1 /* 2 * Copyright (C) 2007 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.content.res.AssetManager; 20 import android.content.res.Resources; 21 import android.os.Trace; 22 import android.util.DisplayMetrics; 23 import android.util.Log; 24 import android.util.TypedValue; 25 26 import java.io.FileDescriptor; 27 import java.io.FileInputStream; 28 import java.io.IOException; 29 import java.io.InputStream; 30 31 /** 32 * Creates Bitmap objects from various sources, including files, streams, 33 * and byte-arrays. 34 */ 35 public class BitmapFactory { 36 private static final int DECODE_BUFFER_SIZE = 16 * 1024; 37 38 public static class Options { 39 /** 40 * Create a default Options object, which if left unchanged will give 41 * the same result from the decoder as if null were passed. 42 */ Options()43 public Options() { 44 inDither = false; 45 inScaled = true; 46 inPremultiplied = true; 47 } 48 49 /** 50 * If set, decode methods that take the Options object will attempt to 51 * reuse this bitmap when loading content. If the decode operation 52 * cannot use this bitmap, the decode method will return 53 * <code>null</code> and will throw an IllegalArgumentException. The 54 * current implementation necessitates that the reused bitmap be 55 * mutable, and the resulting reused bitmap will continue to remain 56 * mutable even when decoding a resource which would normally result in 57 * an immutable bitmap.</p> 58 * 59 * <p>You should still always use the returned Bitmap of the decode 60 * method and not assume that reusing the bitmap worked, due to the 61 * constraints outlined above and failure situations that can occur. 62 * Checking whether the return value matches the value of the inBitmap 63 * set in the Options structure will indicate if the bitmap was reused, 64 * but in all cases you should use the Bitmap returned by the decoding 65 * function to ensure that you are using the bitmap that was used as the 66 * decode destination.</p> 67 * 68 * <h3>Usage with BitmapFactory</h3> 69 * 70 * <p>As of {@link android.os.Build.VERSION_CODES#KITKAT}, any 71 * mutable bitmap can be reused by {@link BitmapFactory} to decode any 72 * other bitmaps as long as the resulting {@link Bitmap#getByteCount() 73 * byte count} of the decoded bitmap is less than or equal to the {@link 74 * Bitmap#getAllocationByteCount() allocated byte count} of the reused 75 * bitmap. This can be because the intrinsic size is smaller, or its 76 * size post scaling (for density / sample size) is smaller.</p> 77 * 78 * <p class="note">Prior to {@link android.os.Build.VERSION_CODES#KITKAT} 79 * additional constraints apply: The image being decoded (whether as a 80 * resource or as a stream) must be in jpeg or png format. Only equal 81 * sized bitmaps are supported, with {@link #inSampleSize} set to 1. 82 * Additionally, the {@link android.graphics.Bitmap.Config 83 * configuration} of the reused bitmap will override the setting of 84 * {@link #inPreferredConfig}, if set.</p> 85 * 86 * <h3>Usage with BitmapRegionDecoder</h3> 87 * 88 * <p>BitmapRegionDecoder will draw its requested content into the Bitmap 89 * provided, clipping if the output content size (post scaling) is larger 90 * than the provided Bitmap. The provided Bitmap's width, height, and 91 * {@link Bitmap.Config} will not be changed. 92 * 93 * <p class="note">BitmapRegionDecoder support for {@link #inBitmap} was 94 * introduced in {@link android.os.Build.VERSION_CODES#JELLY_BEAN}. All 95 * formats supported by BitmapRegionDecoder support Bitmap reuse via 96 * {@link #inBitmap}.</p> 97 * 98 * @see Bitmap#reconfigure(int,int, android.graphics.Bitmap.Config) 99 */ 100 public Bitmap inBitmap; 101 102 /** 103 * If set, decode methods will always return a mutable Bitmap instead of 104 * an immutable one. This can be used for instance to programmatically apply 105 * effects to a Bitmap loaded through BitmapFactory. 