CODEWITHSUNDEEP
androidtabsandroid-viewpager
user2982426
user2982426

Reputation: 11

How to refresh the ViewPager for every tab?

I'm using ViewPager as a main layout and for individual pager views I use Fragments. The tabs are part of Action Bar. I wanna refresh the current tab with the refresh-button in my actionbar.

My MainActivity.java 

@Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


    viewPager = (ViewPager) findViewById(R.id.pager);
    actionBar = getActionBar();
    mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

    viewPager.setAdapter(mAdapter);
    actionBar.setHomeButtonEnabled(false);
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);  

    // Adding Tabs
    for (String tab_name : tabs) {
        actionBar.addTab(actionBar.newTab().setText(tab_name)
                .setTabListener(this));
    }

    /**
     * on swiping the viewpager make respective tab selected
     * */
    viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

        @Override
        public void onPageSelected(int position) {
            // on changing the page
            // make respected tab selected
            actionBar.setSelectedNavigationItem(position);
            mAdapter.notifyDataSetChanged();
        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) {
        }

        @Override
        public void onPageScrollStateChanged(int arg0) {
        }
    });
}


@Override
public boolean onOptionsItemSelected(MenuItem menuItem)
{     
    switch (menuItem.getItemId()) {


    case R.id.action_refresh:

         // code for the refresh             

        return true;

    default:
        this.finish();

        return super.onOptionsItemSelected(menuItem);
    }
    //startActivity(new Intent(this,PreviousActivity.class)); 
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.activity_actions, menu);

    return super.onCreateOptionsMenu(menu);
}

@Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}

@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
    // on tab selected
    // show respected fragment view
    viewPager.setCurrentItem(tab.getPosition());
}

@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}

This is one of my Tabs StartPage.java

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.startpage, container, false);
    return rootView;
}



@Override
public void onTabReselected(Tab arg0, FragmentTransaction arg1) {
    // TODO Auto-generated method stub

}
@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
    // TODO Auto-generated method stub

}
@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
    // TODO Auto-generated method stub

}

Upvotes: 1

Views: 2763

Answers (1)

doorstuck
doorstuck

Reputation: 2308

One way is to find the selected tab in the action bar, cast it to its type, and call a method on it.

That is a dependency you might want to avoid.

I prefer to use broadcasts for this scenario. Register a broadcast receiver in the fragments onResume method, unregister it in onPause. Then let a context broadcast an intent for a refresh and the fragment will do that.

This will let you refresh the fragments from everywhere in your application. Even if the refreshing code ends up in a service running in the background.

Update:

You will have some code like this anywhere you want (this is s context): 

LocalBroadcastManager lbm = LocalBroadcastManager.getInstance(this);
Intent i = new Intent(REFRESH_CONSTANT);
lbm.sendBroadcast(i);

Then in your fragment you listen for this broadcast:

public class MyFragment extends Fragment {

    MyReceiver r;

    public void refresh() {
        // Do the refresh
    }

    public void onPause() {
        LocalBroadcastManager.getInstance(mContext).unregisterReceiver(r);
    }

    public void onResume() {
        r = new MyReceiver ();
        LocalBroadcastManager.getInstance(mContext).registerReceiver(r,
            new IntentFilter(REFRESH_CONSTANT));
    }

    private class MyReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            MyFragment.this.refresh();
        }
    }
}

Upvotes: 2

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