📱 Projeto Lista de Tarefas — Frontend Mobile Android (Java + Views XML)

package br.com.curso.listadetarefas.android.model;

import com.google.gson.annotations.SerializedName;
import java.io.Serializable;
import java.util.Objects;

public class Tarefa implements Serializable {

    @SerializedName("id")
    private Long id;

    @SerializedName("descricao")
    private String descricao;

    @SerializedName("concluida")
    private boolean concluida;

    public Tarefa() {
    }

    public Tarefa(String descricao, boolean concluida) {
        this.descricao = descricao;
        this.concluida = concluida;
    }

    public Tarefa(Long id, String descricao, boolean concluida) {
        this.id = id;
        this.descricao = descricao;
        this.concluida = concluida;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getDescricao() {
        return descricao;
    }

    public void setDescricao(String descricao) {
        this.descricao = descricao;
    }

    public boolean isConcluida() {
        return concluida;
    }

    public void setConcluida(boolean concluida) {
        this.concluida = concluida;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Tarefa tarefa = (Tarefa) o;
        return Objects.equals(id, tarefa.id);
    }

    @Override
    public int hashCode() {
        return Objects.hash(id);
    }
}

package br.com.curso.listadetarefas.android.network;

import br.com.curso.listadetarefas.android.model.Tarefa;
import java.util.List;
import retrofit2.Call;
import retrofit2.http.Body;
import retrofit2.http.DELETE;
import retrofit2.http.GET;
import retrofit2.http.POST;
import retrofit2.http.PUT;
import retrofit2.http.Path;

public interface TarefaApiService {

    @GET("api/tarefas")
    Call<List<Tarefa>> listarTodas();

    @GET("api/tarefas/{id}")
    Call<Tarefa> buscarPorId(@Path("id") Long id);

    @POST("api/tarefas")
    Call<Tarefa> criar(@Body Tarefa tarefa);

    @PUT("api/tarefas/{id}")
    Call<Tarefa> atualizar(@Path("id") Long id, @Body Tarefa tarefa);

    @DELETE("api/tarefas/{id}")
    Call<Void> excluir(@Path("id") Long id);
}

package br.com.curso.listadetarefas.android.network;

import java.util.concurrent.TimeUnit;
import okhttp3.OkHttpClient;
import okhttp3.logging.HttpLoggingInterceptor;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;

public class RetrofitClient {

    public static final String DEFAULT_BASE_URL = "http://10.0.2.2:8080/";
    private static String currentBaseUrl = DEFAULT_BASE_URL;
    private static TarefaApiService apiService = null;

    private RetrofitClient() {}

    public static synchronized TarefaApiService getApiService() {
        if (apiService == null) {
            HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
            logging.setLevel(HttpLoggingInterceptor.Level.BODY);

            OkHttpClient client = new OkHttpClient.Builder()
                    .connectTimeout(10, TimeUnit.SECONDS)
                    .readTimeout(10, TimeUnit.SECONDS)
                    .writeTimeout(10, TimeUnit.SECONDS)
                    .addInterceptor(logging)
                    .build();

            Retrofit retrofit = new Retrofit.Builder()
                    .baseUrl(currentBaseUrl)
                    .client(client)
                    .addConverterFactory(GsonConverterFactory.create())
                    .build();

            apiService = retrofit.create(TarefaApiService.class);
        }
        return apiService;
    }

    public static synchronized void setBaseUrl(String newBaseUrl) {
        if (!newBaseUrl.endsWith("/")) {
            newBaseUrl += "/";
        }
        currentBaseUrl = newBaseUrl;
        apiService = null;
    }
}

package br.com.curso.listadetarefas.android.adapter;

import android.content.Context;
import android.graphics.Paint;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CheckBox;
import android.widget.ImageButton;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.core.content.ContextCompat;
import androidx.recyclerview.widget.RecyclerView;
import br.com.curso.listadetarefas.android.R;
import br.com.curso.listadetarefas.android.model.Tarefa;
import com.google.android.material.card.MaterialCardView;
import java.util.ArrayList;
import java.util.List;