106 */ 107 @SuppressWarnings({"UnusedDeclaration"}) // used in native code 108 public boolean inMutable; 109 110 /** 111 * If set to true, the decoder will return null (no bitmap), but 112 * the out... fields will still be set, allowing the caller to query 113 * the bitmap without having to allocate the memory for its pixels. 114 */ 115 public boolean inJustDecodeBounds; 116 117 /** 118 * If set to a value > 1, requests the decoder to subsample the original 119 * image, returning a smaller image to save memory. The sample size is 120 * the number of pixels in either dimension that correspond to a single 121 * pixel in the decoded bitmap. For example, inSampleSize == 4 returns 122 * an image that is 1/4 the width/height of the original, and 1/16 the 123 * number of pixels. Any value <= 1 is treated the same as 1. Note: the 124 * decoder uses a final value based on powers of 2, any other value will 125 * be rounded down to the nearest power of 2. 126 */ 127 public int inSampleSize; 128 129 /** 130 * If this is non-null, the decoder will try to decode into this 131 * internal configuration. If it is null, or the request cannot be met, 132 * the decoder will try to pick the best matching config based on the 133 * system's screen depth, and characteristics of the original image such 134 * as if it has per-pixel alpha (requiring a config that also does). 135 * 136 * Image are loaded with the {@link Bitmap.Config#ARGB_8888} config by 137 * default. 138 */ 139 public Bitmap.Config inPreferredConfig = Bitmap.Config.ARGB_8888; 140 141 /** 142 * If true (which is the default), the resulting bitmap will have its 143 * color channels pre-multipled by the alpha channel. 144 * 145 * <p>This should NOT be set to false for images to be directly drawn by 146 * the view system or through a {@link Canvas}. The view system and 147 * {@link Canvas} assume all drawn images are pre-multiplied to simplify 148 * draw-time blending, and will throw a RuntimeException when 149 * un-premultiplied are drawn.</p> 150 * 151 * <p>This is likely only useful if you want to manipulate raw encoded 152 * image data, e.g. with RenderScript or custom OpenGL.</p> 153 * 154 * <p>This does not affect bitmaps without an alpha channel.</p> 155 * 156 * <p>Setting this flag to false while setting {@link #inScaled} to true 157 * may result in incorrect colors.</p> 158 * 159 * @see Bitmap#hasAlpha() 160 * @see Bitmap#isPremultiplied() 161 * @see #inScaled 162 */ 163 public boolean inPremultiplied; 164 165 /** 166 * If dither is true, the decoder will attempt to dither the decoded 167 * image. 168 */ 169 public boolean inDither; 170 171 /** 172 * The pixel density to use for the bitmap. This will always result 173 * in the returned bitmap having a density set for it (see 174 * {@link Bitmap#setDensity(int) Bitmap.setDensity(int)}). In addition, 175 * if {@link #inScaled} is set (which it is by default} and this 176 * density does not match {@link #inTargetDensity}, then the bitmap 177 * will be scaled to the target density before being returned. 178 * 179 * <p>If this is 0, 180 * {@link BitmapFactory#decodeResource(Resources, int)}, 181 * {@link BitmapFactory#decodeResource(Resources, int, android.graphics.BitmapFactory.Options)}, 182 * and {@link BitmapFactory#decodeResourceStream} 183 * will fill in the density associated with the resource. The other 184 * functions will leave it as-is and no density will be applied. 185 * 186 * @see #inTargetDensity 187 * @see #inScreenDensity 188 * @see #inScaled 189 * @see Bitmap#setDensity(int) 190 * @see android.util.DisplayMetrics#densityDpi 191 */ 192 public int inDensity; 193 194 /** 195 * The pixel density of the destination this bitmap will be drawn to. 196 * This is used in conjunction with {@link #inDensity} and 197 * {@link #inScaled} to determine if and how to scale the bitmap before 198 * returning it. 199 * 200 * <p>If this is 0, 201 * {@link BitmapFactory#decodeResource(Resources, int)}, 202 * {@link BitmapFactory#decodeResource(Resources, int, android.graphics.BitmapFactory.Options)}, 203 * and {@link BitmapFactory#decodeResourceStream} 204 * will fill in the density associated the Resources object's 205 * DisplayMetrics. The other 206 * functions will leave it as-is and no scaling for density will be 207 * performed. 