| /******************************************************************************* |
| * Copyright (c) 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; |
| |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.eclipse.ui.internal.navigator.extensions.ExtensionStateModel; |
| import org.eclipse.ui.navigator.IExtensionStateModel; |
| import org.eclipse.ui.navigator.INavigatorContentDescriptor; |
| import org.eclipse.ui.navigator.INavigatorContentService; |
| |
| /** |
| * |
| * A content extension may have its content and label providers disposed |
| * whenever the extension is activated or deactivated. However, the state model |
| * lives throughout the life of the viewer to allow Action Providers to drive |
| * their behavior from it. |
| * |
| * @since 3.3 |
| * |
| */ |
| public class NavigatorExtensionStateService { |
| |
| private final Object lock = new Object(); |
| private INavigatorContentService contentService; |
| |
| /** |
| * Create an ExtensionStateServie that will keep track of the state models |
| * of content extensions. |
| * |
| * @param theContentService |
| * The content service which manages this state model service. |
| */ |
| public NavigatorExtensionStateService(INavigatorContentService theContentService) { |
| contentService = theContentService; |
| } |
| |
| /* |
| * A map of (String-based-Navigator-Content-Extension-IDs, |
| * NavigatorContentExtension-objects)-pairs |
| */ |
| private final Map/* <INavigatorContentDescriptor, IExtensionStateModel> */stateModels = new HashMap(); |
| |
| /** |
| * Return the state model for the given descriptor. |
| * |
| * @param aDescriptor A content descriptor |
| * @return The state model for the given descriptor. |
| */ |
| public IExtensionStateModel getExtensionStateModel( |
| INavigatorContentDescriptor aDescriptor) { |
| synchronized (lock) { |
| IExtensionStateModel model = (IExtensionStateModel) stateModels |
| .get(aDescriptor); |
| if (model == null) |
| stateModels.put(aDescriptor, model = new ExtensionStateModel( |
| aDescriptor.getId(), contentService.getViewerId())); |
| return model; |
| } |
| } |
| |
| } |