6.9 eclipse资源改变通知机制
添加和移除监听器：
1 IWorkspace workspace = ResourcesPlugin.getWorkspace(); 2 IResourceChangeListener listener = new IResourceChangeListener() { 3 public void resourceChanged(IResourceChangeEvent event) { 4 System.out.println("Something changed!"); 5 } 6 }; 7 workspace.addResourceChangeListener(listener); 8 9 //... some time later one ... 10 workspace.removeResourceChangeListener(listener);
IResourceChangeEvent：
Event Type
PRE_CHANGE,POST_CHANGE,PRE_BUILD,POST_BUILD,PRE_CLOSE,POST_CLOSE,PRE_DELETE,POST_DELETE
IresourceDelta
IresourceDelta.getKind()
IResourceDelta.ADDED
IResourceDelta.REMOVED
IResourceDelta.CHANGED
IresourceDelta.getFlags()
IResourceDelta.CONTENT
IResourceDelta.REPLACED
IResourceDelta.REMOVED
IResourceDelta.MOVED_FROM
IresourceDelta.getMovedFromPath()
IResourceDelta.MOVED_TO
IresourceDelta.getMovedToPath()
IResourceDelta.MARKERS
（IMarkerDelta[] markers = delta.getMarkerDeltas()）
使用IResourceDelta.findMember(IPath)可以快速定位到我们关注的IresourceDelta,而不必按树状结构依次向下通知。IresourceDelta.accept(IResourceDeltaVistor)来访问我们关心的ResourceDeltaVistor树的分支。
Sample：
1 public class DocIndexUpdater implements IResourceChangeListener {
2 private TableViewer table; //assume this gets initialized somewhere
3 private static final IPath DOC_PATH = new Path("MyProject/doc");
4 public void resourceChanged(IResourceChangeEvent event) {
5 //we are only interested in POST_CHANGE events
6 if (event.getType() != IResourceChangeEvent.POST_CHANGE)
7 return;
8 IResourceDelta rootDelta = event.getDelta();
9 //get the delta, if any, for the documentation directory
10 IResourceDelta docDelta = rootDelta.findMember(DOC_PATH);
11 if (docDelta == null)
12 return;
13 final ArrayList changed = new ArrayList();
14 IResourceDeltaVisitor visitor = new IResourceDeltaVisitor() {
15 public boolean visit(IResourceDelta delta) {
16 //only interested in changed resources (not added or removed)
17 if (delta.getKind() != IResourceDelta.CHANGED)
18 return true;
19 //only interested in content changes
20 if ((delta.getFlags() & IResourceDelta.CONTENT) == 0)
21 return true;
22 IResource resource = delta.getResource();
23 //only interested in files with the "txt" extension
24 if (resource.getType() == IResource.FILE &&
25 "txt".equalsIgnoreCase(resource.getFileExtension())) {
26 changed.add(resource);
27 }
28 return true;
29 }
30 };
31 try {
32 docDelta.accept(visitor);
33 } catch (CoreException e) {
34 //open error dialog with syncExec or print to plugin log file
35 }
36 //nothing more to do if there were no changed text files
37 if (changed.size() == 0)
38 return;
39 //post this update to the table
40 Display display = table.getControl().getDisplay();
41 if (!display.isDisposed()) {
42 display.asyncExec(new Runnable() {
43 public void run() {
44 //make sure the table still exists
45 if (table.getControl().isDisposed())
46 return;
47 table.update(changed.toArray(), null);
48 }
49 });
50 }
51 }
52 }
