1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.view; 18 19 import android.annotation.NonNull; 20 import android.annotation.Nullable; 21 import android.annotation.XmlRes; 22 import android.compat.annotation.UnsupportedAppUsage; 23 import android.content.Context; 24 import android.content.res.Resources; 25 import android.content.res.TypedArray; 26 import android.content.res.XmlResourceParser; 27 import android.graphics.Bitmap; 28 import android.graphics.Canvas; 29 import android.graphics.Paint; 30 import android.graphics.Rect; 31 import android.graphics.RectF; 32 import android.graphics.drawable.AnimationDrawable; 33 import android.graphics.drawable.BitmapDrawable; 34 import android.graphics.drawable.Drawable; 35 import android.hardware.display.DisplayManager; 36 import android.os.Build; 37 import android.os.Parcel; 38 import android.os.Parcelable; 39 import android.util.Log; 40 import android.util.SparseArray; 41 42 import com.android.internal.util.XmlUtils; 43 44 /** 45 * Represents an icon that can be used as a mouse pointer. 46 * <p> 47 * Pointer icons can be provided either by the system using system types, 48 * or by applications using bitmaps or application resources. 49 * </p> 50 */ 51 public final class PointerIcon implements Parcelable { 52 private static final String TAG = "PointerIcon"; 53 54 /** {@hide} Type constant: Custom icon with a user-supplied bitmap. */ 55 public static final int TYPE_CUSTOM = -1; 56 57 /** Type constant: Null icon. It has no bitmap. */ 58 public static final int TYPE_NULL = 0; 59 60 /** Type constant: no icons are specified. If all views uses this, then falls back 61 * to the default type, but this is helpful to distinguish a view explicitly want 62 * to have the default icon. 63 * @hide 64 */ 65 public static final int TYPE_NOT_SPECIFIED = 1; 66 67 /** Type constant: Arrow icon. (Default mouse pointer) */ 68 public static final int TYPE_ARROW = 1000; 69 70 /** {@hide} Type constant: Spot hover icon for touchpads. */ 71 public static final int TYPE_SPOT_HOVER = 2000; 72 73 /** {@hide} Type constant: Spot touch icon for touchpads. */ 74 public static final int TYPE_SPOT_TOUCH = 2001; 75 76 /** {@hide} Type constant: Spot anchor icon for touchpads. */ 77 public static final int TYPE_SPOT_ANCHOR = 2002; 78 79 // Type constants for additional predefined icons for mice. 80 /** Type constant: context-menu. */ 81 public static final int TYPE_CONTEXT_MENU = 1001; 82 83 /** Type constant: hand. */ 84 public static final int TYPE_HAND = 1002; 85 86 /** Type constant: help. */ 87 public static final int TYPE_HELP = 1003; 88 89 /** Type constant: wait. */ 90 public static final int TYPE_WAIT = 1004; 91 92 /** Type constant: cell. */ 93 public static final int TYPE_CELL = 1006; 94 95 /** Type constant: crosshair. */ 96 public static final int TYPE_CROSSHAIR = 1007; 97 98 /** Type constant: text. */ 99 public static final int TYPE_TEXT = 1008; 100 101 /** Type constant: vertical-text. */ 102 public static final int TYPE_VERTICAL_TEXT = 1009; 103 104 /** Type constant: alias (indicating an alias of/shortcut to something is 105 * to be created. */ 106 public static final int TYPE_ALIAS = 1010; 107 108 /** Type constant: copy. */ 109 public static final int TYPE_COPY = 1011; 110 111 /** Type constant: no-drop. */ 112 public static final int TYPE_NO_DROP = 1012; 113 114 /** Type constant: all-scroll. */ 115 public static final int TYPE_ALL_SCROLL = 1013; 116 117 /** Type constant: horizontal double arrow mainly for resizing. */ 118 public static final int TYPE_HORIZONTAL_DOUBLE_ARROW = 1014; 119 120 /** Type constant: vertical double arrow mainly for resizing. */ 121 public