Access a specific component within a listview

0

I have a list of music with a favorite icon, when the user clicks on this icon I want to change the color of the icon as the action to enjoy.

In this framework I have an Activity, a listView in this Activity, an Adapter class that does the inflate of the layout_list.html.xml and it is in this layout that ImageView is ic_favorite_border, that when the user clicks the ImageView (only in the same ImageView and not the whole line because the whole line has another action) I will change the image to R.drawable.ic_favorite.

As the code now, when I click on the ImageView gives a null pointer exception error because it does not resemble the layout component with the Activity because it has another layout.

I'm trying to perform this action within actibity, I do not know if it should be there or in the adapter:

MocidadeActivity.class

public class MocidadeActivity extends AppCompatActivity {
    //ATRIBUTOS
    private ImageView imLike;
    private ListView listView;
    private ArrayList<Hinos> arrayList;
    private ArrayAdapter adapter;
    private DatabaseReference reference;
    private ValueEventListener valueEventListener;
    private Boolean acaoCurtir;

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_mocidade);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        //DEFININDO A TRANSIÇÃO DE ENTRADA DA ACTIVITY
        if (Build.VERSION.SDK_INT >= 22){
            Slide s = new Slide();
            s.setDuration(1000);
            getWindow().setEnterTransition(s);
        }

        //Tentando instanciar o imageview
        imLike = findViewById(R.id.img_like_lista_hinos);

        //Montando a lista de exibição dos hinos
        listView = (ListView) findViewById(R.id.lv_hinos);

        arrayList = new ArrayList<>();
        adapter = new HinosAdapter(MocidadeActivity.this, arrayList);
        listView.setAdapter(adapter);

        //*************** FIREBASE INICIO ************************/
        reference = ConfiguracaoFirebase.getFirebaseReference().child("MOCIDADE")
                .child("HINOS");
        reference.orderByKey();

        valueEventListener = new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                arrayList.clear();

                //Listando os hinos
                for (DataSnapshot data: dataSnapshot.getChildren()){
                    Hinos hinos = data.getValue(Hinos.class);
                    arrayList.add(hinos);
                }

                adapter.notifyDataSetChanged();
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        };

        //*************** FIREBASE FIM ************************/

        /**************** COMPONENTES DA TELA ********************/
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, final int position, long l) {

                if (acaoCurtir == false){
                    try{
                        Hinos hinos = arrayList.get(position);
                        //salvando no shared para ser utilizado depois
                        SharedPreferencias preferences = new SharedPreferencias(MocidadeActivity.this);
                        preferences.salvarHinoPreferences(hinos.getNumero(), hinos.getTitulo(), hinos.getCantor(), hinos.getUrl());

                        Intent letraA = new Intent(MocidadeActivity.this, LetraHinosActivity.class);
                        startActivity(letraA);

                    } catch (Exception e){
                        e.printStackTrace();
                    }
                }

            }
        });
    }

/******************************* METODOS *********************************/
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu_mocidade, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()){
        case R.id.mn_add_hino:

            if (Atalhos.verificarRegente(getApplicationContext()) == true) {
                AdicionarHinoFragment hinoFragment = new AdicionarHinoFragment();
                hinoFragment.show(MocidadeActivity.this.getSupportFragmentManager(), "Alert Adicionar Hino");
            } else {
                Atalhos.acessoNegado(MocidadeActivity.this);
            }
            break;
    }
    return super.onOptionsItemSelected(item);
}

public void favoritarHino(View view){

    Log.d("CURTIR", "Acessou esse metodo");
    int pos = listView.getPositionForView(view);

    acaoCurtir = true;

    Toast.makeText(this, "Clicou no curtir", Toast.LENGTH_SHORT).show();

    imLike.setImageResource(R.drawable.ic_favorite);
}

@Override
protected void onStart() {
    super.onStart();
    reference.addValueEventListener(valueEventListener);
    acaoCurtir = false;
}

@Override
protected void onStop() {
    super.onStop();
    reference.removeEventListener(valueEventListener);
    acaoCurtir = false;
}

HinosAdapter.class

public class HinosAdapter extends ArrayAdapter<Hinos>{
//ATRIBUTOS
Context context;
private ArrayList<Hinos> arrayList;

public HinosAdapter(@NonNull Context c, ArrayList<Hinos> objects) {
    super(c, 0, objects);
    this.context = c;
    this.arrayList = objects;
}

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

    //Validando e criando a lista de hinos
    if (arrayList != null){
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);

        //montando a view a partir do XML
        view = inflater.inflate(R.layout.lista_hinos, parent, false);

        //Recuperando os elementos para exibição
        TextView tvNumero = view.findViewById(R.id.tv_num_hino);
        TextView tvTitulo = view.findViewById(R.id.tv_titulo_hino);
        TextView tvCantor = view.findViewById(R.id.tv_cantor_hino);
        final ImageView imLike = view.findViewById(R.id.img_like_lista_hinos);

        Hinos hinos = arrayList.get(position);
        tvNumero.setText(hinos.getNumero());
        tvCantor.setText(hinos.getCantor());
        tvTitulo.setText(hinos.getTitulo());
        imLike.setImageResource(R.drawable.ic_favorite_border);


        /*imLike.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

            }
        });*/

    }
    return view;
}

}

MocidadeActivity.xml

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

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/AppTheme.PopupOverlay" />

</android.support.design.widget.AppBarLayout>

<ListView
    android:id="@+id/lv_hinos"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

</LinearLayout>

children_list.xml

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

<TextView
    android:id="@+id/tv_num_hino"
    android:layout_width="50dp"
    android:layout_height="wrap_content"
    android:text="33"
    android:textSize="@dimen/numero_hino"
    android:layout_marginLeft="16dp"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    android:layout_marginTop="6dp" />

<TextView
    android:id="@+id/tv_titulo_hino"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Extraordinário"
    android:textSize="@dimen/nome_hino"
    app:layout_constraintTop_toTopOf="parent"
    android:layout_marginTop="6dp"
    app:layout_constraintLeft_toRightOf="@+id/tv_num_hino"
    android:layout_marginLeft="24dp" />

<TextView
    android:id="@+id/tv_cantor_hino"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Jota A"
    android:textSize="@dimen/cantor"
    android:textStyle="italic"
    android:layout_marginTop="8dp"
    app:layout_constraintTop_toBottomOf="@+id/tv_titulo_hino"
    app:layout_constraintLeft_toRightOf="@+id/tv_num_hino"
    android:layout_marginLeft="24dp" />

<ImageView
    android:id="@+id/img_like_lista_hinos"
    android:layout_width="25dp"
    android:layout_height="25dp"
    android:layout_marginRight="36dp"
    android:layout_marginTop="24dp"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    android:onClick="favoritarHino"/>

  </android.support.constraint.ConstraintLayout>
    
asked by anonymous 29.05.2018 / 18:51

1 answer

1

I was able to find the solution to my problem and would like to share, if someone else has the same scenario I had, the solution was very obvious, ie the layout that contains the component in which I want to implement the action is being inflated inside the adapter, then that's where I need to put it, inside the getView itself, I do the implentation of the click event and the code itself already brings me to change the clicked position of the list: My problem was solved with just this code in the getView of the HinosAdapter class:

imLike.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(context, "clicado na posição: "+position, Toast.LENGTH_SHORT).show();
                imLike.setImageResource(R.drawable.ic_favorite);
            }
        });
    
29.05.2018 / 23:52