| /******************************************************************************* |
| * Copyright (C) 2007 The University of Manchester |
| * |
| * Modifications to the initial code base are copyright of their |
| * respective authors, or their employers as appropriate. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public License |
| * as published by the Free Software Foundation; either version 2.1 of |
| * the License, or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 |
| ******************************************************************************/ |
| package net.sf.taverna.t2.workbench.edits; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import uk.org.taverna.scufl2.api.common.WorkflowBean; |
| |
| /** |
| * Implementation of Edit which contains an ordered list of child edits. Child |
| * edits are applied collectively and in order, any failure in any child edit |
| * causes an undo of previously applied children and a propogation of the edit |
| * exception. |
| * |
| * @author Tom Oinn |
| */ |
| public class CompoundEdit implements Edit<WorkflowBean> { |
| private final transient List<Edit<?>> childEdits; |
| private transient boolean applied = false; |
| |
| /** |
| * Create a new compound edit with no existing Edit objects. |
| * |
| */ |
| public CompoundEdit() { |
| this.childEdits = new ArrayList<>(); |
| } |
| |
| /** |
| * Create a new compound edit with the specified edits as children. |
| */ |
| public CompoundEdit(List<Edit<?>> edits) { |
| this.childEdits = edits; |
| } |
| |
| /** |
| * Get the list of edits. |
| * @return a live-editable list. |
| */ |
| public List<Edit<?>> getChildEdits() { |
| return childEdits; |
| } |
| |
| /** |
| * Attempts to call the doEdit method of all child edits. If any of those |
| * children throws an EditException any successful edits are rolled back and |
| * the exception is rethrown as the cause of a new EditException from the |
| * CompoundEdit |
| */ |
| @Override |
| public synchronized WorkflowBean doEdit() throws EditException { |
| if (isApplied()) |
| throw new EditException("Cannot apply an edit more than once!"); |
| List<Edit<?>> doneEdits = new ArrayList<>(); |
| try { |
| for (Edit<?> edit : childEdits) { |
| edit.doEdit(); |
| /* |
| * Insert the done edit at position 0 in the list so we can |
| * iterate over the list in the normal order if we need to |
| * rollback, this ensures that the most recent edit is first. |
| */ |
| doneEdits.add(0, edit); |
| } |
| applied = true; |
| } catch (EditException ee) { |
| for (Edit<?> undoMe : doneEdits) |
| undoMe.undo(); |
| applied = false; |
| throw new EditException("Failed child of compound edit", ee); |
| } |
| return null; |
| } |
| |
| /** |
| * There is no explicit subject for a compound edit, so this method always |
| * returns null. |
| */ |
| @Override |
| public Object getSubject() { |
| return null; |
| } |
| |
| /** |
| * Rolls back all child edits in reverse order |
| */ |
| @Override |
| public synchronized void undo() { |
| for (int i = childEdits.size() - 1; i >= 0; i--) |
| // Undo child edits in reverse order |
| childEdits.get(i).undo(); |
| applied = false; |
| } |
| |
| @Override |
| public boolean isApplied() { |
| return applied; |
| } |
| } |