java-util-observer/src/main/lombok/org/leumasjaffe/observer/ObservableController.java

package org.leumasjaffe.observer;

import java.util.Objects;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.Consumer;

import javax.swing.text.JTextComponent;

import org.leumasjaffe.event.AnyActionDocumentListener;

import lombok.experimental.FieldDefaults;
import lombok.AccessLevel;

@FieldDefaults(level=AccessLevel.PRIVATE, makeFinal=true)
public class ObservableController<S extends JTextComponent, T extends Observable> extends ObservableListener<S, T> {
	BiFunction<String, T, Boolean> func;

	public ObservableController(final S comp, final BiFunction<String, T, Boolean> func,
			final BiConsumer<? super S, ? super T> update) {
		super(comp, update);
		this.func = func;
		AnyActionDocumentListener.skipEmpty(comp, evt -> accept( ) );
	}
	
	public ObservableController(final S comp, final BiFunction<String, T, Boolean> func,
			final BiConsumer<? super S, ? super T> update, final Consumer<T> onEmpty) {
		super(comp, update);
		this.func = func;
		AnyActionDocumentListener.emptyOrText( comp, 
				e -> onEmpty.accept( impl.getModel() ), 
				evt -> accept( ) );
	}

	private boolean update() {
		return func.apply( impl.getComponent().getText( ), impl.getModel() );
	}

	private void accept() {
		Objects.requireNonNull( impl.getModel() );
		if ( update( ) ) {
			impl.notifySubscribers(impl.getModel());
		}
	}
}