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