|
1
11 package org.eclipse.jface.internal.databinding.provisional.viewers;
12
13 import java.util.Collections  ;
14 import java.util.HashSet ;
15 import java.util.Set ;
16
17 import org.eclipse.jface.internal.databinding.provisional.observable.Diffs;
18 import org.eclipse.jface.internal.databinding.provisional.observable.IObservable;
19 import org.eclipse.jface.internal.databinding.provisional.observable.IStaleListener;
20 import org.eclipse.jface.internal.databinding.provisional.observable.set.IObservableSet;
21 import org.eclipse.jface.internal.databinding.provisional.observable.set.ISetChangeListener;
22 import org.eclipse.jface.internal.databinding.provisional.observable.set.ObservableSet;
23 import org.eclipse.jface.internal.databinding.provisional.observable.set.SetDiff;
24 import org.eclipse.jface.viewers.AbstractListViewer;
25 import org.eclipse.jface.viewers.IStructuredContentProvider;
26 import org.eclipse.jface.viewers.TableViewer;
27 import org.eclipse.jface.viewers.Viewer;
28
29
33 public final class ObservableSetContentProvider implements
34 IStructuredContentProvider {
35
36 private class KnownElementsSet extends ObservableSet {
37
38 KnownElementsSet(Set wrappedSet) {
39 super(wrappedSet, Object .class);
40 }
41
42 void doFireDiff(Set added, Set removed) {
43 fireSetChange(Diffs.createSetDiff(added, removed));
44 }
45
46 void doFireStale(boolean isStale) {
47 if (isStale) {
48 fireStale();
49 } else {
50 fireChange();
51 }
52 }
53 }
54
55 private IObservableSet readableSet = new ObservableSet(
56 Collections.EMPTY_SET, Object .class) {
57 };
58
59 private Viewer viewer;
60
61
66 private KnownElementsSet knownElements = new KnownElementsSet(readableSet);
67
68 private ISetChangeListener listener = new ISetChangeListener() {
69
70 public void handleSetChange(IObservableSet source, SetDiff diff) {
71 boolean wasStale = knownElements.isStale();
72 if (isDisposed()) {
73 return;
74 }
75 doDiff(diff.getAdditions(), diff.getRemovals(), true);
76 if (!wasStale && source.isStale()) {
77 knownElements.doFireStale(true);
78 }
79 }
80 };
81
82 private IStaleListener staleListener = new IStaleListener() {
83 public void handleStale(IObservable source) {
84 knownElements.doFireStale(source.isStale());
85 }
86 };
87
88
91 public ObservableSetContentProvider() {
92 }
93
94 public void dispose() {
95 setInput(null);
96 }
97
98 private void doDiff(Set added, Set removed, boolean updateViewer) {
99 knownElements.doFireDiff(added, Collections.EMPTY_SET);
100
101 if (updateViewer) {
102 Object [] toAdd = added.toArray();
103 if (viewer instanceof TableViewer) {
104 TableViewer tv = (TableViewer) viewer;
105 tv.add(toAdd);
106 } else if (viewer instanceof AbstractListViewer) {
107 AbstractListViewer lv = (AbstractListViewer) viewer;
108 lv.add(toAdd);
109 }
110 Object [] toRemove = removed.toArray();
111 if (viewer instanceof TableViewer) {
112 TableViewer tv = (TableViewer) viewer;
113 tv.remove(toRemove);
114 } else if (viewer instanceof AbstractListViewer) {
115 AbstractListViewer lv = (AbstractListViewer) viewer;
116 lv.remove(toRemove);
117 }
118 }
119 knownElements.doFireDiff(Collections.EMPTY_SET, removed);
120 }
121
122 public Object [] getElements(Object inputElement) {
123 return readableSet.toArray();
124 }
125
126
135 public IObservableSet getKnownElements() {
136 return knownElements;
137 }
138
139 public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
140 this.viewer = viewer;
141
142 if (!(viewer instanceof TableViewer || viewer instanceof AbstractListViewer)) {
143 throw new IllegalArgumentException (
144 "This content provider only works with TableViewer or AbstractListViewer"); }
146
147 if (newInput != null && !(newInput instanceof IObservableSet)) {
148 throw new IllegalArgumentException (
149 "This content provider only works with input of type IReadableSet"); }
151
152 setInput((IObservableSet) newInput);
153 }
154
155 private boolean isDisposed() {
156 return viewer.getControl() == null || viewer.getControl().isDisposed();
157 }
158
159 private void setInput(IObservableSet newSet) {
160 boolean updateViewer = true;
161 if (newSet == null) {
162 newSet = new ObservableSet(Collections.EMPTY_SET, Object .class) {
163 };
164 updateViewer = false;
166 }
167
168 boolean wasStale = false;
169 if (readableSet != null) {
170 wasStale = readableSet.isStale();
171 readableSet.removeSetChangeListener(listener);
172 readableSet.removeStaleListener(staleListener);
173 }
174
175 HashSet additions = new HashSet ();
176 HashSet removals = new HashSet ();
177
178 additions.addAll(newSet);
179 additions.removeAll(readableSet);
180
181 removals.addAll(readableSet);
182 removals.removeAll(newSet);
183
184 readableSet = newSet;
185
186 doDiff(additions, removals, updateViewer);
187
188 if (readableSet != null) {
189 readableSet.addSetChangeListener(listener);
190 readableSet.addStaleListener(staleListener);
191 }
192
193 boolean isStale = (readableSet != null && readableSet.isStale());
194 if (isStale != wasStale) {
195 knownElements.doFireStale(isStale);
196 }
197 }
198
199 }
200 |
Popular Tags |
Java API By Example, From Geeks To Geeks.