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