static final int TYPE_VERTICAL_DOUBLE_ARROW = 1015; 122 123 /** Type constant: diagonal double arrow -- top-right to bottom-left. */ 124 public static final int TYPE_TOP_RIGHT_DIAGONAL_DOUBLE_ARROW = 1016; 125 126 /** Type constant: diagonal double arrow -- top-left to bottom-right. */ 127 public static final int TYPE_TOP_LEFT_DIAGONAL_DOUBLE_ARROW = 1017; 128 129 /** Type constant: zoom-in. */ 130 public static final int TYPE_ZOOM_IN = 1018; 131 132 /** Type constant: zoom-out. */ 133 public static final int TYPE_ZOOM_OUT = 1019; 134 135 /** Type constant: grab. */ 136 public static final int TYPE_GRAB = 1020; 137 138 /** Type constant: grabbing. */ 139 public static final int TYPE_GRABBING = 1021; 140 141 // OEM private types should be defined starting at this range to avoid 142 // conflicts with any system types that may be defined in the future. 143 private static final int TYPE_OEM_FIRST = 10000; 144 145 /** The default pointer icon. */ 146 public static final int TYPE_DEFAULT = TYPE_ARROW; 147 148 private static final PointerIcon gNullIcon = new PointerIcon(TYPE_NULL); 149 private static final SparseArray<SparseArray<PointerIcon>> gSystemIconsByDisplay = 150 new SparseArray<SparseArray<PointerIcon>>(); 151 private static boolean sUseLargeIcons = false; 152 153 @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023) 154 private final int mType; 155 private int mSystemIconResourceId; 156 @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) 157 private Bitmap mBitmap; 158 @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) 159 private float mHotSpotX; 160 @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) 161 private float mHotSpotY; 162 // The bitmaps for the additional frame of animated pointer icon. Note that the first frame 163 // will be stored in mBitmap. 164 @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) 165 private Bitmap mBitmapFrames[]; 166 @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) 167 private int mDurationPerFrame; 168 169 /** 170 * Listener for displays lifecycle. 171 * @hide 172 */ 173 private static DisplayManager.DisplayListener sDisplayListener; 174 PointerIcon(int type)175 private PointerIcon(int type) { 176 mType = type; 177 } 178 179 /** 180 * Gets a special pointer icon that has no bitmap. 181 * 182 * @return The null pointer icon. 183 * 184 * @see #TYPE_NULL 185 * @hide 186 */ getNullIcon()187 public static @NonNull PointerIcon getNullIcon() { 188 return gNullIcon; 189 } 190 191 /** 192 * Gets the default pointer icon. 193 * 194 * @param context The context. 195 * @return The default pointer icon. 196 * 197 * @throws IllegalArgumentException if context is null. 198 * @hide 199 */ getDefaultIcon(@onNull Context context)200 public static @NonNull PointerIcon getDefaultIcon(@NonNull Context context) { 201 return getSystemIcon(context, TYPE_DEFAULT); 202 } 203 204 /** 205 * Gets a system pointer icon for the given type. 206 * If typeis not recognized, returns the default pointer icon. 207 * 208 * @param context The context. 209 * @param type The pointer icon type. 210 * @return The pointer icon. 211 * 212 * @throws IllegalArgumentException if context is null. 213 */ getSystemIcon(@onNull Context context, int type)214 public static @NonNull PointerIcon getSystemIcon(@NonNull Context context, int type) { 215 if (context == null) { 216 throw new IllegalArgumentException("context must not be null"); 217 } 218 219 if (type == TYPE_NULL) { 220 return gNullIcon; 221 } 222 223 if (sDisplayListener == null) { 224 registerDisplayListener(context); 225 } 226 227 final int displayId = context.getDisplayId(); 228 SparseArray<PointerIcon> systemIcons = gSystemIconsByDisplay.get(displayId); 229 if (systemIcons == null) { 230 systemIcons = new SparseArray<>(); 231 gSystemIconsByDisplay.put(displayId, systemIcons); 232 } 233 234 PointerIcon icon = systemIcons.get(type); 235 // Reload if not in the same display. 