1 /* 2 * Copyright (C) 2006 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.graphics; 18 19 import android.os.Parcel; 20 import android.os.Parcelable; 21 import android.util.DisplayMetrics; 22 23 import java.io.OutputStream; 24 import java.nio.Buffer; 25 import java.nio.ByteBuffer; 26 import java.nio.IntBuffer; 27 import java.nio.ShortBuffer; 28 29 public final class Bitmap implements Parcelable { 30 /** 31 * Indicates that the bitmap was created for an unknown pixel density. 32 * 33 * @see Bitmap#getDensity() 34 * @see Bitmap#setDensity(int) 35 */ 36 public static final int DENSITY_NONE = 0; 37 38 // Note: mNativeBitmap is used by FaceDetector_jni.cpp 39 // Don't change/rename without updating FaceDetector_jni.cpp 40 private final int mNativeBitmap; 41 42 private final boolean mIsMutable; 43 private byte[] mNinePatchChunk; // may be null 44 private int mWidth = -1; 45 private int mHeight = -1; 46 private boolean mRecycled; 47 48 // Package-scoped for fast access. 49 /*package*/ int mDensity = sDefaultDensity = getDefaultDensity(); 50 51 private static volatile Matrix sScaleMatrix; 52 53 private static volatile int sDefaultDensity = -1; 54 55 /** 56 * For backwards compatibility, allows the app layer to change the default 57 * density when running old apps. 58 * @hide 59 */ 60 public static void setDefaultDensity(int density) { 61 sDefaultDensity = density; 62 } 63 64 /*package*/ static int getDefaultDensity() { 65 if (sDefaultDensity >= 0) { 66 return sDefaultDensity; 67 } 68 sDefaultDensity = DisplayMetrics.DENSITY_DEVICE; 69 return sDefaultDensity; 70 } 71 72 /** 73 * @noinspection UnusedDeclaration 74 */ 75 /* Private constructor that must received an already allocated native 76 bitmap int (pointer). 77 78 This can be called from JNI code. 79 */ 80 private Bitmap(int nativeBitmap, boolean isMutable, byte[] ninePatchChunk, 81 int density) { 82 if (nativeBitmap == 0) { 83 throw new RuntimeException("internal error: native bitmap is 0"); 84 } 85 86 // we delete this in our finalizer 87 mNativeBitmap = nativeBitmap; 88 mIsMutable = isMutable; 89 mNinePatchChunk = ninePatchChunk; 90 if (density >= 0) { 91 mDensity = density; 92 } 93 } 94 95 /** 96 * <p>Returns the density for this bitmap.</p> 97 * 98 * <p>The default density is the same density as the current display, 99 * unless the current application does not support different screen 100 * densities in which case it is 101 * {@link android.util.DisplayMetrics#DENSITY_DEFAULT}. Note that 102 * compatibility mode is determined by the application that was initially 103 * loaded into a process -- applications that share the same process should 104 * all have the same compatibility, or ensure they explicitly set the 105 * density of their bitmaps appropriately.</p> 106 * 107 * @return A scaling factor of the default density or {@link #DENSITY_NONE} 108 * if the scaling factor is unknown. 109 * 110 * @see #setDensity(int) 111 * @see android.util.DisplayMetrics#DENSITY_DEFAULT 112 * @see android.util.DisplayMetrics#densityDpi 113 * @see #DENSITY_NONE 114 */ 115 public int getDensity() { 116 return mDensity; 117 } 118 119 /** 120 * <p>Specifies the density for this bitmap. When the bitmap is 121 * drawn to a Canvas that also has a density, it will be scaled 122 * appropriately.</p> 123 * 124 * @param density The density scaling factor to use with this bitmap or 125 * {@link #DENSITY_NONE} if the density is unknown. 126 * 127 * @see #getDensity() 128 * @see android.util.DisplayMetrics#DENSITY_DEFAULT 129 * @see android.util.DisplayMetrics#densityDpi 130 * @see #DENSITY_NONE 131 */ 132 public void setDensity(int density) { 133 mDensity = density; 134 } 135 136 /** 137 * Sets the nine patch chunk. 138 * 139 * @param chunk The definition of the nine patch 140 * 141 * @hide 142 */ 143 public void setNinePatchChunk(byte[] chunk) { 144 mNinePatchChunk = chunk; 145 } 146 147 /** 148 * Free up the memory associated with this bitmap's pixels, and mark the 149 * bitmap as "dead", meaning it will throw an exception if getPixels() or 150 * setPixels() is called, and will draw nothing. This operation cannot be 151 * reversed, so it should only be called if you are sure there are no 152 * further uses for the bitmap. This is an advanced call, and normally need 153 * not be called, since the normal GC process will free up this memory when 154 * there are no more references to this bitmap. 155 */ 156 public void recycle() { 157 if (!mRecycled) { 158 nativeRecycle(mNativeBitmap); 159 mNinePatchChunk = null; 160 mRecycled = true; 161 } 162 } 163 164 /** 165 * Returns true if this bitmap has been recycled. If so, then it is an error 166 * to try to access its pixels, and the bitmap will not draw. 167 * 168 * @return true if the bitmap has been recycled 169 */ 170 public final boolean isRecycled() { 171 return mRecycled; 172 } 173 174 /** 175 * This is called by methods that want to throw an exception if the bitmap 176 * has already been recycled. 