org.verapdf.pd.font.type1

Class BaseCharStringParser

java.lang.Object

org.verapdf.pd.font.type1.BaseCharStringParser

Direct Known Subclasses:

Type1CharStringParser

public abstract class BaseCharStringParser
extends Object

This is base class for Type1CharStringParser and Type2CharStringParser.

Author:

Sergey Shemyakov

Field Summary

Fields

Modifier and Type	Field and Description
protected int	bias
protected int	gBias
protected CFFIndex	globalSubrs
protected CFFIndex	localSubrs
protected Stack<CFFNumber>	stack
protected ASInputStream	stream

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BaseCharStringParser(ASInputStream stream) Constructor that calls method parse(), so width is extracted right after object is created.
protected	BaseCharStringParser(ASInputStream stream, CFFIndex localSubrs, int bias, CFFIndex globalSubrs, int gBias) Constructor that calls method parse(), so width is extracted right after object is created.

Method Summary

Methods

Modifier and Type	Method and Description
CFFNumber	getWidth()
protected void	popStack(int num) Pops several operands from Type 1 Build Char stack.
protected abstract boolean	processNextOperator(int nextByte) This method processes charstring-encoded operators.
protected abstract CFFNumber	readNextNumber(int firstByte) This method reads next bytes from stream and interprets them as one number.
protected void	setWidth(CFFNumber width)

Methods inherited from class java.lang.Object

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

Field Detail

stream

protected ASInputStream stream

stack

protected Stack<CFFNumber> stack

globalSubrs

protected CFFIndex globalSubrs

localSubrs

protected CFFIndex localSubrs

bias

protected int bias

gBias

protected int gBias

Constructor Detail

BaseCharStringParser

protected BaseCharStringParser(ASInputStream stream)
                        throws IOException

Constructor that calls method parse(), so width is extracted right after object is created. Subroutines are ignored in this case.

Parameters:

stream - is stream with decoded CharString.

Throws:

IOException - if parsing fails.

BaseCharStringParser

protected BaseCharStringParser(ASInputStream stream,
                    CFFIndex localSubrs,
                    int bias,
                    CFFIndex globalSubrs,
                    int gBias)
                        throws IOException

Constructor that calls method parse(), so width is extracted right after object is created.

Parameters:

stream - is stream with decoded CharString.

localSubrs - is local subroutines for this CharString.

bias - is bias value for local subroutines as it is described in The Compact Font Format specification.

gBias - is bias value for global subroutines as it is described in The Compact Font Format specification.

Throws:

IOException - if parsing fails.

Method Detail

getWidth

public CFFNumber getWidth()

Returns:

width of glyph or null if it can't be found in given CharString.

setWidth

protected void setWidth(CFFNumber width)

popStack

protected void popStack(int num)
                 throws IOException

Pops several operands from Type 1 Build Char stack.

Parameters:

num - is amount of numbers to be popped.

Throws:

IOException - if stream reading error occurs.

processNextOperator

protected abstract boolean processNextOperator(int nextByte)
                                        throws IOException

This method processes charstring-encoded operators. It should set width when it can be determined. Methods returns true if width is calculated.

Parameters:

nextByte - is first byte of operator. Note that this byte is already read.

Returns:

true if width was extracted from processed operator.

Throws:

IOException - if stream reading error occurs.

readNextNumber

protected abstract CFFNumber readNextNumber(int firstByte)
                                     throws IOException

This method reads next bytes from stream and interprets them as one number. In Type 1 CharStrings and Type 2 CharStrings this is done a little differently.

Returns:

number that was read.

Throws:

IOException - if stream reading error occurs.