How do I save the state of my tablayout item and associated viewpager content position after reloading the whole view?

Question

I have a tablayout associated with a viewpager. Everytime I pull to refresh, currently I try to reload the entire page (calling finish and starting the activity again).Say I have 4 items in my tab layout (dynamic) , I would like to have it such that, everytime I refresh, I can save the state of the item selected prior to refresh and then display it after the entire screen is reloaded.

I tried a couple of things recommended online but had no luck.

Here's the code I can potentially use, but not sure how to go about it :

 void selectPage(int pageIndex)
    {
        mViewPager.setCurrentItem(pageIndex);
        mTabLayout.setupWithViewPager(mViewPager);
    }

Also,

@BindView(R.id.lists_view_pager)
    ViewPager mViewPager;

    @BindView(R.id.lists_refresh)
    SwipeRefreshLayout mRefresh;

    @BindView(R.id.tab_layout)
    TabLayout mTabLayout;

On create I call:

mRefresh.setOnRefreshListener(this::refreshassistant);

refreshassistant is as follows :

 public void refreshassistant(){
        finish();
        startActivity(getIntent());
        mPagerAdapter.notifyDataSetChanged();
        overridePendingTransition(0, 0);
        mPresenter.onRefresh();
    }

I would like something like if I select tab 2, it shows content of tab 2 and then when I refresh/reload the entire page, i am able to get back tab 2 and its contents. Any idea how to go about it?

Thanks in advance!

Answer 1

You can use following two methods to store and retrieve your values from your pages:

Setting values in Preference:

public static void setDefaults(String key, String value, Context context) {
    SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
    SharedPreferences.Editor editor = preferences.edit();
    editor.putString(key, value);
    editor.commit();
}

Retrive data from Preferences:

public static String getDefaults(String key, Context context) {
    SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
    return preferences.getString(key, null); //if no value found returns null
}