177 */ 178 private void checkRecycled(String errorMessage) { 179 if (mRecycled) { 180 throw new IllegalStateException(errorMessage); 181 } 182 } 183 184 /** 185 * Common code for checking that x and y are >= 0 186 * 187 * @param x x coordinate to ensure is >= 0 188 * @param y y coordinate to ensure is >= 0 189 */ 190 private static void checkXYSign(int x, int y) { 191 if (x < 0) { 192 throw new IllegalArgumentException("x must be >= 0"); 193 } 194 if (y < 0) { 195 throw new IllegalArgumentException("y must be >= 0"); 196 } 197 } 198 199 /** 200 * Common code for checking that width and height are > 0 201 * 202 * @param width width to ensure is > 0 203 * @param height height to ensure is > 0 204 */ 205 private static void checkWidthHeight(int width, int height) { 206 if (width <= 0) { 207 throw new IllegalArgumentException("width must be > 0"); 208 } 209 if (height <= 0) { 210 throw new IllegalArgumentException("height must be > 0"); 211 } 212 } 213 214 public enum Config { 215 // these native values must match up with the enum in SkBitmap.h 216 ALPHA_8 (2), 217 RGB_565 (4), 218 ARGB_4444 (5), 219 ARGB_8888 (6); 220 221 Config(int ni) { 222 this.nativeInt = ni; 223 } 224 final int nativeInt; 225 226 /* package */ static Config nativeToConfig(int ni) { 227 return sConfigs[ni]; 228 } 229 230 private static Config sConfigs[] = { 231 null, null, ALPHA_8, null, RGB_565, ARGB_4444, ARGB_8888 232 }; 233 } 234 235 /** 236 * Copy the bitmap's pixels into the specified buffer (allocated by the 237 * caller). An exception is thrown if the buffer is not large enough to 238 * hold all of the pixels (taking into account the number of bytes per 239 * pixel) or if the Buffer subclass is not one of the support types 240 * (ByteBuffer, ShortBuffer, IntBuffer). 241 */ 242 public void copyPixelsToBuffer(Buffer dst) { 243 int elements = dst.remaining(); 244 int shift; 245 if (dst instanceof ByteBuffer) { 246 shift = 0; 247 } else if (dst instanceof ShortBuffer) { 248 shift = 1; 249 } else if (dst instanceof IntBuffer) { 250 shift = 2; 251 } else { 252 throw new RuntimeException("unsupported Buffer subclass"); 253 } 254 255 long bufferSize = (long)elements << shift; 256 long pixelSize = (long)getRowBytes() * getHeight(); 257 258 if (bufferSize < pixelSize) { 259 throw new RuntimeException("Buffer not large enough for pixels"); 260 } 261 262 nativeCopyPixelsToBuffer(mNativeBitmap, dst); 263 264 // now update the buffer's position 265 int position = dst.position(); 266 position += pixelSize >> shift; 267 dst.position(position); 268 } 269 270 /** 271 * Copy the pixels from the buffer, beginning at the current position, 272 * overwriting the bitmap's pixels. The data in the buffer is not changed 273 * in any way (unlike setPixels(), which converts from unpremultipled 32bit 274 * to whatever the bitmap's native format is. 275 */ 276 public void copyPixelsFromBuffer(Buffer src) { 277 checkRecycled("copyPixelsFromBuffer called on recycled bitmap"); 278 279 int elements = src.remaining(); 280 int shift; 281 if (src instanceof ByteBuffer) { 282 shift = 0; 283 } else if (src instanceof ShortBuffer) { 284 shift = 1; 285 } else if (src instanceof IntBuffer) { 286 shift = 2; 287 } else { 288 throw new RuntimeException("unsupported Buffer subclass"); 289 } 290 291 long bufferBytes = (long)elements << shift; 292 long bitmapBytes = (long)getRowBytes() * getHeight(); 293 294 if (bufferBytes < bitmapBytes) { 295 throw new RuntimeException("Buffer not large enough for pixels"); 296 } 297 298 nativeCopyPixelsFromBuffer(mNativeBitmap, src); 299 } 300 301 /** 302 * Tries to make a new bitmap based on the dimensions of this bitmap, 303 * setting the new bitmap's config to the one specified, and then copying 304 * this bitmap's pixels into the new bitmap. If the conversion is not 305 * supported, or the allocator fails, then this returns NULL. The returned 306 * bitmap initially has the same density as the original. 307 * 308 * @param config The desired config for the resulting bitmap 309 * @param isMutable True if the resulting bitmap should be mutable (i.e. 310 * its pixels can be modified) 311 * @return the new bitmap, or null if the copy could not be made. 312 */ 313 public Bitmap copy(Config config, boolean isMutable) { 314 checkRecycled("Can't copy a recycled bitmap"); 315 Bitmap b = nativeCopy(mNativeBitmap, config.nativeInt, isMutable); 316 if (b != null) { 317 b.mDensity = mDensity; 318 } 319 return b; 320 } 321 322 /** 323 * Creates a new bitmap, scaled from an existing bitmap. 324 * 325 * @param src The source bitmap. 