OnGestureEvent implimentations for use with GestureDetectorCompat. Makes it easer to use lambdas.

GestureDetectors.java

import android.view.GestureDetector;
import android.view.MotionEvent;

import com.fernandocejas.arrow.functions.Function;
import com.fernandocejas.arrow.functions.Predicate;

public class GestureDetectors {
    public static class OnDown implements GestureDetector.OnGestureListener {
        private final Predicate<MotionEvent> predicate;

        public OnDown(Predicate<MotionEvent> predicate) {
            this.predicate = predicate;
        }

        @Override
        public boolean onDown(MotionEvent e) {
            return predicate != null && predicate.apply(e);

        }

        @Override
        public void onShowPress(MotionEvent e) {

        }

        @Override
        public boolean onSingleTapUp(MotionEvent e) {
            return false;
        }

        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
            return false;
        }

        @Override
        public void onLongPress(MotionEvent e) {

        }

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            return false;
        }
    }

    public static class OnShowPress implements GestureDetector.OnGestureListener {
        private final Function<MotionEvent, Void> function;

        public OnShowPress(Function<MotionEvent, Void> function) {
            this.function = function;
        }

        @Override
        public boolean onDown(MotionEvent e) {
            return false;
        }

        @Override
        public void onShowPress(MotionEvent e) {
            function.apply(e);
        }

        @Override
        public boolean onSingleTapUp(MotionEvent e) {
            return false;
        }

        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
            return false;
        }

        @Override
        public void onLongPress(MotionEvent e) {

        }

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            return false;
        }
    }

    public static class OnSingleTapUp implements GestureDetector.OnGestureListener {
        private final Predicate<MotionEvent> predicate;

        public OnSingleTapUp(Predicate<MotionEvent> predicate) {
            this.predicate = predicate;
        }

        @Override
        public boolean onDown(MotionEvent e) {
            return false;
        }

        @Override
        public void onShowPress(MotionEvent e) {

        }

        @Override
        public boolean onSingleTapUp(MotionEvent e) {
            return predicate != null && predicate.apply(e);

        }

        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
            return false;
        }

        @Override
        public void onLongPress(MotionEvent e) {

        }

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            return false;
        }
    }

    public static class OnLongPress implements GestureDetector.OnGestureListener {
        private final Function<MotionEvent, Void> function;

        public OnLongPress(Function<MotionEvent, Void> function) {
            this.function = function;
        }

        @Override
        public boolean onDown(MotionEvent e) {
            return false;
        }

        @Override
        public void onShowPress(MotionEvent e) {

        }

        @Override
        public boolean onSingleTapUp(MotionEvent e) {
            return false;
        }

        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
            return false;
        }

        @Override
        public void onLongPress(MotionEvent e) {
            function.apply(e);
        }

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            return false;
        }
    }
}