| /****************************************************************************** |
| * 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.editpart; |
| |
| 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.gmf.runtime.common.core.service.AbstractProviderConfiguration; |
| import org.eclipse.gmf.runtime.notation.View; |
| |
| /** |
| * @author melaasar |
| * |
| * A provider configuration for the EditPartService. It helps in filtering out |
| * and delay loading unrelated providers. |
| */ |
| public class EditPartProviderConfiguration extends AbstractProviderConfiguration { |
| |
| /** constants corresponding to different symbols in the extention schema */ |
| private static final String CONTEXT = "context"; //$NON-NLS-1$ |
| private static final String VIEWS = "views"; //$NON-NLS-1$ |
| private static final String PROVIDES_ROOT_EDITPART = "providesRootEditPart"; //$NON-NLS-1$ |
| |
| /** a map of requests supported by this provider to their target contexts*/ |
| private List requests = 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 EditPartProviderConfiguration parse(IConfigurationElement configElement) { |
| Assert.isNotNull(configElement, "null provider configuration element"); //$NON-NLS-1$ |
| return new EditPartProviderConfiguration(configElement); |
| } |
| |
| /** |
| * Creates a new <code>ProviderContributionDescriptor</code> instance |
| * given a provider configuration element |
| * |
| * @param configElement The provider XML configuration element |
| */ |
| private EditPartProviderConfiguration(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 views = |
| getObjectList( |
| configChildren[i].getAttribute(VIEWS), |
| objects, configElement); |
| if (views != null) |
| requests.add( |
| new ContextDescriptor(views)); |
| |
| String s = configChildren[i].getAttribute(PROVIDES_ROOT_EDITPART); |
| if (s != null) { |
| requests.add(new ContextDescriptor(Boolean.valueOf(s) |
| .booleanValue())); |
| } |
| } |
| } |
| |
| /** |
| * 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 view The view |
| * @return boolean <code>true</code> if it supports; <code>false</code> otherwise |
| */ |
| public boolean supports(View view) { |
| if (requests.isEmpty()) |
| return true; |
| |
| Iterator iter = requests.iterator(); |
| while (iter.hasNext()) { |
| ContextDescriptor request = (ContextDescriptor) iter.next(); |
| if (request.matches(view)) |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Determines if the provider supports creation of a <code>RootEditPart</code> |
| * The provider understands the request if: |
| * 1- There are no listed provider contexts |
| * 2- The context has <code>providesRootEditPart</code> set to true |
| * |
| * @return boolean <code>true</code> if it supports; <code>false</code> otherwise |
| */ |
| public boolean supportsRootEditPart() { |
| if (requests.isEmpty()) |
| return true; |
| |
| Iterator iter = requests.iterator(); |
| while (iter.hasNext()) { |
| ContextDescriptor request = (ContextDescriptor) iter.next(); |
| if (request.providesRootEditPart()) |
| return true; |
| } |
| return false; |
| } |
| /** |
| * A descriptor for a provider context |
| */ |
| private static class ContextDescriptor { |
| /** the views */ |
| private List views; |
| |
| /** boolean flag for <code>RootEditPart</code> creation */ |
| private boolean providesRootEditPart; |
| |
| /** |
| * creates a new context descriptor from its context info |
| * |
| * @param views The views |
| */ |
| public ContextDescriptor(List views) { |
| this.views = views; |
| } |
| |
| /** |
| * creates a new context descriptor from its context info |
| * |
| * @param boolean |
| * flag for <code>RootEditPart</code> creation |
| */ |
| public ContextDescriptor(boolean providesRootEditPart) { |
| this.providesRootEditPart = providesRootEditPart; |
| } |
| |
| /** |
| * Determines if the context descriptor matches the given context |
| * |
| * @param view The view context |
| * @return boolean |
| */ |
| public boolean matches(View view) { |
| return views != null && objectMatches(view, views); |
| } |
| |
| /** |
| * Returns true if this context provides for |
| * <code>RootEditPart</code> creation. |
| * |
| * @return boolean |
| */ |
| public boolean providesRootEditPart() { |
| return providesRootEditPart; |
| } |
| } |
| } |