326 * @param dstWidth The new bitmap's desired width. 327 * @param dstHeight The new bitmap's desired height. 328 * @param filter true if the source should be filtered. 329 * @return the new scaled bitmap. 330 */ 331 public static Bitmap createScaledBitmap(Bitmap src, int dstWidth, 332 int dstHeight, boolean filter) { 333 Matrix m; 334 synchronized (Bitmap.class) { 335 // small pool of just 1 matrix 336 m = sScaleMatrix; 337 sScaleMatrix = null; 338 } 339 340 if (m == null) { 341 m = new Matrix(); 342 } 343 344 final int width = src.getWidth(); 345 final int height = src.getHeight(); 346 final float sx = dstWidth / (float)width; 347 final float sy = dstHeight / (float)height; 348 m.setScale(sx, sy); 349 Bitmap b = Bitmap.createBitmap(src, 0, 0, width, height, m, filter); 350 351 synchronized (Bitmap.class) { 352 // do we need to check for null? why not just assign everytime? 353 if (sScaleMatrix == null) { 354 sScaleMatrix = m; 355 } 356 } 357 358 return b; 359 } 360 361 /** 362 * Returns an immutable bitmap from the source bitmap. The new bitmap may 363 * be the same object as source, or a copy may have been made. It is 364 * initialized with the same density as the original bitmap. 365 */ 366 public static Bitmap createBitmap(Bitmap src) { 367 return createBitmap(src, 0, 0, src.getWidth(), src.getHeight()); 368 } 369 370 /** 371 * Returns an immutable bitmap from the specified subset of the source 372 * bitmap. The new bitmap may be the same object as source, or a copy may 373 * have been made. It is 374 * initialized with the same density as the original bitmap. 375 * 376 * @param source The bitmap we are subsetting 377 * @param x The x coordinate of the first pixel in source 378 * @param y The y coordinate of the first pixel in source 379 * @param width The number of pixels in each row 380 * @param height The number of rows 381 */ 382 public static Bitmap createBitmap(Bitmap source, int x, int y, int width, int height) { 383 return createBitmap(source, x, y, width, height, null, false); 384 } 385 386 /** 387 * Returns an immutable bitmap from subset of the source bitmap, 388 * transformed by the optional matrix. It is 389 * initialized with the same density as the original bitmap. 390 * 391 * @param source The bitmap we are subsetting 392 * @param x The x coordinate of the first pixel in source 393 * @param y The y coordinate of the first pixel in source 394 * @param width The number of pixels in each row 395 * @param height The number of rows 396 * @param m Optional matrix to be applied to the pixels 397 * @param filter true if the source should be filtered. 398 * Only applies if the matrix contains more than just 399 * translation. 400 * @return A bitmap that represents the specified subset of source 401 * @throws IllegalArgumentException if the x, y, width, height values are 402 * outside of the dimensions of the source bitmap. 403 */ 404 public static Bitmap createBitmap(Bitmap source, int x, int y, int width, int height, 405 Matrix m, boolean filter) { 406 407 checkXYSign(x, y); 408 checkWidthHeight(width, height); 409 if (x + width > source.getWidth()) { 410 throw new IllegalArgumentException("x + width must be <= bitmap.width()"); 411 } 412 if (y + height > source.getHeight()) { 413 throw new IllegalArgumentException("y + height must be <= bitmap.height()"); 414 } 415 416 // check if we can just return our argument unchanged 417 if (!source.isMutable() && x == 0 && y == 0 && width == source.getWidth() && 418 height == source.getHeight() && (m == null || m.isIdentity())) { 419 return source; 420 } 421 422 int neww = width; 423 int newh = height; 424 Canvas canvas = new Canvas(); 425 Bitmap bitmap; 426 Paint paint; 427 428 Rect srcR = new Rect(x, y, x + width, y + height); 429 RectF dstR = new RectF(0, 0, width, height); 430 431 if (m == null || m.isIdentity()) { 432 bitmap = createBitmap(neww, newh, 433 source.hasAlpha() ? Config.ARGB_8888 : Config.RGB_565); 434 paint = null; // not needed 435 } else { 436 /* the dst should have alpha if the src does, or if our matrix 437 doesn't preserve rectness 438 */ 439 boolean hasAlpha = source.hasAlpha() || !m.rectStaysRect(); 440 RectF deviceR = new RectF(); 441 m.mapRect(deviceR, dstR); 442 neww = Math.round(deviceR.width()); 443 newh = Math.round(deviceR.height()); 444 bitmap = createBitmap(neww, newh, hasAlpha ? Config.ARGB_8888 : Config.RGB_565); 445 if (hasAlpha) { 446 bitmap.eraseColor(0); 447 } 448 canvas.translate(-deviceR.left, -deviceR.top); 449 canvas.concat(m); 450 paint = new Paint(); 451 paint.setFilterBitmap(filter); 452 if (!m.rectStaysRect()) { 453 paint.setAntiAlias(true); 454 } 455 } 456 457 // The new bitmap was created from a known bitmap source so assume that 458 // they use the same density 459 bitmap.mDensity = source.mDensity; 460 461 canvas.setBitmap(bitmap); 462 canvas.drawBitmap(source, srcR, dstR, paint); 463 464 return bitmap; 465 } 466 467 /** 468 * Returns a mutable bitmap with the specified width and height. Its 469 * initial density is as per {@link #getDensity}. 