // ... otherwise iterate through all the GCs.
291 GraphicsDevice[] devices = env.getScreenDevices();
292
293 for (int i = 0; i < devices.length; i++) {
294 GraphicsConfiguration[] configs = devices[i].getConfigurations();
295 for (int j = 0; j < configs.length; j++) {
296 if (isTranslucencyCapable(configs[j])) {
297 return true;
298 }
299 }
300 }
301
302 return false;
303 }
304
305 /**
306 * Enables the per-pixel alpha support for the given window.
307 * Once the window becomes non-opaque (the isOpaque is set to false),
308 * the drawing sub-system is starting to respect the alpha value of each
309 * separate pixel. If a pixel gets painted with alpha color component
310 * equal to zero, it becomes visually transparent, if the alpha of the
311 * pixel is equal to 255, the pixel is fully opaque. Interim values
312 * of the alpha color component make the pixel semi-transparent (i.e.
313 * translucent).
314 * <p>Note that in order for the window to support the per-pixel alpha
315 * mode, the window must be created using the GraphicsConfiguration
316 * for which the {@link #isTranslucencyCapable}
317 * method returns true.
318 * <p>Also note that some native systems enable the per-pixel translucency
319 * mode for any window created using the translucency-compatible
320 * graphics configuration. However, it is highly recommended to always
321 * invoke the setWindowOpaque() method for these windows, at least for
322 * the sake of cross-platform compatibility reasons.
323 * <p>Also note that the window must not be in the full-screen mode
324 * when making it non-opaque. Otherwise the IllegalArgumentException
325 * is thrown.
326 * <p>If the window is a {@code Frame} or a {@code Dialog}, the window must
327 * be undecorated prior to enabling the per-pixel translucency effect (see
328 * {@link Frame#setUndecorated} and/or {@link Dialog#setUndecorated}).
329 * If the window becomes decorated through a subsequent call to the
330 * corresponding {@code setUndecorated()} method, the per-pixel
331 * translucency effect will be disabled and the opaque property reset to
332 * {@code true}.
333 * <p>Depending on the platform, the method may return without
334 * effecting the opaque property of the window if the window has a non-null
335 * warning string ({@link Window#getWarningString()}). In this case
336 * the passed 'isOpaque' value is ignored.
337 *
338 * @param window the window to set the shape to
339 * @param isOpaque whether the window must be opaque (true),
340 * or translucent (false)
341 * @throws NullPointerException if the window argument is null
342 * @throws IllegalArgumentException if the window uses
343 * a GraphicsConfiguration for which the
344 * {@code isTranslucencyCapable()}
345 * method returns false
346 * @throws IllegalArgumentException if the window is in full screen mode,
347 * and the isOpaque is false
348 * @throws IllegalArgumentException if the window is decorated and the
349 * isOpaque argument is {@code false}.
350 * @throws UnsupportedOperationException if the PERPIXEL_TRANSLUCENT
351 * translucency kind is not supported
352 */
353 public static void setWindowOpaque(Window window, boolean isOpaque) {
354 if (window == null) {
355 throw new NullPointerException(
356 "The window argument should not be null.");
357 }
358 if (!isOpaque && !isTranslucencySupported(Translucency.PERPIXEL_TRANSLUCENT)) {
359 throw new UnsupportedOperationException(
360 "The PERPIXEL_TRANSLUCENT translucency kind is not supported");
361 }
362 AWTAccessor.getWindowAccessor().setOpaque(window, isOpaque);
363 }
364
365 /**
366 * Returns whether the window is opaque or translucent.
367 *
368 * @param window the window to set the shape to
369 * @return whether the window is currently opaque (true)
370 * or translucent (false)
371 * @throws NullPointerException if the window argument is null
372 */
373 public static boolean isWindowOpaque(Window window) {
374 if (window == null) {
375 throw new NullPointerException(
376 "The window argument should not be null.");
377 }
378
379 return window.isOpaque();
380 }
381
382 /**
383 * Verifies whether a given GraphicsConfiguration supports
384 * the PERPIXEL_TRANSLUCENT kind of translucency.
385 * All windows that are intended to be used with the {@link #setWindowOpaque}
386 * method must be created using a GraphicsConfiguration for which this method
387 * returns true.
388 * <p>Note that some native systems enable the per-pixel translucency
389 * mode for any window created using a translucency-capable
390 * graphics configuration. However, it is highly recommended to always
391 * invoke the setWindowOpaque() method for these windows, at least
392 * for the sake of cross-platform compatibility reasons.
393 *
394 * @param gc GraphicsConfiguration
395 * @throws NullPointerException if the gc argument is null
396 * @return whether the given GraphicsConfiguration supports
397 * the translucency effects.
398 */
399 public static boolean isTranslucencyCapable(GraphicsConfiguration gc) {
400 if (gc == null) {
401 throw new NullPointerException("The gc argument should not be null");
402 }
403 /*
404 return gc.isTranslucencyCapable();
405 */
406 Toolkit curToolkit = Toolkit.getDefaultToolkit();
407 if (!(curToolkit instanceof SunToolkit)) {
408 return false;
409 }
410 return ((SunToolkit)curToolkit).isTranslucencyCapable(gc);
411 }
412
413 /**
414 * Sets a 'mixing-cutout' shape for the given component.
415 *
416 * By default a lightweight component is treated as an opaque rectangle for
417 * the purposes of the Heavyweight/Lightweight Components Mixing feature.
418 * This method enables developers to set an arbitrary shape to be cut out
419 * from heavyweight components positioned underneath the lightweight
420 * component in the z-order.
421 * <p>
422 * The {@code shape} argument may have the following values:
423 * <ul>
424 * <li>{@code null} - reverts the default cutout shape (the rectangle equal
425 * to the component's {@code getBounds()})
426 * <li><i>empty-shape</i> - does not cut out anything from heavyweight
427 * components. This makes the given lightweight component effectively
428 * transparent. Note that descendants of the lightweight component still
429 * affect the shapes of heavyweight components. An example of an
430 * <i>empty-shape</i> is {@code new Rectangle()}.
431 * <li><i>non-empty-shape</i> - the given shape will be cut out from
432 * heavyweight components.
433 * </ul>
434 * <p>
435 * The most common example when the 'mixing-cutout' shape is needed is a
436 * glass pane component. The {@link JRootPane#setGlassPane} method
437 * automatically sets the <i>empty-shape</i> as the 'mixing-cutout' shape
438 * for the given glass pane component. If a developer needs some other
439 * 'mixing-cutout' shape for the glass pane (which is rare), this must be
440 * changed manually after installing the glass pane to the root pane.
441 * <p>
442 * Note that the 'mixing-cutout' shape neither affects painting, nor the
443 * mouse events handling for the given component. It is used exclusively
444 * for the purposes of the Heavyweight/Lightweight Components Mixing
445 * feature.
446 *
447 * @param component the component that needs non-default
448 * 'mixing-cutout' shape
449 * @param shape the new 'mixing-cutout' shape
450 * @throws NullPointerException if the component argument is {@code null}
451 */
452 @Deprecated(since = "9")
453 public static void setComponentMixingCutoutShape(Component component,
454 Shape shape)
455 {
456 if (component == null) {
457 throw new NullPointerException(
458 "The component argument should not be null.");
459 }
460
461 component.setMixingCutoutShape(shape);
462 }
463 }
464