236 if (icon != null) { 237 return icon; 238 } 239 240 int typeIndex = getSystemIconTypeIndex(type); 241 if (typeIndex == 0) { 242 typeIndex = getSystemIconTypeIndex(TYPE_DEFAULT); 243 } 244 245 int defStyle = sUseLargeIcons ? 246 com.android.internal.R.style.LargePointer : com.android.internal.R.style.Pointer; 247 TypedArray a = context.obtainStyledAttributes(null, 248 com.android.internal.R.styleable.Pointer, 249 0, defStyle); 250 int resourceId = a.getResourceId(typeIndex, -1); 251 a.recycle(); 252 253 if (resourceId == -1) { 254 Log.w(TAG, "Missing theme resources for pointer icon type " + type); 255 return type == TYPE_DEFAULT ? gNullIcon : getSystemIcon(context, TYPE_DEFAULT); 256 } 257 258 icon = new PointerIcon(type); 259 if ((resourceId & 0xff000000) == 0x01000000) { 260 icon.mSystemIconResourceId = resourceId; 261 } else { 262 icon.loadResource(context, context.getResources(), resourceId); 263 } 264 systemIcons.append(type, icon); 265 return icon; 266 } 267 268 /** 269 * Updates wheter accessibility large icons are used or not. 270 * @hide 271 */ setUseLargeIcons(boolean use)272 public static void setUseLargeIcons(boolean use) { 273 sUseLargeIcons = use; 274 gSystemIconsByDisplay.clear(); 275 } 276 277 /** 278 * Creates a custom pointer icon from the given bitmap and hotspot information. 279 * 280 * @param bitmap The bitmap for the icon. 281 * @param hotSpotX The X offset of the pointer icon hotspot in the bitmap. 282 * Must be within the [0, bitmap.getWidth()) range. 283 * @param hotSpotY The Y offset of the pointer icon hotspot in the bitmap. 284 * Must be within the [0, bitmap.getHeight()) range. 285 * @return A pointer icon for this bitmap. 286 * 287 * @throws IllegalArgumentException if bitmap is null, or if the x/y hotspot 288 * parameters are invalid. 289 */ create(@onNull Bitmap bitmap, float hotSpotX, float hotSpotY)290 public static @NonNull PointerIcon create(@NonNull Bitmap bitmap, float hotSpotX, 291 float hotSpotY) { 292 if (bitmap == null) { 293 throw new IllegalArgumentException("bitmap must not be null"); 294 } 295 validateHotSpot(bitmap, hotSpotX, hotSpotY); 296 297 PointerIcon icon = new PointerIcon(TYPE_CUSTOM); 298 icon.mBitmap = bitmap; 299 icon.mHotSpotX = hotSpotX; 300 icon.mHotSpotY = hotSpotY; 301 return icon; 302 } 303 304 /** 305 * Loads a custom pointer icon from an XML resource. 306 * <p> 307 * The XML resource should have the following form: 308 * <code> 309 * <?xml version="1.0" encoding="utf-8"?> 310 * <pointer-icon xmlns:android="http://schemas.android.com/apk/res/android" 311 * android:bitmap="@drawable/my_pointer_bitmap" 312 * android:hotSpotX="24" 313 * android:hotSpotY="24" /> 314 * </code> 315 * </p> 316 * 317 * @param resources The resources object. 318 * @param resourceId The resource id. 319 * @return The pointer icon. 320 * 321 * @throws IllegalArgumentException if resources is null. 322 * @throws Resources.NotFoundException if the resource was not found or the drawable 323 * linked in the resource was not found. 324 */ load(@onNull Resources resources, @XmlRes int resourceId)325 public static @NonNull PointerIcon load(@NonNull Resources resources, @XmlRes int resourceId) { 326 if (resources == null) { 327 throw new IllegalArgumentException("resources must not be null"); 328 } 329 330 PointerIcon icon = new PointerIcon(TYPE_CUSTOM); 331 icon.loadResource(null, resources, resourceId); 332 return icon; 333 } 334 335 /** 336 * Loads the bitmap and hotspot information for a pointer icon, if it is not already loaded. 