How to detect the swipe left or Right in Android?

Question

I have a edittext view in android. On this I want to detect a swipe left or right. I am able to get it on a empty space with the below code. But this does not work when I swipe on a edittext. How do i do it? Please let me know If I am doing something wrong. Thank you.

Code Used

    switch (touchevent.getAction())

    {
        case MotionEvent.ACTION_DOWN:
        {
            oldTouchValue = touchevent.getX();
            break;
        }
        case MotionEvent.ACTION_UP:
        {
            float currentX = touchevent.getX();
            if (oldTouchValue < currentX)
            {
                // swiped left
            }
            if (oldTouchValue > currentX )
            {
                swiped right
            }
        break;
        }
    }

Answer 1

I wrote a simple class that makes it easy to detect the swipe events - TOP, RIGHT, BOTTOM, LEFT.

1: Detect single swipe event

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

2: Detect any of the swipe events with one callback.

SwipeEvents.detect( swipeElement, new SwipeEvents.SwipeCallback() {
    @Override
    public void onSwipeTop() {
        //Swiped top
    }

    @Override
    public void onSwipeRight() {
        //Swiped right
    }

    @Override
    public void onSwipeBottom() {
        //Swiped bottom
    }

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

Here is a blog post with the explanation on how to use: http://bmutinda.com/android-detect-swipe-events/

I have also created a Gist for the code snippets available here: https://gist.github.com/bmutinda/9578f70f1df9bd0687b8

Thanks.

Answer 2

Swipe events are a kind of onTouch events. Simply simplifying @Gal Rom 's answer, just keep track of the vertical an horizontal deltas, and with a little math you can determine what kind of swipe a touchEvent was. (Again, let me stress that this was OBSENELY based to a previous answer, but the simplicity may appeal to novices). The idea is to extend an OnTouchListener, detect what kind of swipe (touch) just happened and call specific methods for each kind.

public class SwipeListener implements View.OnTouchListener {
    private int min_distance = 100;
    private float downX, downY, upX, upY;
    View v;

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        this.v = v;
        switch(event.getAction()) { // Check vertical and horizontal touches
            case MotionEvent.ACTION_DOWN: {
                downX = event.getX();
                downY = event.getY();
                return true;
            }
            case MotionEvent.ACTION_UP: {
                upX = event.getX();
                upY = event.getY();

                float deltaX = downX - upX;
                float deltaY = downY - upY;

                //HORIZONTAL SCROLL
                if (Math.abs(deltaX) > Math.abs(deltaY)) {
                    if (Math.abs(deltaX) > min_distance) {
                        // left or right
                        if (deltaX < 0) {
                            this.onLeftToRightSwipe();
                            return true;
                        }
                        if (deltaX > 0) {
                            this.onRightToLeftSwipe();
                            return true;
                        }
                    } else {
                        //not long enough swipe...
                        return false;
                    }
                }
                //VERTICAL SCROLL
                else {
                    if (Math.abs(deltaY) > min_distance) {
                        // top or down
                        if (deltaY < 0) {
                            this.onTopToBottomSwipe();
                            return true;
                        }
                        if (deltaY > 0) {
                            this.onBottomToTopSwipe();
                            return true;
                        }
                    } else {
                        //not long enough swipe...
                        return false;
                    }
                }
                return false;
            }
        }
        return false;
    }

    public void onLeftToRightSwipe(){
        Toast.makeText(v.getContext(),"left to right",   
                                      Toast.LENGTH_SHORT).show();
    }

    public void onRightToLeftSwipe() {
        Toast.makeText(v.getContext(),"right to left",
                                     Toast.LENGTH_SHORT).show();
    }

    public void onTopToBottomSwipe() {
        Toast.makeText(v.getContext(),"top to bottom", 
                                     Toast.LENGTH_SHORT).show();
    }

    public void onBottomToTopSwipe() {
        Toast.makeText(v.getContext(),"bottom to top", 
                                    Toast.LENGTH_SHORT).show();
    }
}

