org.hd.d.pg2k.svrCore.MIME
Class Handler.ThumbnailParams

java.lang.Object
  org.hd.d.pg2k.svrCore.MIME.Handler.ThumbnailParams

Enclosing interface:

Handler

public static final class Handler.ThumbnailParams
extends java.lang.Object

Some constant parameters and hints for thumbnail building. Each handler that can build thumbnails should define one of these statically and return it from getThumbnailParameters().

If canMakeThumbnails() returns true, getThumbnailParameters() must return a non-null value.

This exists to help cluttering the base class API with things relevant only to the internal mechanics of this system.

estimatedBytesPerImagePixelInMemory

public final int estimatedBytesPerImagePixelInMemory

Estimated bytes-per-pixel of image in memory; positive. Defaults to 4 assuming RBG/ARGB int format of image.

minQuality

public final int minQuality

Minimum usable value of "quality" parameter to makeScaledImage(); non-negative.

maxQuality

public final int maxQuality

Maximum usable value of "quality" parameter to makeScaledImage(). Anything higher than this value is treated as equal to this value and implies maximum possible: thus Integer.MAX_VALUE means maximum possible too.

If the same as minQuality this indicates that this is not parametrically variable.

initialQualityHint

public final int initialQualityHint

Suggested initial quality value. This will lie between minQuality and maxQuality inclusive.

Careful choice of this will help reduce the number of redundant image builds done.

thumbnailBppHint

public final int thumbnailBppHint

Suggested target bits-per-pixel for a thumbnail; positive. This should ignore any typical fixed overheads.

This is a hint to generation routines.

approxMinOverheadBytes

public final int approxMinOverheadBytes

Approximate minimum overhead of format in bytes; non-negative. Rough minimum size in this format including magic numbers, cost of file structure, etc.

This is used to help make better estimates of target thumbnail sizes, etc, and need not be (indeed, probably cannot be) exact given that each format may have different representations.

Can be zero, though all reasonable implementations should at least default to the size of any leading "magic" number.

Handler.ThumbnailParams

public Handler.ThumbnailParams(int estimatedBytesPerImagePixelInMemory,
                               int minQuality,
                               int maxQuality,
                               int initialQualityHint,
                               int thumbnailBppHint,
                               int approxMinOverheadBytes)
                        throws java.lang.IllegalArgumentException

Construct an instance. Argument values are range-checked as far as practical.

Throws:

java.lang.IllegalArgumentException