Android: How to handle right to left swipe gestures

Question

I want my app to recognize when a user swipes from right to left on the phone screen.

How to do this?

Solution 1

OnSwipeTouchListener.java:

import android.content.Context;
import android.view.GestureDetector;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;

public class OnSwipeTouchListener implements OnTouchListener {

    private final GestureDetector gestureDetector;

    public OnSwipeTouchListener (Context ctx){
        gestureDetector = new GestureDetector(ctx, new GestureListener());
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        return gestureDetector.onTouchEvent(event);
    }

    private final class GestureListener extends SimpleOnGestureListener {

        private static final int SWIPE_THRESHOLD = 100;
        private static final int SWIPE_VELOCITY_THRESHOLD = 100;

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

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            boolean result = false;
            try {
                float diffY = e2.getY() - e1.getY();
                float diffX = e2.getX() - e1.getX();
                if (Math.abs(diffX) > Math.abs(diffY)) {
                    if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                        if (diffX > 0) {
                            onSwipeRight();
                        } else {
                            onSwipeLeft();
                        }
                        result = true;
                    }
                }
                else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                    if (diffY > 0) {
                        onSwipeBottom();
                    } else {
                        onSwipeTop();
                    }
                    result = true;
                }
            } catch (Exception exception) {
                exception.printStackTrace();
            }
            return result;
        }
    }

    public void onSwipeRight() {
    }

    public void onSwipeLeft() {
    }

    public void onSwipeTop() {
    }

    public void onSwipeBottom() {
    }
}

Usage:

imageView.setOnTouchListener(new OnSwipeTouchListener(MyActivity.this) {
    public void onSwipeTop() {
        Toast.makeText(MyActivity.this, "top", Toast.LENGTH_SHORT).show();
    }
    public void onSwipeRight() {
        Toast.makeText(MyActivity.this, "right", Toast.LENGTH_SHORT).show();
    }
    public void onSwipeLeft() {
        Toast.makeText(MyActivity.this, "left", Toast.LENGTH_SHORT).show();
    }
    public void onSwipeBottom() {
        Toast.makeText(MyActivity.this, "bottom", Toast.LENGTH_SHORT).show();
    }

});

Solution 2

This code detects left and right swipes, avoids deprecated API calls, and has other miscellaneous improvements over earlier answers.

/**
 * Detects left and right swipes across a view.
 */
public class OnSwipeTouchListener implements OnTouchListener {

    private final GestureDetector gestureDetector;

    public OnSwipeTouchListener(Context context) {
        gestureDetector = new GestureDetector(context, new GestureListener());
    }

    public void onSwipeLeft() {
    }

    public void onSwipeRight() {
    }

    public boolean onTouch(View v, MotionEvent event) {
        return gestureDetector.onTouchEvent(event);
    }

    private final class GestureListener extends SimpleOnGestureListener {

        private static final int SWIPE_DISTANCE_THRESHOLD = 100;
        private static final int SWIPE_VELOCITY_THRESHOLD = 100;

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

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            float distanceX = e2.getX() - e1.getX();
            float distanceY = e2.getY() - e1.getY();
            if (Math.abs(distanceX) > Math.abs(distanceY) && Math.abs(distanceX) > SWIPE_DISTANCE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                if (distanceX > 0)
                    onSwipeRight();
                else
                    onSwipeLeft();
                return true;
            }
            return false;
        }
    }
}

Use it like this:

view.setOnTouchListener(new OnSwipeTouchListener(context) {
    @Override
    public void onSwipeLeft() {
        // Whatever
    }
});

Solution 3

If you also need to process click events here some modifications:

public class OnSwipeTouchListener implements OnTouchListener {

    private final GestureDetector gestureDetector = new GestureDetector(new GestureListener());

    public boolean onTouch(final View v, final MotionEvent event) {
        return gestureDetector.onTouchEvent(event);
    }

    private final class GestureListener extends SimpleOnGestureListener {

        private static final int SWIPE_THRESHOLD = 100;
        private static final int SWIPE_VELOCITY_THRESHOLD = 100;


