I am beginner to android application development. I have implemented a Tablayout in my HomeActivity Layout along with a Viewpager and title to display selected fragment in TextView. The I have placed three Tabitems inside the layout. I was implementing updating Activity title to display on toolbar on clicking a tab button and found a solution this link
activity_home.xml
android.support.design.widget.TabLayout
android:id="@+id/tabLayout"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
app:tabSelectedTextColor="@color/clinividPink"
app:tabTextAppearance="@style/MineCustomTabText">
<android.support.design.widget.TabItem
android:id="@+id/contactsTabButton"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:icon="@drawable/contacts_tab_state"
android:text="@string/contacts_tab_name" />
<android.support.design.widget.TabItem
android:id="@+id/casesTabButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:icon="@drawable/cases_tab_state"
android:text="@string/cases_tab_name" />
<android.support.design.widget.TabItem
android:id="@+id/profileTabButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:icon="@drawable/profile_tab_state"
android:text="@string/profile_tab_name" />
</android.support.design.widget.TabLayout>
<android.support.v4.view.ViewPager
android:id="@+id/contactsVIew"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toTopOf="@+id/tabLayout"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/toolbar2" />
<TextView
android:id="@+id/home_activity_title"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginTop="12dp"
android:layout_marginBottom="12dp"
android:text="Contacts"
android:textSize="18sp"
android:textStyle="bold"
app:layout_constraintBottom_toBottomOf="@+id/toolbar2"
app:layout_constraintEnd_toEndOf="@+id/toolbar2"
app:layout_constraintStart_toStartOf="@+id/toolbar2"
app:layout_constraintTop_toTopOf="@+id/toolbar2" />
The viewpager is filled with the Fragment adapter conditionally with 3 different fragments.
HomeTabLayoutAdapter.java
public class HomeTabLayoutAdapter extends FragmentPagerAdapter {
private Context myContext;
int totalTabs;
private static final String LOG_TAG = HomeTabLayoutAdapter.class.getSimpleName();
public HomeTabLayoutAdapter(FragmentManager fm, Context myContext, int totalTabs) {
super(fm);
this.myContext = myContext;
this.totalTabs = totalTabs;
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0: {
Log.d(LOG_TAG, "\nFragment: 0 - Contacts");
ContactsFragment contactsFragment = new ContactsFragment();
return contactsFragment;
}
case 1: {
Log.d(LOG_TAG, "\nFragment: 1 - Cases ");
CasesFragment casesFragment = new CasesFragment();
return casesFragment;
}
case 2: {
Log.d(LOG_TAG, "\nFragment: 2 - Profile");
ProfileFragment profileFragment = new ProfileFragment();
return profileFragment;
}
default: {
Log.d(LOG_TAG, "\nFragment: default");
return new Fragment();
}
}
}
@Override
public int getCount() {
return totalTabs;
}
}
My fragments look something like this
SampleFragment.java
public class CasesFragment extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
private static final String LOG_TAG = CasesFragment.class.getSimpleName();
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
public CasesFragment() {
// Required empty public constructor
}
public static CasesFragment newInstance(String param1, String param2)
{
CasesFragment fragment = new CasesFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View casesFragmentView = inflater.inflate(R.layout.fragment_cases, container, false);
Log.d(LOG_TAG, "\nCASES listener: " + mListener);
if (mListener != null) {
mListener.onFragmentInteraction("Cases");
}
return casesFragmentView;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
String onHomeAndFragment1Listener(String title); // increment number in name for each fragment interface
}
}
In my HomeActivity.java implements the OnFragmentInteractionListener for all three fragments like this
public class HomeActivity
extends AppCompatActivity
implements ContactsFragment.OnFragmentInteractionListener,
ProfileFragment.OnFragmentInteractionListener,
CasesFragment.OnFragmentInteractionListener
{
TabLayout tabLayout;
ViewPager viewPager;
TextView homeActivityTitleView;
private static final String LOG_TAG = HomeActivity.class.getSimpleName();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
tabLayout=(TabLayout)findViewById(R.id.tabLayout);
viewPager=(ViewPager)findViewById(R.id.contactsVIew);
homeActivityTitleView=(TextView) findViewById(R.id.home_activity_title);
final HomeTabLayoutAdapter adapter = new HomeTabLayoutAdapter(getSupportFragmentManager(), this, tabLayout.getTabCount());
viewPager.setAdapter(adapter);
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
Log.d(LOG_TAG, "\nSELECTED tab: " + tab.getPosition());
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
Log.d(LOG_TAG, "\nUNSELECTED tab: " + tab.getPosition());
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
Log.d(LOG_TAG, "\nRESELECTED tab: " + tab.getPosition());
}
});
viewPager.setCurrentItem(1);
}
@Override
public String onHomeAndCasesInteraction(String title) {
Log.d(LOG_TAG, "\nUpdate title: " + title);
homeActivityTitleView.setText(title);
return title;
}
@Override
public String onHomeAndContactsInteraction(String title) {;
Log.d(LOG_TAG, "\nUpdate title: " + title);
homeActivityTitleView.setText(title);
return title;
}
@Override
public String onHomeAndProfileInteraction(String title) {
Log.d(LOG_TAG, "\nUpdate title: " + title);
homeActivityTitleView.setText(title);
return title;
}
@Override
public void onFragmentInteraction(Uri uri) {
}
}
The tablayout UI is working fine but the activity title in my activity_home.xml does not work as expected when I click on the middle tab. it either display the text of the left or right tab depending on the case which was previous tab selected. I have tried to add as much formatting as possible for time being but if you guys need more info, tell me in the comments and I will update.
P.S I have tried experiment with adding a 4th tab and another fragment and the results are even more unpredictable than with 3 tabs. Please someone help me.
UPDATE answer:
Abhisheik's answer works and I changed my tabLayout.addOnTabSelectedListener in my HomeActivity.java as following and removed calls to update title from onCreateView of each fragment.
tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
Log.d(LOG_TAG, "\nSELECTED tab: " + tab.getPosition());
viewPager.setCurrentItem(tab.getPosition());
switch (tab.getPosition()) {
case 0: onHomeAndContactsInteraction("Contacts"); return;
case 1: onHomeAndCasesInteraction("Cases"); return;
case 2: onHomeAndProfileInteraction("Profile"); return;
default: onHomeAndCasesInteraction("Cases"); return;
}
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
Log.d(LOG_TAG, "\nUNSELECTED tab: " + tab.getPosition());
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
Log.d(LOG_TAG, "\nRESELECTED tab: " + tab.getPosition());
}
});
