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1
4 package com.tc.config.schema.dynamic;
5
6 import com.tc.util.Assert;
7 import com.tc.util.stringification.OurStringBuilder;
8
9
12 public abstract class DerivedConfigItem implements ConfigItem, ConfigItemListener {
13
14 private final ConfigItem[] derivedFrom;
15 private final CompoundConfigItemListener listener;
16
17 private Object  currentValue;
18
19 public DerivedConfigItem(ConfigItem[] derivedFrom) {
20 Assert.assertNoNullElements(derivedFrom);
21 this.derivedFrom = derivedFrom;
22
23 for (int i = 0; i < derivedFrom.length; ++i)
24 derivedFrom[i].addListener(this);
25
26 this.listener = new CompoundConfigItemListener();
27 this.currentValue = createValueFrom(this.derivedFrom);
28 }
29
30 public Object getObject() {
31 return currentValue;
32 }
33
34 protected abstract Object createValueFrom(ConfigItem[] fromWhich);
35
36 public void addListener(ConfigItemListener changeListener) {
37 this.listener.addListener(changeListener);
38 }
39
40 public void removeListener(ConfigItemListener changeListener) {
41 this.listener.removeListener(changeListener);
42 }
43
44 public void valueChanged(Object oldValue, Object newValue) {
45 Object ourOldValue = currentValue;
46 this.currentValue = createValueFrom(this.derivedFrom);
47
48 if (((ourOldValue == null) != (this.currentValue == null))
49 || ((ourOldValue != null) && (!ourOldValue.equals(this.currentValue)))) {
50 this.listener.valueChanged(ourOldValue, this.currentValue);
51 }
52 }
53
54 public String toString() {
55 return new OurStringBuilder(this, OurStringBuilder.COMPACT_STYLE).append("derived from", this.derivedFrom)
56 .toString();
57 }
58
59 }
60 |
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