        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            boolean result = false;
            try {
                float diffY = e2.getY() - e1.getY();
                float diffX = e2.getX() - e1.getX();
                if (Math.abs(diffX) > Math.abs(diffY)) {
                    if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                        if (diffX > 0) {
                            result = onSwipeRight();
                        } else {
                            result = onSwipeLeft();
                        }
                    }
                } else {
                    if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                        if (diffY > 0) {
                            result = onSwipeBottom();
                        } else {
                            result = onSwipeTop();
                        }
                    }
                }
            } catch (Exception exception) {
                exception.printStackTrace();
            }
            return result;
        }
    }

    public boolean onSwipeRight() {
        return false;
    }

    public boolean onSwipeLeft() {
        return false;
    }

    public boolean onSwipeTop() {
        return false;
    }

    public boolean onSwipeBottom() {
        return false;
    }
}

And sample usage:

    background.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            toggleSomething();
        }
    });
    background.setOnTouchListener(new OnSwipeTouchListener() {
        public boolean onSwipeTop() {
            Toast.makeText(MainActivity.this, "top", Toast.LENGTH_SHORT).show();
            return true;
        }
        public boolean onSwipeRight() {
            Toast.makeText(MainActivity.this, "right", Toast.LENGTH_SHORT).show();
            return true;
        }
        public boolean onSwipeLeft() {
            Toast.makeText(MainActivity.this, "left", Toast.LENGTH_SHORT).show();
            return true;
        }
        public boolean onSwipeBottom() {
            Toast.makeText(MainActivity.this, "bottom", Toast.LENGTH_SHORT).show();
            return true;
        }
    });

Solution 4

Expanding on Mirek's answer, for the case when you want to use the swipe gestures inside a scroll view. By default the touch listener for the scroll view get disabled and therefore scroll action does not happen. In order to fix this you need to override the dispatchTouchEvent method of the Activity and return the inherited version of this method after you're done with your own listener.

In order to do a few modifications to Mirek's code: I add a getter for the gestureDetector in the OnSwipeTouchListener.

public GestureDetector getGestureDetector(){
    return  gestureDetector;
}

Declare the OnSwipeTouchListener inside the Activity as a class-wide field.

OnSwipeTouchListener onSwipeTouchListener;

Modify the usage code accordingly:

onSwipeTouchListener = new OnSwipeTouchListener(MyActivity.this) {
    public void onSwipeTop() {
        Toast.makeText(MyActivity.this, "top", Toast.LENGTH_SHORT).show();
    }
    public void onSwipeRight() {
        Toast.makeText(MyActivity.this, "right", Toast.LENGTH_SHORT).show();
    }
    public void onSwipeLeft() {
        Toast.makeText(MyActivity.this, "left", Toast.LENGTH_SHORT).show();
    }
    public void onSwipeBottom() {
        Toast.makeText(MyActivity.this, "bottom", Toast.LENGTH_SHORT).show();
    }
});

imageView.setOnTouchListener(onSwipeTouchListener);

And override the dispatchTouchEvent method inside Activity:

@Override
    public boolean dispatchTouchEvent(MotionEvent ev){
        swipeListener.getGestureDetector().onTouchEvent(ev); 
            return super.dispatchTouchEvent(ev);   
    }

Now both scroll and swipe actions should work.

Solution 5

In order to have Click Listener, DoubleClick Listener, OnLongPress Listener, Swipe Left, Swipe Right, Swipe Up, Swipe Down on Single View you need to setOnTouchListener. i.e,

view.setOnTouchListener(new OnSwipeTouchListener(MainActivity.this) {

            @Override
            public void onClick() {
                super.onClick();
                // your on click here
            }

            @Override
            public void onDoubleClick() {
                super.onDoubleClick();
                // your on onDoubleClick here
            }

            @Override
            public void onLongClick() {
                super.onLongClick();
                // your on onLongClick here
            }

            @Override
            public void onSwipeUp() {
                super.onSwipeUp();
                // your swipe up here
            }

            @Override
            public void onSwipeDown() {
                super.onSwipeDown();
                // your swipe down here.
            }

            @Override
            public void onSwipeLeft() {
                super.onSwipeLeft();
                // your swipe left here.
            }

            @Override
            public void onSwipeRight() {
                super.onSwipeRight();
                // your swipe right here.
            }
        });

}

For this you need OnSwipeTouchListener class that implements OnTouchListener.

public class OnSwipeTouchListener implements View.OnTouchListener {

private GestureDetector gestureDetector;

public OnSwipeTouchListener(Context c) {
    gestureDetector = new GestureDetector(c, new GestureListener());
}

public boolean onTouch(final View view, final MotionEvent motionEvent) {
    return gestureDetector.onTouchEvent(motionEvent);
}

private final class GestureListener extends GestureDetector.SimpleOnGestureListener {

    private static final int SWIPE_THRESHOLD = 100;
    private static final int SWIPE_VELOCITY_THRESHOLD = 100;

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

    @Override
    public boolean onSingleTapUp(MotionEvent e) {
        onClick();
        return super.onSingleTapUp(e);
    }

    @Override
    public boolean onDoubleTap(MotionEvent e) {
        onDoubleClick();
        return super.onDoubleTap(e);
    }

