| /****************************************************************************** |
| * Copyright (c) 2002, 2008 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.editpolicy; |
| |
| 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.Assert; |
| import org.eclipse.core.runtime.IConfigurationElement; |
| import org.eclipse.gef.EditPart; |
| import org.eclipse.gmf.runtime.common.core.service.AbstractProviderConfiguration; |
| |
| /** |
| * A provider configuration for the EditPolicy Service. It helps in filtering out |
| * and delay loading unrelated providers. |
| * |
| * @author chmahone |
| * @canBeSeenBy org.eclipse.gmf.runtime.diagram.ui.* |
| */ |
| public class EditPolicyProviderConfiguration |
| extends AbstractProviderConfiguration { |
| |
| /** constants corresponding to different symbols in the extention schema */ |
| private static final String CONTEXT = "context"; //$NON-NLS-1$ |
| private static final String EDITPARTS = "editparts"; //$NON-NLS-1$ |
| |
| /** a map of requests supported by this provider to their target contexts */ |
| private List contextDescriptors = new ArrayList(); |
| |
| /** |
| * Builds a new provider contribution descriptor by parsing its configuration element |
| * |
| * @param configElement A provider configuration element |
| * @return A provider XML contribution descriptor |
| */ |
| public static EditPolicyProviderConfiguration parse(IConfigurationElement configElement) { |
| Assert.isNotNull(configElement, "null provider configuration element"); //$NON-NLS-1$ |
| return new EditPolicyProviderConfiguration(configElement); |
| } |
| |
| /** |
| * Creates a new <code>ProviderContributionDescriptor</code> instance |
| * given a provider configuration element |
| * |
| * @param configElement The provider XML configuration element |
| */ |
| private EditPolicyProviderConfiguration(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 editParts = |
| getObjectList( |
| configChildren[i].getAttribute(EDITPARTS), |
| objects, configElement); |
| if (editParts != null) |
| contextDescriptors.add(new ContextDescriptor(editParts)); |
| } |
| } |
| |
| /** |
| * 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 editPart the editPart |
| * @return boolean <code>true</code> if it supports; <code>false</code> otherwise |
| */ |
| public boolean supports(EditPart editPart) { |
| if (contextDescriptors.isEmpty()) |
| return true; |
| |
| Iterator iter = contextDescriptors.iterator(); |
| while (iter.hasNext()) { |
| ContextDescriptor descriptor = (ContextDescriptor) iter.next(); |
| if (descriptor.matches(editPart)) |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * A descriptor for a provider context |
| */ |
| private static class ContextDescriptor { |
| |
| /** the editparts */ |
| private final List editParts; |
| |
| /** |
| * creates a new context descriptor from some context info |
| * |
| * @param editParts the list of editParts |
| */ |
| public ContextDescriptor(List editParts) { |
| this.editParts = editParts; |
| } |
| |
| /** |
| * Determines if the context descriptor matches the given context |
| * |
| * @param editPart the editPart |
| * @return boolean |
| */ |
| public boolean matches(EditPart editPart) { |
| if (editParts != null) { |
| if (!objectMatches(editPart, editParts)) |
| return false; |
| } |
| return true; |
| } |
| } |
| |
| } |