Tracking selected tab and changing a textview accordingly - android-studio

Question

I'm working on my 1st android project, which uses a tab layout. I want to keep track of the active tab and change a textview present in the appbar (main activity).
Here is my main activity, tab manager, and a fragment
MAIN ACTIVITY
private static final String TAG = "MainActivity";
private SectionsPageAdapter mSectionsPageAdapter;
private ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSectionsPageAdapter = new SectionsPageAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.container);
setupViewPager(mViewPager);
TabLayout tabLayout = (TabLayout) findViewById(R.id.Tabs);
tabLayout.setupWithViewPager(mViewPager);
tabLayout.getTabAt(0).setIcon(R.drawable.tab_rooms_24dp);
tabLayout.getTabAt(1).setIcon(R.drawable.tab_feed_24dp);
tabLayout.getTabAt(2).setIcon(R.drawable.tab_profile_24dp);
tabLayout.getTabAt(0).getIcon().setColorFilter(getResources().getColor(R.color.Accent), PorterDuff.Mode.SRC_IN);
tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
tab.getIcon().setColorFilter(getResources().getColor(R.color.Accent),PorterDuff.Mode.SRC_IN);
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
tab.getIcon().clearColorFilter();
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
private void setupViewPager(ViewPager viewPager){
SectionsPageAdapter adapter = new SectionsPageAdapter(getSupportFragmentManager());
adapter.addFragment(new Tab1Fragment(), "");
adapter.addFragment(new Tab2Fragment(), "");
adapter.addFragment(new Tab3Fragment(), "");
viewPager.setAdapter(adapter);
}
TAB MANAGER
private final List<Fragment> mFragmentList =new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public void addFragment(Fragment fragment, String title){
mFragmentList.add(fragment);
mFragmentTitleList.add(title );
}
public SectionsPageAdapter(FragmentManager fm) {
super(fm);
}
#Nullable
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
#Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
#Override
public int getCount() {
return mFragmentList.size();
}
FRAGMENT
private static final String TAG = "Tab3Fragment";
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_tab1,container,false);
return view;
}
I tried creating a variable in an abstract class then extending it into all three of these scripts which would be a simple solution but fragments dont seem to work well with extending, not to mention that probably isnt the most efficient method.
So I'm thinking the best method would be to simply handle it from the SectionsPageManager script?

Answer 1

Use addOnPageChangeListener on you pager.
mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
if (position == 1) {
setTitle("Tab 1");
} else if (position == 2)
{
setTitle("Tab 2");
}
else
{
setTitle("Home");
}
}

Answer 2

So I got it worked out and figured I'd come post the answer for anyone who may need it.
Not that the above answer sets the app title, not a TextView withing the appbar as stated in the question.
private static final String TAG = "MainActivity";
private SectionsPageAdapter mSectionsPageAdapter;
private ViewPager mViewPager;
private TextView activeTab;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
activeTab = (TextView)findViewById(R.id.PageTitle);
mSectionsPageAdapter = new SectionsPageAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.container);
setupViewPager(mViewPager);
}
private void setupViewPager(ViewPager viewPager)
{
SectionsPageAdapter adapter = new SectionsPageAdapter(getSupportFragmentManager());
adapter.addFragment(new Tab1Fragment(), "");
adapter.addFragment(new Tab2Fragment(), "");
adapter.addFragment(new Tab3Fragment(), "");
viewPager.setAdapter(adapter);
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { }
#Override
public void onPageSelected(int position)
{
switch (position){
case 0: activeTab.setText("text");
break;
case 1: activeTab.setText("better text");
break;
case 2: activeTab.setText("best text");
break;
}
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
}