public class TarefaAdapter extends RecyclerView.Adapter<TarefaAdapter.TarefaViewHolder> {

    public interface OnTarefaInteractionListener {
        void onToggleStatus(Tarefa tarefa, boolean novoStatus);
        void onEdit(Tarefa tarefa);
        void onDelete(Tarefa tarefa);
    }

    private final List<Tarefa> tarefas = new ArrayList<>();
    private final OnTarefaInteractionListener listener;

    public TarefaAdapter(OnTarefaInteractionListener listener) {
        this.listener = listener;
    }

    public void setTarefas(List<Tarefa> novasTarefas) {
        this.tarefas.clear();
        if (novasTarefas != null) {
            this.tarefas.addAll(novasTarefas);
        }
        notifyDataSetChanged();
    }

    @NonNull
    @Override
    public TarefaViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.item_tarefa, parent, false);
        return new TarefaViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull TarefaViewHolder holder, int position) {
        holder.bind(tarefas.get(position), listener);
    }

    @Override
    public int getItemCount() {
        return tarefas.size();
    }

    static class TarefaViewHolder extends RecyclerView.ViewHolder {

        private final MaterialCardView cardItemTarefa;
        private final CheckBox cbConcluida;
        private final TextView tvDescricao;
        private final ImageButton btnEditar;
        private final ImageButton btnExcluir;

        public TarefaViewHolder(@NonNull View itemView) {
            super(itemView);
            cardItemTarefa = itemView.findViewById(R.id.cardItemTarefa);
            cbConcluida = itemView.findViewById(R.id.cbConcluida);
            tvDescricao = itemView.findViewById(R.id.tvDescricao);
            btnEditar = itemView.findViewById(R.id.btnEditar);
            btnExcluir = itemView.findViewById(R.id.btnExcluir);
        }

        public void bind(final Tarefa tarefa, final OnTarefaInteractionListener listener) {
            Context context = itemView.getContext();
            tvDescricao.setText(tarefa.getDescricao());

            // Estilização visual (tachado / cor / opacidade)
            if (tarefa.isConcluida()) {
                tvDescricao.setPaintFlags(tvDescricao.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
                tvDescricao.setTextColor(ContextCompat.getColor(context, R.color.text_completed));
                cardItemTarefa.setAlpha(0.85f);
            } else {
                tvDescricao.setPaintFlags(tvDescricao.getPaintFlags() & (~Paint.STRIKE_THRU_TEXT_FLAG));
                tvDescricao.setTextColor(ContextCompat.getColor(context, R.color.text_primary));
                cardItemTarefa.setAlpha(1.0f);
            }

            // Previne disparos fantasmas ao reciclar
            cbConcluida.setOnCheckedChangeListener(null);
            cbConcluida.setChecked(tarefa.isConcluida());

            cbConcluida.setOnCheckedChangeListener((buttonView, isChecked) -> {
                if (buttonView.isPressed() && listener != null) {
                    listener.onToggleStatus(tarefa, isChecked);
                }
            });

            btnEditar.setOnClickListener(v -> {
                if (listener != null) listener.onEdit(tarefa);
            });

            btnExcluir.setOnClickListener(v -> {
                if (listener != null) listener.onDelete(tarefa);
            });
        }
    }
}

package br.com.curso.listadetarefas.android;

import android.app.AlertDialog;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import br.com.curso.listadetarefas.android.adapter.TarefaAdapter;
import br.com.curso.listadetarefas.android.model.Tarefa;
import br.com.curso.listadetarefas.android.network.RetrofitClient;
import br.com.curso.listadetarefas.android.network.TarefaApiService;
import com.google.android.material.button.MaterialButton;
import java.util.List;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;

public class MainActivity extends AppCompatActivity implements TarefaAdapter.OnTarefaInteractionListener {

    private EditText etNovaTarefa;
    private MaterialButton btnAdicionar;
    private ImageButton btnRecarregar;
    private ProgressBar progressBar;
    private RecyclerView rvTarefas;
    private TextView tvEmptyState;

    private TarefaAdapter adapter;
    private TarefaApiService apiService;

