diff options
| -rw-r--r-- | graphics/java/android/graphics/BitmapFactory.java | 41 |
1 files changed, 29 insertions, 12 deletions
diff --git a/graphics/java/android/graphics/BitmapFactory.java b/graphics/java/android/graphics/BitmapFactory.java index 4193dbb32449..e3adc59244b3 100644 --- a/graphics/java/android/graphics/BitmapFactory.java +++ b/graphics/java/android/graphics/BitmapFactory.java @@ -56,15 +56,26 @@ public class BitmapFactory { * mutable even when decoding a resource which would normally result in * an immutable bitmap.</p> * + * <p>You should still always use the returned Bitmap of the decode + * method and not assume that reusing the bitmap worked, due to the + * constraints outlined above and failure situations that can occur. + * Checking whether the return value matches the value of the inBitmap + * set in the Options structure will indicate if the bitmap was reused, + * but in all cases you should use the Bitmap returned by the decoding + * function to ensure that you are using the bitmap that was used as the + * decode destination.</p> + * + * <h3>Usage with BitmapFactory</h3> + * * <p>As of {@link android.os.Build.VERSION_CODES#KITKAT}, any - * mutable bitmap can be reused to decode any other bitmaps as long as - * the resulting {@link Bitmap#getByteCount() byte count} of the decoded - * bitmap is less than or equal to the {@link + * mutable bitmap can be reused by {@link BitmapFactory} to decode any + * other bitmaps as long as the resulting {@link Bitmap#getByteCount() + * byte count} of the decoded bitmap is less than or equal to the {@link * Bitmap#getAllocationByteCount() allocated byte count} of the reused * bitmap. This can be because the intrinsic size is smaller, or its * size post scaling (for density / sample size) is smaller.</p> * - * <p>Prior to {@link android.os.Build.VERSION_CODES#KITKAT} + * <p class="note">Prior to {@link android.os.Build.VERSION_CODES#KITKAT} * additional constraints apply: The image being decoded (whether as a * resource or as a stream) must be in jpeg or png format. Only equal * sized bitmaps are supported, with {@link #inSampleSize} set to 1. @@ -72,14 +83,17 @@ public class BitmapFactory { * configuration} of the reused bitmap will override the setting of * {@link #inPreferredConfig}, if set.</p> * - * <p>You should still always use the returned Bitmap of the decode - * method and not assume that reusing the bitmap worked, due to the - * constraints outlined above and failure situations that can occur. - * Checking whether the return value matches the value of the inBitmap - * set in the Options structure will indicate if the bitmap was reused, - * but in all cases you should use the Bitmap returned by the decoding - * function to ensure that you are using the bitmap that was used as the - * decode destination.</p> + * <h3>Usage with BitmapRegionDecoder</h3> + * + * <p>BitmapRegionDecoder will draw its requested content into the Bitmap + * provided, clipping if the output content size (post scaling) is larger + * than the provided Bitmap. The provided Bitmap's width, height, and + * {@link Bitmap.Config} will not be changed. + * + * <p class="note">BitmapRegionDecoder support for {@link #inBitmap} was + * introduced in {@link android.os.Build.VERSION_CODES#JELLY_BEAN}. All + * formats supported by BitmapRegionDecoder support Bitmap reuse via + * {@link #inBitmap}.</p> * * @see Bitmap#reconfigure(int,int, android.graphics.Bitmap.Config) */ @@ -229,6 +243,9 @@ public class BitmapFactory { * rather than relying on the graphics system scaling it each time it * is drawn to a Canvas. * + * <p>BitmapRegionDecoder ignores this flag, and will not scale output + * based on density. (though {@link #inSampleSize} is supported)</p> + * * <p>This flag is turned on by default and should be turned off if you need * a non-scaled version of the bitmap. Nine-patch bitmaps ignore this * flag and are always scaled. |