| /** |
| * <copyright> |
| * |
| * Copyright (c) 2007, 2008 Obeo. |
| * 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 |
| * |
| * </copyright> |
| * |
| * Contributors: |
| * Quentin Glineur - initial API and implementation |
| * |
| * $Id: ProviderDescriptor.java,v 1.4 2008/10/09 17:21:03 qglineur Exp $ |
| */ |
| package org.eclipse.qvt.declarative.common.framework.service; |
| |
| |
| public abstract class ProviderDescriptor implements Provider{ |
| |
| public static enum Priority { |
| lowest, low, normal, high, highest |
| } |
| protected Provider describedProvider; |
| |
| public abstract Provider getDescribedProvider(); |
| |
| public abstract Priority getPriority() ; |
| |
| public boolean provides(Operation operation) { |
| if (describedProvider == null) { |
| describedProvider = getDescribedProvider(); |
| if (describedProvider == null) { |
| return false; |
| } |
| } |
| try { |
| return describedProvider.provides(operation); |
| } |
| catch (Throwable e) { |
| if (e instanceof ThreadDeath) { |
| throw (ThreadDeath) e; |
| } |
| if (e instanceof VirtualMachineError) { |
| throw (VirtualMachineError) e; |
| } |
| return false; |
| } |
| } |
| |
| } |
