Searchview with listview didn't work properly

Question

I have a fragment activity. I implemented a searchview on it and items for it's are loaded from firebase that lists as listview. It works when I waits for some time and loads data. But, when I clicked on searchview immediately before the load happens, it didn't load any data even after long time . Then when I go back to the main fragment and return again loads data immediately. I think it's a small problem, but I am a beginner in android development, so it's very hard for me. Here is my code:

public class FragmentHome extends Fragment {
private SearchView search;
View view;
DatabaseReference dataRef;
private  FirebaseListAdapter<String> firebaseListAdapter;
ListView mListView;
private TextView text;
ArrayList<String> city=new ArrayList<String>();
private int i=0;
private String data,val,var;
ArrayAdapter<String> adapter;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable final Bundle savedInstanceState) {
    View v= inflater.inflate(R.layout.activity_fragment_home,container,false);
    if (container!=null){
        container.removeAllViews();
    }
    search= (SearchView) v.findViewById(R.id.search);
    search.onActionViewExpanded();
    search.setIconified(false);
    search.setQueryHint("Search Docter By City Or Department");
    mListView= (ListView) v.findViewById(R.id.mList);
    mListView.setVisibility(View.INVISIBLE);
    dataRef=FirebaseDatabase.getInstance().getReference().child("Docters");
    adapter=new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, city);
    mListView.setAdapter(adapter);
    dataRef.addChildEventListener(new ChildEventListener() {
        @Override
        public void onChildAdded(DataSnapshot dataSnapshot, String s) {
            data=dataSnapshot.child("city").getValue(String.class);
            val=dataSnapshot.child("department").getValue(String.class);
            if (!city.contains(data)){
                city.add(data);
            }
            if (!city.contains(val)){
                city.add(val);
            }
            adapter.notifyDataSetChanged();

        }
        @Override
        public void onChildChanged(DataSnapshot dataSnapshot, String s) {
            data=dataSnapshot.child("city").getValue(String.class);
            val=dataSnapshot.child("department").getValue(String.class);
            city.add(data);
            city.add(val);
            city.add(var);
            adapter.notifyDataSetChanged();
        }

        @Override
        public void onChildRemoved(DataSnapshot dataSnapshot) {

        }

        @Override
        public void onChildMoved(DataSnapshot dataSnapshot, String s) {
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });
    search.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
        @Override
        public boolean onQueryTextSubmit(String text) {

            return false;
        }

        @Override
        public boolean onQueryTextChange(String text) {
            if (!text.isEmpty()){
            mListView.setVisibility(View.VISIBLE);
                adapter.getFilter().filter(text);
            }else{
                mListView.setVisibility(View.INVISIBLE);
            }
            return false;
        }

    });

    mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            String itemRef = (String) adapter.getItem(position);
            search.setVisibility(View.INVISIBLE);
            mListView.setVisibility(View.INVISIBLE);
            FragmentTransaction ft=getChildFragmentManager().beginTransaction();
            DocterList fragment=new DocterList();
            Bundle item=new Bundle();
            item.putString("item",itemRef);
            fragment.setArguments(item);
            ft.replace(R.id.activity_fragment_home,fragment);
            ft.addToBackStack(null);
            ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
            ft.commit();
        }
    });
    return v;
  }}

If anybody knows how to fix this please help me. Thanks in advance...

Answer 1

make a method filter in your adapter like this

public void filter(String charText) {
    charText = charText.toLowerCase(Locale.getDefault());
    contactList.clear();
    if (charText.length() == 0) {
        contactList.addAll(contactListFiler);
    }else{
        for (Contacts contact : contactListFiler)
        {
            if (contact.getNumber().toLowerCase(Locale.getDefault()).contains(charText.toLowerCase(Locale.getDefault())))
            if (contact.getContact_name().toLowerCase(Locale.getDefault()).contains(charText.toLowerCase(Locale.getDefault())))
            {
                contactList.add(contact);
            }
        }
    }
    notifyDataSetChanged();
}

Now call it from your activity or fragment by implementing

edittext_searchname.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

        }

        @Override
        public void afterTextChanged(Editable s) {
            String str = edittext_searchname.getText().toString().toLowerCase(Locale.getDefault());
            adapter.filter(str);
        }
    });