470 * 471 * @param width The width of the bitmap 472 * @param height The height of the bitmap 473 * @param config The bitmap config to create. 474 * @throws IllegalArgumentException if the width or height are <= 0 475 */ 476 public static Bitmap createBitmap(int width, int height, Config config) { 477 Bitmap bm = nativeCreate(null, 0, width, width, height, config.nativeInt, true); 478 bm.eraseColor(0); // start with black/transparent pixels 479 return bm; 480 } 481 482 /** 483 * Returns a immutable bitmap with the specified width and height, with each 484 * pixel value set to the corresponding value in the colors array. Its 485 * initial density is as per {@link #getDensity}. 486 * 487 * @param colors Array of {@link Color} used to initialize the pixels. 488 * @param offset Number of values to skip before the first color in the 489 * array of colors. 490 * @param stride Number of colors in the array between rows (must be >= 491 * width or <= -width). 492 * @param width The width of the bitmap 493 * @param height The height of the bitmap 494 * @param config The bitmap config to create. If the config does not 495 * support per-pixel alpha (e.g. RGB_565), then the alpha 496 * bytes in the colors[] will be ignored (assumed to be FF) 497 * @throws IllegalArgumentException if the width or height are <= 0, or if 498 * the color array's length is less than the number of pixels. 499 */ 500 public static Bitmap createBitmap(int colors[], int offset, int stride, 501 int width, int height, Config config) { 502 503 checkWidthHeight(width, height); 504 if (Math.abs(stride) < width) { 505 throw new IllegalArgumentException("abs(stride) must be >= width"); 506 } 507 int lastScanline = offset + (height - 1) * stride; 508 int length = colors.length; 509 if (offset < 0 || (offset + width > length) || lastScanline < 0 || 510 (lastScanline + width > length)) { 511 throw new ArrayIndexOutOfBoundsException(); 512 } 513 return nativeCreate(colors, offset, stride, width, height, 514 config.nativeInt, false); 515 } 516 517 /** 518 * Returns a immutable bitmap with the specified width and height, with each 519 * pixel value set to the corresponding value in the colors array. Its 520 * initial density is as per {@link #getDensity}. 521 * 522 * @param colors Array of {@link Color} used to initialize the pixels. 523 * This array must be at least as large as width * height. 524 * @param width The width of the bitmap 525 * @param height The height of the bitmap 526 * @param config The bitmap config to create. If the config does not 527 * support per-pixel alpha (e.g. RGB_565), then the alpha 528 * bytes in the colors[] will be ignored (assumed to be FF) 529 * @throws IllegalArgumentException if the width or height are <= 0, or if 530 * the color array's length is less than the number of pixels. 531 */ 532 public static Bitmap createBitmap(int colors[], int width, int height, Config config) { 533 return createBitmap(colors, 0, width, width, height, config); 534 } 535 536 /** 537 * Returns an optional array of private data, used by the UI system for 538 * some bitmaps. Not intended to be called by applications. 539 */ 540 public byte[] getNinePatchChunk() { 541 return mNinePatchChunk; 542 } 543 544 /** 545 * Specifies the known formats a bitmap can be compressed into 546 */ 547 public enum CompressFormat { 548 JPEG (0), 549 PNG (1); 550 551 CompressFormat(int nativeInt) { 552 this.nativeInt = nativeInt; 553 } 554 final int nativeInt; 555 } 556 557 /** 558 * Number of bytes of temp storage we use for communicating between the 559 * native compressor and the java OutputStream. 560 */ 561 private final static int WORKING_COMPRESS_STORAGE = 4096; 562 563 /** 564 * Write a compressed version of the bitmap to the specified outputstream. 565 * If this returns true, the bitmap can be reconstructed by passing a 566 * corresponding inputstream to BitmapFactory.decodeStream(). Note: not 567 * all Formats support all bitmap configs directly, so it is possible that 568 * the returned bitmap from BitmapFactory could be in a different bitdepth, 569 * and/or may have lost per-pixel alpha (e.g. JPEG only supports opaque 570 * pixels). 571 * 572 * @param format The format of the compressed image 573 * @param quality Hint to the compressor, 0-100. 0 meaning compress for 574 * small size, 100 meaning compress for max quality. Some 575 * formats, like PNG which is lossless, will ignore the 576 * quality setting 577 * @param stream The outputstream to write the compressed data. 578 * @return true if successfully compressed to the specified stream. 