Answer 3

the best answer is @Gal Rom 's. there is more information about it: touch event return's to child views first. and if you define onClick or onTouch listener for them, parnt view (for example fragment) will not receive any touch listener. So if you want define swipe listener for fragment in this situation, you must implement it in a new class:

    package com.neganet.QRelations.fragments;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.FrameLayout;

public class SwipeListenerFragment extends FrameLayout {
    private float x1,x2;
    static final int MIN_DISTANCE=150;
    private onSwipeEventDetected mSwipeDetectedListener;


    public SwipeListenerFragment(Context context) {
        super(context);
    }

    public SwipeListenerFragment(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public SwipeListenerFragment(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        boolean result=false;
        switch(ev.getAction())
        {
            case MotionEvent.ACTION_DOWN:
                x1 = ev.getX();
                break;
            case MotionEvent.ACTION_UP:
                x2 = ev.getX();
                float deltaX = x2 - x1;
                if (Math.abs(deltaX) > MIN_DISTANCE)
                {
                    if(deltaX<0)
                    {
                        result=true;
                        if(mSwipeDetectedListener!=null)
                            mSwipeDetectedListener.swipeLeftDetected();

                    }else if(deltaX>0){
                        result=true;
                        if(mSwipeDetectedListener!=null)
                            mSwipeDetectedListener.swipeRightDetected();
                    }
                }
                break;
        }
        return result;
    }

    public interface onSwipeEventDetected
    {
        public void swipeLeftDetected();
        public void swipeRightDetected();

    }

    public void registerToSwipeEvents(onSwipeEventDetected listener)
    {
        this.mSwipeDetectedListener=listener;
    }
}

I changed @Gal Rom 's class. So it can detect both right and left swipe and specially it returns onInterceptTouchEvent true after detect. its important because if we dont do it some times child views maybe receive event and both of Swipe for fragment and onClick for child view (for example) runs and cause some issues. after making this class, you must change your fragment xml file:

    <com.neganet.QRelations.fragments.SwipeListenerFragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:id="@+id/main_list_layout"
    android:clickable="true"
    android:focusable="true"
    android:focusableInTouchMode="true"
    android:layout_height="match_parent" tools:context="com.neganet.QRelations.fragments.mainList"
    android:background="@color/main_frag_back">

    <!-- TODO: Update blank fragment layout -->
    <android.support.v7.widget.RecyclerView
        android:id="@+id/farazList"
        android:scrollbars="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="left|center_vertical" />
</com.neganet.QRelations.fragments.SwipeListenerFragment>

you see that begin tag is the class that we made. now in fragment class:

            View view=inflater.inflate(R.layout.fragment_main_list, container, false);
        SwipeListenerFragment tdView=(SwipeListenerFragment) view;
        tdView.registerToSwipeEvents(this);


and then Implement SwipeListenerFragment.onSwipeEventDetected in it:

        @Override
    public void swipeLeftDetected() {
        Toast.makeText(getActivity(), "left", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void swipeRightDetected() {
        Toast.makeText(getActivity(), "right", Toast.LENGTH_SHORT).show();
    }

It's a little complicated but works perfect :)

Answer 4

After a full day working on this feature finally able to get the right answer.

First, create the following classes:

import android.util.Log;
import android.view.MotionEvent;
import android.view.View;

