/******************************************************************************* * Copyright (c) 2000, 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.wst.jsdt.internal.ui.viewsupport; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Stack; import org.eclipse.core.resources.IResource; import org.eclipse.swt.widgets.Item; import org.eclipse.swt.widgets.Widget; import org.eclipse.wst.jsdt.core.IJavaScriptUnit; import org.eclipse.wst.jsdt.core.IJavaScriptElement; /** * Helper class for updating error markers and other decorators that work on resources. * Items are mapped to their element's underlying resource. * Method <code>resourceChanged</code> updates all items that are affected from the changed * elements. */ public class ResourceToItemsMapper { public static interface IContentViewerAccessor { public void doUpdateItem(Widget item); } private static final int NUMBER_LIST_REUSE= 10; // map from resource to item private HashMap fResourceToItem; private Stack fReuseLists; private IContentViewerAccessor fContentViewerAccess; public ResourceToItemsMapper(IContentViewerAccessor viewer) { fResourceToItem= new HashMap(); fReuseLists= new Stack(); fContentViewerAccess= viewer; } /** * Must be called from the UI thread. * @param changedResource Changed resource */ public void resourceChanged(IResource changedResource) { Object obj= fResourceToItem.get(changedResource); if (obj == null) { // not mapped } else if (obj instanceof Item) { updateItem((Item) obj); } else { // List of Items List list= (List) obj; for (int k= 0; k < list.size(); k++) { updateItem((Item) list.get(k)); } } } private void updateItem(Item item) { if (!item.isDisposed()) { fContentViewerAccess.doUpdateItem(item); } } /** * Adds a new item to the map. * @param element Element to map * @param item The item used for the element */ public void addToMap(Object element, Item item) { IResource resource= getCorrespondingResource(element); if (resource != null) { Object existingMapping= fResourceToItem.get(resource); if (existingMapping == null) { fResourceToItem.put(resource, item); } else if (existingMapping instanceof Item) { if (existingMapping != item) { List list= getNewList(); list.add(existingMapping); list.add(item); fResourceToItem.put(resource, list); } } else { // List List list= (List) existingMapping; if (!list.contains(item)) { list.add(item); } } } } /** * Removes an element from the map. * @param element The data element * @param item The table or tree item */ public void removeFromMap(Object element, Item item) { IResource resource= getCorrespondingResource(element); if (resource != null) { Object existingMapping= fResourceToItem.get(resource); if (existingMapping == null) { return; } else if (existingMapping instanceof Item) { fResourceToItem.remove(resource); } else { // List List list= (List) existingMapping; list.remove(item); if (list.isEmpty()) { fResourceToItem.remove(list); releaseList(list); } } } } private List getNewList() { if (!fReuseLists.isEmpty()) { return (List) fReuseLists.pop(); } return new ArrayList(2); } private void releaseList(List list) { if (fReuseLists.size() < NUMBER_LIST_REUSE) { fReuseLists.push(list); } } /** * Clears the map. */ public void clearMap() { fResourceToItem.clear(); } /** * Tests if the map is empty * @return Returns if there are mappings */ public boolean isEmpty() { return fResourceToItem.isEmpty(); } /** * Method that decides which elements can have error markers * Returns null if an element can not have error markers. * @param element The input element * @return Returns the corresponding resource or null */ private static IResource getCorrespondingResource(Object element) { if (element instanceof IJavaScriptElement) { IJavaScriptElement elem= (IJavaScriptElement) element; IResource res= elem.getResource(); if (res == null) { IJavaScriptUnit cu= (IJavaScriptUnit) elem.getAncestor(IJavaScriptElement.JAVASCRIPT_UNIT); if (cu != null) { // elements in compilation units are mapped to the underlying resource of the original cu res= cu.getResource(); } } return res; } else if (element instanceof IResource) { return (IResource) element; } return null; } }