/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.graphics;
import android.content.res.AssetManager;
import android.content.res.Resources;
import android.os.Trace;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.TypedValue;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* Creates Bitmap objects from various sources, including files, streams,
* and byte-arrays.
*/
public class BitmapFactory {
private static final int DECODE_BUFFER_SIZE = 16 * 1024;
public static class Options {
/**
* Create a default Options object, which if left unchanged will give
* the same result from the decoder as if null were passed.
*/
public Options() {
inDither = false;
inScaled = true;
inPremultiplied = true;
}
/**
* If set, decode methods that take the Options object will attempt to
* reuse this bitmap when loading content. If the decode operation
* cannot use this bitmap, the decode method will return
* <code>null</code> and will throw an IllegalArgumentException. The
* current implementation necessitates that the reused bitmap be
* mutable, and the resulting reused bitmap will continue to remain
* 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 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 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.
* Additionally, the {@link android.graphics.Bitmap.Config
* configuration} of the reused bitmap will override the setting of
* {@link #inPreferredConfig}, if set.</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)
*/
public Bitmap inBitmap;
/**
* If set, decode methods will always return a mutable Bitmap instead of
* an immutable one. This can be used for instance to programmatically apply
* effects to a Bitmap loaded through BitmapFactory.
*/
@SuppressWarnings({"UnusedDeclaration"}) // used in native code
public boolean inMutable;
/**
* If set to true, the decoder will return null (no bitmap), but
* the out... fields will still be set, allowing the caller to query
* the bitmap without having to allocate the memory for its pixels.
*/
public boolean inJustDecodeBounds;
/**
* If set to a value > 1, requests the decoder to subsample the original
* image, returning a smaller image to save memory. The sample size is
* the number of pixels in either dimension that correspond to a single
* pixel in the decoded bitmap. For example, inSampleSize == 4 returns
* an image that is 1/4 the width/height of the original, and 1/16 the
* number of pixels. Any value <= 1 is treated the same as 1. Note: the
* decoder uses a final value based on powers of 2, any other value will
* be rounded down to the nearest power of 2.
*/
public int inSampleSize;
/**
* If this is non-null, the decoder will try to decode into this
* internal configuration. If it is null, or the request cannot be met,
* the decoder will try to pick the best matching config based on the
* system's screen depth, and characteristics of the original image such
* as if it has per-pixel alpha (requiring a config that also does).
*
* Image are loaded with the {@link Bitmap.Config#ARGB_8888} config by
* default.
*/
public Bitmap.Config inPreferredConfig = Bitmap.Config.ARGB_8888;
/**
* If true (which is the default), the resulting bitmap will have its
* color channels pre-multipled by the alpha channel.
*
* <p>This should NOT be set to false for images to be directly drawn by
* the view system or through a {@link Canvas}. The view system and
* {@link Canvas} assume all drawn images are pre-multiplied to simplify
* draw-time blending, and will throw a RuntimeException when
* un-premultiplied are drawn.</p>
*
* <p>This is likely only useful if you want to manipulate raw encoded
* image data, e.g. with RenderScript or custom OpenGL.</p>
*
* <p>This does not affect bitmaps without an alpha channel.</p>
*
* <p>Setting this flag to false while setting {@link #inScaled} to true
* may result in incorrect colors.</p>
*
* @see Bitmap#hasAlpha()
* @see Bitmap#isPremultiplied()
* @see #inScaled
*/
public boolean inPremultiplied;
/**
* If dither is true, the decoder will attempt to dither the decoded
* image.
*/
public boolean inDither;
/**
* The pixel density to use for the bitmap. This will always result
* in the returned bitmap having a density set for it (see
* {@link Bitmap#setDensity(int) Bitmap.setDensity(int)}). In addition,
* if {@link #inScaled} is set (which it is by default} and this
* density does not match {@link #inTargetDensity}, then the bitmap
* will be scaled to the target density before being returned.
*
* <p>If this is 0,
* {@link BitmapFactory#decodeResource(Resources, int)},
* {@link BitmapFactory#decodeResource(Resources, int, android.graphics.BitmapFactory.Options)},
* and {@link BitmapFactory#decodeResourceStream}
* will fill in the density associated with the resource. The other
* functions will leave it as-is and no density will be applied.
*
* @see #inTargetDensity
* @see #inScreenDensity
* @see #inScaled
* @see Bitmap#setDensity(int)
* @see android.util.DisplayMetrics#densityDpi
*/
public int inDensity;
/**
* The pixel density of the destination this bitmap will be drawn to.
