edu.bsu.cs.jive.contour
Interface InteractiveContourModel

All Superinterfaces:

ContourModel, Iterable<Contour>

public interface InteractiveContourModel
extends ContourModel

Identifies a contour model that supports forward and reverse program execution.

An interactive contour model will throw an exception if the client tries to modify the state of the contour model while stepping back through previous states.

Nested Class Summary

Nested classes/interfaces inherited from interface edu.bsu.cs.jive.contour.ContourModel

ContourModel.Exporter, ContourModel.Importer, ContourModel.Listener, ContourModel.Visitor

Method Summary

boolean	canStepBackward() Returns true if this interactive contour model can step backwards.
boolean	canStepForwardThroughRecordedStates() Returns true if this interactive contour model can step forward through pre-recorded states.
int	countTransactions() Count the number of transactions in this interactive contour model.
long	getEventNumber(int transactionIndex) Returns the number of the event which initiated the transaction identified by the supplied index.
int	getNextTransactionIndex() Get the index of the next transaction, the transaction that would be played if we call stepForward().
int	getPrevTransactionIndex() Get the index of the previous transaction, the transaction that would be played if we call stepBackward().
int	getTransactionIndex(long eventNumber) Returns the index of the transaction created as a result of the event with the supplied event number.
boolean	readyToRecord() Indicates if this object is in a state that is ready to record a transaction.
void	stepBackward() Play a step-backward transaction.
void	stepForward() Play a step-forward transaction.

Methods inherited from interface edu.bsu.cs.jive.contour.ContourModel

addListener, contains, contains, countChildren, countChildren, export, getChildren, getChildren, getChildren, getChildren, getContour, getModelLock, getParent, getParent, getRoots, getRoots, removeListener, size, visitBreadthFirst, visitDepthFirst

Methods inherited from interface java.lang.Iterable

iterator

Method Detail

countTransactions

int countTransactions()

Count the number of transactions in this interactive contour model.

Returns:

transaction count

stepForward

void stepForward()
                 throws NoSuchElementException

Play a step-forward transaction. This only works if there is a transaction available to be committed.

This is a synchronous method: when it returns, the stepping backward has completed. (Do not confuse this with a synchronized method.)

Throws:

NoSuchElementException - if there is no forward step to be executed.

stepBackward

void stepBackward()
                  throws NoSuchElementException,
                         IndexOutOfBoundsException

Play a step-backward transaction. This is only possible if there is a transaction to roll back.

This is a synchronous method: when it returns, the stepping backward has completed. (Do not confuse this with a synchronized method.)

Throws:

NoSuchElementException - if the step backwards cannot be completed because that information is either not available (not cached).

IndexOutOfBoundsException - if the request was to move back from the initial state (state zero).

getNextTransactionIndex

int getNextTransactionIndex()

Get the index of the next transaction, the transaction that would be played if we call stepForward().

Returns:

index of the next (forward) transaction

Throws:

NoSuchElementException - if there is no recorded "next" transaction that can be committed.

getPrevTransactionIndex

int getPrevTransactionIndex()

Get the index of the previous transaction, the transaction that would be played if we call stepBackward().

Returns:

index of the previous (backward) transaction.

Throws:

NoSuchElementException - if there is no recorded "previous transaction that can be rolled back.

readyToRecord

boolean readyToRecord()

Indicates if this object is in a state that is ready to record a transaction. The model is ready to record if it is not playing back through history, meaning that there are no future transactions recorded and all previous transactions are committed.

Returns:

true if this is ready to record

canStepBackward

boolean canStepBackward()

Returns true if this interactive contour model can step backwards.

Returns:

true if there are recorded states and we can step backwards

canStepForwardThroughRecordedStates

boolean canStepForwardThroughRecordedStates()

Returns true if this interactive contour model can step forward through pre-recorded states.

Returns:

true if there are pre-recorded states through which we can step forward

See Also:

readyToRecord()

getTransactionIndex

int getTransactionIndex(long eventNumber)

Returns the index of the transaction created as a result of the event with the supplied event number.

Parameters:

eventNumber - the event resulting in the transaction

Returns:

the transaction index corresponding to the event number

Throws:

NoSuchElementException - if there is no such transaction

getEventNumber

long getEventNumber(int transactionIndex)

Returns the number of the event which initiated the transaction identified by the supplied index.

Parameters:

transactionIndex - the transaction index resulting from the event number

Returns:

the event number corresponding to the transaction index