208 * 209 * @see #inDensity 210 * @see #inScreenDensity 211 * @see #inScaled 212 * @see android.util.DisplayMetrics#densityDpi 213 */ 214 public int inTargetDensity; 215 216 /** 217 * The pixel density of the actual screen that is being used. This is 218 * purely for applications running in density compatibility code, where 219 * {@link #inTargetDensity} is actually the density the application 220 * sees rather than the real screen density. 221 * 222 * <p>By setting this, you 223 * allow the loading code to avoid scaling a bitmap that is currently 224 * in the screen density up/down to the compatibility density. Instead, 225 * if {@link #inDensity} is the same as {@link #inScreenDensity}, the 226 * bitmap will be left as-is. Anything using the resulting bitmap 227 * must also used {@link Bitmap#getScaledWidth(int) 228 * Bitmap.getScaledWidth} and {@link Bitmap#getScaledHeight 229 * Bitmap.getScaledHeight} to account for any different between the 230 * bitmap's density and the target's density. 231 * 232 * <p>This is never set automatically for the caller by 233 * {@link BitmapFactory} itself. It must be explicitly set, since the 234 * caller must deal with the resulting bitmap in a density-aware way. 235 * 236 * @see #inDensity 237 * @see #inTargetDensity 238 * @see #inScaled 239 * @see android.util.DisplayMetrics#densityDpi 240 */ 241 public int inScreenDensity; 242 243 /** 244 * When this flag is set, if {@link #inDensity} and 245 * {@link #inTargetDensity} are not 0, the 246 * bitmap will be scaled to match {@link #inTargetDensity} when loaded, 247 * rather than relying on the graphics system scaling it each time it 248 * is drawn to a Canvas. 249 * 250 * <p>BitmapRegionDecoder ignores this flag, and will not scale output 251 * based on density. (though {@link #inSampleSize} is supported)</p> 252 * 253 * <p>This flag is turned on by default and should be turned off if you need 254 * a non-scaled version of the bitmap. Nine-patch bitmaps ignore this 255 * flag and are always scaled. 256 * 257 * <p>If {@link #inPremultiplied} is set to false, and the image has alpha, 258 * setting this flag to true may result in incorrect colors. 259 */ 260 public boolean inScaled; 261 262 /** 263 * If this is set to true, then the resulting bitmap will allocate its 264 * pixels such that they can be purged if the system needs to reclaim 265 * memory. In that instance, when the pixels need to be accessed again 266 * (e.g. the bitmap is drawn, getPixels() is called), they will be 267 * automatically re-decoded. 268 * 269 * <p>For the re-decode to happen, the bitmap must have access to the 270 * encoded data, either by sharing a reference to the input 271 * or by making a copy of it. This distinction is controlled by 272 * inInputShareable. If this is true, then the bitmap may keep a shallow 273 * reference to the input. If this is false, then the bitmap will 274 * explicitly make a copy of the input data, and keep that. Even if 275 * sharing is allowed, the implementation may still decide to make a 276 * deep copy of the input data.</p> 277 * 278 * <p>While inPurgeable can help avoid big Dalvik heap allocations (from 279 * API level 11 onward), it sacrifices performance predictability since any 280 * image that the view system tries to draw may incur a decode delay which 281 * can lead to dropped frames. Therefore, most apps should avoid using 282 * inPurgeable to allow for a fast and fluid UI. To minimize Dalvik heap 283 * allocations use the {@link #inBitmap} flag instead.</p> 284 * 285 * <p class="note"><strong>Note:</strong> This flag is ignored when used 286 * with {@link #decodeResource(Resources, int, 287 * android.graphics.BitmapFactory.Options)} or {@link #decodeFile(String, 288 * android.graphics.BitmapFactory.Options)}.