| /******************************************************************************* |
| * Copyright (c) 2001, 2008 Oracle 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: |
| * Oracle Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jst.jsf.core.internal; |
| |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import org.eclipse.core.resources.IProject; |
| import org.eclipse.core.runtime.content.IContentType; |
| import org.eclipse.jst.jsf.common.internal.policy.CanonicallyOrderedIteratorPolicy; |
| import org.eclipse.jst.jsf.common.internal.policy.IIteratorPolicy; |
| import org.eclipse.jst.jsf.common.internal.strategy.IIdentifiableStrategy; |
| import org.eclipse.jst.jsf.common.internal.strategy.IteratorPolicyBasedStrategyComposite; |
| import org.eclipse.jst.jsf.designtime.internal.view.model.ITagRegistry; |
| import org.eclipse.jst.jsf.designtime.internal.view.model.TagRegistryFactory.TagRegistryFactoryException; |
| |
| /** |
| * Employs a policy-based strategy to construct a TagRegistry for a particular |
| * content-type in a particular project. |
| * |
| * @author cbateman |
| * |
| */ |
| public final class CompositeTagRegistryFactory |
| { |
| private static CompositeTagRegistryFactory INSTANCE; |
| |
| /** |
| * @return the single instance of the registry factory |
| */ |
| public static synchronized CompositeTagRegistryFactory getInstance() |
| { |
| if (INSTANCE == null) |
| { |
| INSTANCE = new CompositeTagRegistryFactory(); |
| } |
| return INSTANCE; |
| } |
| |
| private final Map<IContentType, Set<TagRegistryFactoryInfo>> _cachedExtensionsByType = |
| new HashMap<IContentType, Set<TagRegistryFactoryInfo>>(4); |
| |
| private CompositeTagRegistryFactory() |
| { |
| // singleton: no external instantiation |
| } |
| |
| |
| /** |
| * @param id |
| * @return a tag registry for the id or null if there isn't one. |
| */ |
| public final ITagRegistry getRegistry(final TagRegistryIdentifier id) |
| { |
| final Set<TagRegistryFactoryInfo> handlers = TagLibraryRegistryLoader |
| .getAllHandlers(); |
| |
| final Set<TagRegistryFactoryInfo> matchingHandlers = findMatchingExtensions( |
| id, handlers); |
| |
| if (matchingHandlers.size() > 0) |
| { |
| // optimize: if there is only one handler, no need for strategy |
| if (matchingHandlers.size() == 1) |
| { |
| try |
| { |
| return matchingHandlers.iterator().next().getTagRegistryFactory() |
| .createTagRegistry(id.getProject()); |
| } |
| catch (TagRegistryFactoryException e) |
| { |
| JSFCorePlugin.log(e, "While trying to acquire a registry"); //$NON-NLS-1$ |
| } |
| } |
| else |
| { |
| // for now, we will order by the canonical name of the extension |
| // id in ascending order. Later, we may make this preference |
| // based. |
| final TagRegistrySelectionStrategy selectionStrategy = new TagRegistrySelectionStrategy( |
| new CanonicallyOrderedIteratorPolicy<String>()); |
| |
| for (final Iterator<TagRegistryFactoryInfo> it = matchingHandlers |
| .iterator(); it.hasNext();) |
| { |
| selectionStrategy.addStrategy(it.next().getTagRegistryFactory()); |
| } |
| return selectionStrategy.perform(id.getProject()); |
| } |
| } |
| |
| return null; |
| } |
| |
| /** |
| * @return get all tag registry factories |
| */ |
| public Set<TagRegistryFactoryInfo> getAllTagRegistryFactories() |
| { |
| return TagLibraryRegistryLoader.getAllHandlers(); |
| } |
| |
| private Set<TagRegistryFactoryInfo> findMatchingExtensions( |
| TagRegistryIdentifier id, Set<TagRegistryFactoryInfo> handlers) |
| { |
| Set<TagRegistryFactoryInfo> matching = _cachedExtensionsByType.get(id |
| .getContentType()); |
| |
| if (matching == null) |
| { |
| matching = new HashSet<TagRegistryFactoryInfo>(4); |
| |
| for (final TagRegistryFactoryInfo handler : handlers) |
| { |
| if (handler.getContentTypes().contains(id.getContentType())) |
| { |
| matching.add(handler); |
| } |
| } |
| |
| // if there is nothing matching, just store the empty set and |
| // discard |
| // the extra memory |
| if (matching.size() > 0) |
| { |
| _cachedExtensionsByType.put(id.getContentType(), matching); |
| } |
| else |
| { |
| _cachedExtensionsByType.put(id.getContentType(), |
| Collections.EMPTY_SET); |
| } |
| } |
| return matching; |
| } |
| |
| /** |
| * Identifies a content type/project context in which to request a tag |
| * registry. |
| * |
| * @author cbateman |
| * |
| */ |
| public final static class TagRegistryIdentifier |
| { |
| private final IProject _project; |
| private final IContentType _contentType; |
| |
| /** |
| * @param project |
| * @param contentType |
| */ |
| public TagRegistryIdentifier(final IProject project, |
| final IContentType contentType) |
| { |
| _project = project; |
| _contentType = contentType; |
| } |
| |
| IProject getProject() |
| { |
| return _project; |
| } |
| |
| IContentType getContentType() |
| { |
| return _contentType; |
| } |
| |
| } |
| |
| private static class TagRegistrySelectionStrategy |
| extends |
| IteratorPolicyBasedStrategyComposite<IProject, ITagRegistry, String, IIdentifiableStrategy<IProject, ITagRegistry, String>> |
| { |
| private static final ITagRegistry NO_RESULT = null; |
| |
| protected TagRegistrySelectionStrategy(IIteratorPolicy<String> policy) |
| { |
| super(policy); |
| } |
| |
| @Override |
| public ITagRegistry getNoResult() |
| { |
| return NO_RESULT; |
| } |
| } |
| } |