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

        apiService = RetrofitClient.getApiService();

        inicializarComponentes();
        configurarRecyclerView();
        configurarEventos();

        carregarTarefas();
    }

    private void inicializarComponentes() {
        etNovaTarefa = findViewById(R.id.etNovaTarefa);
        btnAdicionar = findViewById(R.id.btnAdicionar);
        btnRecarregar = findViewById(R.id.btnRecarregar);
        progressBar = findViewById(R.id.progressBar);
        rvTarefas = findViewById(R.id.rvTarefas);
        tvEmptyState = findViewById(R.id.tvEmptyState);
    }

    private void configurarRecyclerView() {
        adapter = new TarefaAdapter(this);
        rvTarefas.setLayoutManager(new LinearLayoutManager(this));
        rvTarefas.setAdapter(adapter);
    }

    private void configurarEventos() {
        btnAdicionar.setOnClickListener(v -> adicionarTarefa());
        btnRecarregar.setOnClickListener(v -> carregarTarefas());
    }

    private void setCarregando(boolean carregando) {
        progressBar.setVisibility(carregando ? View.VISIBLE : View.GONE);
        btnAdicionar.setEnabled(!carregando);
        btnRecarregar.setEnabled(!carregando);
    }

    private void atualizarVisibilidadeLista(int totalTarefas) {
        if (totalTarefas == 0) {
            rvTarefas.setVisibility(View.GONE);
            tvEmptyState.setVisibility(View.VISIBLE);
        } else {
            rvTarefas.setVisibility(View.VISIBLE);
            tvEmptyState.setVisibility(View.GONE);
        }
    }

    private void carregarTarefas() {
        setCarregando(true);
        apiService.listarTodas().enqueue(new Callback<List<Tarefa>>() {
            @Override
            public void onResponse(@NonNull Call<List<Tarefa>> call, @NonNull Response<List<Tarefa>> response) {
                setCarregando(false);
                if (response.isSuccessful() && response.body() != null) {
                    List<Tarefa> lista = response.body();
                    adapter.setTarefas(lista);
                    atualizarVisibilidadeLista(lista.size());
                } else {
                    Toast.makeText(MainActivity.this, "Erro HTTP: " + response.code(), Toast.LENGTH_SHORT).show();
                }
            }

            @Override
            public void onFailure(@NonNull Call<List<Tarefa>> call, @NonNull Throwable t) {
                setCarregando(false);
                Toast.makeText(MainActivity.this, "Falha de conexão: " + t.getMessage(), Toast.LENGTH_LONG).show();
            }
        });
    }

    private void adicionarTarefa() {
        String texto = etNovaTarefa.getText() != null ? etNovaTarefa.getText().toString().trim() : "";
        if (texto.isEmpty()) {
            Toast.makeText(this, R.string.erro_campo_vazio, Toast.LENGTH_SHORT).show();
            return;
        }

        Tarefa nova = new Tarefa(texto, false);
        setCarregando(true);

        apiService.criar(nova).enqueue(new Callback<Tarefa>() {
            @Override
            public void onResponse(@NonNull Call<Tarefa> call, @NonNull Response<Tarefa> response) {
                setCarregando(false);
                if (response.isSuccessful() && response.body() != null) {
                    etNovaTarefa.setText("");
                    Toast.makeText(MainActivity.this, R.string.sucesso_adicionada, Toast.LENGTH_SHORT).show();
                    carregarTarefas();
                } else {
                    Toast.makeText(MainActivity.this, "Erro ao salvar: " + response.code(), Toast.LENGTH_SHORT).show();
                }
            }

