Input Controls &
Event Handling 🎛️

package example.com.myapp;

import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.*;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import android.content.DialogInterface;

public class MainActivity extends AppCompatActivity {

    // 1. Deklarasikan variabel UI
    private ImageView imgKopi;
    private EditText inputNama;
    private Spinner spinnerMenu;
    private RadioGroup radioSuhu;
    private CheckBox checkEkstra;
    private Button btnPesan;

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

        // 2. Hubungkan variabel dengan ID XML
        imgKopi = findViewById(R.id.imgKopi);
        inputNama = findViewById(R.id.inputNama);
        spinnerMenu = findViewById(R.id.spinnerMenu);
        radioSuhu = findViewById(R.id.radioSuhu);
        checkEkstra = findViewById(R.id.checkEkstra);
        btnPesan = findViewById(R.id.btnPesan);

        // 3. Isi Spinner dengan Data Menu Kopi
        String[] menuKopi = {"Americano", "Kopi Susu Aren", "Matcha Latte"};
        ArrayAdapter<String> adapter = new ArrayAdapter<>(
                this, android.R.layout.simple_spinner_dropdown_item, menuKopi);
        spinnerMenu.setAdapter(adapter);

        // 4. Event Handler: Ubah Gambar Saat Spinner Diganti!
        spinnerMenu.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                String menuTerpilih = menuKopi[position];
                if (menuTerpilih.equals("Americano")) {
                    imgKopi.setImageResource(R.drawable.kopi_hitam);
                } else if (menuTerpilih.equals("Kopi Susu Aren")) {
                    imgKopi.setImageResource(R.drawable.kopi_susu);
                } else if (menuTerpilih.equals("Matcha Latte")) {
                    imgKopi.setImageResource(R.drawable.matcha);
                }
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {}
        });

        // 5. Event Handler saat tombol ditekan
        btnPesan.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                
                String nama = inputNama.getText().toString();
                
                // 6. Validasi Satpam!
                if (TextUtils.isEmpty(nama)) {
                    inputNama.setError("Nama wajib diisi!");
                    Toast.makeText(MainActivity.this, "Isi nama dulu!", Toast.LENGTH_SHORT).show();
                    return; // Hentikan proses
                }

                // 7. Ambil data pilihan UI
                String menu = spinnerMenu.getSelectedItem().toString();
                
                // Cek RadioButton yg aktif
                int selectedId = radioSuhu.getCheckedRadioButtonId();
                RadioButton radioTerpilih = findViewById(selectedId);
                String suhu = radioTerpilih.getText().toString();
                
                // Cek CheckBox (True/False)
                String ekstra = checkEkstra.isChecked() ? "Ya (+Rp 5.000)" : "Tidak";

                // 8. Tampilkan AlertDialog Konfirmasi
                String ringkasan = "Pesanan: " + menu + " (" + suhu + ")\nEkstra Shot: " + ekstra;
                
                new AlertDialog.Builder(MainActivity.this)
                    .setTitle("Atas Nama: " + nama)
                    .setMessage(ringkasan)
                    .setPositiveButton("OKE, PESAN!", new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {
                            Toast.makeText(MainActivity.this, "Pesanan diproses!", Toast.LENGTH_LONG).show();
                        }
                    })
                    .setNegativeButton("BATAL", null)
                    .show();
            }
        });
    }
}