Examples

import com.irurueta.hermes.CollectionItemChangeAction;
import com.irurueta.hermes.CollectionItemChangeDetector;
import com.irurueta.hermes.UpdatedCollectionItemChange;

import java.util.List;

record User(long id, String displayName, boolean active) { }

var oldUsers = List.of(
        new User(1, "Ada", true),
        new User(2, "Grace", true));

var newUsers = List.of(
        new User(1, "Ada Lovelace", true),
        new User(2, "Grace", true));

var detector = new CollectionItemChangeDetector<User>(
        (left, right) -> left.id() == right.id(),
        (left, right) -> left.displayName().equals(right.displayName())
                && left.active() == right.active());

var changes = detector.detectChanges(newUsers, oldUsers);

for (var change : changes) {
    if (change.getAction() == CollectionItemChangeAction.UPDATED) {
        var updated = (UpdatedCollectionItemChange<User>) change;
        System.out.println(updated.getOldItem() + " -> " + updated.getNewItem());
    }
}

import com.irurueta.hermes.InsertedListItemChange;
import com.irurueta.hermes.ListItemChange;
import com.irurueta.hermes.MovedListItemChange;
import com.irurueta.hermes.RemovedListItemChange;
import com.irurueta.hermes.SequentialListItemChangeDetector;
import com.irurueta.hermes.UpdatedListItemChange;

import java.util.ArrayList;
import java.util.List;

record Row(String id, String label) { }

var oldRows = List.of(
        new Row("a", "Alpha"),
        new Row("b", "Beta"),
        new Row("c", "Gamma"));

var newRows = List.of(
        new Row("c", "Gamma"),
        new Row("b", "Beta v2"),
        new Row("d", "Delta"));

var detector = new SequentialListItemChangeDetector<Row>(
        (left, right) -> left.id().equals(right.id()),
        (left, right) -> left.label().equals(right.label()));

var changes = detector.detectChanges(newRows, oldRows);
var working = new ArrayList<>(oldRows);

for (ListItemChange change : changes) {
    switch (change.getAction()) {
        case REMOVED -> {
            var removed = (RemovedListItemChange<Row>) change;
            working.remove(removed.getOldPosition());
        }
        case INSERTED -> {
            var inserted = (InsertedListItemChange<Row>) change;
            working.add(inserted.getNewPosition(), inserted.getNewItem());
        }
        case MOVED -> {
            var moved = (MovedListItemChange<Row>) change;
            var row = working.remove(moved.getOldPosition());
            working.add(moved.getNewPosition(), row);
        }
        case UPDATED -> {
            var updated = (UpdatedListItemChange<Row>) change;
            working.set(updated.getPosition(), updated.getNewItem());
        }
    }
}

import com.irurueta.hermes.ComparableItem;
import com.irurueta.hermes.ComparableCollectionItemChangeDetector;

record Account(String number, String owner, String status)
        implements ComparableItem<Account> {

    @Override
    public boolean equals(Object other) {
        return other instanceof Account account
                && number.equals(account.number);
    }

    @Override
    public int hashCode() {
        return number.hashCode();
    }

    @Override
    public boolean equalContent(Account other) {
        return owner.equals(other.owner) && status.equals(other.status);
    }
}

var detector = new ComparableCollectionItemChangeDetector<Account>();
var changes = detector.detectChanges(newAccounts, oldAccounts);