/**
 * Created by hoshyar on 1/19/17.
 */

public class SwipeDetector implements View.OnTouchListener {

    public static enum Action {
        LR, // Left to Right
        RL, // Right to Left
        TB, // Top to bottom
        BT, // Bottom to Top
        None // when no action was detected
    }

    private static final String logTag = "Swipe";
    private static final int MIN_DISTANCE = 100;
    private float downX, downY, upX, upY;
    private Action mSwipeDetected = Action.None;

    public boolean swipeDetected() {
        return mSwipeDetected != Action.None;
    }

    public Action getAction() {
        return mSwipeDetected;
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                downX = event.getX();
                downY = event.getY();
                mSwipeDetected = Action.None;
                return false;

            case MotionEvent.ACTION_MOVE:
                upX = event.getX();
                upY = event.getY();

                float deltaX = downX - upX;
                float deltaY = downY - upY;
                Log.i(logTag,String.valueOf(deltaX));
                Log.i(logTag,String.valueOf(deltaX));

                if (deltaY>0 && deltaY<10 && deltaX<0 || deltaY==0 && deltaX>-15 && deltaX<0){
                    Log.i(logTag,"to right");
                }if (deltaY>=0 && deltaY<10 && deltaX>0 || deltaY<0 && deltaX>15 && deltaX<40){
                Log.i(logTag,"to left");
            }





                if (Math.abs(deltaX) > MIN_DISTANCE) {
                    // left or right
                    if (deltaX < 0) {
                        mSwipeDetected = Action.LR;
                        return false;
                    }
                    if (deltaX > 0) {


                        mSwipeDetected = Action.RL;
                        return false;
                    }
                } else if (Math.abs(deltaY) > MIN_DISTANCE) {


                    if (deltaY < 0) {
                        Log.i(logTag,"to bottom");
                        mSwipeDetected = Action.TB;
                        return false;
                    }
                    if (deltaY > 0) {
                        Log.i(logTag,"to up");
                        mSwipeDetected = Action.BT;
                        return false;
                    }
                }
                return true;
        }
        return false;
    }
}

Finally on the object that you want to apply. My example:

SwipeDetector swipeDetector = new SwipeDetector();
listView.setOnTouchListener(swipeDetector);

Good luck .

Answer 5

I want to add on to the accepted answer which works partially, but is missing the time variable, that makes it perfect.

Simplest left to right swipe detector with a time variable:

In your activity class add following attributes:

private float x1,x2;
private long startClickTime;
static final int MIN_DISTANCE = 150;
static final int MAX_SWIPE_TIME = 200;

and override onTouchEvent () method:

    @Override
    public boolean onTouchEvent(MotionEvent event)
    {
        switch(event.getAction())
        {
            case MotionEvent.ACTION_DOWN:
                startClickTime = Calendar.getInstance().getTimeInMillis();
                x1 = event.getX();
                break;
            case MotionEvent.ACTION_UP:
                long clickDuration = Calendar.getInstance().getTimeInMillis() - startClickTime;
                x2 = event.getX();
                float deltaX = x2 - x1;
                if (Math.abs(deltaX) > MIN_DISTANCE && clickDuration < MAX_SWIPE_TIME)
                {
                    Toast.makeText(this, "left2right swipe", Toast.LENGTH_SHORT).show ();
                }
                else
                {
                    // consider as something else - a screen tap for example
                }
                break;
        }
        return super.onTouchEvent(event);
    }

Answer 6

Detect swipe in four direction

private float x1,x2,y1,y2;
static final int MIN_DISTANCE = 70;

and

switch(pSceneTouchEvent.getAction())
     {
       case MotionEvent.ACTION_DOWN:
           x1 = pSceneTouchEvent.getX();     
           y1 = pSceneTouchEvent.getY();
       break;         
       case MotionEvent.ACTION_UP:
           x2 = pSceneTouchEvent.getX();
           y2 = pSceneTouchEvent.getY();
           float deltaX = x2 - x1;
           float deltaY = y2 - y1;
           if (deltaX > MIN_DISTANCE)
           {
               swipeLeftToRight();
           }
           else if( Math.abs(deltaX) > MIN_DISTANCE)
           {
               swipeRightToLeft();
           } 
           else if(deltaY > MIN_DISTANCE){
               swipeTopToBottom();
           } 
           else if( Math.abs(deltaY) > MIN_DISTANCE){
               swipeBottopmToTop();
           }

       break;   
     }