    @Override
    public void onLongPress(MotionEvent e) {
        onLongClick();
        super.onLongPress(e);
    }

    // Determines the fling velocity and then fires the appropriate swipe event accordingly
    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        boolean result = false;
        try {
            float diffY = e2.getY() - e1.getY();
            float diffX = e2.getX() - e1.getX();
            if (Math.abs(diffX) > Math.abs(diffY)) {
                if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                    if (diffX > 0) {
                        onSwipeRight();
                    } else {
                        onSwipeLeft();
                    }
                }
            } else {
                if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                    if (diffY > 0) {
                        onSwipeDown();
                    } else {
                        onSwipeUp();
                    }
                }
            }
        } catch (Exception exception) {
            exception.printStackTrace();
        }
        return result;
    }
}

public void onSwipeRight() {
}

public void onSwipeLeft() {
}

public void onSwipeUp() {
}

public void onSwipeDown() {
}

public void onClick() {

}

public void onDoubleClick() {

}

public void onLongClick() {

}
}

View more solutions

Comments

[clusterflux]

Needs some minor updates. Variables are mismatched in the onTouch method, and exception class is not imported. Would make more sense to just return false from onFling(), instead of initiating a variable, assigning it a value, doing nothing with it, and just returning it. Some parts of onTouch method are incorrect. See stackoverflow.com/questions/14107293/… One helpful tip that would've saved me some time and I hope may help others: when you use this method, you only want to add the "implements" tag to your OnSwipeTouchListener class

[Opiatefuchs]

works great, but super.onTouch(view, motionEvent); gives me error warning in eclipse "is undefinied for the type object". Deleting this works great.

[Hugo Alves]

Thanks works like a charm but you should add a constructor to OnSwipeTouchListener that receives a context because that constructor of GestureDetector is deprecated since API level 3, and instantiate the GestureDetectorin that constructor.

[Manny265]

this is in the main activity right? and then the list itself how do I load that? my main extends listactivity?

[Nicolas Zozol]

I don't see easily the modifications in your modified OnSwipeTouchListener. Where is it exactly ?

[hpique]

Shouldn't the THRESHOLD be expressed in dp?

[Libathos]

@Mirek Rusin Hi great code! can you telle me how can I use this code inside a viewPager? in order to recognize if i get a swipe from left to right

[Hesam]

public GestureDetector getGestureDetector() {return gestureDetector;} method should be add to the OnSwipeTouchListener class and be used inside onTouch() method.

[Aneez]

This thing worked for me. Now Can u please tell me how to give different actions(or simply toast) for right side vertical swipe and left side vertical swipe ?

[Arash]

thanks it worked for me with these modifications : stackoverflow.com/a/19506010/401403

[RicNjesh]

How do you get a touch event for a listview item?

[mangusta]

but "onDown" is never called. as a consequence, my e1 is always null and I can do nothing about it.

[mangusta]

onDown() is never called, so I can't intercept null value of e1 and it remains null, so swipe never works

[Jona]

sorry if this sounds thick, but (A) Where does the second piece of code go? (view.setOn...), (B) what is the "context" that is being passed? I'm quite new, appreciate any help! Thanks in advance

[Edward Brey]

@mangusta I'm not sure what you're seeing. onDown should be called with e (not e1) if the user moves vertically, but since this code snippet is for left-right swiping, it tells Android to ignore the vertical movement.

[Edward Brey]

@Jona You'll definitely want to get a good book or other resource on Android fundamentals; otherwise, trying to cobble solutions together from StackOverflow will prove frustrating. A good option is the official Training for Android developers. The section Starting an Activity tells about where you would put setOnTouchListener (typically in onCreate). context is the this pointer (unless you're creating a fragment).

[Jona]

thank you Edward - I'm doing both simultaneously! (cobbling and reading)

[Lara]

It works great for swipes, thanx. My problem is that I still want to receive the onTouchEvent when there is no swipe. Can't figure that one out.

[Edward Brey]

@Lara, I haven't tried this, but you could try overriding SimpleOnGestureListener.onSingleTapConfirmed.

[Lara]

Thanks, Edward. I also found that changing the return of onDown from true to false does the trick.

[Jessica]

@Mirek Rusin What will happen if I change private static final int SWIPE_THRESHOLD to private final int SWIPE_THRESHOLD ?! I need to set swipe sensitivity in run time !!!

[Figen Güngör]

When I add code to touch event and tried to swipe, touch event occurs, too. How can I avoid that?

