How to reset a List to its initial state

Question

I am a beginner when it comes to AndroidStudio and I am developing this app, where I am having problems with filtering information from a firebase database. When clicking on switch1 (activating it), I get the filtered Informations, but when I deactivate it, I don't get a list with all Infos but only the filtered ones added one more time. The part of the code that's supposed to be responsible for that is commented under //delivery service

public class SearchActivity extends AppCompatActivity {
private final FirebaseFirestore db = FirebaseFirestore.getInstance();
private AppModel appModel;

//Datenkategorien
private boolean[] checkedDK;

//Betriebsart
private boolean[] checkedBA;

//Produktgruppe
private boolean[] checkedPr;


private String[] orgaList;

//bzw. Liste aus Organization-Objekte getname().toString
//final Organization[] organisations = ...;
private boolean[] checkedOrgas;
private List<Company> companies;
private ListView listView;
private CompanyAdapter adapter;
private int layout;

@RequiresApi(api = Build.VERSION_CODES.N)
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.search_main);

    layout = R.layout.company_list;
    appModel = new AppModel();

    //Daten von FireStore ablesen und konvertieren
    ParseData parseData = new ParseData(db, appModel);
    parseData.parseFrom();



    //Liste von Betrieben aus dem Datenbank
    companies = appModel.getCompanies();
    

    checkedDK = new boolean[getResources().getStringArray(R.array.dataCategories).length];
    checkedBA = new boolean[getResources().getStringArray(R.array.betriebsarten).length];
    checkedPr = new boolean[getResources().getStringArray(R.array.products).length];
    checkedOrgas = new boolean[4];

    this.listView = findViewById(R.id.companiesList);

    this.adapter = new CompanyAdapter(this, this.layout, this.companies,false);
    this.listView.setAdapter(this.adapter);

    //Swicth, ob alle Informationen gezeigt werden sollen
    SwitchCompat allInfo = findViewById(R.id.switch3);
    allInfo.setOnCheckedChangeListener((buttonView, isChecked) -> {
        if(isChecked) {
            this.adapter.setChecked(true);
            this.layout = R.layout.all_info_company;
        } else {
            this.adapter.setChecked(false);
            this.layout = R.layout.company_list;
        }
        this.adapter.setLayout(this.layout);
        this.adapter.notifyDataSetChanged();

    });

    //delivery service
    SwitchCompat deliveryService = findViewById(R.id.switch1);
    deliveryService.setOnCheckedChangeListener((buttonView, isChecked) -> {
        if(isChecked) {
            companies.removeIf(company -> !company.hasDeliveryService());
        } else {
            this.companies = this.appModel.getCompanies();

        }
        adapter.clear();
        adapter.addAll(companies);
        adapter.notifyDataSetChanged();
    });

Here is the other class used (not the full code, Company is a self-defined class):

public class AppModel {
List<Company> companies;
List<DataCategory> dataCategories;

List<String> organizationsName;
List<Types> companyTypes;
List<Categories> productCategories;
boolean isOpen;
TimeInterval openingHours;
boolean deliveryService;


public AppModel(){
    this.companies = new ArrayList<>();
    this.dataCategories = new ArrayList<>();
    this.organizationsName = new ArrayList<>();
    this.companyTypes = new ArrayList<>();
    this.productCategories = new ArrayList<>();
    this.isOpen = false;
    this.deliveryService = false;
}



public List<Company> getCompanies() {
    return companies;
}

I tried creating another ArrayList temp = new ArrayList(); and then temp.addAll(companies) and only after that altering companies and by else clearing companies and then addAll(temp) but it didn't work

Answer 1

Looks like you are trying to use same AppModel instance when you uncheck. That's why you got already filtered value again. try this code instead.

deliveryService.setOnCheckedChangeListener((buttonView, isChecked) -> {
        if(isChecked) {
            appModel = new AppModel();
            companies = appModel.getCompanies();
            companies.removeIf(company -> !company.hasDeliveryService());
        } else {
            appModel = new AppModel();
            companies = appModel.getCompanies();
           
        }
        adapter.clear();
        adapter.addAll(companies);
        adapter.notifyDataSetChanged();}