</p> 289 */ 290 public boolean inPurgeable; 291 292 /** 293 * This field works in conjuction with inPurgeable. If inPurgeable is 294 * false, then this field is ignored. If inPurgeable is true, then this 295 * field determines whether the bitmap can share a reference to the 296 * input data (inputstream, array, etc.) or if it must make a deep copy. 297 */ 298 public boolean inInputShareable; 299 300 /** 301 * If inPreferQualityOverSpeed is set to true, the decoder will try to 302 * decode the reconstructed image to a higher quality even at the 303 * expense of the decoding speed. Currently the field only affects JPEG 304 * decode, in the case of which a more accurate, but slightly slower, 305 * IDCT method will be used instead. 306 */ 307 public boolean inPreferQualityOverSpeed; 308 309 /** 310 * The resulting width of the bitmap, set independent of the state of 311 * inJustDecodeBounds. However, if there is an error trying to decode, 312 * outWidth will be set to -1. 313 */ 314 315 public int outWidth; 316 317 /** 318 * The resulting height of the bitmap, set independent of the state of 319 * inJustDecodeBounds. However, if there is an error trying to decode, 320 * outHeight will be set to -1. 321 */ 322 public int outHeight; 323 324 /** 325 * If known, this string is set to the mimetype of the decoded image. 326 * If not know, or there is an error, it is set to null. 327 */ 328 public String outMimeType; 329 330 /** 331 * Temp storage to use for decoding. Suggest 16K or so. 332 */ 333 public byte[] inTempStorage; 334 requestCancel()335 private native void requestCancel(); 336 337 /** 338 * Flag to indicate that cancel has been called on this object. This 339 * is useful if there's an intermediary that wants to first decode the 340 * bounds and then decode the image. In that case the intermediary 341 * can check, inbetween the bounds decode and the image decode, to see 342 * if the operation is canceled. 343 */ 344 public boolean mCancel; 345 346 /** 347 * This can be called from another thread while this options object is 348 * inside a decode... call. Calling this will notify the decoder that 349 * it should cancel its operation. This is not guaranteed to cancel 350 * the decode, but if it does, the decoder... operation will return 351 * null, or if inJustDecodeBounds is true, will set outWidth/outHeight 352 * to -1 353 */ requestCancelDecode()354 public void requestCancelDecode() { 355 mCancel = true; 356 requestCancel(); 357 } 358 } 359 360 /** 361 * Decode a file path into a bitmap. If the specified file name is null, 362 * or cannot be decoded into a bitmap, the function returns null. 363 * 364 * @param pathName complete path name for the file to be decoded. 365 * @param opts null-ok; Options that control downsampling and whether the 366 * image should be completely decoded, or just is size returned. 367 * @return The decoded bitmap, or null if the image data could not be 368 * decoded, or, if opts is non-null, if opts requested only the 369 * size be returned (in opts.outWidth and opts.outHeight) 370 */ decodeFile(String pathName, Options opts)371 public static Bitmap decodeFile(String pathName, Options opts) { 372 Bitmap bm = null; 373 InputStream stream = null; 374 try { 375 stream = new FileInputStream(pathName); 376 bm = decodeStream(stream, null, opts); 377 } catch (Exception e) { 378 /* do nothing. 379 If the exception happened on open, bm will be null. 380 */ 381 Log.e("BitmapFactory", "Unable to decode stream: " + e); 382 } finally { 383 if (stream != null) { 384 try { 385 stream.close(); 386 } catch (IOException e) { 387 // do nothing here 388 } 389 } 390 } 391 return bm; 392 } 393 394 /** 395 * Decode a file path into a bitmap. If the specified file name is null, 396 * or cannot be decoded into a bitmap, the function returns null. 397 * 398 * @param pathName complete path name for the file to be decoded. 399 * @return the resulting decoded bitmap, or null if it could not be decoded. 