* This is used in conjunction with {@link #inDensity} and
* {@link #inScaled} to determine if and how to scale the bitmap before
* returning it.
*
* <p>If this is 0,
* {@link BitmapFactory#decodeResource(Resources, int)},
* {@link BitmapFactory#decodeResource(Resources, int, android.graphics.BitmapFactory.Options)},
* and {@link BitmapFactory#decodeResourceStream}
* will fill in the density associated the Resources object's
* DisplayMetrics. The other
* functions will leave it as-is and no scaling for density will be
* performed.
*
* @see #inDensity
* @see #inScreenDensity
* @see #inScaled
* @see android.util.DisplayMetrics#densityDpi
*/
public int inTargetDensity;
/**
* The pixel density of the actual screen that is being used. This is
* purely for applications running in density compatibility code, where
* {@link #inTargetDensity} is actually the density the application
* sees rather than the real screen density.
*
* <p>By setting this, you
* allow the loading code to avoid scaling a bitmap that is currently
* in the screen density up/down to the compatibility density. Instead,
* if {@link #inDensity} is the same as {@link #inScreenDensity}, the
* bitmap will be left as-is. Anything using the resulting bitmap
* must also used {@link Bitmap#getScaledWidth(int)
* Bitmap.getScaledWidth} and {@link Bitmap#getScaledHeight
* Bitmap.getScaledHeight} to account for any different between the
* bitmap's density and the target's density.
*
* <p>This is never set automatically for the caller by
* {@link BitmapFactory} itself. It must be explicitly set, since the
* caller must deal with the resulting bitmap in a density-aware way.
*
* @see #inDensity
* @see #inTargetDensity
* @see #inScaled
* @see android.util.DisplayMetrics#densityDpi
*/
public int inScreenDensity;
/**
* When this flag is set, if {@link #inDensity} and
* {@link #inTargetDensity} are not 0, the
* bitmap will be scaled to match {@link #inTargetDensity} when loaded,
* 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.
*
* <p>If {@link #inPremultiplied} is set to false, and the image has alpha,
* setting this flag to true may result in incorrect colors.
*/
public boolean inScaled;
/**
* @deprecated As of {@link android.os.Build.VERSION_CODES#LOLLIPOP}, this is
* ignored.
*
* In {@link android.os.Build.VERSION_CODES#KITKAT} and below, if this
* is set to true, then the resulting bitmap will allocate its
* pixels such that they can be purged if the system needs to reclaim
* memory. In that instance, when the pixels need to be accessed again
* (e.g. the bitmap is drawn, getPixels() is called), they will be
* automatically re-decoded.
*
* <p>For the re-decode to happen, the bitmap must have access to the
* encoded data, either by sharing a reference to the input
* or by making a copy of it. This distinction is controlled by
* inInputShareable. If this is true, then the bitmap may keep a shallow
* reference to the input. If this is false, then the bitmap will
* explicitly make a copy of the input data, and keep that. Even if
* sharing is allowed, the implementation may still decide to make a
* deep copy of the input data.</p>
*
* <p>While inPurgeable can help avoid big Dalvik heap allocations (from
* API level 11 onward), it sacrifices performance predictability since any
* image that the view system tries to draw may incur a decode delay which
* can lead to dropped frames. Therefore, most apps should avoid using
* inPurgeable to allow for a fast and fluid UI. To minimize Dalvik heap
* allocations use the {@link #inBitmap} flag instead.</p>
*
* <p class="note"><strong>Note:</strong> This flag is ignored when used
* with {@link #decodeResource(Resources, int,
* android.graphics.BitmapFactory.Options)} or {@link #decodeFile(String,
* android.graphics.BitmapFactory.Options)}.</p>
*/
@Deprecated
public boolean inPurgeable;
/**
* @deprecated As of {@link android.os.Build.VERSION_CODES#LOLLIPOP}, this is
* ignored.
*
* In {@link android.os.Build.VERSION_CODES#KITKAT} and below, this
* field works in conjuction with inPurgeable. If inPurgeable is false,
* then this field is ignored. If inPurgeable is true, then this field
* determines whether the bitmap can share a reference to the input
* data (inputstream, array, etc.) or if it must make a deep copy.
