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1
11 package org.eclipse.jdt.internal.ui.viewsupport;
12
13 import java.util.HashMap  ;
14 import java.util.Map ;
15
16 import org.eclipse.core.runtime.IProgressMonitor;
17 import org.eclipse.core.runtime.IStatus;
18 import org.eclipse.core.runtime.ListenerList;
19 import org.eclipse.core.runtime.NullProgressMonitor;
20 import org.eclipse.core.runtime.OperationCanceledException;
21 import org.eclipse.core.runtime.Status;
22 import org.eclipse.core.runtime.jobs.Job;
23
24 import org.eclipse.jface.viewers.ISelection;
25 import org.eclipse.jface.viewers.ISelectionChangedListener;
26 import org.eclipse.jface.viewers.ISelectionProvider;
27 import org.eclipse.jface.viewers.SelectionChangedEvent;
28
29 import org.eclipse.jface.text.ITextSelection;
30
31 import org.eclipse.ui.ISelectionListener;
32 import org.eclipse.ui.IWorkbenchPart;
33 import org.eclipse.ui.texteditor.ITextEditor;
34
35 import org.eclipse.jdt.core.IJavaElement;
36 import org.eclipse.jdt.core.dom.CompilationUnit;
37
38 import org.eclipse.jdt.internal.ui.JavaPlugin;
39 import org.eclipse.jdt.internal.ui.JavaUIMessages;
40 import org.eclipse.jdt.internal.ui.javaeditor.ASTProvider;
41 import org.eclipse.jdt.internal.ui.javaeditor.EditorUtility;
42
43
46 public class SelectionListenerWithASTManager {
47
48 private static SelectionListenerWithASTManager fgDefault;
49
50
53 public static SelectionListenerWithASTManager getDefault() {
54 if (fgDefault == null) {
55 fgDefault= new SelectionListenerWithASTManager();
56 }
57 return fgDefault;
58 }
59
60
61 private final static class PartListenerGroup {
62 private ITextEditor fPart;
63 private ISelectionListener fPostSelectionListener;
64 private ISelectionChangedListener fSelectionListener;
65 private Job fCurrentJob;
66 private ListenerList fAstListeners;
67
71 private final Object fJobLock= new Object ();
72
73 public PartListenerGroup(ITextEditor editorPart) {
74 fPart= editorPart;
75 fCurrentJob= null;
76 fAstListeners= new ListenerList(ListenerList.IDENTITY);
77
78 fSelectionListener= new ISelectionChangedListener() {
79 public void selectionChanged(SelectionChangedEvent event) {
80 ISelection selection= event.getSelection();
81 if (selection instanceof ITextSelection) {
82 fireSelectionChanged((ITextSelection) selection);
83 }
84 }
85 };
86
87 fPostSelectionListener= new ISelectionListener() {
88 public void selectionChanged(IWorkbenchPart part, ISelection selection) {
89 if (part == fPart && selection instanceof ITextSelection)
90 firePostSelectionChanged((ITextSelection) selection);
91 }
92 };
93 }
94
95 public boolean isEmpty() {
96 return fAstListeners.isEmpty();
97 }
98
99 public void install(ISelectionListenerWithAST listener) {
100 if (isEmpty()) {
101 fPart.getEditorSite().getPage().addPostSelectionListener(fPostSelectionListener);
102 ISelectionProvider selectionProvider= fPart.getSelectionProvider();
103 if (selectionProvider != null)
104 selectionProvider.addSelectionChangedListener(fSelectionListener);
105 }
106 fAstListeners.add(listener);
107 }
108
109 public void uninstall(ISelectionListenerWithAST listener) {
110 fAstListeners.remove(listener);
111 if (isEmpty()) {
112 fPart.getEditorSite().getPage().removePostSelectionListener(fPostSelectionListener);
113 ISelectionProvider selectionProvider= fPart.getSelectionProvider();
114 if (selectionProvider != null)
115 selectionProvider.removeSelectionChangedListener(fSelectionListener);
116 }
117 }
118
119 public void fireSelectionChanged(final ITextSelection selection) {
120 if (fCurrentJob != null) {
121 fCurrentJob.cancel();
122 }
123 }
124
125 public void firePostSelectionChanged(final ITextSelection selection) {
126 if (fCurrentJob != null) {
127 fCurrentJob.cancel();
128 }
129 final IJavaElement input= EditorUtility.getEditorInputJavaElement(fPart, false);
130 if (input == null) {
131 return;
132 }
133
134 fCurrentJob= new Job(JavaUIMessages.SelectionListenerWithASTManager_job_title) {
135 public IStatus run(IProgressMonitor monitor) {
136 if (monitor == null) {
137 monitor= new NullProgressMonitor();
138 }
139 synchronized (fJobLock) {
140 return calculateASTandInform(input, selection, monitor);
141 }
142 }
143 };
144 fCurrentJob.setPriority(Job.DECORATE);
145 fCurrentJob.setSystem(true);
146 fCurrentJob.schedule();
147 }
148
149 protected IStatus calculateASTandInform(IJavaElement input, ITextSelection selection, IProgressMonitor monitor) {
150 if (monitor.isCanceled()) {
151 return Status.CANCEL_STATUS;
152 }
153 try {
155 CompilationUnit astRoot= JavaPlugin.getDefault().getASTProvider().getAST(input, ASTProvider.WAIT_ACTIVE_ONLY, monitor);
156
157 if (astRoot != null && !monitor.isCanceled()) {
158 Object [] listeners;
159 synchronized (PartListenerGroup.this) {
160 listeners= fAstListeners.getListeners();
161 }
162 for (int i= 0; i < listeners.length; i++) {
163 ((ISelectionListenerWithAST) listeners[i]).selectionChanged(fPart, selection, astRoot);
164 if (monitor.isCanceled()) {
165 return Status.CANCEL_STATUS;
166 }
167 }
168 return Status.OK_STATUS;
169 }
170 } catch (OperationCanceledException e) {
171 }
173 return Status.CANCEL_STATUS;
174 }
175 }
176
177
178 private Map fListenerGroups;
179
180 private SelectionListenerWithASTManager() {
181 fListenerGroups= new HashMap ();
182 }
183
184
189 public void addListener(ITextEditor part, ISelectionListenerWithAST listener) {
190 synchronized (this) {
191 PartListenerGroup partListener= (PartListenerGroup) fListenerGroups.get(part);
192 if (partListener == null) {
193 partListener= new PartListenerGroup(part);
194 fListenerGroups.put(part, partListener);
195 }
196 partListener.install(listener);
197 }
198 }
199
200
205 public void removeListener(ITextEditor part, ISelectionListenerWithAST listener) {
206 synchronized (this) {
207 PartListenerGroup partListener= (PartListenerGroup) fListenerGroups.get(part);
208 if (partListener != null) {
209 partListener.uninstall(listener);
210 if (partListener.isEmpty()) {
211 fListenerGroups.remove(part);
212 }
213 }
214 }
215 }
216 }
217 |
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