org.extex.unit.tex.register.count
Class Mag

java.lang.Object
  org.extex.interpreter.type.AbstractCode
      org.extex.interpreter.type.AbstractAssignment
          org.extex.unit.tex.register.count.AbstractCount
              org.extex.unit.tex.register.count.Mag

All Implemented Interfaces:

java.io.Serializable, CountConvertible, Code, Advanceable, Divideable, Multiplyable, ExpandableCode, InitializableCode, Theable

public class Mag
extends AbstractCount
implements ExpandableCode, Advanceable, Multiplyable, Divideable, Theable, CountConvertible

This class provides an implementation for the primitive \mag. It sets the named count register to the value given, and as a side effect all prefixes are zeroed.

The Primitive \mag

The primitive \mag provides a means to set the magnification factor for the current document. The primitive acts like a normal count register. The magnification factor is given in multiples of 1000. This means that the default value 1000 corresponds to an unmagnified output.

The effect of the setting of the magnification factor is that all length values are multiplied with the magnification factor (divided by 1000). An exception are the true length values. This means a length of 1 pt at a magnification of 1200 is in effect 1.2 pt long. Whereas a length of 1 true pt remains unaffected by the magnification.

The magnification can only changed once at the beginning of a run.

An attempt to assign a non-positive number to \mag leads to an error.

Syntax

The formal description of this primitive is the following:

    ⟨mag⟩
      → ⟨optional prefix⟩ \mag ⟨equals⟩ ⟨number⟩

    ⟨optional prefix⟩
      →
       |  \global
       |  \immediate  

Examples

    \mag=1600  

Version:

$Revision: 4770 $

Author:

Gerd Neugebauer

See Also:

Advanceable, Divideable, Multiplyable, Theable, Serialized Form

Field Summary

protected static long

serialVersionUID The constant serialVersionUID contains the id for serialization.

Constructor Summary

Mag(CodeToken token)
Creates a new object.

Method Summary

void	advance(Flags prefix, Context context, TokenSource source, Typesetter typesetter) This method is called when the macro \advance has been seen.
void	assign(Flags prefix, Context context, TokenSource source, Typesetter typesetter) The method assign is the core of the functionality of execute().
long	convertCount(Context context, TokenSource source, Typesetter typesetter) This method converts a register into a count.
void	divide(Flags prefix, Context context, TokenSource source, Typesetter typesetter) This method is called when the macro \divide has been seen.
void	expand(Flags prefix, Context context, TokenSource source, Typesetter typesetter) This method takes the first token and expands it.
void	init(Context context, TokenSource source, Typesetter typesetter) Initialize the Code with some value coming from a String.
void	multiply(Flags prefix, Context context, TokenSource source, Typesetter typesetter) This method is called when the macro \multiply has been seen.
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.unit.tex.register.count.AbstractCount

getKey

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

execute

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

Mag

public Mag(CodeToken token)

Creates a new object.

Parameters:

token - the initial token for the primitive

Method Detail

advance

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

This method is called when the macro \advance has been seen. It performs the remaining tasks for the expansion.

Specified by:

advance in interface Advanceable

Parameters:

prefix - the prefix for the command

context - the processor context

source - the token source to parse

typesetter - the typesetter

Throws:

HelpingException - in case of an error

TypesetterException - in case of an error in the typesetter

See Also:

Advanceable.advance( org.extex.interpreter.Flags, org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, org.extex.typesetter.Typesetter)

assign

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

The method assign is the core of the functionality of execute(). This method is preferable to execute() since the execute() method provided in this class takes care of \afterassignment and \globaldefs as well.

Specified by:

assign in class AbstractAssignment

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:

AbstractAssignment.assign( org.extex.interpreter.Flags, org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, org.extex.typesetter.Typesetter)

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)

divide

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

This method is called when the macro \divide has been seen. It performs the remaining tasks for the expansion.

Specified by:

divide in interface Divideable

Parameters:

prefix - the prefix for the command

context - the processor context

source - the token source to parse

typesetter - the typesetter

Throws:

HelpingException - in case of an error

TypesetterException - in case of an error in the typesetter

See Also:

Divideable.divide( org.extex.interpreter.Flags, org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, org.extex.typesetter.Typesetter)

expand

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

This method takes the first token and expands it. The result is placed on the stack. This means that expandable code does one step of expansion and puts the result on the stack. To expand a token it might be necessary to consume further tokens.

Specified by:

expand in interface ExpandableCode

Parameters:

prefix - the prefix flags controlling the expansion

context - the interpreter context

source - the token source

typesetter - the typesetter

Throws:

HelpingException - in case of an error

See Also:

ExpandableCode.expand( org.extex.interpreter.Flags, org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, org.extex.typesetter.Typesetter)

init

public void init(Context context,
                 TokenSource source,
                 Typesetter typesetter)
          throws HelpingException,
                 TypesetterException

Initialize the Code with some value coming from a String.

Specified by:

init in interface InitializableCode

Overrides:

init in class AbstractCount

Parameters:

context - the interpreter context

source - the source of information for the initialization

typesetter - the typesetter

Throws:

HelpingException - in case of an error

TypesetterException - in case of an error in the typesetter

See Also:

InitializableCode.init( org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, org.extex.typesetter.Typesetter)

multiply

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

This method is called when the macro \multiply has been seen. It performs the remaining tasks for the expansion.

Specified by:

multiply in interface Multiplyable

Parameters:

prefix - the prefix for the command

context - the processor context

source - the token source to parse

typesetter - the typesetter

Throws:

HelpingException - in case of an error

TypesetterException - in case of an error in the typesetter

See Also:

Multiplyable.multiply( 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, org.extex.typesetter.Typesetter)