PandaLib/Core/src/main/java/fr/pandacube/lib/core/util/MappedListView.java
2021-03-21 20:17:31 +01:00

54 lines
1.8 KiB
Java

package fr.pandacube.lib.core.util;
import java.util.AbstractList;
import java.util.List;
import java.util.function.Function;
public class MappedListView<S, T> extends AbstractList<T> {
private final List<S> backend;
private final Function<S, T> getter;
private final Function<T, S> setter;
/**
*
* @param backend the list backing this list
* @param getter the function converting the value from the backing list to the value of this list.
* It is used for every operation involving reading data from the backing list and comparing existing data.
* For instance, {@link #indexOf(Object)} iterate through the backing list, converting all the values
* with {@code getter} before comparing them with the parameter of {@link #indexOf(Object)}.
* before comparing
* @param setter used for modification of the data in the list (typically {@code add} and {@code set} methods)
*/
public MappedListView(List<S> backend, Function<S, T> getter, Function<T, S> setter) {
this.backend = backend;
this.getter = getter;
this.setter = setter;
}
@Override
public int size() { return backend.size(); }
@Override
public T get(int index) { return getter.apply(backend.get(index)); }
@Override
public T set(int index, T element) { return getter.apply(backend.set(index, setter.apply(element))); }
@Override
public void add(int index, T element) { backend.add(index, setter.apply(element)); }
@Override
public T remove(int index) { return getter.apply(backend.remove(index)); }
@Override
public void clear() { backend.clear(); }
@Override
public List<T> subList(int fromIndex, int toIndex) {
return new MappedListView<S, T>(backend.subList(fromIndex, toIndex), getter, setter);
}
@Override
protected void removeRange(int fromIndex, int toIndex) {
backend.subList(fromIndex, toIndex).clear();
}
}