| /******************************************************************************* |
| * Copyright (c) 2006 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.core.commands.operations; |
| |
| import org.eclipse.core.commands.ExecutionException; |
| import org.eclipse.core.runtime.IProgressMonitor; |
| import org.eclipse.core.runtime.IStatus; |
| |
| /** |
| * <p> |
| * 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 |
| * {@link 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. |
| * </p> |
| * |
| * @since 3.3 |
| * |
| */ |
| public interface IAdvancedUndoableOperation2 { |
| /** |
| * Return 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 {@link IUndoableOperation#canExecute()}. It is not called by |
| * the operation history, but instead is used by clients (such as |
| * implementers of {@link 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 |
| * <code>false</code> on subsequent calls to |
| * {@link IUndoableOperation#canExecute()}. |
| * |
| * @param monitor |
| * the progress monitor (or <code>null</code>) to use for |
| * reporting progress to the user while computing the validity. |
| * |
| * @return the IStatus indicating the validity of the execute. The status |
| * severity should be set to <code>OK</code> if the execute can |
| * successfully be performed, and <code>ERROR</code> if it cannot. |
| * Any other severity is assumed to represent an ambiguous state. |
| * @throws ExecutionException |
| * if an exception occurs while computing the validity. |
| */ |
| IStatus computeExecutionStatus(IProgressMonitor monitor) |
| throws ExecutionException; |
| |
| /** |
| * 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 <code>false</code>. |
| * This flag should only be set to <code>true</code> while the execution, |
| * undo, or redo status computations are being performed in the background, |
| * and should be restored to <code>false</code> when complete. |
| * <p> |
| * 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 <code>true</code>. 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 <code>false</code> just before the actual execution, undo, |
| * or redo occurs, so the user can be consulted for the final outcome. |
| * |
| * @param quiet |
| * <code>true</code> if it is inappropriate to consult or |
| * otherwise prompt the user while computing status, and |
| * <code>false</code> if the user may be prompted. |
| * |
| * @see #computeExecutionStatus(IProgressMonitor) |
| * @see IAdvancedUndoableOperation#computeUndoableStatus(IProgressMonitor) |
| * @see IAdvancedUndoableOperation#computeRedoableStatus(IProgressMonitor) |
| */ |
| public void setQuietCompute(boolean quiet); |
| |
| /** |
| * Return a boolean that instructs whether the operation should be executed, |
| * undone, or redone in a background thread. |
| * |
| * @return <code>true</code> if the operation should be run in the |
| * background, <code>false</code> if it should not. |
| */ |
| public boolean runInBackground(); |
| } |