net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/ui/viewsupport/ResourceToItemsMapper.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2004 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package net.sourceforge.phpdt.internal.ui.viewsupport;
  12
  13 import java.util.ArrayList;
  14 import java.util.HashMap;
  15 import java.util.List;
  16 import java.util.Stack;
  17
  18 import org.eclipse.core.resources.IResource;
  19
  20 import org.eclipse.swt.graphics.Image;
  21 import org.eclipse.swt.widgets.Item;
  22
  23 import org.eclipse.jface.viewers.ContentViewer;
  24 import org.eclipse.jface.viewers.ILabelProvider;
  25 import org.eclipse.jface.viewers.IViewerLabelProvider;
  26 import org.eclipse.jface.viewers.ViewerLabel;
  27
  28 import net.sourceforge.phpdt.core.ICompilationUnit;
  29 import net.sourceforge.phpdt.core.IJavaElement;
  30
  31 /**
  32  * Helper class for updating error markers and other decorators that work on resources.
  33  * Items are mapped to their element's underlying resource.
  34  * Method <code>resourceChanged</code> updates all items that are affected from the changed
  35  * elements.
  36  */
  37 public class ResourceToItemsMapper {
  38
  39         private static final int NUMBER_LIST_REUSE= 10;
  40
  41         // map from resource to item
  42         private HashMap fResourceToItem;
  43         private Stack fReuseLists;
  44
  45         private ContentViewer fContentViewer;
  46
  47         public ResourceToItemsMapper(ContentViewer viewer) {
  48                 fResourceToItem= new HashMap();
  49                 fReuseLists= new Stack();
  50
  51                 fContentViewer= viewer;
  52         }
  53
  54         /**
  55          * Must be called from the UI thread.
  56          */
  57         public void resourceChanged(IResource changedResource) {
  58                 Object obj= fResourceToItem.get(changedResource);
  59                 if (obj == null) {
  60                         // not mapped
  61                 } else if (obj instanceof Item) {
  62                         updateItem((Item) obj);
  63                 } else { // List of Items
  64                         List list= (List) obj;
  65                         for (int k= 0; k < list.size(); k++) {
  66                                 updateItem((Item) list.get(k));
  67                         }
  68                 }
  69         }
  70
  71         private void updateItem(Item item) {
  72                 if (!item.isDisposed()) { // defensive code
  73                         ILabelProvider lprovider= (ILabelProvider) fContentViewer.getLabelProvider();
  74
  75                         Object data= item.getData();
  76
  77                         // If it is an IItemLabelProvider than short circuit: patch Tod (bug 55012)
  78                         if (lprovider instanceof IViewerLabelProvider) {
  79                                 IViewerLabelProvider provider= (IViewerLabelProvider) lprovider;
  80
  81                                 ViewerLabel updateLabel= new ViewerLabel(item.getText(), item.getImage());
  82                                 provider.updateLabel(updateLabel, data);
  83
  84                                 if (updateLabel.hasNewImage()) {
  85                                         item.setImage(updateLabel.getImage());
  86                                 }
  87                                 if (updateLabel.hasNewText()) {
  88                                         item.setText(updateLabel.getText());
  89                                 }
  90                         } else {
  91                                 Image oldImage= item.getImage();
  92                                 Image image= lprovider.getImage(data);
  93                                 if (image != null && !image.equals(oldImage)) {
  94                                         item.setImage(image);
  95                                 }
  96                                 String oldText= item.getText();
  97                                 String text= lprovider.getText(data);
  98                                 if (text != null && !text.equals(oldText)) {
  99                                         item.setText(text);
 100                                 }
 101                         }
 102                 }
 103         }
 104
 105         /**
 106          * Adds a new item to the map.
 107          * @param element Element to map
 108          * @param item The item used for the element
 109          */
 110         public void addToMap(Object element, Item item) {
 111                 IResource resource= getCorrespondingResource(element);
 112                 if (resource != null) {
 113                         Object existingMapping= fResourceToItem.get(resource);
 114                         if (existingMapping == null) {
 115                                 fResourceToItem.put(resource, item);
 116                         } else if (existingMapping instanceof Item) {
 117                                 if (existingMapping != item) {
 118                                         List list= getNewList();
 119                                         list.add(existingMapping);
 120                                         list.add(item);
 121                                         fResourceToItem.put(resource, list);
 122                                 }
 123                         } else { // List
 124                                 List list= (List) existingMapping;
 125                                 if (!list.contains(item)) {
 126                                         list.add(item);
 127                                 }
 128                         }
 129                 }
 130         }
 131
 132         /**
 133          * Removes an element from the map.
 134          */
 135         public void removeFromMap(Object element, Item item) {
 136                 IResource resource= getCorrespondingResource(element);
 137                 if (resource != null) {
 138                         Object existingMapping= fResourceToItem.get(resource);
 139                         if (existingMapping == null) {
 140                                 return;
 141                         } else if (existingMapping instanceof Item) {
 142                                 fResourceToItem.remove(resource);
 143                         } else { // List
 144                                 List list= (List) existingMapping;
 145                                 list.remove(item);
 146                                 if (list.isEmpty()) {
 147                                         fResourceToItem.remove(list);
 148                                         releaseList(list);
 149                                 }
 150                         }
 151                 }
 152         }
 153
 154         private List getNewList() {
 155                 if (!fReuseLists.isEmpty()) {
 156                         return (List) fReuseLists.pop();
 157                 }
 158                 return new ArrayList(2);
 159         }
 160
 161         private void releaseList(List list) {
 162                 if (fReuseLists.size() < NUMBER_LIST_REUSE) {
 163                         fReuseLists.push(list);
 164                 }
 165         }
 166
 167         /**
 168          * Clears the map.
 169          */
 170         public void clearMap() {
 171                 fResourceToItem.clear();
 172         }
 173
 174         /**
 175          * Tests if the map is empty
 176          */
 177         public boolean isEmpty() {
 178                 return fResourceToItem.isEmpty();
 179         }
 180
 181         /**
 182          * Method that decides which elements can have error markers
 183          * Returns null if an element can not have error markers.
 184          */
 185         private static IResource getCorrespondingResource(Object element) {
 186                 if (element instanceof IJavaElement) {
 187                         IJavaElement elem= (IJavaElement) element;
 188                         if (!elem.isReadOnly()) { // only modifieable elements can get error ticks
 189                                 IResource res= elem.getResource();
 190                                 if (res == null) {
 191                                         ICompilationUnit cu= (ICompilationUnit) elem.getAncestor(IJavaElement.COMPILATION_UNIT);
 192                                         if (cu != null) {
 193                                                 // elements in compilation units are mapped to the underlying resource of the original cu
 194                                                 res= cu.getResource();
 195                                         }
 196                                 }
 197                                 return res;
 198                         }
 199                         return null;
 200                 } else if (element instanceof IResource) {
 201                         return (IResource) element;
 202                 }
 203                 return null;
 204         }
 205
 206 }