*/
@Deprecated
public boolean inInputShareable;
/**
* If inPreferQualityOverSpeed is set to true, the decoder will try to
* decode the reconstructed image to a higher quality even at the
* expense of the decoding speed. Currently the field only affects JPEG
* decode, in the case of which a more accurate, but slightly slower,
* IDCT method will be used instead.
*/
public boolean inPreferQualityOverSpeed;
/**
* The resulting width of the bitmap. If {@link #inJustDecodeBounds} is
* set to false, this will be width of the output bitmap after any
* scaling is applied. If true, it will be the width of the input image
* without any accounting for scaling.
*
* <p>outWidth will be set to -1 if there is an error trying to decode.</p>
*/
public int outWidth;
/**
* The resulting height of the bitmap. If {@link #inJustDecodeBounds} is
* set to false, this will be height of the output bitmap after any
* scaling is applied. If true, it will be the height of the input image
* without any accounting for scaling.
*
* <p>outHeight will be set to -1 if there is an error trying to decode.</p>
*/
public int outHeight;
/**
* If known, this string is set to the mimetype of the decoded image.
* If not know, or there is an error, it is set to null.
*/
public String outMimeType;
/**
* Temp storage to use for decoding. Suggest 16K or so.
*/
public byte[] inTempStorage;
private native void requestCancel();
/**
* Flag to indicate that cancel has been called on this object. This
* is useful if there's an intermediary that wants to first decode the
* bounds and then decode the image. In that case the intermediary
* can check, inbetween the bounds decode and the image decode, to see
* if the operation is canceled.
*/
public boolean mCancel;
/**
* This can be called from another thread while this options object is
* inside a decode... call. Calling this will notify the decoder that
* it should cancel its operation. This is not guaranteed to cancel
* the decode, but if it does, the decoder... operation will return
* null, or if inJustDecodeBounds is true, will set outWidth/outHeight
* to -1
*/
public void requestCancelDecode() {
mCancel = true;
requestCancel();
}
}
/**
* Decode a file path into a bitmap. If the specified file name is null,
* or cannot be decoded into a bitmap, the function returns null.
*
* @param pathName complete path name for the file to be decoded.
* @param opts null-ok; Options that control downsampling and whether the
* image should be completely decoded, or just is size returned.
* @return The decoded bitmap, or null if the image data could not be
* decoded, or, if opts is non-null, if opts requested only the
* size be returned (in opts.outWidth and opts.outHeight)
*/
public static Bitmap decodeFile(String pathName, Options opts) {
Bitmap bm = null;
InputStream stream = null;
try {
stream = new FileInputStream(pathName);
bm = decodeStream(stream, null, opts);
} catch (Exception e) {
/* do nothing.
If the exception happened on open, bm will be null.
*/
Log.e("BitmapFactory", "Unable to decode stream: " + e);
} finally {
if (stream != null) {
try {
stream.close();
} catch (IOException e) {
// do nothing here
}
}
}
return bm;
}
/**
* Decode a file path into a bitmap. If the specified file name is null,
* or cannot be decoded into a bitmap, the function returns null.
*
* @param pathName complete path name for the file to be decoded.
* @return the resulting decoded bitmap, or null if it could not be decoded.
*/
public static Bitmap decodeFile(String pathName) {
return decodeFile(pathName, null);
}
/**
* Decode a new Bitmap from an InputStream. This InputStream was obtained from
* resources, which we pass to be able to scale the bitmap accordingly.
*/
public static Bitmap decodeResourceStream(Resources res, TypedValue value,
InputStream is, Rect pad, Options opts) {
if (opts == null) {
opts = new Options();
}
if (opts.inDensity == 0 && value != null) {
final int density = value.density;
if (density == TypedValue.DENSITY_DEFAULT) {
opts.inDensity = DisplayMetrics.DENSITY_DEFAULT;
} else if (density != TypedValue.DENSITY_NONE) {
opts.inDensity = density;
}
}
if (opts.inTargetDensity == 0 && res != null) {
opts.inTargetDensity = res.getDisplayMetrics().densityDpi;
}
return decodeStream(is, pad, opts);
}
/**
* Synonym for opening the given resource and calling
* {@link #decodeResourceStream}.
*
* @param res The resources object containing the image data
* @param id The resource id of the image data
* @param opts null-ok; Options that control downsampling and whether the
* image should be completely decoded, or just is size returned.
