Coffee ordering app for Android device

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<ScrollView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/activity_just_java"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:paddingBottom="@dimen/activity_vertical_margin"
        android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/activity_vertical_margin"
        android:orientation="vertical">

        <EditText
            android:id="@+id/name_field"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="Name"
            android:inputType="textCapWords"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Topings"
            android:textAllCaps="true"
            android:textColor="#000000"/>

        <CheckBox
            android:id="@+id/whipped_cream_checkbox"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:paddingleft="24dp"
            android:text="Whipped cream"
            android:textSize="16sp"
            />

        <CheckBox
            android:id="@+id/chocolate"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:paddingLeft="24dp"
            android:text="Chocolate"
            android:textSize="16sp" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="QUANTITY"
            android:id="@+id/quantity_name"
            android:layout_marginBottom="16dp"
            android:textColor="#000000"/>
        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal">
            <Button
                android:layout_height="48dp"
                android:layout_width="48dp"
                android:text="+"
                android:id="@+id/button3"
                android:onClick="increment"/>
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/quantity_text_view"
                android:text="1"
                android:textSize="16sp"
                android:padding="10dp"
                android:layout_below="@id/quantity_name"
                android:textColor="#000000"/>
            <Button
                android:layout_height="48dp"
                android:layout_width="48dp"
                android:text="-"
                android:id="@+id/button4"
                android:onClick="decrement"/>
        </LinearLayout>


        <Button
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:text="Order"
            android:id="@+id/button2"
            android:layout_marginTop="16dp"
            android:onClick="submitOrder"/>
    </LinearLayout>
</ScrollView>

MainActivity.java

package com.example.android.justjava;

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

import com.example.android.justjava.R;

import java.text.NumberFormat;

/**
 * This app displays an order form to order coffee.
 */
public class MainActivity extends AppCompatActivity {

    int quantity = 2;

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

    /**
     * This method is called when the order button is clicked.
     */
    public void submitOrder(View view) {

        // Find the user's name
        EditText nameField = (EditText) findViewById(R.id.name_field);
        String name = nameField.getText().toString();
        Log.v("Main activity", "Name: " + name);

        // Figure out if the user wants whipped cream topping
        CheckBox whippedCreamCheckBox = (CheckBox) findViewById(R.id.whipped_cream_checkbox);
        boolean hasWhippedCream = whippedCreamCheckBox.isChecked();

        // Figure out if the user wants chocolate topping
        CheckBox chocolate = (CheckBox) findViewById(R.id.chocolate);
        boolean hasChocolate = chocolate.isChecked();


        int price = calculatePrice(hasWhippedCream, hasChocolate);
        String priceMessage = createOrderSummary(name, price, hasWhippedCream, hasChocolate);

        // This intent sends the data to an email app. It already provides the receiver, the subject
        // and the body of the message.
        Intent intent = new Intent(Intent.ACTION_SENDTO);
        intent.setType("message/rfc822");
        intent.setData(Uri.parse("mailto:")); // only email apps should handle this
        intent.putExtra(Intent.EXTRA_SUBJECT, "Coffee order for " + name);
        intent.putExtra(Intent.EXTRA_TEXT, priceMessage);
        if (intent.resolveActivity(getPackageManager()) != null) {
            startActivity(intent);
        }
    }


    /**
     * Calculates the price of the order.
     *
     * @return total price
     */

    private int calculatePrice(boolean hasWhippedCream, boolean hasChocolate) {
        //Price of one cup of coffee.
        int basePrice = 5;

        //Price of one cup of coffee with whipped cream topping + 1 $.
        if (hasWhippedCream) {
            basePrice = basePrice + 1;
        }

        //Price of one cup of coffee with chocolate topping + 2 $ .
        if (hasChocolate) {
            basePrice = basePrice + 2;
        }

        //calculate the total price by multiplying by quantity.

        return quantity * basePrice;
    }


    /**
     * Creates  the order summary.
     *
     * @param name            the client
     * @param price           of the order
     * @param hasWhippedCream is whether or not the user wants whipped cream topping
     * @return text summary
     */

    private String createOrderSummary(String name, int price, boolean hasWhippedCream, boolean hasChocolate) {

        String priceMessage = "Name: " + name;
        priceMessage += "\nAdd whipped cream?" + hasWhippedCream;
        priceMessage += "\nAdd chocolate?" + hasChocolate;
        priceMessage = priceMessage + "\nQuantity: " + quantity;
        priceMessage = priceMessage + "\nTotal: £" + price;
        priceMessage = priceMessage + "\nThank you!";
        return priceMessage;

    }

    /**
     * This method is called when the plus button is clicked.
     */
    public void increment(View view) {

        quantity = quantity + 1;
        displayQuantity(quantity);
    }

    /**
     * This method is called when the minus button is clicked.
     */
    public void decrement(View view) {
        quantity = quantity - 1;
        displayQuantity(quantity);
    }

    /**
     * This method displays the given quantity value on the screen.
     */
    private void displayQuantity(int number) {
        TextView quantityTextView = (TextView) findViewById(
                R.id.quantity_text_view);
        quantityTextView.setText("" + number);
    }
}