public class MainActivity extends AppCompatActivity {

    //definisi widget
    EditText etNama, etNPM, etAlamat;
    Spinner spProdi;
    CheckBox cbxTeknologi, cbxKuliner;
    RadioGroup rgDomisili;
    RadioButton rbDomisili;
    Button btToast, btNotifikasi, btDialog, btKeluar, btDetail, btSnack;

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

        //hubungkan XML dengan java
        etNama = (EditText) findViewById(R.id.et_nama);
        etNPM = (EditText) findViewById(R.id.et_npm);
        etAlamat = (EditText) findViewById(R.id.et_alamat);
        spProdi = (Spinner) findViewById(R.id.sp_prodi);
        cbxTeknologi = (CheckBox) findViewById(R.id.cb_teknologi);
        cbxKuliner = (CheckBox) findViewById(R.id.cb_kuliner);
        rgDomisili = (RadioGroup) findViewById(R.id.rg_domisili);
        btToast = (Button) findViewById(R.id.bt_toast);
        btDialog = (Button) findViewById(R.id.bt_dialog);
        btNotifikasi = (Button) findViewById(R.id.bt_notif);
        btKeluar = (Button) findViewById(R.id.bt_keluar);
        btDetail = (Button) findViewById(R.id.bt_detil);
        btSnack = (Button) findViewById(R.id.bt_snack);

        //memberikan fungsi pada tombol
        btToast.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(getApplicationContext(), "Hai kawan, apa kabar?", Toast.LENGTH_SHORT).show();
            }
        });

        btDialog.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
            //menampilkan dialog
            new AlertDialog.Builder(MainActivity.this)
                .setIcon(R.mipmap.ic_launcher)
                .setTitle("Perhatian")
                .setMessage("Ini dialog box")
                .setCancelable(true)
                .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        Toast.makeText(getApplicationContext(),
                                "Anda baru menekan tombol OK",
                                Toast.LENGTH_SHORT)
                                .show();
                    }
                })
                .setNegativeButton("Batal", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        Toast.makeText(getApplicationContext(),
                                "Tombol Batal ditekan",
                                Toast.LENGTH_SHORT)
                                .show();
                    }
                })
                .setNeutralButton("Netral", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        Toast.makeText(getApplicationContext(),
                                "Tombol Netral ditekan",
                                Toast.LENGTH_SHORT)
                                .show();
                    }
                }).show();
            }
        });

        btNotifikasi.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //notifikasi
                NotificationCompat.Builder mBuilder =
                        new NotificationCompat.Builder(getApplicationContext(), "notify_001");
                Intent ii = new Intent(getApplicationContext(), MainActivity.class);
                PendingIntent pendingIntent = PendingIntent.getActivity(getApplicationContext(), 0, ii, 0);

                NotificationCompat.BigTextStyle bigText = new NotificationCompat.BigTextStyle();
                bigText.setBigContentTitle("Latihan01");
                bigText.setSummaryText("Ini adalah notifikasi dariku");

                mBuilder.setContentIntent(pendingIntent);
                mBuilder.setSmallIcon(R.mipmap.ic_launcher);
                mBuilder.setContentTitle("Aplikasi buatanku");
                mBuilder.setContentText("Notifikasi ini menggunakan java");
                mBuilder.setPriority(Notification.PRIORITY_MAX);
                mBuilder.setStyle(bigText);
                mBuilder.setDefaults(Notification.DEFAULT_SOUND); //suara
                mBuilder.setVibrate(new long[] {1000, 1000, 1000, 1000, 1000, 1000}); //getar

                NotificationManager mNotificationManager =
                        (NotificationManager) getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE);

                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                    NotificationChannel channel = new NotificationChannel("notify_001",
                            "channelku",
                            NotificationManager.IMPORTANCE_DEFAULT);
                    mNotificationManager.createNotificationChannel(channel);
                }

                mNotificationManager.notify(0, mBuilder.build());
            }
        });

        btKeluar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish(); //tutup aplikasi
            }
        });

        btDetail.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(getApplicationContext(),
                                "Belum dibuat!",
                                Toast.LENGTH_SHORT)
                                .show();
            }
        });

        btSnack.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                View v = findViewById(R.id.main_layout_id);
                String message = "Snackbar message";
                int duration = Snackbar.LENGTH_SHORT;
                Snackbar.make(v, message, duration).show();
            }
        });
    }
}