- All Known Implementing Classes:
public interface IAdvancedUndoableOperation2
IAdvancedUndoableOperation2 defines a method for computing the validity of executing an operation before attempting to execute it. It also defines a way for clients to specify that computing status should be done quietly, without consulting the user. This interface is useful when implementing
IOperationApprover2, or any other object that performs validation of the undo history. It also allows operations to specify whether they should be run in the UI thread.
All Methods Instance Methods Abstract Methods Modifier and Type Method Description
computeExecutionStatus(IProgressMonitor monitor)Return a status indicating the projected outcome of executing the receiver.
runInBackground()Return a boolean that instructs whether the operation should be executed, undone, or redone in a background thread.
setQuietCompute(boolean quiet)Set a boolean that instructs whether the computation of the receiver's execution, undo, or redo status should quietly compute status without consulting or prompting the user.
IStatus computeExecutionStatus(IProgressMonitor monitor) throws ExecutionExceptionReturn a status indicating the projected outcome of executing the receiver. This method should be used to report the possible outcome of executing an operation when computing the validity of an execute is too expensive to perform in
IUndoableOperation.canExecute(). It is not called by the operation history, but instead is used by clients (such as implementers of
IOperationApprover2) who wish to perform advanced validation of an operation before attempting to execute it. If the result of this method is the discovery that an operation can in fact not be executed, then the operation is expected to correctly answer
falseon subsequent calls to
monitor- the progress monitor (or
null) to use for reporting progress to the user while computing the validity.
- the IStatus indicating the validity of the execute. The status
severity should be set to
OKif the execute can successfully be performed, and
ERRORif it cannot. Any other severity is assumed to represent an ambiguous state.
ExecutionException- if an exception occurs while computing the validity.
void setQuietCompute(boolean quiet)Set a boolean that instructs whether the computation of the receiver's execution, undo, or redo status should quietly compute status without consulting or prompting the user. The default value is
false. This flag should only be set to
truewhile the execution, undo, or redo status computations are being performed in the background, and should be restored to
If the status computation methods typically need to consult the user in order to determine the severity of a particular situation, the least severe status that could be chosen by the user should be returned when this flag is
true. This can help to prevent overzealous disposal of the operation history when an operation is in an ambiguous state. Typically, the status computation methods are invoked with this flag set to
falsejust before the actual execution, undo, or redo occurs, so the user can be consulted for the final outcome.
trueif it is inappropriate to consult or otherwise prompt the user while computing status, and
falseif the user may be prompted.
- See Also:
trueif the operation should be run in the background,
falseif it should not.