/*******************************************************************************
* Copyright (c) 2005, 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.ui.internal.operations;
import org.eclipse.core.commands.operations.DefaultOperationHistory;
import org.eclipse.core.commands.operations.IOperationApprover;
import org.eclipse.core.commands.operations.IOperationHistory;
import org.eclipse.core.commands.operations.IUndoContext;
import org.eclipse.core.commands.operations.ObjectUndoContext;
import org.eclipse.core.commands.operations.OperationHistoryFactory;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.internal.misc.Policy;
import org.eclipse.ui.operations.IWorkbenchOperationSupport;
/**
* <p>
* Provides undoable operation support for the workbench. This includes providing access to the default
* operation history and installing a workbench-specific operation approver that enforces a linear
* undo strategy.
* </p>
*
* @since 3.1
*/
public class WorkbenchOperationSupport implements IWorkbenchOperationSupport {
private ObjectUndoContext undoContext;
private IOperationApprover approver;
// initialize debug options
static {
DefaultOperationHistory.DEBUG_OPERATION_HISTORY_UNEXPECTED = Policy.DEBUG_OPERATIONS;
DefaultOperationHistory.DEBUG_OPERATION_HISTORY_OPENOPERATION = Policy.DEBUG_OPERATIONS;
DefaultOperationHistory.DEBUG_OPERATION_HISTORY_APPROVAL = Policy.DEBUG_OPERATIONS;
DefaultOperationHistory.DEBUG_OPERATION_HISTORY_NOTIFICATION = Policy.DEBUG_OPERATIONS && Policy.DEBUG_OPERATIONS_VERBOSE;
DefaultOperationHistory.DEBUG_OPERATION_HISTORY_DISPOSE = Policy.DEBUG_OPERATIONS && Policy.DEBUG_OPERATIONS_VERBOSE;
}
/**
* Disposes of anything created by the operation support.
*/
public void dispose() {
/*
* uninstall the operation approver that we added to the operation history
*/
getOperationHistory().removeOperationApprover(approver);
/*
* dispose of all operations using our context
*/
getOperationHistory().dispose(getUndoContext(), true, true, true);
}
/**
* Returns the undo context for workbench operations.
* The workbench configures an undo context with the appropriate policies
* for the workbench undo model.
*
* @return the workbench operation context.
* @since 3.1
*/
public IUndoContext getUndoContext() {
if (undoContext == null) {
undoContext = new ObjectUndoContext(PlatformUI.getWorkbench(),
"Workbench Context"); //$NON-NLS-1$
}
return undoContext;
}
/**
* Returns the workbench operation history.
*
* @return the operation history for workbench operations.
* @since 3.1
*/
public IOperationHistory getOperationHistory() {
IOperationHistory history = OperationHistoryFactory.getOperationHistory();
/*
* Set up the history if we have not done so before.
*/
if (approver == null) {
/*
* install an operation approver that prevents linear undo violations
* in any context
*/
approver = new AdvancedValidationUserApprover(getUndoContext());
history.addOperationApprover(approver);
/*
* set a limit for the workbench undo context
*/
history.setLimit(getUndoContext(), 25);
}
return history;
}
}