579 */ 580 public boolean compress(CompressFormat format, int quality, OutputStream stream) { 581 checkRecycled("Can't compress a recycled bitmap"); 582 // do explicit check before calling the native method 583 if (stream == null) { 584 throw new NullPointerException(); 585 } 586 if (quality < 0 || quality > 100) { 587 throw new IllegalArgumentException("quality must be 0..100"); 588 } 589 return nativeCompress(mNativeBitmap, format.nativeInt, quality, 590 stream, new byte[WORKING_COMPRESS_STORAGE]); 591 } 592 593 /** 594 * Returns true if the bitmap is marked as mutable (i.e. can be drawn into) 595 */ 596 public final boolean isMutable() { 597 return mIsMutable; 598 } 599 600 /** Returns the bitmap's width */ 601 public final int getWidth() { 602 return mWidth == -1 ? mWidth = nativeWidth(mNativeBitmap) : mWidth; 603 } 604 605 /** Returns the bitmap's height */ 606 public final int getHeight() { 607 return mHeight == -1 ? mHeight = nativeHeight(mNativeBitmap) : mHeight; 608 } 609 610 /** 611 * Convenience for calling {@link #getScaledWidth(int)} with the target 612 * density of the given {@link Canvas}. 613 */ 614 public int getScaledWidth(Canvas canvas) { 615 return scaleFromDensity(getWidth(), mDensity, canvas.mDensity); 616 } 617 618 /** 619 * Convenience for calling {@link #getScaledHeight(int)} with the target 620 * density of the given {@link Canvas}. 621 */ 622 public int getScaledHeight(Canvas canvas) { 623 return scaleFromDensity(getHeight(), mDensity, canvas.mDensity); 624 } 625 626 /** 627 * Convenience for calling {@link #getScaledWidth(int)} with the target 628 * density of the given {@link DisplayMetrics}. 629 */ 630 public int getScaledWidth(DisplayMetrics metrics) { 631 return scaleFromDensity(getWidth(), mDensity, metrics.densityDpi); 632 } 633 634 /** 635 * Convenience for calling {@link #getScaledHeight(int)} with the target 636 * density of the given {@link DisplayMetrics}. 637 */ 638 public int getScaledHeight(DisplayMetrics metrics) { 639 return scaleFromDensity(getHeight(), mDensity, metrics.densityDpi); 640 } 641 642 /** 643 * Convenience method that returns the width of this bitmap divided 644 * by the density scale factor. 645 * 646 * @param targetDensity The density of the target canvas of the bitmap. 647 * @return The scaled width of this bitmap, according to the density scale factor. 648 */ 649 public int getScaledWidth(int targetDensity) { 650 return scaleFromDensity(getWidth(), mDensity, targetDensity); 651 } 652 653 /** 654 * Convenience method that returns the height of this bitmap divided 655 * by the density scale factor. 656 * 657 * @param targetDensity The density of the target canvas of the bitmap. 658 * @return The scaled height of this bitmap, according to the density scale factor. 659 */ 660 public int getScaledHeight(int targetDensity) { 661 return scaleFromDensity(getHeight(), mDensity, targetDensity); 662 } 663 664 /** 665 * @hide 666 */ 667 static public int scaleFromDensity(int size, int sdensity, int tdensity) { 668 if (sdensity == DENSITY_NONE || sdensity == tdensity) { 669 return size; 670 } 671 672 // Scale by tdensity / sdensity, rounding up. 673 return ( (size * tdensity) + (sdensity >> 1) ) / sdensity; 674 } 675 676 /** 677 * Return the number of bytes between rows in the bitmap's pixels. Note that 678 * this refers to the pixels as stored natively by the bitmap. If you call 679 * getPixels() or setPixels(), then the pixels are uniformly treated as 680 * 32bit values, packed according to the Color class. 681 * 682 * @return number of bytes between rows of the native bitmap pixels. 683 */ 684 public final int getRowBytes() { 685 return nativeRowBytes(mNativeBitmap); 686 } 687 688 /** 689 * If the bitmap's internal config is in one of the public formats, return 690 * that config, otherwise return null. 691 */ 692 public final Config getConfig() { 693 return Config.nativeToConfig(nativeConfig(mNativeBitmap)); 694 } 695 696 /** Returns true if the bitmap's config supports per-pixel alpha, and 697 * if the pixels may contain non-opaque alpha values. For some configs, 698 * this is always false (e.g. RGB_565), since they do not support per-pixel 699 * alpha. However, for configs that do, the bitmap may be flagged to be 700 * known that all of its pixels are opaque. In this case hasAlpha() will 701 * also return false. If a config such as ARGB_8888 is not so flagged, 702 * it will return true by default. 703 */ 704 public final boolean hasAlpha() { 705 return nativeHasAlpha(mNativeBitmap); 706 } 707 708 /** 709 * Tell the bitmap if all of the pixels are known to be opaque (false) 710 * or if some of the pixels may contain non-opaque alpha values (true). 