Нажатие кнопки поиска очищает все элементы / модели в представлении списка

Question

Мой ListView отлично работает при запуске.Проблема заключается в том, что всякий раз, когда я нажимаю кнопку поиска Button, которая вызывает представление поиска, все элементы в моем ListView исчезают.Даже после очистки текстового поля на моем searchview мой ListView все еще находится в состоянии, в котором он пуст.

Loanist_Full.java (Основная деятельность)

package com.memger.pautanganapp;

import android.content.DialogInterface;
import android.content.Intent;
import android.database.DataSetObserver;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.SearchView;
import android.text.TextUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ListView;
import android.widget.TextView;

import com.getbase.floatingactionbutton.FloatingActionButton;

import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;

public class Loanist_Full extends AppCompatActivity {

    private ListView listView;
    private ListView_Adapter adapter;
    private ListView_Model model;
    private ArrayList<ListView_Model> arrayList = new ArrayList<ListView_Model>();

    private MenuItem searchItem;
    private SearchView searchView;

    private TextView totalText, totalCount;
    private ImageButton sortBy;
    private FloatingActionButton addDebtorButton;

    public static final String currency = "₱";
    public static final DecimalFormat formatter = new DecimalFormat("###,###,###.##");

    String mContact[] = {"Craig", "Agatha", "Dave", "Brandon", "Russel", "Gleceper", "Percy", "Test"};
    double mDebt[] = {2000, 525, 8000, 5000, 955, 4000, 50123, 51247};
    double mDebtTotal = 0;
    String mDesc[] = {"This is a description et. cetera", "Ito bata pa dapat di pa pinapautang", "Lalo na to kakatuto lang mag bike nangungutang na", "", "", "", "", ""};
    String mDate[] = {"Apr. 21, 2016", "Mar. 4, 2017", "May 14, 2011", "Mar. 1, 2000", "Jul. 14, 1971", "", "", ""};
    int mImg[] = {R.drawable.debtcontact_craig, R.drawable.debtcontact_agatha, R.drawable.debtcontact_dave, R.drawable.debtcontact_brandon, R.drawable.debtcontact_russel, R.drawable.debtcontact_gleceper, R.drawable.debtcontact_lola, R.drawable.ic_launcher_background};

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

        totalText = findViewById(R.id.TotalTextView);
        totalCount = findViewById(R.id.CountTextView);
        listView = findViewById(R.id.listView);
        adapter = new ListView_Adapter(this, arrayList);
        listView.setAdapter(adapter);
        sortBy = findViewById(R.id.SortByButton);
        addDebtorButton = findViewById(R.id.AddDebtorButton);

        /* TO DO */
        displayListViewContents();
        setTextTotal();

        /* OnClickListeners below */

        /* Listview item */
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                makeDialog(ListView_Adapter.modellist.get(i).getModelContact(),
                        ListView_Adapter.modellist.get(i).getModelDebt(),
                        ListView_Adapter.modellist.get(i).getModelDesc(),
                        ListView_Adapter.modellist.get(i).getModelDate());
            }
        });

        /* Sort by button*/
        sortBy.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                sortArray();
                sortArrayList();
            }
        });

        /* Debtor Button*/
        addDebtorButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                startActivity(new Intent(Loanist_Full.this, Loanist_Add_Debtor.class));
            }
        });

    } /* END onCreate*/

    /* Display listview contents */
    private void displayListViewContents(){
        /* Display contents of listview*/
        for(int i = 0; i < mDebt.length; i++){
            model = new ListView_Model(mContact[i], mDebt[i], mDesc[i], mDate[i], mImg[i]);
            arrayList.add(model);
        }

        totalCount.setText("Count: " + adapter.getCount());

        adapter.registerDataSetObserver(new DataSetObserver() {
            @Override
            public void onChanged() {
                totalCount.setText("Count: " + adapter.getCount());
            }
        });
    }

    /* Set "Total" view text */
    private void setTextTotal(){
        /* Set text of Total based on total amt of mDebt*/
        for (double x: mDebt) { //Compute total mDebt
            mDebtTotal += x;
        }
        if (mDebtTotal == 0){ //If mDebtTotal == 0
            totalText.setText("Create a debt with an amount first.");
        } else {
            totalText.setText("Total: " + currency + " " + formatter.format(mDebtTotal));
        }
    }

    /* Sort item list */
    private void sortArray(){
        Arrays.sort(mContact);
        adapter.notifyDataSetChanged();
    }

    /* Sort array list */
    private void sortArrayList(){
        Collections.sort(arrayList, new Comparator<ListView_Model>() {
            @Override
            public int compare(ListView_Model listView_model, ListView_Model t1) {
                return listView_model.getModelContact().compareTo(t1.getModelContact());
            }
        });
        adapter.notifyDataSetChanged();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);

        searchItem = menu.findItem(R.id.app_searchbutton);
        searchItem.getActionView();

        searchView = (SearchView) searchItem.getActionView();
        searchView.setQueryHint("Enter a contact e.g 'Robert'");