[Gábor]

This should be the accepted answer... Differences are subtle but very important. First, there is no onDown(). Second, the handlers return a boolean to signal whether they consumed the event or not. This is of utmost importance if you need more than just one handler for the same view (which should be the default case, anyway).

[LS_]

i get error on the context here here: view.setOnTouchListener(new OnSwipeTouchListener(context) how can I solve it?

[Edward Brey]

@Signo, the activity containing the view provides context. In the common case of adding the view to a fragment, use Fragment.getActivity().

[Ge Rong]

My fix for this answer is to move onTouch into the OnSwipeTouchListener definition, otherwise my IDE will pop up "accessing private member" error

[tung]

What's that toggleSomething() Method?

[ruX]

@tung just normal tap(not gesture) handler

[ruX]

@NicolasZozol java code style, all swipe directions, on click handler

[tung]

Note for the View you wanna attach it has to be focusable and clickable

[coderVishal]

has anybody extended the code to detect top and down swipes?

[Edward Brey]

@coderVishal Depending on your purpose, you may find useful SwipeRefreshLayout, the SwipeRefreshLayoutBasic sample, or one of its variants.

[Neil]

@ruX "Thanks but in this case not initialized object can be root of NPE errors It's always safer to assign something not null to callback instance" The final modifier guarantees gestureDetector will always be initialized, and if not caught by the compiler. The edit I suggested to update to non-deprecated API is perfectly safe.

[Alaa M.]

This is great, but when I attached it to a listView.setOnTouchListener(), it slowed down the scrolling (even though I was using a ViewHolderand some other optimizations.) To solve this, just don't call onSwipeBottom() and onSwipeTop() and make result = false on those cases. By "slowing down" I mean scrolling (smooth) and then stopping all at once - instead of stopping at a decreasing speed

[serv-inc]

How do you handle the android lint warning about ClickableViewAccessibility? (If you know a way, please post at my SO question at stackoverflow.com/questions/31344451/…)

[Edward Falk]

Isn't this a copy of Thomas Fankhauser's answer? Credit where credit is due, please.

[anubhav16]

I'm new to Android. I tried this code. Did not work. Application crashed with Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setOnTouchListener(android.view.Vie‌​w$OnTouchListener)' on a null object reference Where to write Usage Code?

[Jennifer]

Zala's solution is simple and clear, helped me greatly with swipe actions in android. This solution will solve beginners who have trouble with swipe gestures.

[Awadesh]

please tell me how to swipe smoothly even user swipe somewhat in downward manner , right now I am also using android.support.v4.widget.SwipeRefreshLayout ,when i swipe in some zigzag manner both refresh and swipe try to take place

[Awadesh]

listview item is not sliding smoothly I mean if user swipe slightly downward then swipe action is not detected. Any help is appreciated. Thanks in advance

[Pravinsingh Waghela]

Plus one from my side, its very useful and the Tutorial link given by you is also very Interesting. Thanks for double help Edward.

[tomDev]

Thanks, this works, but I have some issues with this code. When gesture starts over a button it is not detected. Any idea why?

[Edward Brey]

@tomDev Likely it's because the button is handling the events, leaving nothing for the touch listener underneath. However, you should consider whether you really want a button on a control that supports swiping. The typical UI for such situations is for the swipe action to reveal buttons "behind" the list item. The class above doesn't support those buttons, but there are libraries available that do.

[tomDev]

@EdwardBreyYes, that's whats is happening. When the gesture starts over a button, the button is clicked and the gesture is not detected. On iOS it's the opposite, the gesture has the "priority". What other libraries can be used? No code needed, just some directions. Thanks!

[Mohammad Rajob]

How can I use this in OnItemClickListener for listview?

[TejaDroid]

@Jaydipsinh Zala, You save my time, amazing. this will solve my problem of indicator of scroll top and bottom while scrolling.

[Ajit Sharma]

Its working nice but how to give color change effect while swipe?

[Singagirl]

Should I disregard Eclipse's warning OnSwipeTouchListener#onTouch should call View#performClick when a click is detected?

[Edward Brey]

@DmitriyR I think so. I don't get that warning in Android Studio.

[shobhan]

How to restrict the user in down swipe i.e swipe bottom in your case , I want to disable down swipe in my case . please let me know

[soshial]

@AlaaM., how did you make scrolling in a ListView work?

[soshial]

I switched from ListView to RecyclerView and it helped!

[vijay chhalotre]

how to get there is not more item both side (left and right) ... please guide me on this. I need to enable and disable the arrow indicator. Thanks

[Andrêves Dickow]

does anyone know how to call this 'Usage' in MainActivity on Xamarin.Android?

