com.google.typography.font.sfntly.data

Class ReadableFontData

java.lang.Object

com.google.typography.font.sfntly.data.FontData

com.google.typography.font.sfntly.data.ReadableFontData

Direct Known Subclasses:

WritableFontData

public class ReadableFontData
extends FontData

Writable font data wrapper. Supports reading of data primitives in the TrueType / OpenType spec.

The data types used are as listed:

BYTE	8-bit unsigned integer.
CHAR	8-bit signed integer.
USHORT	16-bit unsigned integer.
SHORT	16-bit signed integer.
UINT24	24-bit unsigned integer.
ULONG	32-bit unsigned integer.
LONG	32-bit signed integer.
Fixed	32-bit signed fixed-point number (16.16)
FUNIT	Smallest measurable distance in the em space.
FWORD	16-bit signed integer (SHORT) that describes a quantity in FUnits.
UFWORD	16-bit unsigned integer (USHORT) that describes a quantity in FUnits.
F2DOT14	16-bit signed fixed number with the low 14 bits of fraction (2.14).
LONGDATETIME	Date represented in number of seconds since 12:00 midnight, January 1, 1904. The value is represented as a signed 64-bit integer.

Author:

Stuart Gill

See Also:

WritableFontData

Nested Class Summary

Nested classes/interfaces inherited from class com.google.typography.font.sfntly.data.FontData

FontData.DataSize

Method Summary

Modifier and Type	Method and Description
long	checksum() Gets a computed checksum for the data.
int[]	checkSumRange() Gets the ranges that are used for computing the checksum.
int	copyTo(java.io.OutputStream os) Copy the FontData to an OutputStream.
int	copyTo(WritableFontData wfd) Copies the FontData to a WritableFontData.
static ReadableFontData	createReadableFontData(byte[] b)
int	readByte(int index) Reads the BYTE at the given index.
int	readBytes(int index, byte[] b, int offset, int length) Reads the bytes at the given index into the array.
int	readChar(int index) Reads the CHAR at the given index.
long	readDateTimeAsLong(int index) Reads the LONGDATETIME at the given index.
java.math.BigDecimal	readF2Dot14(int index) Reads the F2DOT14 at the given index.
int	readFixed(int index) Reads the Fixed at the given index.
int	readFUnit(int index) Reads the FUNIT at the given index.
int	readFWord(int index) Reads the FWORD at the given index.
int	readLong(int index) Reads the LONG at the given index.
java.util.Date	readLongDateTime(int index) Reads the LONGDATETIME at the given index.
int	readShort(int index) Reads the SHORT at the given index.
int	readUByte(int index) Reads the UBYTE at the given index.
int	readUFWord(int index) Reads the UFWORD at the given index.
int	readUInt24(int index) Reads the UINT24 at the given index.
long	readULong(int index) Reads the ULONG at the given index.
int	readULongAsInt(int index) Reads the ULONG at the given index as an int.
long	readULongLE(int index) Reads the ULONG at the given index, little-endian variant.
int	readUShort(int index) Reads the USHORT at the given index.
int	searchULong(int startIndex, int startOffset, int endIndex, int endOffset, int length, int key) Search for the key value in the range tables provided.
int	searchUShort(int startIndex, int startOffset, int length, int key) Search for the key value in the table provided.
int	searchUShort(int startIndex, int startOffset, int endIndex, int endOffset, int length, int key) Search for the key value in the range tables provided.
void	setCheckSumRanges(int... ranges) Sets the ranges to use for computing the checksum.
ReadableFontData	slice(int offset) Makes a bottom bound only slice of this array.
ReadableFontData	slice(int offset, int length) Makes a slice of this FontData.
java.lang.String	toString()
java.lang.String	toString(int length) Generates a String representation of the object with a certain number of data bytes.

Methods inherited from class com.google.typography.font.sfntly.data.FontData

bound, bound, length, size

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

createReadableFontData

public static ReadableFontData createReadableFontData(byte[] b)

slice

public ReadableFontData slice(int offset,
                              int length)

Makes a slice of this FontData. The returned slice will share the data with the original FontData.

Specified by:

slice in class FontData

Parameters:

offset - the start of the slice

length - the number of bytes in the slice

Returns:

a slice of the original FontData

slice

public ReadableFontData slice(int offset)

Makes a bottom bound only slice of this array. The returned slice will share the data with the original FontData.

Specified by:

slice in class FontData

Parameters:

offset - the start of the slice

Returns:

a slice of the original FontData

toString

public java.lang.String toString(int length)

Generates a String representation of the object with a certain number of data bytes.

Parameters:

length - number of bytes of the data to include in the String

Returns:

String representation of the object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

checksum

public long checksum()

Gets a computed checksum for the data. This checksum uses the OpenType spec calculation. Every ULong value (32 bit unsigned) in the data is summed and the resulting value is truncated to 32 bits. If the data length in bytes is not an integral multiple of 4 then any remaining bytes are treated as the start of a 4 byte sequence whose remaining bytes are zero.

Returns:

the checksum

setCheckSumRanges

public void setCheckSumRanges(int... ranges)

Sets the ranges to use for computing the checksum. These ranges are in begin and end pairs. If an odd number is given then the final range is assumed to extend to the end of the data. The lengths of each range must be a multiple of 4.

Parameters:

ranges - the range bounds to use for the checksum

checkSumRange

public int[] checkSumRange()

Gets the ranges that are used for computing the checksum. These ranges are in begin and end pairs. If an odd number is given then the final range is assumed to extend to the end of the data. The lengths of each range must be a multiple of 4.

