| /****************************************************************************** |
| * Copyright (c) 2004, 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.gmf.runtime.diagram.ui.internal.services.decorator; |
| |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| |
| import org.eclipse.core.runtime.IConfigurationElement; |
| import org.eclipse.gmf.runtime.common.core.service.AbstractProviderConfiguration; |
| import org.eclipse.gmf.runtime.diagram.ui.services.decorator.IDecoratorTarget; |
| import org.eclipse.jface.util.Assert; |
| |
| |
| /** |
| * A provider configuration for the Decorator Service. It helps in filtering out |
| * and delay the loading of unrelated providers. |
| * |
| * @see AbstractProviderConfiguration |
| * |
| * @author cmahoney |
| * @canBeSeenBy %level1 |
| */ |
| public class DecoratorProviderConfiguration |
| extends AbstractProviderConfiguration { |
| |
| /** constants corresponding to different symbols in the extension schema */ |
| private static final String CONTEXT = "context"; //$NON-NLS-1$ |
| private static final String DECORATOR_TARGETS = "decoratorTargets"; //$NON-NLS-1$ |
| |
| /** a list of object descriptors supported by this provider */ |
| private List contextDescriptors = new ArrayList(); |
| |
| /** |
| * Creates and builds a new provider contribution descriptor (<code>DecoratorProviderConfiguration</code>) by parsing its configuration element. |
| * |
| * @param configElement A provider XML configuration element |
| * @return A provider XML contribution descriptor |
| */ |
| public static DecoratorProviderConfiguration parse(IConfigurationElement configElement) { |
| Assert.isNotNull(configElement, "null provider configuration element"); //$NON-NLS-1$ |
| return new DecoratorProviderConfiguration(configElement); |
| } |
| |
| /** |
| * Creates a new <code>ProviderContributionDescriptor</code> instance |
| * by parsing its configuration element. |
| * |
| * @param configElement The provider XML configuration element |
| */ |
| private DecoratorProviderConfiguration(IConfigurationElement configElement) { |
| IConfigurationElement configChildren[]; |
| |
| // read the object descriptors |
| Map objects = new HashMap(); |
| configChildren = configElement.getChildren(OBJECT); |
| for (int i = 0; i < configChildren.length; i++) { |
| String id = configChildren[i].getAttribute(ID); |
| if (id != null) |
| objects.put(id, new ObjectDescriptor(configChildren[i])); |
| } |
| |
| // read the context descriptors |
| configChildren = configElement.getChildren(CONTEXT); |
| for (int i = 0; i < configChildren.length; i++) { |
| List decoratorTargets = |
| getObjectList( |
| configChildren[i].getAttribute(DECORATOR_TARGETS), |
| objects, configElement); |
| if (decoratorTargets != null) |
| contextDescriptors.add(new ContextDescriptor(decoratorTargets)); |
| } |
| } |
| |
| /** |
| * Determines if the provider understands the given context |
| * The provider understands the request if: |
| * 1- There are no listed provider contexts |
| * 2- The context matches one of the provider contexts |
| * |
| * @param decoratorTarget the decoratorTarget |
| * @return boolean <code>true</code> if it supports; <code>false</code> otherwise |
| */ |
| public boolean supports(IDecoratorTarget decoratorTarget) { |
| if (contextDescriptors.isEmpty()) |
| return true; |
| |
| Iterator iter = contextDescriptors.iterator(); |
| while (iter.hasNext()) { |
| ContextDescriptor descriptor = (ContextDescriptor) iter.next(); |
| if (descriptor.matches(decoratorTarget)) |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * A descriptor for a provider context |
| */ |
| private static class ContextDescriptor { |
| |
| /** the decoratorTargets */ |
| private final List decoratorTargets; |
| |
| /** |
| * creates a new context descriptor from some context info |
| * |
| * @param decoratorTargets the list of decoratorTargets |
| */ |
| public ContextDescriptor(List decoratorTargets) { |
| this.decoratorTargets = decoratorTargets; |
| } |
| |
| /** |
| * Determines if the context descriptor matches the given context |
| * |
| * @param decoratorTarget the decoratorTarget |
| * @return boolean |
| */ |
| public boolean matches(IDecoratorTarget decoratorTarget) { |
| if (decoratorTargets != null) { |
| if (!objectMatches(decoratorTarget, decoratorTargets)) |
| return false; |
| } |
| return true; |
| } |
| } |
| |
| } |