Cantor::Expression Class Reference

#include <expression.h>

Inheritance diagram for Cantor::Expression:

Public Types
enum	FinishingBehavior { DoNotDelete, DeleteOnFinish }
enum	Status { Computing, Done, Error, Interrupted }

Signals
void	gotResult ()
void	idChanged ()
void	needsAdditionalInformation (const QString &question)
void	statusChanged (Cantor::Expression::Status status)

Public Member Functions
	Expression (Session *session)
virtual	~Expression ()
virtual void	addInformation (const QString &information)
void	clearResult ()
QString	command ()
QString	errorMessage ()
virtual void	evaluate ()=0
FinishingBehavior	finishingBehavior ()
int	id ()
virtual void	interrupt ()=0
bool	isInternal ()
Result *	result ()
void	saveAdditionalData (KZip *archive)
Session *	session ()
void	setCommand (const QString &cmd)
void	setErrorMessage (const QString &cmd)
void	setFinishingBehavior (FinishingBehavior behavior)
void	setId (int id)
void	setInternal (bool internal)
Status	status ()
QDomElement	toXml (QDomDocument &doc)

Protected Member Functions
virtual QString	additionalLatexHeaders ()
void	setResult (Result *result)
void	setStatus (Status status)

Detailed Description

An Expression object is used, to store the information needed when running a command of a Session Evaluation of Expression is an asynchroneous process in most cases, so most of the members of this class are not useful directly after its construction.

Therefore there are signals indicating, when the Expression goes through the different stages of the Running process. An Expression is never constructed directly, but by using Session::evaluateExpression()

Author

Alexander Rieder

Definition at line 49 of file expression.h.

Member Enumeration Documentation

enum Cantor::Expression::FinishingBehavior

Enum indicating how this Expression behaves on finishing.

Enumerator
DoNotDelete	This Expression will not be deleted. This is the normal behaviour.
DeleteOnFinish	< The Object will delete itself when finished. This is used for fire-and-forget commands. All output/results will be dropped

Definition at line 62 of file expression.h.

enum Cantor::Expression::Status

Enumerator
Computing	The Expression is still being computed.
Done	The Running of the Expression is finished sucessfully.
Error	An Error occurred when running the Expression.
Interrupted	The Expression was interrupted by the user while running.

Definition at line 53 of file expression.h.

Constructor & Destructor Documentation

Expression::Expression

(

Session *

session

)

Expression constructor.

Should only be called from Session::evaulateExpression

Parameters

session

the session, this Expression belongs to

Definition at line 75 of file expression.cpp.

Expression::~Expression ( )

virtual

destructor

Definition at line 82 of file expression.cpp.

Member Function Documentation

void Expression::addInformation ( const QString &  information )

virtual

Adds some additional information/input to this expression.

this is needed, when the Expression has emitted the needsAdditionalInformation signal, and the user has answered the question. This is used for e.g. if maxima asks wether n+1 is zero or not when running the command "integrate(x^n,x)" This method is part of the InteractiveMode feature

Definition at line 232 of file expression.cpp.

QString Expression::additionalLatexHeaders ( )

protectedvirtual

Definition at line 237 of file expression.cpp.

void Expression::clearResult

(

)

Deletes the result of this expression.

Definition at line 142 of file expression.cpp.

QString Expression::command

(

)

Returns the command, represented by this Expression.

Returns

the command, represented by this Expression

Definition at line 93 of file expression.cpp.

QString Expression::errorMessage

(

)

returns the Error message, if an error occurred during the evaluation of the expression.

Returns

the error message

Definition at line 103 of file expression.cpp.

virtual void Cantor::Expression::evaluate ( )

pure virtual

Evaluate the Expression.

before this is called, you should set the Command first This method can be implemented asynchroneous, thus the Evaluation doesn't need to happen in the method, It can also only be scheduled for evaluating.

See also

setCommand()

Expression::FinishingBehavior Expression::finishingBehavior

(

)

get the Expressions finishing behaviour

Returns

the current finishing behaviour

Definition at line 258 of file expression.cpp.

void Cantor::Expression::gotResult ( )

signal

A Result of the Expression has arrived.

int Expression::id

(

)

Returns the unique id of the Expression.

Returns

the unique id of the Expression

Definition at line 242 of file expression.cpp.

void Cantor::Expression::idChanged ( )

signal

the Id of this Expression changed

virtual void Cantor::Expression::interrupt ( )

pure virtual

Interrupt the running of the Expression.

This should set the state to Interrupted.

bool Expression::isInternal

(

)

returns whether or not this expression is internal, or comes from the user

Definition at line 268 of file expression.cpp.

void Cantor::Expression::needsAdditionalInformation ( const QString &  question )

signal

the Expression needs more information for the evaluation

See also

addInformation()

Parameters

question

question, the user needs to answer

Result * Expression::result

(

)

The result of this Expression.

It can have different types, represented by various subclasses of Result, like text, image, etc. The result will be null, until the computation is completed. When the result changes, the gotResult() signal is emitted. The Result object is owned by the Expression, and will get deleted, as soon as the Expression dies, or newer results appear.

Returns

the result of the Expression, 0 if it isn't yet set

Definition at line 137 of file expression.cpp.

void Expression::saveAdditionalData

(

KZip *

archive

)

saves all the data, that can't be saved in xml in an extra file in the archive.

for Example images of plots

Parameters

archive

a Zip archive, the data should be stored in

Definition at line 225 of file expression.cpp.

Session * Expression::session

(

)

Returns the Session, this Expression belongs to.

Definition at line 164 of file expression.cpp.

void Expression::setCommand

(

const QString &

cmd

)

Sets the command, represented by this Expression.

Parameters

cmd	the command

Definition at line 88 of file expression.cpp.

void Expression::setErrorMessage

(

const QString &

cmd

)

Sets the error message.

Parameters

cmd	the error message

See also

errorMessage()

Definition at line 98 of file expression.cpp.

void Expression::setFinishingBehavior

(

Expression::FinishingBehavior

behavior

)

set the finishing behaviour

Parameters

behavior

the new Finishing Behaviour

Definition at line 253 of file expression.cpp.

void Expression::setId

(

int

id

)

set the id of the Expression.

It should be unique

Parameters

id	the new Id

Definition at line 247 of file expression.cpp.

void Expression::setInternal

(

bool

internal

)

mark this expression as an internal expression, so for example latex will not be run on it

Definition at line 263 of file expression.cpp.

void Expression::setResult ( Result *  result )

protected

Set the result of the Expression.

this will cause gotResult() to be emited The old result will be deleted, and the Expression takes over ownership of the result object, taking care of deleting it.

Parameters

result

the new result

Definition at line 108 of file expression.cpp.

void Expression::setStatus ( Expression::Status  status )

protected

Set the status statusChanged will be emitted.

Parameters

status

the new status

Definition at line 150 of file expression.cpp.

Expression::Status Expression::status

(

)

Returns the status of this Expression.

Returns

the status of this Expression

Definition at line 159 of file expression.cpp.

void Cantor::Expression::statusChanged ( Cantor::Expression::Status  status )

signal

the status of the Expression has changed.

Parameters

status

the new status

QDomElement Expression::toXml

(

QDomDocument &

doc

)

returns an xml representation of this expression used for saving the worksheet

Parameters

doc	DomDocument used for storing the information

Returns

QDomElemt containing the representation of this Expression

Definition at line 208 of file expression.cpp.

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The documentation for this class was generated from the following files:

• expression.h
• expression.cpp