[baldraider]

Getting this error JNI DETECTED ERROR IN APPLICATION: JNI CallVoidMethodV called with pending exception java.lang.NullPointerException: Attempt to invoke virtual method 'float android.view.MotionEvent.getX()' on a null object reference why this error is thrown?

[user3561494]

Can someone please show me an example of how to use Kotlin to detect both left swipe's and a normal click on the same view.

[user3561494]

How do you use this in a list view? It does not return the position of the view that was touched so how do you know which row was touched?

[Nathan F.]

It might make more sense to make the OnSwipeTouchListener class abstract as well as the onSwipe* functions.

[kamal]

For Kotlin You can use something like this:

[kamal]

Usage:gv_calendar!!.setOnTouchListener(OnSwipeTouchListener(‌​activity,onSwipeCall‌​Back!!))

[Mark Rotteveel]

Please don't just dump code, include an explanation of what your code does.

[Hitesh Danidhariya]

Can I do something like , if I swipe half the screen then on swipeDown() function is called or I get value to when swipe if done half the screen.

[loshkin]

what is OnSwipeCallBack?

[Soon Santos]

This is what I call a complete answer. When I added the swipes, I lost my click properties, so I needed to override the onClick method as in this answer. Thanks guy!

[hiddeneyes02]

Can you add rtl support please? That is onSwipeRight() and onSwipeLeft() get switched when rtl

[Michał Ziobro]

I am getting NullPointerException on Orientation Changes while used in Fragment

[JPM]

Gesture comes from what import? import android.gesture.Gesture does not have a SWIPE_RIGHT global.

[Arnold Brown]

Its working well, but have a doubt that the onClick is not working for the view the swipe is applied.! @Meric

[Anonymous-E]

why you did not write down the complete code of this gesture, where to put SwipeDown, left, right etc?

[Starwave]

sifted through all the garbage here, you are right, no need for over-complicating things - this one works perfectly

[Starwave]

a giant minus here - if I do a gesture anywhere on my scrollview, the touchListener is called, even if it wasn't applied to the scrollview itself, but to a random button inside it

[MHSFisher]

Kotlin equivalent is here : stackoverflow.com/a/53791260/2201814

[luckybilly]

There are many SwipeConsumers for different sideslip effects, such as SlidingConsumer/StretchConsumer/SpaceConsumer/... and so on within SmartSwipe

[Gerrit Beuze]

Should VELOCITY_THRESHOLD not be screen density dependent?

[M D P]

@GerritBeuze No, Android system handles that. It sends the right values through velocityX and velocityY in onFling method. although you can experiment to see which value best suits your needs but the final number would be universal.

[Gerrit Beuze]

The answers here suppose the opposite: they are not scaled ? : stackoverflow.com/questions/18812479/…

[M D P]

@GerritBeuze It's because they are doing the math manually themselves by calculating the amount of pixels the finger has traveled and that's wrong because it depends on pixel density. you should only use velocity like I did, velocity is almost dpi independent.

[Dinith Rukshan Kumara]

Greate answer. Works fine, but SwipeRight and onSwipeLeft directions should change. Swap it.

[AL̲̳I]

@Jaydipsinh Zala Not sure what am I doing wrong, when I add the OnSwipeTouchListener to my webView, it removes the interaction with the website inside webview. Can you help please?

[Faizan Haidar Khan]

Can we decrease the sensitivity? If yes then how?

[K Pradeep Kumar Reddy]

Why we need to make the class open ??

[K Pradeep Kumar Reddy]

Can we also detect tap gesture ?

[K Pradeep Kumar Reddy]

In kotlin, we can replace Math.abs with abs() function

[Amr]

giving a complete sample on how to use the code would have been great!

[ThomasRS]

Added missing class and exaple

[Vitaly]

NullPointerException: Attempt to invoke virtual method 'float android.view.MotionEvent.getX()' on a null object reference

[Dexter Legaspi]

this library was hosted in jcenter/bintray so since jcenter/bintray is no longer available to public since 2021, no bueno on this library.

[Benjamin Basmaci]

I don't quite see the use for abstraction here. Doesn't it just mandate that any inheriting class override every function? Meaning onSwipeLeft, onSwipeBottom etc. I'd say sometimes that is not necessary and only makes your code ugly.

[Benjamin Basmaci]

From your own source: "This is the kind of processing you would have to do for a custom gesture. However, if your app uses common gestures such as double tap, long press, fling, and so on, you can take advantage of the GestureDetector class." So I would guess that the accepted approach might be right here. Not sure how these MotionEvent ACTIONS are supposed to work. Because while they look like they might are defined as complete gestures, the paragraph I just posted and the Doc suggests otherwise. Didnt test it though. So maybe some extra explanation would help.