org.extex.unit.tex.typesetter.paragraph
Class Parshape

java.lang.Object
  org.extex.interpreter.type.AbstractCode
      org.extex.unit.tex.typesetter.paragraph.Parshape

All Implemented Interfaces:

java.io.Serializable, CountConvertible, Code, Theable

public class Parshape
extends AbstractCode
implements CountConvertible, Theable

This class provides an implementation for the primitive \relax.

The Primitive \parshape

The primitive \parshape is a declaration of the shape of the paragraph. With its help it is possible to control the left and right margin of the current paragraph.

The shape of the paragraph is controlled on a line base. For each line the left indentation and the width are given. The first argument of \parshape determines the number of such pairs to follow.

When the paragraph is typeset the lines are indented and adjusted according to the specification given. If there are more lines specified as actually present in the current paragraph then the remaining specifications are discarded at the end of the paragraph. If there are less lines then the last specification is repeated.

If several \parshape declarations are given in one paragraph then the one is used which is in effect at the end of the paragraph. This means that later declarations overrule earlier ones.

Syntax

The formal description of this primitive is the following:

    ⟨parshape⟩
        → \parshape ⟨8-bit number⟩ ... 

Examples

    \parshape 3 20pt \linewidth
                20pt \linewidth
                0pt \linewidth 

    \parshape 0 

\parshape as special integer

\parshape acts as special count register which can be queried. It returns the size of the current parshape specification or 0 if none is present.

Examples

    \count1=\parshape  

Version:

$Revision:4431 $

Author:

Gerd Neugebauer

See Also:

Serialized Form

Field Summary

protected static long

serialVersionUID The constant serialVersionUID contains the id for serialization.

Constructor Summary

Parshape(CodeToken token)
Creates a new object.

Method Summary

long	convertCount(Context context, TokenSource source, Typesetter typesetter) This method converts a register into a count.
void	execute(Flags prefix, Context context, TokenSource source, Typesetter typesetter) This method takes the first token and executes it. The result is placed on the stack. This operation might have side effects. To execute a token it might be necessary to consume further tokens.
Tokens	the(Context context, TokenSource source, Typesetter typesetter) This method is the getter for the description of the primitive.

Methods inherited from class org.extex.interpreter.type.AbstractCode

getLocalizer, getName, getToken, isIf, isOuter, readResolve, toString, toText, toText

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

protected static final long serialVersionUID

The constant serialVersionUID contains the id for serialization.

See Also:

Constant Field Values

Constructor Detail

Parshape

public Parshape(CodeToken token)

Creates a new object.

Parameters:

token - the initial token for the primitive

Method Detail

convertCount

public long convertCount(Context context,
                         TokenSource source,
                         Typesetter typesetter)
                  throws HelpingException,
                         TypesetterException

This method converts a register into a count. It might be necessary to read further tokens to determine which value to use. For instance an additional register number might be required. In this case the additional arguments Context and TokenSource can be used.

Specified by:

convertCount in interface CountConvertible

Parameters:

context - the interpreter context

source - the source for new tokens

typesetter - the typesetter to use for conversion

Returns:

the converted value

Throws:

HelpingException - in case of an error

TypesetterException - in case of an error in the typesetter

See Also:

CountConvertible.convertCount( org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, org.extex.typesetter.Typesetter)

execute

public void execute(Flags prefix,
                    Context context,
                    TokenSource source,
                    Typesetter typesetter)
             throws HelpingException,
                    TypesetterException

This method takes the first token and executes it. The result is placed on the stack. This operation might have side effects. To execute a token it might be necessary to consume further tokens.

Specified by:

execute in interface Code

Overrides:

execute in class AbstractCode

Parameters:

prefix - the prefix controlling the execution

context - the interpreter context

source - the token source

typesetter - the typesetter

Throws:

HelpingException - in case of an error

TypesetterException - in case of an error in the typesetter

See Also:

AbstractCode.execute( org.extex.interpreter.Flags, org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, org.extex.typesetter.Typesetter)

the

public Tokens the(Context context,
                  TokenSource source,
                  Typesetter typesetter)
           throws CatcodeException,
                  HelpingException,
                  TypesetterException

This method is the getter for the description of the primitive.

Specified by:

the in interface Theable

Parameters:

context - the interpreter context

source - the source for further tokens to qualify the request

typesetter - the typesetter to use

Returns:

the description of the primitive as list of Tokens

Throws:

CatcodeException - in case of an error in token creation

HelpingException - in case of an error

TypesetterException - in case of an error

See Also:

Theable.the( org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, Typesetter)