400 */ decodeFile(String pathName)401 public static Bitmap decodeFile(String pathName) { 402 return decodeFile(pathName, null); 403 } 404 405 /** 406 * Decode a new Bitmap from an InputStream. This InputStream was obtained from 407 * resources, which we pass to be able to scale the bitmap accordingly. 408 */ decodeResourceStream(Resources res, TypedValue value, InputStream is, Rect pad, Options opts)409 public static Bitmap decodeResourceStream(Resources res, TypedValue value, 410 InputStream is, Rect pad, Options opts) { 411 412 if (opts == null) { 413 opts = new Options(); 414 } 415 416 if (opts.inDensity == 0 && value != null) { 417 final int density = value.density; 418 if (density == TypedValue.DENSITY_DEFAULT) { 419 opts.inDensity = DisplayMetrics.DENSITY_DEFAULT; 420 } else if (density != TypedValue.DENSITY_NONE) { 421 opts.inDensity = density; 422 } 423 } 424 425 if (opts.inTargetDensity == 0 && res != null) { 426 opts.inTargetDensity = res.getDisplayMetrics().densityDpi; 427 } 428 429 return decodeStream(is, pad, opts); 430 } 431 432 /** 433 * Synonym for opening the given resource and calling 434 * {@link #decodeResourceStream}. 435 * 436 * @param res The resources object containing the image data 437 * @param id The resource id of the image data 438 * @param opts null-ok; Options that control downsampling and whether the 439 * image should be completely decoded, or just is size returned. 440 * @return The decoded bitmap, or null if the image data could not be 441 * decoded, or, if opts is non-null, if opts requested only the 442 * size be returned (in opts.outWidth and opts.outHeight) 443 */ decodeResource(Resources res, int id, Options opts)444 public static Bitmap decodeResource(Resources res, int id, Options opts) { 445 Bitmap bm = null; 446 InputStream is = null; 447 448 try { 449 final TypedValue value = new TypedValue(); 450 is = res.openRawResource(id, value); 451 452 bm = decodeResourceStream(res, value, is, null, opts); 453 } catch (Exception e) { 454 /* do nothing. 455 If the exception happened on open, bm will be null. 456 If it happened on close, bm is still valid. 457 */ 458 } finally { 459 try { 460 if (is != null) is.close(); 461 } catch (IOException e) { 462 // Ignore 463 } 464 } 465 466 if (bm == null && opts != null && opts.inBitmap != null) { 467 throw new IllegalArgumentException("Problem decoding into existing bitmap"); 468 } 469 470 return bm; 471 } 472 473 /** 474 * Synonym for {@link #decodeResource(Resources, int, android.graphics.BitmapFactory.Options)} 475 * will null Options. 476 * 477 * @param res The resources object containing the image data 478 * @param id The resource id of the image data 479 * @return The decoded bitmap, or null if the image could not be decode. 480 */ decodeResource(Resources res, int id)481 public static Bitmap decodeResource(Resources res, int id) { 482 return decodeResource(res, id, null); 483 } 484 485 /** 486 * Decode an immutable bitmap from the specified byte array. 487 * 488 * @param data byte array of compressed image data 489 * @param offset offset into imageData for where the decoder should begin 490 * parsing. 491 * @param length the number of bytes, beginning at offset, to parse 492 * @param opts null-ok; Options that control downsampling and whether the 493 * image should be completely decoded, or just is size returned. 494 * @return The decoded bitmap, or null if the image data could not be 495 * decoded, or, if opts is non-null, if opts requested only the 496 * size be returned (in opts.outWidth and opts.outHeight) 497 */ decodeByteArray(byte[] data, int offset, int length, Options opts)498 public static Bitmap decodeByteArray(byte[] data, int offset, int length, Options opts) { 499 if ((offset | length) < 0 || data.length < offset + length) { 500 throw new ArrayIndexOutOfBoundsException(); 501 } 502 503 Bitmap bm; 504 505 Trace.traceBegin(Trace.TRACE_TAG_GRAPHICS, "decodeBitmap"); 506 try { 507 bm = nativeDecodeByteArray(data, offset, length, opts); 508 509 if (bm == null && opts != null && opts.inBitmap != null) { 510 throw new IllegalArgumentException("Problem decoding into existing bitmap"); 511 } 512 setDensityFromOptions(bm, opts); 513 } finally { 514 Trace.traceEnd(Trace.TRACE_TAG_GRAPHICS); 515 } 516 517 return bm; 518 } 519 520 /** 521 * Decode an immutable bitmap from the specified byte array. 