337 * Returns a pointer icon (not necessarily the same instance) with the information filled in. 338 * 339 * @param context The context. 340 * @return The loaded pointer icon. 341 * 342 * @throws IllegalArgumentException if context is null. 343 * @hide 344 */ 345 @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023) load(@onNull Context context)346 public @NonNull PointerIcon load(@NonNull Context context) { 347 if (context == null) { 348 throw new IllegalArgumentException("context must not be null"); 349 } 350 351 if (mSystemIconResourceId == 0 || mBitmap != null) { 352 return this; 353 } 354 355 PointerIcon result = new PointerIcon(mType); 356 result.mSystemIconResourceId = mSystemIconResourceId; 357 result.loadResource(context, context.getResources(), mSystemIconResourceId); 358 return result; 359 } 360 361 /** @hide */ getType()362 public int getType() { 363 return mType; 364 } 365 366 public static final @NonNull Parcelable.Creator<PointerIcon> CREATOR 367 = new Parcelable.Creator<PointerIcon>() { 368 public PointerIcon createFromParcel(Parcel in) { 369 int type = in.readInt(); 370 if (type == TYPE_NULL) { 371 return getNullIcon(); 372 } 373 374 int systemIconResourceId = in.readInt(); 375 if (systemIconResourceId != 0) { 376 PointerIcon icon = new PointerIcon(type); 377 icon.mSystemIconResourceId = systemIconResourceId; 378 return icon; 379 } 380 381 Bitmap bitmap = Bitmap.CREATOR.createFromParcel(in); 382 float hotSpotX = in.readFloat(); 383 float hotSpotY = in.readFloat(); 384 return PointerIcon.create(bitmap, hotSpotX, hotSpotY); 385 } 386 387 public PointerIcon[] newArray(int size) { 388 return new PointerIcon[size]; 389 } 390 }; 391 describeContents()392 public int describeContents() { 393 return 0; 394 } 395 writeToParcel(Parcel out, int flags)396 public void writeToParcel(Parcel out, int flags) { 397 out.writeInt(mType); 398 399 if (mType != TYPE_NULL) { 400 out.writeInt(mSystemIconResourceId); 401 if (mSystemIconResourceId == 0) { 402 mBitmap.writeToParcel(out, flags); 403 out.writeFloat(mHotSpotX); 404 out.writeFloat(mHotSpotY); 405 } 406 } 407 } 408 409 @Override equals(@ullable Object other)410 public boolean equals(@Nullable Object other) { 411 if (this == other) { 412 return true; 413 } 414 415 if (other == null || !(other instanceof PointerIcon)) { 416 return false; 417 } 418 419 PointerIcon otherIcon = (PointerIcon) other; 420 if (mType != otherIcon.mType 421 || mSystemIconResourceId != otherIcon.mSystemIconResourceId) { 422 return false; 423 } 424 425 if (mSystemIconResourceId == 0 && (mBitmap != otherIcon.mBitmap 426 || mHotSpotX != otherIcon.mHotSpotX 427 || mHotSpotY != otherIcon.mHotSpotY)) { 428 return false; 429 } 430 431 return true; 432 } 433 434 /** 435 * Get the Bitmap from the Drawable. 436 * 437 * If the Bitmap needed to be scaled up to account for density, BitmapDrawable 438 * handles this at draw time. But this class doesn't actually draw the Bitmap; 439 * it is just a holder for native code to access its SkBitmap. So this needs to 440 * get a version that is scaled to account for density. 