| /******************************************************************************* |
| * Copyright (c) 2006, 2007 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.ui.internal.navigator.extensions; |
| |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.LinkedHashSet; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import org.eclipse.jface.viewers.IStructuredSelection; |
| import org.eclipse.jface.viewers.StructuredSelection; |
| import org.eclipse.ui.IEditorInput; |
| import org.eclipse.ui.internal.navigator.NavigatorContentService; |
| import org.eclipse.ui.navigator.ILinkHelper; |
| |
| /** |
| * @since 3.2 |
| * |
| */ |
| public class LinkHelperService { |
| |
| private static final ILinkHelper[] CANT_GET_NO_HELP = new ILinkHelper[0]; |
| |
| private NavigatorContentService contentService; |
| |
| private final Map linkHelpers = new HashMap(); |
| |
| /** |
| * @param aContentService |
| * The associated content service for this link helper service. |
| */ |
| public LinkHelperService(NavigatorContentService aContentService) { |
| contentService = aContentService; |
| } |
| |
| /** |
| * |
| * @param anObject |
| * An object from the viewer |
| * @return An array of link helpers that know about elements in the |
| * selection or null |
| */ |
| public ILinkHelper[] getLinkHelpersFor(Object anObject) { |
| |
| LinkHelperDescriptor[] descriptors = LinkHelperManager.getInstance() |
| .getLinkHelpersFor(anObject, contentService); |
| if (descriptors.length == 0) { |
| return CANT_GET_NO_HELP; |
| } |
| |
| Set helpers = new LinkedHashSet(); |
| for (int i = 0; i < descriptors.length; i++) { |
| helpers.add(getLinkHelper(descriptors[i])); |
| } |
| if (helpers.size() == 0) |
| return CANT_GET_NO_HELP; |
| return (ILinkHelper[]) helpers.toArray(new ILinkHelper[helpers.size()]); |
| |
| } |
| |
| /** |
| * |
| * @param input |
| * The Editor input from the active viewer. |
| * @return An array of link helpers that know about elements in the |
| * selection or null |
| */ |
| public ILinkHelper[] getLinkHelpersFor(IEditorInput input) { |
| LinkHelperDescriptor[] descriptors = LinkHelperManager.getInstance() |
| .getLinkHelpersFor(input, contentService); |
| if (descriptors.length == 0) { |
| return CANT_GET_NO_HELP; |
| } |
| |
| Set helpers = new LinkedHashSet(); |
| for (int i = 0; i < descriptors.length; i++) { |
| helpers.add(getLinkHelper(descriptors[i])); |
| } |
| if (helpers.size() == 0) |
| return CANT_GET_NO_HELP; |
| return (ILinkHelper[]) helpers.toArray(new ILinkHelper[helpers.size()]); |
| } |
| |
| private ILinkHelper getLinkHelper(LinkHelperDescriptor descriptor) { |
| ILinkHelper helper = (ILinkHelper) linkHelpers.get(descriptor); |
| if (helper == null) { |
| synchronized (this) { |
| if (helper == null) { |
| linkHelpers.put(descriptor, helper = descriptor |
| .createLinkHelper()); |
| } |
| } |
| } |
| return helper; |
| } |
| |
| /** |
| * Return a selection that contains the elements that the given editor input |
| * represent. |
| * @param input the editor input |
| * @return a selection that contains the elements that the given editor input |
| * represent |
| */ |
| public IStructuredSelection getSelectionFor(IEditorInput input) { |
| ILinkHelper[] helpers = getLinkHelpersFor(input); |
| |
| IStructuredSelection selection = StructuredSelection.EMPTY; |
| IStructuredSelection newSelection = StructuredSelection.EMPTY; |
| |
| for (int i = 0; i < helpers.length; i++) { |
| selection = helpers[i].findSelection(input); |
| if (selection != null && !selection.isEmpty()) { |
| newSelection = mergeSelection(newSelection, selection); |
| } |
| } |
| return newSelection; |
| } |
| |
| private IStructuredSelection mergeSelection(IStructuredSelection aBase, |
| IStructuredSelection aSelectionToAppend) { |
| if (aBase == null || aBase.isEmpty()) { |
| return (aSelectionToAppend != null) ? aSelectionToAppend |
| : StructuredSelection.EMPTY; |
| } else if (aSelectionToAppend == null || aSelectionToAppend.isEmpty()) { |
| return aBase; |
| } else { |
| List newItems = new ArrayList(aBase.toList()); |
| newItems.addAll(aSelectionToAppend.toList()); |
| return new StructuredSelection(newItems); |
| } |
| } |
| } |