Android swipe events detector

activity_swipe.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <RelativeLayout
        android:id="@+id/swipeElement"
        android:layout_width="match_parent"
        android:layout_height="300dp"
        android:background="#FFD"
        android:clickable="true">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="@dimen/abc_text_size_title_material"
            android:text="@string/swipe_element"
            android:layout_centerInParent="true"/>

    </RelativeLayout>
</LinearLayout>

SwipeEvents.java

package bmutinda.com.androidutils.libs;

import android.view.MotionEvent;
import android.view.View;

/**
 * Created by Mutinda Boniface on 7/5/2015.
 */
public class SwipeEvents implements View.OnTouchListener {
    private SwipeCallback swipeCallback;
    private SwipeSingleCallback swipeSingleCallback;
    private SwipeDirection detectSwipeDirection;

    float x1, x2, y1, y2;
    View view;

    private static SwipeEvents newInstance(){
        return new SwipeEvents();
    }

    public static void detect( View view, SwipeCallback swipeCallback  ){
        SwipeEvents evt = SwipeEvents.newInstance();
        evt.swipeCallback = swipeCallback;
        evt.view = view;
        evt.detect();
    }

    public static void detectTop( View view, SwipeSingleCallback swipeSingleCallback){
        SwipeEvents evt = SwipeEvents.newInstance();
        evt.swipeSingleCallback = swipeSingleCallback;
        evt.view = view;
        evt.detectSingle(SwipeDirection.TOP);
    }

    public static void detectRight( View view, SwipeSingleCallback swipeSingleCallback){
        SwipeEvents evt = SwipeEvents.newInstance();
        evt.swipeSingleCallback = swipeSingleCallback;
        evt.view = view;
        evt.detectSingle(SwipeDirection.RIGHT);
    }

    public static void detectBottom( View view, SwipeSingleCallback swipeSingleCallback){
        SwipeEvents evt = SwipeEvents.newInstance();
        evt.swipeSingleCallback = swipeSingleCallback;
        evt.view = view;
        evt.detectSingle(SwipeDirection.BOTTOM);
    }
    public static void detectLeft( View view, SwipeSingleCallback swipeSingleCallback){
        SwipeEvents evt = SwipeEvents.newInstance();
        evt.swipeSingleCallback = swipeSingleCallback;
        evt.view = view;
        evt.detectSingle(SwipeDirection.LEFT);
    }

    private void detect( ){
        view.setOnTouchListener(this);
    }

    private void detectSingle( SwipeDirection direction ){
        this.detectSwipeDirection = direction;
        view.setOnTouchListener(this);
    }

    @Override
    public boolean onTouch(View view, MotionEvent event) {
        switch (event.getAction() ){
            case MotionEvent.ACTION_DOWN:
                x1 = event.getX();
                y1 = event.getY();
                break;
            case MotionEvent.ACTION_UP:
                x2 = event.getX();
                y2 = event.getY();
                SwipeDirection direction =null;

                float xDiff = x2-x1;
                float yDiff = y2- y1;
                if( Math.abs(xDiff) > Math.abs(yDiff) ){
                    if (x1<x2){
                        direction = SwipeDirection.RIGHT;
                    }else{
                        direction = SwipeDirection.LEFT;
                    }
                }else {
                    if (y1 > y2) {
                        direction = SwipeDirection.TOP;
                    } else {
                        direction = SwipeDirection.BOTTOM;
                    }
                }

                // Only trigger the requested event only if there
                if ( detectSwipeDirection !=null && swipeSingleCallback !=null ){
                    if ( direction == detectSwipeDirection ){
                        swipeSingleCallback.onSwipe();
                    }
                }else{
                    if ( direction == SwipeDirection.RIGHT ){
                        swipeCallback.onSwipeRight();
                    }
                    if ( direction == SwipeDirection.LEFT ){
                        swipeCallback.onSwipeLeft();
                    }
                    if ( direction == SwipeDirection.TOP ){
                        swipeCallback.onSwipeTop();
                    }
                    if ( direction == SwipeDirection.BOTTOM ){
                        swipeCallback.onSwipeBottom();
                    }
                }

                break;
        }
        return false;
    }

    public enum SwipeDirection{
        TOP, RIGHT, BOTTOM, LEFT
    }

    public interface SwipeCallback{
        public void onSwipeTop();
        public void onSwipeRight();
        public void onSwipeBottom();
        public void onSwipeLeft();
    }

    public interface SwipeSingleCallback{
        public void onSwipe();
    }
}

SwipeEventsDemoActivity.java

package bmutinda.com.androidutils;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Gravity;
import android.widget.RelativeLayout;
import android.widget.Toast;

import bmutinda.com.androidutils.libs.SwipeEvents;

public class SwipeActivity extends ActionBarActivity {
    RelativeLayout swipeElement;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_swipe);

        swipeElement = (RelativeLayout) findViewById( R.id.swipeElement );

        // Detect and consume all events
        SwipeEvents.detect( swipeElement, new SwipeEvents.SwipeCallback() {
            @Override
            public void onSwipeTop() {
                showToast( "Swiped top");
            }

            @Override
            public void onSwipeRight() {
                showToast( "Swiped right");
            }

            @Override
            public void onSwipeBottom() {
                showToast( "Swiped bottom");
            }

            @Override
            public void onSwipeLeft() {
                showToast( "Swiped left");
            }
        });

        // Detect and consume specific events
        // {Available methods} - detectTop, detectRight, detectBottom, detectLeft
        SwipeEvents.detectTop(swipeElement, new SwipeEvents.SwipeSingleCallback() {
            @Override
            public void onSwipe() {
                showToast("Swiped - detectTop");
            }
        });
    }

    public void showToast( String message ){
        Toast toast = Toast.makeText(this, message, Toast.LENGTH_SHORT);
        toast.setGravity(Gravity.CENTER, 0, 0);
        toast.show();
    }
}

Blog post for this snippet is available here http://bmutinda.com/android-detect-swipe-events/