* @return The decoded bitmap, or null if the image data could not be
* decoded, or, if opts is non-null, if opts requested only the
* size be returned (in opts.outWidth and opts.outHeight)
*/
public static Bitmap decodeResource(Resources res, int id, Options opts) {
Bitmap bm = null;
InputStream is = null;
try {
final TypedValue value = new TypedValue();
is = res.openRawResource(id, value);
bm = decodeResourceStream(res, value, is, null, opts);
} catch (Exception e) {
/* do nothing.
If the exception happened on open, bm will be null.
If it happened on close, bm is still valid.
*/
} finally {
try {
if (is != null) is.close();
} catch (IOException e) {
// Ignore
}
}
if (bm == null && opts != null && opts.inBitmap != null) {
throw new IllegalArgumentException("Problem decoding into existing bitmap");
}
return bm;
}
/**
* Synonym for {@link #decodeResource(Resources, int, android.graphics.BitmapFactory.Options)}
* with null Options.
*
* @param res The resources object containing the image data
* @param id The resource id of the image data
* @return The decoded bitmap, or null if the image could not be decoded.
*/
public static Bitmap decodeResource(Resources res, int id) {
return decodeResource(res, id, null);
}
/**
* Decode an immutable bitmap from the specified byte array.
*
* @param data byte array of compressed image data
* @param offset offset into imageData for where the decoder should begin
* parsing.
* @param length the number of bytes, beginning at offset, to parse
* @param opts null-ok; Options that control downsampling and whether the
* image should be completely decoded, or just is size returned.
* @return The decoded bitmap, or null if the image data could not be
* decoded, or, if opts is non-null, if opts requested only the
* size be returned (in opts.outWidth and opts.outHeight)
*/
public static Bitmap decodeByteArray(byte[] data, int offset, int length, Options opts) {
if ((offset | length) < 0 || data.length < offset + length) {
throw new ArrayIndexOutOfBoundsException();
}
Bitmap bm;
Trace.traceBegin(Trace.TRACE_TAG_GRAPHICS, "decodeBitmap");
try {
bm = nativeDecodeByteArray(data, offset, length, opts);
if (bm == null && opts != null && opts.inBitmap != null) {
throw new IllegalArgumentException("Problem decoding into existing bitmap");
}
setDensityFromOptions(bm, opts);
} finally {
Trace.traceEnd(Trace.TRACE_TAG_GRAPHICS);
}
return bm;
}
/**
* Decode an immutable bitmap from the specified byte array.
*
* @param data byte array of compressed image data
* @param offset offset into imageData for where the decoder should begin
* parsing.
* @param length the number of bytes, beginning at offset, to parse
* @return The decoded bitmap, or null if the image could not be decoded.
*/
public static Bitmap decodeByteArray(byte[] data, int offset, int length) {
return decodeByteArray(data, offset, length, null);
}
/**
* Set the newly decoded bitmap's density based on the Options.
*/
private static void setDensityFromOptions(Bitmap outputBitmap, Options opts) {
if (outputBitmap == null || opts == null) return;
final int density = opts.inDensity;
if (density != 0) {
outputBitmap.setDensity(density);
final int targetDensity = opts.inTargetDensity;
if (targetDensity == 0 || density == targetDensity || density == opts.inScreenDensity) {
return;
}
byte[] np = outputBitmap.getNinePatchChunk();
final boolean isNinePatch = np != null && NinePatch.isNinePatchChunk(np);
if (opts.inScaled || isNinePatch) {
outputBitmap.setDensity(targetDensity);
}
} else if (opts.inBitmap != null) {
// bitmap was reused, ensure density is reset
outputBitmap.setDensity(Bitmap.getDefaultDensity());
}
}
/**
* Decode an input stream into a bitmap. If the input stream is null, or
* cannot be used to decode a bitmap, the function returns null.
* The stream's position will be where ever it was after the encoded data
* was read.
*
* @param is The input stream that holds the raw data to be decoded into a
* bitmap.
* @param outPadding If not null, return the padding rect for the bitmap if
* it exists, otherwise set padding to [-1,-1,-1,-1]. If
* no bitmap is returned (null) then padding is
* unchanged.
* @param opts null-ok; Options that control downsampling and whether the
* image should be completely decoded, or just is size returned.