Returns:

the range bounds used for the checksum

readUByte

public int readUByte(int index)

Reads the UBYTE at the given index.

Parameters:

index - index into the font data

Returns:

the UBYTE; -1 if outside the bounds of the font data

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readByte

public int readByte(int index)

Reads the BYTE at the given index.

Parameters:

index - index into the font data

Returns:

the BYTE

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readBytes

public int readBytes(int index,
                     byte[] b,
                     int offset,
                     int length)

Reads the bytes at the given index into the array.

Parameters:

index - index into the font data

b - the destination for the bytes read

offset - offset in the byte array to place the bytes

length - the length of bytes to read

Returns:

the number of bytes actually read; -1 if the index is outside the bounds of the font data

readChar

public int readChar(int index)

Reads the CHAR at the given index.

Parameters:

index - index into the font data

Returns:

the CHAR

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readUShort

public int readUShort(int index)

Reads the USHORT at the given index.

Parameters:

index - index into the font data

Returns:

the USHORT

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readShort

public int readShort(int index)

Reads the SHORT at the given index.

Parameters:

index - index into the font data

Returns:

the SHORT

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readUInt24

public int readUInt24(int index)

Reads the UINT24 at the given index.

Parameters:

index - index into the font data

Returns:

the UINT24

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readULong

public long readULong(int index)

Reads the ULONG at the given index.

Parameters:

index - index into the font data

Returns:

the ULONG

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readULongAsInt

public int readULongAsInt(int index)

Reads the ULONG at the given index as an int.

Parameters:

index - index into the font data

Returns:

the ULONG

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

java.lang.ArithmeticException - if the value will not fit into an integer

readULongLE

public long readULongLE(int index)

Reads the ULONG at the given index, little-endian variant.

Parameters:

index - index into the font data

Returns:

the ULONG

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readLong

public int readLong(int index)

Reads the LONG at the given index.

Parameters:

index - index into the font data

Returns:

the LONG

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readFixed

public int readFixed(int index)

Reads the Fixed at the given index.

Parameters:

index - index into the font data

Returns:

the Fixed

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readF2Dot14

public java.math.BigDecimal readF2Dot14(int index)

Reads the F2DOT14 at the given index.

Parameters:

index - index into the font data

Returns:

the F2DOT14

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readDateTimeAsLong

public long readDateTimeAsLong(int index)

Reads the LONGDATETIME at the given index.

Parameters:

index - index into the font data

Returns:

the LONGDATETIME

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readLongDateTime

public java.util.Date readLongDateTime(int index)

Reads the LONGDATETIME at the given index.

Parameters:

index - index into the font data

Returns:

the F2DOT14

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readFUnit

public int readFUnit(int index)

Reads the FUNIT at the given index.

Parameters:

index - index into the font data

Returns:

the FUNIT

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readFWord

public int readFWord(int index)

Reads the FWORD at the given index.

Parameters:

index - index into the font data

Returns:

the FWORD

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

readUFWord

public int readUFWord(int index)

Reads the UFWORD at the given index.

Parameters:

index - index into the font data

Returns:

the UFWORD

Throws:

java.lang.IndexOutOfBoundsException - if index is outside the FontData's range

copyTo

public int copyTo(java.io.OutputStream os)
           throws java.io.IOException

Copy the FontData to an OutputStream.

Parameters:

os - the destination

Returns:

number of bytes copied

Throws:

java.io.IOException

copyTo

public int copyTo(WritableFontData wfd)

Copies the FontData to a WritableFontData.

Parameters:

wfd - the destination

Returns:

number of bytes copied

searchUShort

public int searchUShort(int startIndex,
                        int startOffset,
                        int endIndex,
                        int endOffset,
                        int length,
                        int key)

Search for the key value in the range tables provided. The search looks through the start-end pairs looking for the key value. It is assumed that the start-end pairs are both represented by UShort values, ranges do not overlap, and are monotonically increasing.

Parameters:

startIndex - the position to read the first start value from

startOffset - the offset between subsequent start values

endIndex - the position to read the first end value from

endOffset - the offset between subsequent end values

length - the number of start-end pairs

key - the value to search for

Returns:

the index of the start-end pairs in which the key was found; -1 otherwise

searchULong

public int searchULong(int startIndex,
                       int startOffset,
                       int endIndex,
                       int endOffset,
                       int length,
                       int key)

Search for the key value in the range tables provided. The search looks through the start-end pairs looking for the key value. It is assumed that the start-end pairs are both represented by ULong values that can be represented within 31 bits, ranges do not overlap, and are monotonically increasing.

Parameters:

startIndex - the position to read the first start value from

startOffset - the offset between subsequent start values

endIndex - the position to read the first end value from

endOffset - the offset between subsequent end values

length - the number of start-end pairs

key - the value to search for

Returns:

the index of the start-end pairs in which the key was found; -1 otherwise

searchUShort

public int searchUShort(int startIndex,
                        int startOffset,
                        int length,
                        int key)

Search for the key value in the table provided. The search looks through the values looking for the key value. It is assumed that the are represented by UShort values and are monotonically increasing.

Parameters:

startIndex - the position to read the first start value from

startOffset - the offset between subsequent start values

length - the number of start-end pairs

key - the value to search for

Returns:

the index of the start-end pairs in which the key was found; -1 otherwise