711 * Note, for some configs (e.g. RGB_565) this call is ignore, since it does 712 * not support per-pixel alpha values. 713 * 714 * This is meant as a drawing hint, as in some cases a bitmap that is known 715 * to be opaque can take a faster drawing case than one that may have 716 * non-opaque per-pixel alpha values. 717 * 718 * @hide 719 */ 720 public void setHasAlpha(boolean hasAlpha) { 721 nativeSetHasAlpha(mNativeBitmap, hasAlpha); 722 } 723 724 /** 725 * Fills the bitmap's pixels with the specified {@link Color}. 726 * 727 * @throws IllegalStateException if the bitmap is not mutable. 728 */ 729 public void eraseColor(int c) { 730 checkRecycled("Can't erase a recycled bitmap"); 731 if (!isMutable()) { 732 throw new IllegalStateException("cannot erase immutable bitmaps"); 733 } 734 nativeErase(mNativeBitmap, c); 735 } 736 737 /** 738 * Returns the {@link Color} at the specified location. Throws an exception 739 * if x or y are out of bounds (negative or >= to the width or height 740 * respectively). 741 * 742 * @param x The x coordinate (0...width-1) of the pixel to return 743 * @param y The y coordinate (0...height-1) of the pixel to return 744 * @return The argb {@link Color} at the specified coordinate 745 * @throws IllegalArgumentException if x, y exceed the bitmap's bounds 746 */ 747 public int getPixel(int x, int y) { 748 checkRecycled("Can't call getPixel() on a recycled bitmap"); 749 checkPixelAccess(x, y); 750 return nativeGetPixel(mNativeBitmap, x, y); 751 } 752 753 /** 754 * Returns in pixels[] a copy of the data in the bitmap. Each value is 755 * a packed int representing a {@link Color}. The stride parameter allows 756 * the caller to allow for gaps in the returned pixels array between 757 * rows. For normal packed results, just pass width for the stride value. 758 * 759 * @param pixels The array to receive the bitmap's colors 760 * @param offset The first index to write into pixels[] 761 * @param stride The number of entries in pixels[] to skip between 762 * rows (must be >= bitmap's width). Can be negative. 763 * @param x The x coordinate of the first pixel to read from 764 * the bitmap 765 * @param y The y coordinate of the first pixel to read from 766 * the bitmap 767 * @param width The number of pixels to read from each row 768 * @param height The number of rows to read 769 * @throws IllegalArgumentException if x, y, width, height exceed the 770 * bounds of the bitmap, or if abs(stride) < width. 771 * @throws ArrayIndexOutOfBoundsException if the pixels array is too small 772 * to receive the specified number of pixels. 773 */ 774 public void getPixels(int[] pixels, int offset, int stride, 775 int x, int y, int width, int height) { 776 checkRecycled("Can't call getPixels() on a recycled bitmap"); 777 if (width == 0 || height == 0) { 778 return; // nothing to do 779 } 780 checkPixelsAccess(x, y, width, height, offset, stride, pixels); 781 nativeGetPixels(mNativeBitmap, pixels, offset, stride, 782 x, y, width, height); 783 } 784 785 /** 786 * Shared code to check for illegal arguments passed to getPixel() 787 * or setPixel() 788 * @param x x coordinate of the pixel 789 * @param y y coordinate of the pixel 790 */ 791 private void checkPixelAccess(int x, int y) { 792 checkXYSign(x, y); 793 if (x >= getWidth()) { 794 throw new IllegalArgumentException("x must be < bitmap.width()"); 795 } 796 if (y >= getHeight()) { 797 throw new IllegalArgumentException("y must be < bitmap.height()"); 798 } 799 } 800 801 /** 802 * Shared code to check for illegal arguments passed to getPixels() 803 * or setPixels() 804 * 805 * @param x left edge of the area of pixels to access 806 * @param y top edge of the area of pixels to access 807 * @param width width of the area of pixels to access 808 * @param height height of the area of pixels to access 809 * @param offset offset into pixels[] array 810 * @param stride number of elements in pixels[] between each logical row 811 * @param pixels array to hold the area of pixels being accessed 812 */ 813 private void checkPixelsAccess(int x, int y, int width, int height, 814 int offset, int stride, int pixels[]) { 815 checkXYSign(x, y); 816 if (width < 0) { 817 throw new IllegalArgumentException("width must be >= 0"); 818 } 819 if (height < 0) { 820 throw new IllegalArgumentException("height must be >= 0"); 821 } 822 if (x + width > getWidth()) { 823 throw new IllegalArgumentException( 824 "x + width must be <= bitmap.width()"); 825 } 826 if (y + height > getHeight()) { 827 throw new IllegalArgumentException( 828 "y + height must be <= bitmap.height()"); 829 } 830 if (Math.abs(stride) < width) { 831 throw new IllegalArgumentException("abs(stride) must be >= width"); 832 } 833 int lastScanline = offset + (height - 1) * stride; 834 int length = pixels.length; 835 if (offset < 0 || (offset + width > length) 836 || lastScanline < 0 837 || (lastScanline + width > length)) { 838 throw new ArrayIndexOutOfBoundsException(); 839 } 840 } 841 842 /** 843 * Write the specified {@link Color} into the bitmap (assuming it is 844 * mutable) at the x,y coordinate. 