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13 package com.tonbeller.wcf.tree;
14
15 import java.text.MessageFormat  ;
16 import java.util.Comparator ;
17 import java.util.HashMap ;
18 import java.util.Locale ;
19 import java.util.Map ;
20 import java.util.TreeMap ;
21
22 import com.tonbeller.tbutils.res.Resources;
23 import com.tonbeller.wcf.controller.RequestContext;
24 import com.tonbeller.wcf.selection.Unselectable;
25
26
38 public class GroupingTreeModelDecorator extends TreeModelDecorator {
39
40 private int limit;
41 private LabelProvider labelProvider;
42 private Map mapChild2Parent;
43 private Map mapParent2Children;
44 private MessageFormat format;
45 private static final Object NULL = new Object ();
46
47
54 public GroupingTreeModelDecorator(LabelProvider labelProvider, TreeModel decoree, int limit) {
55 super(decoree);
56 this.mapChild2Parent = new HashMap ();
57 this.mapParent2Children = new HashMap ();
58 initialize(labelProvider, limit);
59 }
60
61
69 public GroupingTreeModelDecorator(Comparator nodeComparator, LabelProvider labelProvider,
70 TreeModel decoree, int limit) {
71 super(decoree);
72 Comparator comp = new GroupComparator(nodeComparator);
73 this.mapChild2Parent = new TreeMap (comp);
74 this.mapParent2Children = new TreeMap (comp);
75 initialize(labelProvider, limit);
76 }
77
78 class GroupComparator implements Comparator {
79 Comparator nodeComparator;
80
81 public GroupComparator(Comparator nodeComparator) {
82 this.nodeComparator = nodeComparator;
83 }
84
85 public int compare(Object o1, Object o2) {
86
87 if (o1 == NULL && o2 == NULL)
89 return 0;
90 else if (o1 == NULL)
91 return -1;
92 else if (o2 == NULL)
93 return 1;
94
95 if (o1 instanceof Group) {
97 if (o2 instanceof Group)
98 return ((Group) o1).compareTo(o2);
99 return 1;
100 } else if (o2 instanceof Group)
101 return -1;
102
103 return nodeComparator.compare(o1, o2);
105 }
106 };
107
108 TreeModelChangeListener listener = new TreeModelChangeListener() {
109 public void treeModelChanged(TreeModelChangeEvent event) {
110 if (event.getSubtree() != null) {
111 invalidateSubtree(event.getSubtree());
112 } else {
113 mapChild2Parent.clear();
114 mapParent2Children.clear();
115 }
116 }
117
118 };
119
120 private void invalidateSubtree(Object parent) {
121 Object [] children = (Object []) mapParent2Children.remove(parent);
122 if (children != null) {
123 for (int i = 0; i < children.length; i++) {
124 mapChild2Parent.remove(children[i]);
125 invalidateSubtree(children[i]);
126 }
127 }
128 }
129
130 private void initialize(LabelProvider labelProvider, int limit) {
131 this.limit = limit;
132 this.labelProvider = labelProvider;
133 super.getDecoree().addTreeModelChangeListener(listener);
134
135 RequestContext ctx = RequestContext.instance(false);
137 if (ctx != null) {
138 Resources res = ctx.getResources(GroupingTreeModelDecorator.class);
139 String fmt = res.getString("tree.group.label");
140 Locale loc = res.getLocale();
141 this.format = new MessageFormat (fmt, loc);
142 } else {
143
144 this.format = new MessageFormat ("{0} ...");
145 }
146 }
147
148 public class Group implements Unselectable, Comparable {
149
150 String label;
151
152 public Group(String label) {
153 this.label = label;
154 }
155
156 public Group(Object [] children) {
157 Object [] args = new Object [2];
158 args[0] = labelProvider.getLabel(children[0]);
159 args[1] = labelProvider.getLabel(children[children.length - 1]);
160 label = format.format(args, new StringBuffer (), null).toString();
161 }
162
163 public String toString() {
164 return label;
165 }
166
167 public int compareTo(Object o) {
168 Group g = (Group) o;
169 return label.compareTo(g.label);
170 }
171 }
172
173 private void updateCache(Object parent, Object [] children) {
174 if (parent == null)
175 parent = NULL;
176 mapParent2Children.put(parent, children);
177 for (int i = 0; i < children.length; i++)
178 mapChild2Parent.put(children[i], parent);
179 }
180
181 Object [] group(Object parent, Object [] children) {
182 if (limit <= 0 || children.length <= limit) {
184 updateCache(parent, children);
185 return children;
186 }
187 int groupCount = (children.length + limit - 1) / limit;
189 Group[] groups = new Group[groupCount];
190 for (int i = 0; i < groupCount; i++) {
191 int fromIndex = i * limit;
193 int toIndex = (i + 1) * limit;
194 if (toIndex > children.length)
195 toIndex = children.length;
196 int count = toIndex - fromIndex;
197 Object [] arr = new Object [count];
199 System.arraycopy(children, fromIndex, arr, 0, count);
200 groups[i] = new Group(arr);
201 updateCache(groups[i], arr);
202 }
203 updateCache(parent, groups);
204 return group(parent, groups);
205 }
206
207 public Object [] getRoots() {
208 Object [] roots = (Object []) mapParent2Children.get(NULL);
209 if (roots != null)
210 return roots;
211 return group(NULL, super.getRoots());
212 }
213
214 public boolean hasChildren(Object node) {
215 return node instanceof Group || super.hasChildren(node);
216 }
217
218 public Object [] getChildren(Object node) {
219 Object [] children = (Object []) mapParent2Children.get(node);
220 if (children != null)
221 return children;
222 return group(node, super.getChildren(node));
223 }
224
225 public Object getParent(Object node) {
226 Object parent = mapChild2Parent.get(node);
227 if (parent == null) {
228 parent = super.getParent(node);
229 Object [] children;
230 if (parent == null)
231 children = super.getRoots();
232 else
233 children = super.getChildren(parent);
234 group(parent, children);
235 }
236 parent = mapChild2Parent.get(node);
238 return parent == NULL ? null : parent;
239 }
240
241 public int getLimit() {
242 return limit;
243 }
244
245 public void setLimit(int limit) {
246 this.limit = limit;
247 fireModelChanged(false);
248 }
249 } |
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