        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                if (TextUtils.isEmpty(newText)){
                    adapter.filter("");
                    listView.clearTextFilter();
                }
                else {
                    adapter.filter(newText);
                }

                //totalCount.setText("Count: " + adapter.getCount());
                return true;
            }
        });

        return true;
    }

    /* Creates a dialog whenever an item on listview is clicked*/
    private void makeDialog(String contact, double debtAmt, String debtDesc, String debtDate){
        AlertDialog alertDialog = new AlertDialog.Builder(Loanist_Full.this).create();
        alertDialog.setTitle("Debt Information");

        if (debtDesc.length() < 1)
            debtDesc = "N/A";
        if (debtDate.length() < 1)
            debtDate = "N/A";

        alertDialog.setMessage("\n" + contact + "'s debt is " + this.currency + " " + debtAmt + "\n\nDescription: " + debtDesc + "\nDebt created: " + debtDate);
        alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                    }
                });
        alertDialog.show();
    }
}

Loanist_full.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    tools:context=".Loanist_Full">

    <LinearLayout
        android:id="@+id/TotalBar"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="#eaeaea"
        android:orientation="horizontal"
        >

        <TextView
            android:id="@+id/TotalTextView"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_marginLeft="15dp"
            android:gravity="center_vertical"
            android:text="Total"
            android:textSize="16dp"
            android:textStyle="bold"
            android:layout_weight="1"
            />

        <TextView
            android:id="@+id/CountTextView"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_marginRight="15dp"
            android:gravity="center_vertical"
            android:text="Count"
            android:textSize="14dp"
            />

        <ImageButton
            android:id="@+id/SortByButton"
            android:layout_width="24dp"
            android:layout_height="24dp"
            android:layout_marginRight="15dp"
            android:layout_gravity="center_vertical"
            android:src="@drawable/ic_sort_black_24dp"
            android:background="?android:selectableItemBackground"/>

    </LinearLayout>

    <View
        android:layout_width="match_parent"
        android:layout_height="3.0dip"
        android:background="@drawable/divider_total"
        android:layout_below="@id/TotalBar"
        />

    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:divider="@drawable/divider_listview"
        android:dividerHeight="0.2dp"
        android:layout_below="@id/TotalBar"
        />

    <com.getbase.floatingactionbutton.AddFloatingActionButton
        android:id="@+id/AddDebtorButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentEnd="true"
        android:layout_alignParentBottom="true"
        android:layout_margin="8dp"
        app:fab_colorNormal="@color/lightYellow"
        app:fab_colorPressed="@color/lightYellowPressed"
        />

</RelativeLayout>

ListView_Adapter.java

package com.memger.pautanganapp;

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

public class ListView_Adapter extends BaseAdapter {
    Context mcontext;
    LayoutInflater inflater;
    public static List<ListView_Model> modellist;
    ArrayList<ListView_Model> arrayList;

    public ListView_Adapter(Context context, List<ListView_Model> modellist){
        mcontext = context;
        inflater = LayoutInflater.from(mcontext);
        this.modellist = modellist;
        this.arrayList = new ArrayList<ListView_Model>();
        this.arrayList.addAll(modellist);

    }

    public class ViewHolder{
        TextView myContact, myDebt, myDesc, myDate;
        ImageView myImg;
    }

    @Override
    public int getCount() {
        return modellist.size();
    }

    @Override
    public Object getItem(int i) {
        return modellist.get(i);
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {

        ViewHolder holder;

        if (convertView == null){
            holder = new ViewHolder();
            convertView = inflater.inflate(R.layout.listview_row, null);

            holder.myContact = convertView.findViewById(R.id.Contact);
            holder.myDebt = convertView.findViewById(R.id.Debt);
            holder.myDesc = convertView.findViewById(R.id.Desc);
            holder.myDate = convertView.findViewById(R.id.Date);
            holder.myImg = convertView.findViewById(R.id.ContactImage);

            convertView.setTag(holder);

        } else {
            holder = (ViewHolder)convertView.getTag();
        }

        holder.myContact.setText(modellist.get(position).getModelContact());
        holder.myDebt.setText(Loanist_Full.currency + " " + Loanist_Full.formatter.format(modellist.get(position).getModelDebt()));
        holder.myDate.setText(modellist.get(position).getModelDate());
        holder.myDesc.setText(modellist.get(position).getModelDesc());
        holder.myImg.setImageResource(modellist.get(position).getModelImg());

        return convertView;
    }

    /* Filter */
    public void filter(String charText){
        charText = charText.toLowerCase(Locale.getDefault());
        modellist.clear();
        if (charText.length()==0){
            modellist.addAll(arrayList);
        }
        else {
            for (ListView_Model model : arrayList){
                if (model.getModelContact().toLowerCase(Locale.getDefault()).contains(charText)){
                    modellist.add(model); //Add to modellist those who contain the words in the search bar
                }
            }
        }
        notifyDataSetChanged();
    }

}