522 * 523 * @param data byte array of compressed image data 524 * @param offset offset into imageData for where the decoder should begin 525 * parsing. 526 * @param length the number of bytes, beginning at offset, to parse 527 * @return The decoded bitmap, or null if the image could not be decode. 528 */ decodeByteArray(byte[] data, int offset, int length)529 public static Bitmap decodeByteArray(byte[] data, int offset, int length) { 530 return decodeByteArray(data, offset, length, null); 531 } 532 533 /** 534 * Set the newly decoded bitmap's density based on the Options. 535 */ setDensityFromOptions(Bitmap outputBitmap, Options opts)536 private static void setDensityFromOptions(Bitmap outputBitmap, Options opts) { 537 if (outputBitmap == null || opts == null) return; 538 539 final int density = opts.inDensity; 540 if (density != 0) { 541 outputBitmap.setDensity(density); 542 final int targetDensity = opts.inTargetDensity; 543 if (targetDensity == 0 || density == targetDensity || density == opts.inScreenDensity) { 544 return; 545 } 546 547 byte[] np = outputBitmap.getNinePatchChunk(); 548 final boolean isNinePatch = np != null && NinePatch.isNinePatchChunk(np); 549 if (opts.inScaled || isNinePatch) { 550 outputBitmap.setDensity(targetDensity); 551 } 552 } else if (opts.inBitmap != null) { 553 // bitmap was reused, ensure density is reset 554 outputBitmap.setDensity(Bitmap.getDefaultDensity()); 555 } 556 } 557 558 /** 559 * Decode an input stream into a bitmap. If the input stream is null, or 560 * cannot be used to decode a bitmap, the function returns null. 561 * The stream's position will be where ever it was after the encoded data 562 * was read. 563 * 564 * @param is The input stream that holds the raw data to be decoded into a 565 * bitmap. 566 * @param outPadding If not null, return the padding rect for the bitmap if 567 * it exists, otherwise set padding to [-1,-1,-1,-1]. If 568 * no bitmap is returned (null) then padding is 569 * unchanged. 570 * @param opts null-ok; Options that control downsampling and whether the 571 * image should be completely decoded, or just is size returned. 572 * @return The decoded bitmap, or null if the image data could not be 573 * decoded, or, if opts is non-null, if opts requested only the 574 * size be returned (in opts.outWidth and opts.outHeight) 575 * 576 * <p class="note">Prior to {@link android.os.Build.VERSION_CODES#KITKAT}, 577 * if {@link InputStream#markSupported is.markSupported()} returns true, 578 * <code>is.mark(1024)</code> would be called. As of 579 * {@link android.os.Build.VERSION_CODES#KITKAT}, this is no longer the case.</p> 580 */ decodeStream(InputStream is, Rect outPadding, Options opts)581 public static Bitmap decodeStream(InputStream is, Rect outPadding, Options opts) { 582 // we don't throw in this case, thus allowing the caller to only check 583 // the cache, and not force the image to be decoded. 584 if (is == null) { 585 return null; 586 } 587 588 Bitmap bm = null; 589 590 Trace.traceBegin(Trace.TRACE_TAG_GRAPHICS, "decodeBitmap"); 591 try { 592 if (is instanceof AssetManager.AssetInputStream) { 593 final int asset = ((AssetManager.AssetInputStream) is).getAssetInt(); 594 bm = nativeDecodeAsset(asset, outPadding, opts); 595 } else { 596 bm = decodeStreamInternal(is, outPadding, opts); 597 } 598 599 if (bm == null && opts != null && opts.inBitmap != null) { 600 throw new IllegalArgumentException("Problem decoding into existing bitmap"); 601 } 602 603 setDensityFromOptions(bm, opts); 604 } finally { 605 Trace.traceEnd(Trace.TRACE_TAG_GRAPHICS); 606 } 607 608 return bm; 609 } 610 611 /** 612 * Private helper function for decoding an InputStream natively. Buffers the input enough to 613 * do a rewind