Examples with AbstractListChange com.vaadin.flow.internal.change.AbstractListChange used on opensource projects

Example 1 with AbstractListChange

use of com.vaadin.flow.internal.change.AbstractListChange in project flow by vaadin.

the class NodeList method collectChanges.

@Override
public void collectChanges(Consumer<NodeChange> collector) {
    // This map contains items wrapped by AbstractListChanges as keys and
    // index in the following allChanges list as a value (it allows to get
    // AbstractListChange by the index)
    Map<Object, Integer> indices = new IdentityHashMap<>();
    // This list contains all changes in the tracker. These changes will be
    // modified: each "remove" change following by a corresponding "add"
    // will be replaced by null and "add" will be adjusted. Indeces in
    // changes in between will be adjusted
    List<AbstractListChange<T>> allChanges = new ArrayList<>();
    int index = 0;
    for (AbstractListChange<T> change : getChangeTracker()) {
        if (change instanceof ListRemoveChange<?>) {
            // the remove change => find an appropriate "add" event, adjust
            // it and adjust everything in between
            adjustChanges(index, (ListRemoveChange<T>) change, indices, allChanges);
        } else if (change instanceof ListAddChange<?>) {
            allChanges.add(change);
            int i = index;
            // put all items into "indeces" as keys and "index" as a value
            // so that the "change" can be retrieved from the "allChanges"
            // by the index
            ((ListAddChange<T>) change).getNewItems().forEach(item -> indices.put(item, i));
        } else if (change instanceof ListClearChange<?>) {
            allChanges.add(change);
        } else {
            assert false : "AbstractListChange has only three subtypes: add, remove and clear";
        }
        index++;
    }
    List<AbstractListChange<T>> changes = allChanges.stream().filter(this::acceptChange).collect(Collectors.toList());
    if (isPopulated) {
        changes.forEach(collector);
    } else {
        if (changes.isEmpty()) {
            collector.accept(new EmptyChange(this));
        } else {
            changes.forEach(collector);
        }
        isPopulated = true;
    }
}