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1
11 package org.eclipse.jdt.internal.ui.javaeditor.selectionactions;
12
13 import java.util.ArrayList  ;
14 import java.util.List ;
15
16 import org.eclipse.core.runtime.Assert;
17
18 import org.eclipse.jface.viewers.ISelectionChangedListener;
19 import org.eclipse.jface.viewers.SelectionChangedEvent;
20
21 import org.eclipse.jdt.core.ISourceRange;
22
23 import org.eclipse.jdt.internal.ui.javaeditor.JavaEditor;
24
25 public class SelectionHistory {
26
27 private List fHistory;
28 private JavaEditor fEditor;
29 private ISelectionChangedListener fSelectionListener;
30 private int fSelectionChangeListenerCounter;
31 private StructureSelectHistoryAction fHistoryAction;
32
33 public SelectionHistory(JavaEditor editor) {
34 Assert.isNotNull(editor);
35 fEditor= editor;
36 fHistory= new ArrayList (3);
37 fSelectionListener= new ISelectionChangedListener() {
38 public void selectionChanged(SelectionChangedEvent event) {
39 if (fSelectionChangeListenerCounter == 0)
40 flush();
41 }
42 };
43 fEditor.getSelectionProvider().addSelectionChangedListener(fSelectionListener);
44 }
45
46 public void setHistoryAction(StructureSelectHistoryAction action) {
47 Assert.isNotNull(action);
48 fHistoryAction= action;
49 }
50
51 public boolean isEmpty() {
52 return fHistory.isEmpty();
53 }
54
55 public void remember(ISourceRange range) {
56 fHistory.add(range);
57 fHistoryAction.update();
58 }
59
60 public ISourceRange getLast() {
61 if (isEmpty())
62 return null;
63 int size= fHistory.size();
64 ISourceRange result= (ISourceRange)fHistory.remove(size - 1);
65 fHistoryAction.update();
66 return result;
67 }
68
69 public void flush() {
70 if (fHistory.isEmpty())
71 return;
72 fHistory.clear();
73 fHistoryAction.update();
74 }
75
76 public void ignoreSelectionChanges() {
77 fSelectionChangeListenerCounter++;
78 }
79
80 public void listenToSelectionChanges() {
81 fSelectionChangeListenerCounter--;
82 }
83
84 public void dispose() {
85 fEditor.getSelectionProvider().removeSelectionChangedListener(fSelectionListener);
86 }
87 }
88 |
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