visad.formula
Class FormulaManager

java.lang.Object
  visad.formula.FormulaManager

public class FormulaManager
extends Object

The FormulaManager class is the gateway into the visad.formula package, a general-purpose formula parser and evaluator. Variables update automatically when the variables upon which they depend change. For an example of usage, see the FormulaUtil.createStandardManager() method.

Constructor Summary

FormulaManager(String[] binOps, int[] binPrec, String[] binMethods, String[] unaryOps, int[] unaryPrec, String[] unaryMethods, String[] functions, String[] funcMethods, int implicitPrec, String[] implicitMethods, String preParseMethod)
construct a new FormulaManager object

Method Summary

void	assignFormula(String name, String formula) assign a formula to a variable
boolean	canBeRemoved(String name) check whether it is safe to remove a variable from the database
void	createVar(String name, ThingReference tr) add a variable to the database that uses tr as its ThingReference
boolean	exists(String name) check whether a given variable is currently in the database
String[]	getErrors(String name) get the current list of errors that occurred when evaluating "name" and clear the list
String	getFormula(String name) get a variable's current formula
ThingReference	getReference(String name) get a variable's associated ThingReference
Thing	getThing(String name) get a variable's current value
void	remove(String name) remove a variable from the database
void	setReference(String name, ThingReference tr) set a variable's ThingReference
void	setTextRef(String name, ThingReference textRef) set a variable to auto-update its formula based on a Text object referenced by a ThingReference (useful for remote formula updates)
void	setThing(String name, Thing t) set a variable's value directly
void	waitForFormula(String name) blocks until this variable's formula is finished computing

Methods inherited from class java.lang.Object

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

Constructor Detail

FormulaManager

public FormulaManager(String[] binOps,
                      int[] binPrec,
                      String[] binMethods,
                      String[] unaryOps,
                      int[] unaryPrec,
                      String[] unaryMethods,
                      String[] functions,
                      String[] funcMethods,
                      int implicitPrec,
                      String[] implicitMethods,
                      String preParseMethod)
               throws FormulaException

construct a new FormulaManager object

Throws:

FormulaException

Method Detail

createVar

public void createVar(String name,
                      ThingReference tr)
               throws VisADException

add a variable to the database that uses tr as its ThingReference

Throws:

VisADException

assignFormula

public void assignFormula(String name,
                          String formula)
                   throws VisADException

assign a formula to a variable

Throws:

VisADException

waitForFormula

public void waitForFormula(String name)
                    throws VisADException

blocks until this variable's formula is finished computing

Throws:

VisADException

setTextRef

public void setTextRef(String name,
                       ThingReference textRef)
                throws VisADException,
                       RemoteException

set a variable to auto-update its formula based on a Text object referenced by a ThingReference (useful for remote formula updates)

Throws:

VisADException

RemoteException

getErrors

public String[] getErrors(String name)

get the current list of errors that occurred when evaluating "name" and clear the list

canBeRemoved

public boolean canBeRemoved(String name)
                     throws FormulaException

check whether it is safe to remove a variable from the database

Throws:

FormulaException

exists

public boolean exists(String name)

check whether a given variable is currently in the database

remove

public void remove(String name)
            throws FormulaException

remove a variable from the database

Throws:

FormulaException

setThing

public void setThing(String name,
                     Thing t)
              throws VisADException,
                     RemoteException

set a variable's value directly

Throws:

VisADException

RemoteException

setReference

public void setReference(String name,
                         ThingReference tr)
                  throws VisADException

set a variable's ThingReference

Throws:

VisADException

getThing

public Thing getThing(String name)
               throws FormulaException

get a variable's current value

Throws:

FormulaException

getReference

public ThingReference getReference(String name)
                            throws FormulaException

get a variable's associated ThingReference

Throws:

FormulaException

getFormula

public String getFormula(String name)
                  throws FormulaException

get a variable's current formula

Throws:

FormulaException