            @Override
            public void onFailure(@NonNull Call<Tarefa> call, @NonNull Throwable t) {
                setCarregando(false);
                Toast.makeText(MainActivity.this, "Erro de rede: " + t.getMessage(), Toast.LENGTH_LONG).show();
            }
        });
    }

    @Override
    public void onToggleStatus(Tarefa tarefa, boolean novoStatus) {
        tarefa.setConcluida(novoStatus);
        setCarregando(true);

        apiService.atualizar(tarefa.getId(), tarefa).enqueue(new Callback<Tarefa>() {
            @Override
            public void onResponse(@NonNull Call<Tarefa> call, @NonNull Response<Tarefa> response) {
                setCarregando(false);
                carregarTarefas();
            }

            @Override
            public void onFailure(@NonNull Call<Tarefa> call, @NonNull Throwable t) {
                setCarregando(false);
                Toast.makeText(MainActivity.this, "Falha ao atualizar status: " + t.getMessage(), Toast.LENGTH_SHORT).show();
                carregarTarefas();
            }
        });
    }

    @Override
    public void onEdit(Tarefa tarefa) {
        View dialogView = LayoutInflater.from(this).inflate(R.layout.dialog_editar_tarefa, null);
        EditText etEditar = dialogView.findViewById(R.id.etEditarDescricao);
        etEditar.setText(tarefa.getDescricao());
        etEditar.setSelection(etEditar.getText().length());

        new AlertDialog.Builder(this)
                .setView(dialogView)
                .setPositiveButton(R.string.dialog_btn_salvar, (dialog, which) -> {
                    String novoTexto = etEditar.getText().toString().trim();
                    if (novoTexto.isEmpty()) {
                        Toast.makeText(this, R.string.erro_campo_vazio, Toast.LENGTH_SHORT).show();
                        return;
                    }
                    tarefa.setDescricao(novoTexto);
                    salvarEdicao(tarefa);
                })
                .setNegativeButton(R.string.dialog_btn_cancelar, null)
                .show();
    }

    private void salvarEdicao(Tarefa tarefa) {
        setCarregando(true);
        apiService.atualizar(tarefa.getId(), tarefa).enqueue(new Callback<Tarefa>() {
            @Override
            public void onResponse(@NonNull Call<Tarefa> call, @NonNull Response<Tarefa> response) {
                setCarregando(false);
                if (response.isSuccessful()) {
                    Toast.makeText(MainActivity.this, R.string.sucesso_atualizada, Toast.LENGTH_SHORT).show();
                    carregarTarefas();
                }
            }

            @Override
            public void onFailure(@NonNull Call<Tarefa> call, @NonNull Throwable t) {
                setCarregando(false);
                Toast.makeText(MainActivity.this, "Falha de conexão: " + t.getMessage(), Toast.LENGTH_SHORT).show();
            }
        });
    }

    @Override
    public void onDelete(Tarefa tarefa) {
        String msg = getString(R.string.dialog_excluir_msg, tarefa.getDescricao());

        new AlertDialog.Builder(this)
                .setTitle(R.string.dialog_excluir_titulo)
                .setMessage(msg)
                .setPositiveButton(R.string.dialog_btn_excluir, (dialog, which) -> executarExclusao(tarefa.getId()))
                .setNegativeButton(R.string.dialog_btn_cancelar, null)
                .show();
    }

    private void executarExclusao(Long id) {
        setCarregando(true);
        apiService.excluir(id).enqueue(new Callback<Void>() {
            @Override
            public void onResponse(@NonNull Call<Void> call, @NonNull Response<Void> response) {
                setCarregando(false);
                if (response.isSuccessful()) {
                    Toast.makeText(MainActivity.this, R.string.sucesso_excluida, Toast.LENGTH_SHORT).show();
                    carregarTarefas();
                }
            }

            @Override
            public void onFailure(@NonNull Call<Void> call, @NonNull Throwable t) {
                setCarregando(false);
                Toast.makeText(MainActivity.this, "Falha ao excluir: " + t.getMessage(), Toast.LENGTH_SHORT).show();
            }
        });
    }
}