CODEWITHSUNDEEP
android
Marian Pavel
Marian Pavel

Reputation: 2876

ViewPager returning wrong fragment

I want to use ViewPager to swipe through songs in my Media Player ( going forward or backward like SoundCloud app for android ). I have created a fragment which I inflate and set inside information like song name, author etc.

I have read some topics on StackOverflow about the ViewPager displays wrong items ( Viewpager shows wrong page and Android Viewpager show wrong pages and a lot more ) but I don't have fixed number of XML's to use with the ViewPager.

My Data is displayed in a RecyclerView, when I am pressing the item on index 4 for example I call the following method:

       mPager.setCurrentItem(position);

So the mPager is set to position 4.

    @Override
    public Fragment getItem(int position) {
        Log.i("TEST","Returnin a fragment on position "+position);
        return fragment = new MusicSliderFragment();
    }

But on my Adapter when it's changing I get the following output:

02-23 10:39:57.131 7599-7599/************** I/TEST: Returning a fragment on position 4
02-23 10:39:57.131 7599-7599/************** I/TEST: Returning a fragment on position 3
02-23 10:39:57.131 7599-7599/************** I/TEST: Returning a fragment on position 5

And when my application is launched I get the following output:

I/TEST: Returning a fragment on position 0
I/TEST: Returning a fragment on position 1

The main problem is when I am opening the app first time and set the song on position 4 the fragment information are displayed in the next fragment.

Is there a way how can I fix this?

Adapter Class:

 private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {

        private MusicSliderFragment fragment;

        public ScreenSlidePagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            Log.i("TEST","Returnin a fragment on position "+position);
            return fragment = new MusicSliderFragment();
        }

        @Override
        public int getCount() {
            return NUM_PAGES;
        }

        public void updateSongName(String name) {
            fragment.setSongName(name);
        }
    }

The RecyclerView Listener :

            musicList.addOnItemTouchListener(
            new RecyclerItemClickListener(getApplicationContext(), new RecyclerItemClickListener.OnItemClickListener() {
                @Override
                public void onItemClick(View view, final int position) {

                        Log.i("TEST", "Setting the mPager position to: "+position);
                        mPager.setCurrentItem(position);
                    }
                }


And the `Listener` of the `mPager` where I update the song name for example:

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

            }

            @Override
            public void onPageSelected(int position) {

                play(position);

                ScreenSlidePagerAdapter adapter = (ScreenSlidePagerAdapter) mPager.getAdapter();
                adapter.updateSongName(splitName(myDataList.get(position))[0]);

                Log.i("TEST", "Playing the position: "+position);
                mPagerAdapter.notifyDataSetChanged();
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

Upvotes: 0

Views: 1595

Answers (2)

Murali krishna
Murali krishna

Reputation: 823

Viewpager indexing starts from zero if you want to load the fourth Fragment then you need to set the position 3.

  mPager.setCurrentItem(3); //Load the 4th fragment according to you.(0-3)

Upvotes: 0

Konstantin Volkov
Konstantin Volkov

Reputation: 300

View pager can load neighbour fragments when you choose current. Method setOffscreenPageLimit() defines how many neighbours you want to preload. onPageSelected(int position) should work correct and returns current item.

Upvotes: 2

Related Questions