Implementing Search Filter Causing Problem When Pressed Backspace

I am trying to implement a search filter on complex object data in recyclerview when I type in the Edit text first-time it works properly, but whenever I try to delete characters b

Solution 1:

I assume the arrcopy is the copy of arr like:

ArrayList<User> arrcopy = new ArrayList<>(arr);

If you modify arr, it also change the content of arrcopy. And when no result matches, the arr is empty, so is the arrcopy.

else {
    temp.addAll(arrcopy);
}
arr.clear();
arr.addAll(temp);

Now temp is empty, the arr data you set for adapter is empty, so issues happens. Please try: In MyAdapter:

Context cxt;
ArrayList<user> arr;
publicMyAdapter(Context context){
    cxt = context;
    dref = FirebaseDatabase.getInstance().getReference("users");
}

publicvoidsetData(ArrayList<User> arrayList){
    arr = arrayList;
    notifyDataSetChanged();
}

Also put the filter() in your activity/fragment:

protectedvoidonCreate(final Bundle savedInstanceState) {
    etSearch = (EditText) findViewById(R.id.edittext);
    etSearch.setOnClickListener(newView.OnClickListener() {
        @OverridepublicvoidonClick(View v) {
            etSearch.requestFocus();
        }
    });
    etSearch.addTextChangedListener(newTextWatcher() {
        @OverridepublicvoidbeforeTextChanged(CharSequence s, int start, int count, int after) {
        }

        @OverridepublicvoidonTextChanged(CharSequence s, int start, int before, int count) {
                filter(etSearch.getText().toString());
        }

        @OverridepublicvoidafterTextChanged(Editable s) {
        }
    });
    etSearch.clearFocus();

    mAdapter = newMyAdapter(this);
    mAdapter.setData(arrayList);
    mRecyclerView.setAdapter(mAdapter);
    ...
}

publicvoidfilter(String input) {
    if (!TextUtils.isEmpty(input)) {
        ArrayList<User> temp = newArrayList<>();
        for (user s : arr) {
            if (s.getName().toLowerCase().contains(input)) {
                temp.add(s);
            }
        }
        mAdapter.setData(temp);
    } else {
        mAdapter.setData(arr);
    }
    mAdapter.notifyDataSetChanged();
}

Solution 2:

Implement Filterable in your MyAdapter

publicclassMyAdapterextendsRecyclerView.Adapter<MyAdapter.MyHolder> 
    implementsFilterable {
      // change MyObject to user class//replace myObjects with arr and reservedList with arrcopy

    Context cxt;
    ArrayList<MyObject> myObjects;
    ArrayList<MyObject> reservedList;
    DatabaseReference dref;


publicMyAdapter(Context context, ArrayList<MyObject> arrayList){
        cxt = context;
        myObjects = arrayList;
        reservedList = arrayList
        Log.d("Very start arr",myObjects.toString());
       // notifyDataSetChanged();
        dref = FirebaseDatabase.getInstance().getReference("users");
    }

   //...@Overridepublic Filter getFilter() {
    returnnewFilter() {
        @Overrideprotected FilterResults performFiltering(CharSequence charSequence) {
            StringcharString= charSequence.toString().toLowerCase();
            if (!charString.isEmpty()) {
                List<MyObject> filteredList = newArrayList<>();
                for (MyObject row : reservedList) {
                    if (row.getName().toLowerCase().contains(charString)){
                        filteredList.add(row);
                    }
                }
                myObjects = filteredList;
            } else {
                myObjects = reservedList;
            }

            FilterResultsfilterResults=newFilterResults();
            filterResults.values = myObjects;
            return filterResults;
        }

        @OverrideprotectedvoidpublishResults(CharSequence charSequence, FilterResults filterResults) {
            myObjects = (ArrayList<MyObject>) filterResults.values;
            notifyDataSetChanged();
        }
    };
}

and from your activity

etSearch = (EditText) findViewById(R.id.edittext);

etSearch.addTextChangedListener(newTextWatcher() {
    @OverridepublicvoidbeforeTextChanged(CharSequence s, int start, int count, int after) {

    }

    @OverridepublicvoidonTextChanged(CharSequence s, int start, int before, int count) {

      myAdapter.getFilter().filter(s);

    }

    @OverridepublicvoidafterTextChanged(Editable s) {

    }
});