CODEWITHSUNDEEP
androidandroid-viewpagerandroid-tablayoutandroid-pageradapter
Julia
Julia

Reputation: 1399

TabLayout Preload next tab

I have a tablayout (tab1, tab2, tab3) with a ViewPager. It seems that on app startup the tab2 is preloaded which is fine.

However, I need to input some data on tab1 and I want the tab2 to update its fragment and hide some buttons based on the data input from tab1.

How to do that? Is there a way to not preload the tab so that when I swipe to tab2, it will be getting the latest data instead of the old data?

Here's my code

private ViewPager viewPager;
private PagerAdapter adapter;
private TabLayout tabLayout;

in my onCreate method within an activity.

    tabLayout.addTab(tabLayout.newTab().setText("Input"));
    tabLayout.addTab(tabLayout.newTab().setText("Detail"));
    tabLayout.addTab(tabLayout.newTab().setText("Chart"));
    tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);

    viewPager = (ViewPager) findViewById(R.id.pager);
    adapter = new PagerAdapter(getSupportFragmentManager(), tabLayout.getTabCount());
    viewPager.setAdapter(adapter);
    viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
    tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            viewPager.setCurrentItem(tab.getPosition());
        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });

Here's my pageadapater class

public class PagerAdapter extends FragmentPagerAdapter {
int mNumOfTabs;
private InputFragment inputFragment;
private DetailFragment detailFragment;
private ChartFragment chartFragment;

public PagerAdapter(FragmentManager fm, int NumOfTabs) {
    super(fm);
    this.mNumOfTabs = NumOfTabs;
}

@Override
public int getItemPosition(Object object) {
    // TODO Auto-generated method stub
    return POSITION_NONE;
}


@Override
public Fragment getItem(int position) {
    switch (position) {
        case 0:
            inputFragment = new InputFragment();
            return inputFragment;
        case 1:
            detailFragment = new detailFragment();
            return detailFragment;
        case 2:
            chartFragment = new ChartFragment();
            return chartFragment;
        default:
            return null;
    }
}

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

Upvotes: 1

Views: 535

Answers (1)

Frankenxtein
Frankenxtein

Reputation: 493

on your detailfragment fragment

@Override
    public void setUserVisibleHint(boolean isVisibleToUser) {
    super.setUserVisibleHint(isVisibleToUser);
    if (isVisibleToUser) {
//check values on tab 1 and try to update your tab 2 views accordingly
    }
    }

Upvotes: 1

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