Android viewpager detect swipe beyond the bounds

Question

In my Android application, I am using a viewpager for image swiping. My requirement is, if a user swipes out of the first and last page, the activity should finish.

I ha

Answer 1

I changed M.A.Murali's code:

public class CheckBoundsPager extends ViewPager {
    public CheckBoundsPager(Context context) {
        super(context);
    }

    public CheckBoundsPager(Context context, AttributeSet attrs) {
        super(context, attrs);

    }

    OnSwipeOutListener mListener;

    public void setOnSwipeOutListener(OnSwipeOutListener listener) {
        mListener = listener;
    }

    private float mStartDragX;
    private float mStartDragY;
    private float MIN_MOVE=50; //minimal movement in px - change it to you value


    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        float x = ev.getX();
        float y = ev.getY();
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN: {
                //here we set x and y on user start drag
                mStartDragX = x;
                mStartDragY = y;

                }
                break;
            case MotionEvent.ACTION_MOVE: {

                //most important to check if x drag is more than y
                float xDiff=Math.abs(mStartDragX-x);
                float yDiff=Math.abs(mStartDragY-y);

                //added condition if swipe y is less than x
                if (mStartDragX < x-MIN_MOVE && xDiff>yDiff &&  getCurrentItem() == 0) {
                    mListener.onSwipeOutAtStart();
                } else if (mStartDragX > x+MIN_MOVE
                        && xDiff>yDiff && getCurrentItem() == getAdapter().getCount() - 1) {
                    mListener.onSwipeOutAtEnd();
                }
                }
                break;
        }
        return super.onInterceptTouchEvent(ev);
    }

    public interface OnSwipeOutListener {

        public void onSwipeOutAtStart();

        public void onSwipeOutAtEnd();
    }
}

This solutions checks if we drag left or right and our drag's movement is in the x-axis. Remember to change MIN_MOVE.

Answer 2

In my case, onInterceptTouchEvent does not work. I change the method with onTouchEvent and it is working. The original solution is from tjlian616

    @Override
public boolean onTouchEvent(MotionEvent ev){
    if(getCurrentItem()==getAdapter().getCount()-1){
        final int action = ev.getAction();
        float x = ev.getX();
        switch(action & MotionEventCompat.ACTION_MASK){
        case MotionEvent.ACTION_DOWN:
            mStartDragX = x;
            break;
        case MotionEvent.ACTION_MOVE:
            break;
        case MotionEvent.ACTION_UP:
            if (x<mStartDragX){
                mListener.onSwipeOutAtEnd();
            }else{
                mStartDragX = 0;
            }
            break;
        }
    }else{
        mStartDragX=0;
    }
    return super.onTouchEvent(ev);
}    

Answer 3

*You can achive this by impementing OnPageChangeListener

http://developer.android.com/reference/android/support/v4/view/ViewPager.OnPageChangeListener.html

myPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
    @Override
    public void onPageScrolled(int i, float v, int i2) {

    }
    @Override
    public void onPageSelected( int i) {
      if(i == 0 || i == list.size()- 1){
         finish();
      }
    }
    @Override
    public void onPageScrollStateChanged(int i) {
    }
});*

Answer 4

I have also used the code from this SO answer. Make sure you make the necessary changes to your activity class. Here's what I did...

I changed my activity so it implements CustomViewPager.OnSwipeOutListener.

In my activity, after my mPager = (CustomViewPager) findViewById(R.id.pager); line, I call mPager.setOnSwipeOutListener(this);

All you need to do then is override the onSwipeOutAtStart() and onSwipeOutAtEnd() methods in your activity.