441 */ getBitmapFromDrawable(BitmapDrawable bitmapDrawable)442 private Bitmap getBitmapFromDrawable(BitmapDrawable bitmapDrawable) { 443 Bitmap bitmap = bitmapDrawable.getBitmap(); 444 final int scaledWidth = bitmapDrawable.getIntrinsicWidth(); 445 final int scaledHeight = bitmapDrawable.getIntrinsicHeight(); 446 if (scaledWidth == bitmap.getWidth() && scaledHeight == bitmap.getHeight()) { 447 return bitmap; 448 } 449 450 Rect src = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()); 451 RectF dst = new RectF(0, 0, scaledWidth, scaledHeight); 452 453 Bitmap scaled = Bitmap.createBitmap(scaledWidth, scaledHeight, bitmap.getConfig()); 454 Canvas canvas = new Canvas(scaled); 455 Paint paint = new Paint(); 456 paint.setFilterBitmap(true); 457 canvas.drawBitmap(bitmap, src, dst, paint); 458 return scaled; 459 } 460 loadResource(Context context, Resources resources, @XmlRes int resourceId)461 private void loadResource(Context context, Resources resources, @XmlRes int resourceId) { 462 final XmlResourceParser parser = resources.getXml(resourceId); 463 final int bitmapRes; 464 final float hotSpotX; 465 final float hotSpotY; 466 try { 467 XmlUtils.beginDocument(parser, "pointer-icon"); 468 469 final TypedArray a = resources.obtainAttributes( 470 parser, com.android.internal.R.styleable.PointerIcon); 471 bitmapRes = a.getResourceId(com.android.internal.R.styleable.PointerIcon_bitmap, 0); 472 hotSpotX = a.getDimension(com.android.internal.R.styleable.PointerIcon_hotSpotX, 0); 473 hotSpotY = a.getDimension(com.android.internal.R.styleable.PointerIcon_hotSpotY, 0); 474 a.recycle(); 475 } catch (Exception ex) { 476 throw new IllegalArgumentException("Exception parsing pointer icon resource.", ex); 477 } finally { 478 parser.close(); 479 } 480 481 if (bitmapRes == 0) { 482 throw new IllegalArgumentException("<pointer-icon> is missing bitmap attribute."); 483 } 484 485 Drawable drawable; 486 if (context == null) { 487 drawable = resources.getDrawable(bitmapRes); 488 } else { 489 drawable = context.getDrawable(bitmapRes); 490 } 491 if (drawable instanceof AnimationDrawable) { 492 // Extract animation frame bitmaps. 493 final AnimationDrawable animationDrawable = (AnimationDrawable) drawable; 494 final int frames = animationDrawable.getNumberOfFrames(); 495 drawable = animationDrawable.getFrame(0); 496 if (frames == 1) { 497 Log.w(TAG, "Animation icon with single frame -- simply treating the first " 498 + "frame as a normal bitmap icon."); 499 } else { 500 // Assumes they have the exact duration. 501 mDurationPerFrame = animationDrawable.getDuration(0); 502 mBitmapFrames = new Bitmap[frames - 1]; 503 final int width = drawable.getIntrinsicWidth(); 504 final int height = drawable.getIntrinsicHeight(); 505 for (int i = 1; i < frames; ++i) { 506 Drawable drawableFrame = animationDrawable.getFrame(i); 507 if (!(drawableFrame instanceof BitmapDrawable)) { 508 throw new IllegalArgumentException("Frame of an animated pointer icon " 509 + "must refer to a bitmap drawable."); 510 } 511 if (drawableFrame.getIntrinsicWidth() != width || 512 drawableFrame.getIntrinsicHeight() != height) { 513 throw new IllegalArgumentException("The bitmap size of " + i + "-th frame " 514 + "is different. All frames should have the exact same size and " 515 + "share the same hotspot."); 516 } 517 BitmapDrawable bitmapDrawableFrame = (BitmapDrawable) drawableFrame; 518 mBitmapFrames[i - 1] = getBitmapFromDrawable(bitmapDrawableFrame); 519 } 520 } 521 } 522 if (!(drawable instanceof BitmapDrawable)) { 523 throw new IllegalArgumentException("<pointer-icon> bitmap attribute must " 524 + "refer to a bitmap drawable."); 525 } 526 527 BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable; 528 final Bitmap bitmap = getBitmapFromDrawable(bitmapDrawable); 529 validateHotSpot(bitmap, hotSpotX, hotSpotY); 530 // Set the properties now that we have successfully loaded the icon. 531 mBitmap = bitmap; 532 mHotSpotX = hotSpotX; 533 mHotSpotY = hotSpotY; 534 } 535 validateHotSpot(Bitmap bitmap, float hotSpotX, float hotSpotY)536 private static void validateHotSpot(Bitmap bitmap, float hotSpotX, float hotSpotY) { 537 if (hotSpotX < 0 || hotSpotX >= bitmap.getWidth()) { 538 throw new IllegalArgumentException("x hotspot lies outside of the bitmap area"); 539 } 540 if (hotSpotY < 0 || hotSpotY >= bitmap.getHeight()) { 541 throw new IllegalArgumentException("y hotspot lies outside of the bitmap area"); 542 } 543 } 544 getSystemIconTypeIndex(int type)545 private static int getSystemIconTypeIndex(int type) { 546 switch (type) { 547 case TYPE_ARROW: 548 return com.android.internal.R.styleable.Pointer_pointerIconArrow; 549 case TYPE_SPOT_HOVER: 550 return com.android.internal.R.styleable.Pointer_pointerIconSpotHover; 551 case TYPE_SPOT_TOUCH: 552 return com.android.internal.R.styleable.Pointer_pointerIconSpotTouch; 553 case TYPE_SPOT_ANCHOR: 554 return com.android.internal.R.styleable.Pointer_pointerIconSpotAnchor; 555 case TYPE_HAND: 556 return com.android.internal.R.styleable.Pointer_pointerIconHand; 557 case TYPE_CONTEXT_MENU: 558 return com.android.internal.R.styleable.Pointer_pointerIconContextMenu; 559 case TYPE_HELP: 560 return com.android.internal.R.styleable.Pointer_pointerIconHelp; 561 case TYPE_WAIT: 562 return com.android.internal.R.styleable.Pointer_pointerIconWait; 563 case TYPE_CELL: 564 return com.android.internal.R.styleable.Pointer_pointerIconCell; 565 case TYPE_CROSSHAIR: 566 return com.android.internal.R.styleable.Pointer_pointerIconCrosshair; 567 case TYPE_TEXT: 568 return com.android.internal.R.styleable.Pointer_pointerIconText; 569 case TYPE_VERTICAL_TEXT: 570 return com.android.internal.R.styleable.Pointer_pointerIconVerticalText; 571 case TYPE_ALIAS: 572 return com.android.internal.R.styleable.Pointer_pointerIconAlias; 573 case TYPE_COPY: 574 return com.android.internal.R.styleable.Pointer_pointerIconCopy; 575 case TYPE_ALL_SCROLL: 576 return com.android.internal.R.styleable.Pointer_pointerIconAllScroll; 577 case TYPE_NO_DROP: 578 return com.android.internal.R.styleable.Pointer_pointerIconNodrop; 579 case TYPE_HORIZONTAL_DOUBLE_ARROW: 580 return com.android.internal.R.styleable.Pointer_pointerIconHorizontalDoubleArrow; 581 case TYPE_VERTICAL_DOUBLE_ARROW: 582 return com.android.internal.R.styleable.Pointer_pointerIconVerticalDoubleArrow; 583 case TYPE_TOP_RIGHT_DIAGONAL_DOUBLE_ARROW: 584 return com.android.internal.R.styleable. 585 Pointer_pointerIconTopRightDiagonalDoubleArrow; 586 case TYPE_TOP_LEFT_DIAGONAL_DOUBLE_ARROW: 587 return com.android.internal.R.styleable. 588 Pointer_pointerIconTopLeftDiagonalDoubleArrow; 589 case TYPE_ZOOM_IN: 590 return com.android.internal.R.styleable.Pointer_pointerIconZoomIn; 591 case TYPE_ZOOM_OUT: 592 return com.android.internal.R.styleable.Pointer_pointerIconZoomOut; 593 case TYPE_GRAB: 594 return com.android.internal.R.styleable.Pointer_pointerIconGrab; 595 case TYPE_GRABBING: 596 return com.android.internal.R.styleable.Pointer_pointerIconGrabbing; 597 default: 598 return 0; 599 } 600 } 601 602 /** 603 * Manage system icon cache handled by display lifecycle. 604 * @param context The context. 605 */ registerDisplayListener(@onNull Context context)606 private static void registerDisplayListener(@NonNull Context context) { 607 sDisplayListener = new DisplayManager.DisplayListener() { 608 @Override 609 public void onDisplayAdded(int displayId) { 610 } 611 612 @Override 613 public void onDisplayRemoved(int displayId) { 614 gSystemIconsByDisplay.remove(displayId); 615 } 616 617 @Override 618 public void onDisplayChanged(int displayId) { 619 gSystemIconsByDisplay.remove(displayId); 620 } 621 }; 622 623 DisplayManager displayManager = context.getSystemService(DisplayManager.class); 624 displayManager.registerDisplayListener(sDisplayListener, null /* handler */); 625 } 626 627 } 628