* @return The decoded bitmap, or null if the image data could not be
* decoded, or, if opts is non-null, if opts requested only the
* size be returned (in opts.outWidth and opts.outHeight)
*
* <p class="note">Prior to {@link android.os.Build.VERSION_CODES#KITKAT},
* if {@link InputStream#markSupported is.markSupported()} returns true,
* <code>is.mark(1024)</code> would be called. As of
* {@link android.os.Build.VERSION_CODES#KITKAT}, this is no longer the case.</p>
*/
public static Bitmap decodeStream(InputStream is, Rect outPadding, Options opts) {
// we don't throw in this case, thus allowing the caller to only check
// the cache, and not force the image to be decoded.
if (is == null) {
return null;
}
Bitmap bm = null;
Trace.traceBegin(Trace.TRACE_TAG_GRAPHICS, "decodeBitmap");
try {
if (is instanceof AssetManager.AssetInputStream) {
final long asset = ((AssetManager.AssetInputStream) is).getNativeAsset();
bm = nativeDecodeAsset(asset, outPadding, opts);
} else {
bm = decodeStreamInternal(is, outPadding, opts);
}
if (bm == null && opts != null && opts.inBitmap != null) {
throw new IllegalArgumentException("Problem decoding into existing bitmap");
}
setDensityFromOptions(bm, opts);
} finally {
Trace.traceEnd(Trace.TRACE_TAG_GRAPHICS);
}
return bm;
}
/**
* Private helper function for decoding an InputStream natively. Buffers the input enough to
* do a rewind as needed, and supplies temporary storage if necessary. is MUST NOT be null.
*/
private static Bitmap decodeStreamInternal(InputStream is, Rect outPadding, Options opts) {
// ASSERT(is != null);
byte [] tempStorage = null;
if (opts != null) tempStorage = opts.inTempStorage;
if (tempStorage == null) tempStorage = new byte[DECODE_BUFFER_SIZE];
return nativeDecodeStream(is, tempStorage, outPadding, opts);
}
/**
* Decode an input stream into a bitmap. If the input stream is null, or
* cannot be used to decode a bitmap, the function returns null.
* The stream's position will be where ever it was after the encoded data
* was read.
*
* @param is The input stream that holds the raw data to be decoded into a
* bitmap.
* @return The decoded bitmap, or null if the image data could not be decoded.
*/
public static Bitmap decodeStream(InputStream is) {
return decodeStream(is, null, null);
}
/**
* Decode a bitmap from the file descriptor. If the bitmap cannot be decoded
* return null. The position within the descriptor will not be changed when
* this returns, so the descriptor can be used again as-is.
*
* @param fd The file descriptor containing the bitmap data to decode
* @param outPadding If not null, return the padding rect for the bitmap if
* it exists, otherwise set padding to [-1,-1,-1,-1]. If
* no bitmap is returned (null) then padding is
* unchanged.
* @param opts null-ok; Options that control downsampling and whether the
* image should be completely decoded, or just its size returned.
* @return the decoded bitmap, or null
*/
public static Bitmap decodeFileDescriptor(FileDescriptor fd, Rect outPadding, Options opts) {
Bitmap bm;
Trace.traceBegin(Trace.TRACE_TAG_GRAPHICS, "decodeFileDescriptor");
try {
if (nativeIsSeekable(fd)) {
bm = nativeDecodeFileDescriptor(fd, outPadding, opts);
} else {
FileInputStream fis = new FileInputStream(fd);
try {
bm = decodeStreamInternal(fis, outPadding, opts);
} finally {
try {
fis.close();
} catch (Throwable t) {/* ignore */}
}
}
if (bm == null && opts != null && opts.inBitmap != null) {
throw new IllegalArgumentException("Problem decoding into existing bitmap");
}
setDensityFromOptions(bm, opts);
} finally {
Trace.traceEnd(Trace.TRACE_TAG_GRAPHICS);
}
return bm;
}
/**
* Decode a bitmap from the file descriptor. If the bitmap cannot be decoded
* return null. The position within the descriptor will not be changed when
* this returns, so the descriptor can be used again as is.
*
* @param fd The file descriptor containing the bitmap data to decode
* @return the decoded bitmap, or null
*/
public static Bitmap decodeFileDescriptor(FileDescriptor fd) {
return decodeFileDescriptor(fd, null, null);
}
private static native Bitmap nativeDecodeStream(InputStream is, byte[] storage,
Rect padding, Options opts);
private static native Bitmap nativeDecodeFileDescriptor(FileDescriptor fd,
Rect padding, Options opts);
private static native Bitmap nativeDecodeAsset(long nativeAsset, Rect padding, Options opts);
private static native Bitmap nativeDecodeByteArray(byte[] data, int offset,
int length, Options opts);
private static native boolean nativeIsSeekable(FileDescriptor fd);
}
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