845 * 846 * @param x The x coordinate of the pixel to replace (0...width-1) 847 * @param y The y coordinate of the pixel to replace (0...height-1) 848 * @param color The {@link Color} to write into the bitmap 849 * @throws IllegalStateException if the bitmap is not mutable 850 * @throws IllegalArgumentException if x, y are outside of the bitmap's 851 * bounds. 852 */ 853 public void setPixel(int x, int y, int color) { 854 checkRecycled("Can't call setPixel() on a recycled bitmap"); 855 if (!isMutable()) { 856 throw new IllegalStateException(); 857 } 858 checkPixelAccess(x, y); 859 nativeSetPixel(mNativeBitmap, x, y, color); 860 } 861 862 /** 863 * Replace pixels in the bitmap with the colors in the array. Each element 864 * in the array is a packed int prepresenting a {@link Color} 865 * 866 * @param pixels The colors to write to the bitmap 867 * @param offset The index of the first color to read from pixels[] 868 * @param stride The number of colors in pixels[] to skip between rows. 869 * Normally this value will be the same as the width of 870 * the bitmap, but it can be larger (or negative). 871 * @param x The x coordinate of the first pixel to write to in 872 * the bitmap. 873 * @param y The y coordinate of the first pixel to write to in 874 * the bitmap. 875 * @param width The number of colors to copy from pixels[] per row 876 * @param height The number of rows to write to the bitmap 877 * @throws IllegalStateException if the bitmap is not mutable 878 * @throws IllegalArgumentException if x, y, width, height are outside of 879 * the bitmap's bounds. 880 * @throws ArrayIndexOutOfBoundsException if the pixels array is too small 881 * to receive the specified number of pixels. 882 */ 883 public void setPixels(int[] pixels, int offset, int stride, 884 int x, int y, int width, int height) { 885 checkRecycled("Can't call setPixels() on a recycled bitmap"); 886 if (!isMutable()) { 887 throw new IllegalStateException(); 888 } 889 if (width == 0 || height == 0) { 890 return; // nothing to do 891 } 892 checkPixelsAccess(x, y, width, height, offset, stride, pixels); 893 nativeSetPixels(mNativeBitmap, pixels, offset, stride, 894 x, y, width, height); 895 } 896 897 public static final Parcelable.Creator<Bitmap> CREATOR 898 = new Parcelable.Creator<Bitmap>() { 899 /** 900 * Rebuilds a bitmap previously stored with writeToParcel(). 901 * 902 * @param p Parcel object to read the bitmap from 903 * @return a new bitmap created from the data in the parcel 904 */ 905 public Bitmap createFromParcel(Parcel p) { 906 Bitmap bm = nativeCreateFromParcel(p); 907 if (bm == null) { 908 throw new RuntimeException("Failed to unparcel Bitmap"); 909 } 910 return bm; 911 } 912 public Bitmap[] newArray(int size) { 913 return new Bitmap[size]; 914 } 915 }; 916 917 /** 918 * No special parcel contents. 919 */ 920 public int describeContents() { 921 return 0; 922 } 923 924 /** 925 * Write the bitmap and its pixels to the parcel. The bitmap can be 926 * rebuilt from the parcel by calling CREATOR.createFromParcel(). 927 * @param p Parcel object to write the bitmap data into 928 */ 929 public void writeToParcel(Parcel p, int flags) { 930 checkRecycled("Can't parcel a recycled bitmap"); 931 if (!nativeWriteToParcel(mNativeBitmap, mIsMutable, mDensity, p)) { 932 throw new RuntimeException("native writeToParcel failed"); 933 } 934 } 935 936 /** 937 * Returns a new bitmap that captures the alpha values of the original. 938 * This may be drawn with Canvas.drawBitmap(), where the color(s) will be 939 * taken from the paint that is passed to the draw call. 940 * 941 * @return new bitmap containing the alpha channel of the original bitmap. 942 */ 943 public Bitmap extractAlpha() { 944 return extractAlpha(null, null); 945 } 946 947 /** 948 * Returns a new bitmap that captures the alpha values of the original. 949 * These values may be affected by the optional Paint parameter, which 950 * can contain its own alpha, and may also contain a MaskFilter which 951 * could change the actual dimensions of the resulting bitmap (e.g. 952 * a blur maskfilter might enlarge the resulting bitmap). If offsetXY 953 * is not null, it returns the amount to offset the returned bitmap so 954 * that it will logically align with the original. For example, if the 955 * paint contains a blur of radius 2, then offsetXY[] would contains 956 * -2, -2, so that drawing the alpha bitmap offset by (-2, -2) and then 957 * drawing the original would result in the blur visually aligning with 958 * the original. 