Is there anyway i can detect a scroll and scroll stop events ?

Question

I am using a scrollview in my layout. I need to animate when there is a scroll event and stop the animation when a scroll is ended.

I checked scrollview but it didnt seem to provide these events. Do i need to use Gesture Detector?

Please help.

Thanks, Sneha

score 2 · Accepted Answer · answered Oct 01 '14 at 05:11

This solved my problem ! :)

svMovieDetails.setOnTouchListener( new View.OnTouchListener( ) {

        @Override
        public boolean onTouch( View v, MotionEvent event ) {
            switch ( event.getAction( ) ) {
                case MotionEvent.ACTION_SCROLL:
                case MotionEvent.ACTION_MOVE:
                    Log.e( "SCROLL", "ACTION_SCROLL" );
                    break;
                case MotionEvent.ACTION_DOWN:
                    Log.e( "SCROLL", "ACTION_DOWN" );
                    break;
                case MotionEvent.ACTION_CANCEL:
                case MotionEvent.ACTION_UP:
                    Log.e( "SCROLL", "SCROLL_STOP" );
                    break;
            }
            return false;
        }
    } );

score 1 · Answer 2 · answered Sep 30 '14 at 14:17

1

You can extend ScrollView, and override

@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt)

to get the scroll. To get this values in your activity/fragment, you can also define a listener

answered Sep 30 '14 at 14:17

Blackbelt

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Thanks. But how do it get if the scroll is taking place or ended ? – user2234 Sep 30 '14 at 14:18
1

I think that you can consider the scroll idle when `oldt== t` and `oldl==l`. If it is taking place the values will be different – Blackbelt Sep 30 '14 at 14:24

score 0 · Answer 3 · edited May 23 '17 at 11:57

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());
    }

    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() {
    }
}

might be this one help you i get from this discussion

Is there anyway i can detect a scroll and scroll stop events ?

3 Answers3