as needed, and supplies temporary storage if necessary. is MUST NOT be null. 614 */ decodeStreamInternal(InputStream is, Rect outPadding, Options opts)615 private static Bitmap decodeStreamInternal(InputStream is, Rect outPadding, Options opts) { 616 // ASSERT(is != null); 617 byte [] tempStorage = null; 618 if (opts != null) tempStorage = opts.inTempStorage; 619 if (tempStorage == null) tempStorage = new byte[DECODE_BUFFER_SIZE]; 620 return nativeDecodeStream(is, tempStorage, outPadding, opts); 621 } 622 623 /** 624 * Decode an input stream into a bitmap. If the input stream is null, or 625 * cannot be used to decode a bitmap, the function returns null. 626 * The stream's position will be where ever it was after the encoded data 627 * was read. 628 * 629 * @param is The input stream that holds the raw data to be decoded into a 630 * bitmap. 631 * @return The decoded bitmap, or null if the image data could not be decoded. 632 */ decodeStream(InputStream is)633 public static Bitmap decodeStream(InputStream is) { 634 return decodeStream(is, null, null); 635 } 636 637 /** 638 * Decode a bitmap from the file descriptor. If the bitmap cannot be decoded 639 * return null. The position within the descriptor will not be changed when 640 * this returns, so the descriptor can be used again as-is. 641 * 642 * @param fd The file descriptor containing the bitmap data to decode 643 * @param outPadding If not null, return the padding rect for the bitmap if 644 * it exists, otherwise set padding to [-1,-1,-1,-1]. If 645 * no bitmap is returned (null) then padding is 646 * unchanged. 647 * @param opts null-ok; Options that control downsampling and whether the 648 * image should be completely decoded, or just its size returned. 649 * @return the decoded bitmap, or null 650 */ decodeFileDescriptor(FileDescriptor fd, Rect outPadding, Options opts)651 public static Bitmap decodeFileDescriptor(FileDescriptor fd, Rect outPadding, Options opts) { 652 Bitmap bm; 653 654 Trace.traceBegin(Trace.TRACE_TAG_GRAPHICS, "decodeFileDescriptor"); 655 try { 656 if (nativeIsSeekable(fd)) { 657 bm = nativeDecodeFileDescriptor(fd, outPadding, opts); 658 } else { 659 FileInputStream fis = new FileInputStream(fd); 660 try { 661 bm = decodeStreamInternal(fis, outPadding, opts); 662 } finally { 663 try { 664 fis.close(); 665 } catch (Throwable t) {/* ignore */} 666 } 667 } 668 669 if (bm == null && opts != null && opts.inBitmap != null) { 670 throw new IllegalArgumentException("Problem decoding into existing bitmap"); 671 } 672 673 setDensityFromOptions(bm, opts); 674 } finally { 675 Trace.traceEnd(Trace.TRACE_TAG_GRAPHICS); 676 } 677 return bm; 678 } 679 680 /** 681 * Decode a bitmap from the file descriptor. If the bitmap cannot be decoded 682 * return null. The position within the descriptor will not be changed when 683 * this returns, so the descriptor can be used again as is. 684 * 685 * @param fd The file descriptor containing the bitmap data to decode 686 * @return the decoded bitmap, or null 687 */ decodeFileDescriptor(FileDescriptor fd)688 public static Bitmap decodeFileDescriptor(FileDescriptor fd) { 689 return decodeFileDescriptor(fd, null, null); 690 } 691 nativeDecodeStream(InputStream is, byte[] storage, Rect padding, Options opts)692 private static native Bitmap nativeDecodeStream(InputStream is, byte[] storage, 693 Rect padding, Options opts); nativeDecodeFileDescriptor(FileDescriptor fd, Rect padding, Options opts)694 private static native Bitmap nativeDecodeFileDescriptor(FileDescriptor fd, 695 Rect padding, Options opts); nativeDecodeAsset(int asset, Rect padding, Options opts)696 private static native Bitmap nativeDecodeAsset(int asset, Rect padding, Options opts); nativeDecodeByteArray(byte[] data, int offset, int length, Options opts)697 private static native Bitmap nativeDecodeByteArray(byte[] data, int offset, 698 int length, Options opts); nativeIsSeekable(FileDescriptor fd)699 private static native boolean nativeIsSeekable(FileDescriptor fd); 700 } 701