MainActivity.java

package justjava.alessiosferro.com.justjava;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import java.text.NumberFormat;

public class MainActivity extends AppCompatActivity {

    // Attributi Privati
    private EditText editText;
    private CheckBox checkBox;
    private TextView quantity;
    private TextView price;
    private TextView finalPrice;
    private TextView summary;
    private TextView orders;
    private TextView whippedCream;
    private TextView name;
    private int var;
    private boolean order;

    // Metodo protetto (ereditato da AppCompatActivity)
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        editText = (EditText) findViewById(R.id.editText);
        checkBox = (CheckBox) findViewById(R.id.prova_check_box);
        quantity = (TextView) findViewById(R.id.quantity_text_view);
        price = (TextView) findViewById(R.id.price_text_view);
        finalPrice = (TextView) findViewById(R.id.finalPrice);
        summary = (TextView) findViewById(R.id.summary);
        orders = (TextView) findViewById(R.id.orders);
        whippedCream = (TextView) findViewById(R.id.panna);
        name = (TextView) findViewById(R.id.nome);
        order = false;
    }

    // Metodi pubblici

    /**
     * Questo metodo resetta le textView a default alla pressione del bottone CANCELLA
     * @param view prende la view come parametro
     */

    public void canc(View view){
        editText.setText("");
        checkBox.setChecked(false);
        quantity.setText("0");
        price.setText("0,00 €");
        finalPrice.setText("");
        summary.setText("");
        orders.setText("");
        whippedCream.setText("");
        name.setText("");
        var = 0;
        order = false;
    }

    /**
     * Questo metodo imposta un ordine alla pressione del bottone ORDINA
     * @param view prende la view corrente come parametro
     */

    public void submitOrder(View view) {
        if(editText.length() == 0){
            Toast.makeText(MainActivity.this, "Inserisci il nome!", Toast.LENGTH_LONG).show();
            return;
        }else if(var == 0){
            Toast.makeText(MainActivity.this, "Nessun ordine inserito!", Toast.LENGTH_LONG).show();
            return;
        }

        order = true;

        summary.setText("Riepilogo ordine");
        orders.setText("Numero ordini: " + quantity.getText());
        finalPrice.setText("Prezzo: " + price.getText());

        if(checkBox.isChecked()){
            whippedCream.setText("Panna: SI");
        }else{
            whippedCream.setText("Panna: NO");
        }

        name.setText("Nome: " + editText.getText());
    }

    /**
     * Questo metodo invoca il metodo composeEmail alla pressione del bottone EMAIL
     * @param view prende la view corrente come parametro
     */

    public void email(View view){
        if(!order){
            Toast.makeText(MainActivity.this, "Ordina qualcosa!", Toast.LENGTH_LONG).show();
            return;
        }
        composeEmail("" + summary.getText() + "\n" + name.getText() + "\n" + orders.getText() + "\n"
                + whippedCream.getText() + "\n" + finalPrice.getText(), "Ordine");
    }

    public void pannaMont(View view){
        if(checkBox.isChecked())
            price.setText(NumberFormat.getCurrencyInstance().format(var*.80));
        else
            price.setText(NumberFormat.getCurrencyInstance().format(var*.50));
    }

    public void increment(View view){
        var++;
        quantity.setText("" + var);
        displayPrice();
    }

    public void decrement(View view){
        if(var > 0) {
            var--;
            quantity.setText("" + var);
            displayPrice();
        }else{
            Toast.makeText(MainActivity.this, "Impossibile decrementare", Toast.LENGTH_SHORT).show();
        }
    }

    /**
     * Questo metodo crea un intent per le app di posta elettronica
     * @param body corpo dell'email
     * @param subject oggetto dell'email
     */

    public void composeEmail(String body, String subject) {
        Intent intent = new Intent(Intent.ACTION_SENDTO);
        intent.setData(Uri.parse("mailto:")); // only email apps should handle this
        intent.putExtra(Intent.EXTRA_TEXT, body);
        intent.putExtra(Intent.EXTRA_SUBJECT, subject);
        if (intent.resolveActivity(getPackageManager()) != null) {
            startActivity(intent);
        }
    }
}