IT. Expert System.

Enclosing class:

BitmapFactory

public static class BitmapFactory.Options
extends Object

• Field Summary

  Fields

  Modifier and Type	Field and Description
  Bitmap	inBitmap If set, decode methods that take the Options object will attempt to reuse this bitmap when loading content.
  int	inDensity The pixel density to use for the bitmap.
  boolean	inDither If dither is true, the decoder will attempt to dither the decoded image.
  boolean	inInputShareable This field works in conjuction with inPurgeable.
  boolean	inJustDecodeBounds If set to true, the decoder will return null (no bitmap), but the out...
  boolean	inMutable If set, decode methods will always return a mutable Bitmap instead of an immutable one.
  boolean	inPreferQualityOverSpeed 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.
  Bitmap.Config	inPreferredConfig If this is non-null, the decoder will try to decode into this internal configuration.
  boolean	inPurgeable 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.
  int	inSampleSize If set to a value > 1, requests the decoder to subsample the original image, returning a smaller image to save memory.
  boolean	inScaled When this flag is set, if inDensity and inTargetDensity are not 0, the bitmap will be scaled to match inTargetDensity when loaded, rather than relying on the graphics system scaling it each time it is drawn to a Canvas.
  int	inScreenDensity The pixel density of the actual screen that is being used.
  int	inTargetDensity The pixel density of the destination this bitmap will be drawn to.
  byte[]	inTempStorage Temp storage to use for decoding.
  boolean	mCancel Flag to indicate that cancel has been called on this object.
  int	outHeight The resulting height of the bitmap, set independent of the state of inJustDecodeBounds.
  String	outMimeType If known, this string is set to the mimetype of the decoded image.
  int	outWidth The resulting width of the bitmap, set independent of the state of inJustDecodeBounds.

• Constructor Summary

  Constructors

  Constructor and Description
  BitmapFactory.Options() Create a default Options object, which if left unchanged will give the same result from the decoder as if null were passed.

• Method Summary

  Methods

  Modifier and Type	Method and Description
  void	requestCancelDecode() This can be called from another thread while this options object is inside a decode...

  • Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

• Field Detail

  • inBitmap

    public Bitmap inBitmap

    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 null and will throw an IllegalArgumentException. The current implementation necessitates that the reused bitmap be of the same size as the source content and in jpeg or png format (whether as a resource or as a stream). The configuration of the reused bitmap will override the setting of inPreferredConfig, if set.

    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 is a way to see if the bitmap was reused, but in all cases you should use the returned Bitmap to make sure that you are using the bitmap that was used as the decode destination.

  • inMutable

    public boolean inMutable

    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.

  • inJustDecodeBounds

    public boolean inJustDecodeBounds

    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.

  • inSampleSize

    public int inSampleSize

    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 will try to fulfill this request, but the resulting bitmap may have different dimensions that precisely what has been requested. also, powers of 2 are often faster/easier for the decoder to honor.

  • inPreferredConfig

    public Bitmap.Config inPreferredConfig

    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 Bitmap.Config.ARGB_8888 config by default.

  • inDither

    public boolean inDither

    If dither is true, the decoder will attempt to dither the decoded image.

  • inDensity

    public int inDensity

    The pixel density to use for the bitmap. This will always result in the returned bitmap having a density set for it (see Bitmap.setDensity(int)). In addition, if inScaled is set (which it is by default} and this density does not match inTargetDensity, then the bitmap will be scaled to the target density before being returned.

    If this is 0, BitmapFactory.decodeResource(Resources, int), BitmapFactory.decodeResource(Resources, int, android.graphics.BitmapFactory.Options), and BitmapFactory.decodeResourceStream(android.content.res.Resources, android.util.TypedValue, java.io.InputStream, android.graphics.Rect, android.graphics.BitmapFactory.Options) will fill in the density associated with the resource. The other functions will leave it as-is and no density will be applied.

    See Also:

    inTargetDensity, inScreenDensity, inScaled, Bitmap.setDensity(int), DisplayMetrics.densityDpi

  • inTargetDensity

    public int inTargetDensity

    The pixel density of the destination this bitmap will be drawn to. This is used in conjunction with inDensity and inScaled to determine if and how to scale the bitmap before returning it.

    If this is 0, BitmapFactory.decodeResource(Resources, int), BitmapFactory.decodeResource(Resources, int, android.graphics.BitmapFactory.Options), and BitmapFactory.decodeResourceStream(android.content.res.Resources, android.util.TypedValue, java.io.InputStream, android.graphics.Rect, android.graphics.BitmapFactory.Options) 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 Also:

    inDensity, inScreenDensity, inScaled, DisplayMetrics.densityDpi

  • inScreenDensity

    public int inScreenDensity

    The pixel density of the actual screen that is being used. This is purely for applications running in density compatibility code, where inTargetDensity is actually the density the application sees rather than the real screen density.

    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 inDensity is the same as inScreenDensity, the bitmap will be left as-is. Anything using the resulting bitmap must also used Bitmap.getScaledWidth and Bitmap.getScaledHeight to account for any different between the bitmap's density and the target's density.

    This is never set automatically for the caller by BitmapFactory itself. It must be explicitly set, since the caller must deal with the resulting bitmap in a density-aware way.

    See Also:

    inDensity, inTargetDensity, inScaled, DisplayMetrics.densityDpi

  • inScaled

    public boolean inScaled

    When this flag is set, if inDensity and inTargetDensity are not 0, the bitmap will be scaled to match inTargetDensity when loaded, rather than relying on the graphics system scaling it each time it is drawn to a Canvas.

    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.

  • inPurgeable

    public boolean inPurgeable

    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. 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.

  • inInputShareable

    public boolean inInputShareable

    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.

  • inPreferQualityOverSpeed

    public boolean inPreferQualityOverSpeed

    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.

  • outWidth

    public int outWidth

    The resulting width of the bitmap, set independent of the state of inJustDecodeBounds. However, if there is an error trying to decode, outWidth will be set to -1.

  • outHeight

    public int outHeight

    The resulting height of the bitmap, set independent of the state of inJustDecodeBounds. However, if there is an error trying to decode, outHeight will be set to -1.

  • outMimeType

    public String outMimeType

    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.

  • inTempStorage

    public byte[] inTempStorage

    Temp storage to use for decoding. Suggest 16K or so.

  • mCancel

    public boolean mCancel

    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.

• Constructor Detail

  • BitmapFactory.Options

    public BitmapFactory.Options()

    Create a default Options object, which if left unchanged will give the same result from the decoder as if null were passed.

• Method Detail

  • requestCancelDecode

    public void requestCancelDecode()

    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