visad

Interface DataReference

All Superinterfaces:

ThingReference

All Known Subinterfaces:

RemoteDataReference

All Known Implementing Classes:

DataReferenceImpl, RemoteDataReferenceImpl

public interface DataReference
extends ThingReference

DataReference is the VisAD interface for named holders for data objects. It can provide a symbol table binding between a name and a variable for a user interface that includes a formula interpreter, or a full language interpreter (e.g., a Java interpreter).

During computations the Data object referenced by a DataReference may change. DataReference objects are passed to Display objects, so that a display may depict the changing values of named variables.

DataReference is a source of ThingChangedEvent-s, and thus defines addThingChangedListener and removeThingChangedListener.

DataReference objects may be local (DataReferenceImpl) or remote (RemoteDataReferenceImpl).

Method Summary

Modifier and Type	Method and Description
Data	getData()
MathType	getType() this is more efficient than getData().getType() for RemoteDataReferences
void	setData(Data d) set reference to data, replacing any currently referenced Data object; if this is local (i.e., an instance of DataReferenceImpl) then the Data argument must also be local (i.e., an instance of DataImpl); if this is Remote (i.e., an instance of RemoteDataReference) then a local Data argument (i.e., an instance of DataImpl) will be passed by copy and a remote Data argument (i.e., an instance of RemoteData) will be passed by remote reference; invokes d.addReference(DataReference r)

Methods inherited from interface visad.ThingReference

acknowledgeThingChanged, addThingChangedListener, getName, getThing, getTick, incTick, peekThingChanged, removeThingChangedListener, setThing

Method Detail

setData

void setData(Data d)
      throws VisADException,
             RemoteException

set reference to data, replacing any currently referenced Data object; if this is local (i.e., an instance of DataReferenceImpl) then the Data argument must also be local (i.e., an instance of DataImpl); if this is Remote (i.e., an instance of RemoteDataReference) then a local Data argument (i.e., an instance of DataImpl) will be passed by copy and a remote Data argument (i.e., an instance of RemoteData) will be passed by remote reference; invokes d.addReference(DataReference r)

Parameters:

d - Data object to be set

Throws:

VisADException - a VisAD error occurred

RemoteException - an RMI error occurred

getData

Data getData()
      throws VisADException,
             RemoteException

Returns:

referenced Data object, or null if none

Throws:

VisADException - a VisAD error occurred

RemoteException - an RMI error occurred

getType

MathType getType()
          throws VisADException,
                 RemoteException

this is more efficient than getData().getType() for RemoteDataReferences

Returns:

the MathType of referenced Data object, or null if none;

Throws:

VisADException - a VisAD error occurred

RemoteException - an RMI error occurred