[12267] | 1 | // License: GPL. For details, see LICENSE file.
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| 2 | package org.openstreetmap.josm.tools;
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| 3 |
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| 4 | import java.util.AbstractCollection;
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| 5 | import java.util.Iterator;
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[12269] | 6 | import java.util.List;
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[12267] | 7 |
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| 8 | /**
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| 9 | * This is a proxy of a collection that notifies a listener on every collection change
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| 10 | * @author Michael Zangl
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| 11 | *
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| 12 | * @param <T> The entry type
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| 13 | * @since 12267 (extracted from GpxData)
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| 14 | * @since 12156
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| 15 | */
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| 16 | public class ListeningCollection<T> extends AbstractCollection<T> {
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[12269] | 17 | private final List<T> base;
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[12267] | 18 | private final Runnable runOnModification;
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| 19 |
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| 20 | /**
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| 21 | * Constructs a new {@code ListeningCollection}.
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| 22 | * @param base base collection
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| 23 | * @param runOnModification runnable run at each modification
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[12269] | 24 | * @since 12269
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[12267] | 25 | */
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[12269] | 26 | public ListeningCollection(List<T> base, Runnable runOnModification) {
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[12267] | 27 | this.base = base;
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| 28 | this.runOnModification = runOnModification;
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| 29 | }
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| 30 |
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| 31 | @Override
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| 32 | public final Iterator<T> iterator() {
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| 33 | Iterator<T> it = base.iterator();
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| 34 | return new Iterator<T>() {
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| 35 | private T object;
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| 36 |
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| 37 | @Override
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| 38 | public boolean hasNext() {
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| 39 | return it.hasNext();
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| 40 | }
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| 41 |
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| 42 | @Override
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| 43 | public T next() {
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| 44 | object = it.next();
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| 45 | return object;
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| 46 | }
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| 47 |
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| 48 | @Override
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| 49 | public void remove() {
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| 50 | if (object != null) {
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| 51 | removed(object);
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| 52 | object = null;
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| 53 | }
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| 54 | it.remove();
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| 55 | }
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| 56 | };
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| 57 | }
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| 58 |
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| 59 | @Override
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| 60 | public final int size() {
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| 61 | return base.size();
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| 62 | }
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| 63 |
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| 64 | @Override
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| 65 | @SuppressWarnings("unchecked")
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| 66 | public final boolean remove(Object o) {
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| 67 | boolean remove = base.remove(o);
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| 68 | if (remove) {
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| 69 | removed((T) o);
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| 70 | }
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| 71 | return remove;
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| 72 | }
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| 73 |
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| 74 | @Override
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| 75 | public final boolean add(T e) {
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| 76 | boolean add = base.add(e);
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| 77 | added(e);
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| 78 | return add;
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| 79 | }
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| 80 |
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| 81 | /**
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| 82 | * Called when an object is removed.
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| 83 | * @param object the removed object
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| 84 | */
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| 85 | protected void removed(T object) {
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| 86 | runOnModification.run();
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| 87 | }
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| 88 |
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| 89 | /**
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| 90 | * Called when an object is added.
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| 91 | * @param object the added object
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| 92 | */
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| 93 | protected void added(T object) {
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| 94 | runOnModification.run();
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| 95 | }
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| 96 | }
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