959 * 960 * <p>The initial density of the returned bitmap is the same as the original's. 961 * 962 * @param paint Optional paint used to modify the alpha values in the 963 * resulting bitmap. Pass null for default behavior. 964 * @param offsetXY Optional array that returns the X (index 0) and Y 965 * (index 1) offset needed to position the returned bitmap 966 * so that it visually lines up with the original. 967 * @return new bitmap containing the (optionally modified by paint) alpha 968 * channel of the original bitmap. This may be drawn with 969 * Canvas.drawBitmap(), where the color(s) will be taken from the 970 * paint that is passed to the draw call. 971 */ 972 public Bitmap extractAlpha(Paint paint, int[] offsetXY) { 973 checkRecycled("Can't extractAlpha on a recycled bitmap"); 974 int nativePaint = paint != null ? paint.mNativePaint : 0; 975 Bitmap bm = nativeExtractAlpha(mNativeBitmap, nativePaint, offsetXY); 976 if (bm == null) { 977 throw new RuntimeException("Failed to extractAlpha on Bitmap"); 978 } 979 bm.mDensity = mDensity; 980 return bm; 981 } 982 983 /** 984 * Given another bitmap, return true if it has the same dimensions, config, 985 * and pixel data as this bitmap. If any of those differ, return false. 986 * If other is null, return false. 987 * 988 * @hide (just needed internally right now) 989 */ 990 public boolean sameAs(Bitmap other) { 991 return this == other || 992 (other != null && 993 nativeSameAs(mNativeBitmap, other.mNativeBitmap)); 994 } 995 996 /** 997 * Rebuilds any caches associated with the bitmap that are used for 998 * drawing it. In the case of purgeable bitmaps, this call will attempt to 999 * ensure that the pixels have been decoded. 1000 * If this is called on more than one bitmap in sequence, the priority is 1001 * given in LRU order (i.e. the last bitmap called will be given highest 1002 * priority). 1003 * 1004 * For bitmaps with no associated caches, this call is effectively a no-op, 1005 * and therefore is harmless. 1006 */ 1007 public void prepareToDraw() { 1008 nativePrepareToDraw(mNativeBitmap); 1009 } 1010 1011 @Override 1012 protected void finalize() throws Throwable { 1013 try { 1014 nativeDestructor(mNativeBitmap); 1015 } finally { 1016 super.finalize(); 1017 } 1018 } 1019 1020 //////////// native methods 1021 1022 private static native Bitmap nativeCreate(int[] colors, int offset, 1023 int stride, int width, int height, 1024 int nativeConfig, boolean mutable); 1025 private static native Bitmap nativeCopy(int srcBitmap, int nativeConfig, 1026 boolean isMutable); 1027 private static native void nativeDestructor(int nativeBitmap); 1028 private static native void nativeRecycle(int nativeBitmap); 1029 1030 private static native boolean nativeCompress(int nativeBitmap, int format, 1031 int quality, OutputStream stream, 1032 byte[] tempStorage); 1033 private static native void nativeErase(int nativeBitmap, int color); 1034 private static native int nativeWidth(int nativeBitmap); 1035 private static native int nativeHeight(int nativeBitmap); 1036 private static native int nativeRowBytes(int nativeBitmap); 1037 private static native int nativeConfig(int nativeBitmap); 1038 private static native boolean nativeHasAlpha(int nativeBitmap); 1039 1040 private static native int nativeGetPixel(int nativeBitmap, int x, int y); 1041 private static native void nativeGetPixels(int nativeBitmap, int[] pixels, 1042 int offset, int stride, int x, 1043 int y, int width, int height); 1044 1045 private static native void nativeSetPixel(int nativeBitmap, int x, int y, 1046 int color); 1047 private static native void nativeSetPixels(int nativeBitmap, int[] colors, 1048 int offset, int stride, int x, 1049 int y, int width, int height); 1050 private static native void nativeCopyPixelsToBuffer(int nativeBitmap, 1051 Buffer dst); 1052 private static native void nativeCopyPixelsFromBuffer(int nb, Buffer src); 1053 1054 private static native Bitmap nativeCreateFromParcel(Parcel p); 1055 // returns true on success 1056 private static native boolean nativeWriteToParcel(int nativeBitmap, 1057 boolean isMutable, 1058 int density, 1059 Parcel p); 1060 // returns a new bitmap built from the native bitmap's alpha, and the paint 1061 private static native Bitmap nativeExtractAlpha(int nativeBitmap, 1062 int nativePaint, 1063 int[] offsetXY); 1064 1065 private static native void nativePrepareToDraw(int nativeBitmap); 1066 private static native void nativeSetHasAlpha(int nBitmap, boolean hasAlpha); 1067 private static native boolean nativeSameAs(int nb0, int nb1); 1068 1069 /* package */ final int ni() { 1070 return mNativeBitmap; 1071 } 1072 } 1073