Moving view pager to first item when the end of view pager is reached

Question

Following is my instantiateItem method

@Override
    public Object instantiateItem(ViewGroup container, int position) {
        View itemView = mLayoutInflater.inflate(R.layout.pager_item, container, false);

        ImageView imageView = (ImageView) itemView.findViewById(R.id.img);
        TextView textView = (TextView) itemView.findViewById(R.id.txt);
        imageView.setImageResource(mResources[position]);
        textView.setText(mCompanies[position]);
        container.addView(itemView);

        return itemView;
    }

I want to detect if user has reached the end of view pager by scrolling and if the user has reached the end, I wanna shake the entire viewpager from left to right. How can I do so?

https://stackoverflow.com/a/76712000/19856629 this is worked — Kanan, Jul 18 '23 at 10:56

score 0 · Answer 1 · answered Mar 18 '16 at 11:44

0

you can use OnPageChangeListener for this

pager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                if(position == lastPosition){
                    pager.setCurrentItem(0, true);
                }
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

answered Mar 18 '16 at 11:44

Ankit Aggarwal

5,317
2
30
53

Thank you but how to get the last position? – Mar 18 '16 at 12:15
pager.getAdapter().getCount() - 1; – Ankit Aggarwal Mar 18 '16 at 12:28
3

When I swipe to the last view pager screen, it is automatically getting scrolling to the first one. It should scroll to the first view pager screen only if I scroll the last one. – Srikar Reddy Jul 22 '16 at 11:00
https://stackoverflow.com/a/76712000/19856629 this is worked – Kanan Jul 18 '23 at 10:54

score 0 · Accepted Answer · edited Sep 23 '16 at 07:00

0

@Override
public void onPageScrollStateChanged(int state) {

     //mImageResource is image array

    if(state<mImageResources.length)
    {
   //intro_images is viewpager           
   intro_images.setCurrentItem(0,true);
    }

}

edited Sep 23 '16 at 07:00

Petter Friberg

21,252
9
60
109

answered Sep 23 '16 at 06:49

NewLearnr

32
3

1

this is incorrect. the state for onPageScrollStateChanged have only 0 1 2 – Anonymous-E Nov 21 '19 at 09:41
https://stackoverflow.com/a/76712000/19856629 this is worked – Kanan Jul 18 '23 at 10:54
https://stackoverflow.com/a/76712000/19856629 this is worked – Kanan Jul 18 '23 at 10:56

score 0 · Answer 3 · answered Mar 01 '22 at 20:41

One solution could be to override touch listener of viewPager to perform the required actions. You can see how it is working in this Video ViewPager Example.

What I'm doing here is storing the touchDown x coordinate and comparing it with the touchUp x coordinate to find if it is a movement from left to right or right to left. As x starts from left with 0 and increases towards the right. So when downX is smaller than upX, it is moving from left to right and vice versa.

For Right to Left, I'm moving the viewPager forward, and if it is at the last position, move to first. And similarly, for Left to Right, I'm moving the viewPager backward and if it is at the first position, move to last.

To override the TouchListener return 'true' in the last line.

viewPager.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            switch (event.getActionMasked()) {
                case MotionEvent.ACTION_DOWN:
                    // store the x coordinate of touch down
                    actionDownX = event.getX();
                    break;

                case MotionEvent.ACTION_UP:
                    int currentPosition = viewPager.getCurrentItem();

                    // the x coordinate of action up
                    float actionUpX = event.getX();

                    // Swiped from Left to Right -> Move Backward
                    if (actionDownX < actionUpX) {

                        // Move to Last item 
                        if (currentPosition == 0) {
                            viewPager.setCurrentItem(size - 1, true);
                        }

                        // Move Backward
                        else {
                            int nextPosition = Math.max(0, currentPosition - 1);
                            viewPager.setCurrentItem(nextPosition, true);
                        }
                    }

                    // Swiped from Right to Left -> Move Forward
                    else if (actionDownX > actionUpX) {

                        // Move to First item
                        if (currentPosition == size - 1) {
                            viewPager.setCurrentItem(0, true);
                        }

                        // Move Forward
                        else {
                            int nextPosition = Math.min(size - 1, currentPosition + 1);
                            viewPager.setCurrentItem(nextPosition, true);
                        }
                    }
            }

            // This is important. To override the default behavior, return true
            return true;
        }
    });

NOTE: Please note that this is not a complete solution but just an idea of how you can perform your required actions. It does not behave exactly like a viewPager (you can see that in the video) when swiping. So it is advised not to just copy-paste this code instead you should expand/improve the cod and add all the necessary checks.

Moving view pager to first item when the end of view pager is reached

3 Answers3