Android for Beginners : Localization Solution

activity_main.xml

<ScrollView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    tools:context=".MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:paddingBottom="@dimen/activity_vertical_margin"
        android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/activity_vertical_margin">

        <EditText
            android:id="@+id/name_field"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="@string/name"
            android:inputType="text" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="16dp"
            android:layout_marginTop="16dp"
            android:text="@string/toppings"
            android:textAllCaps="true" />

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

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

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="16dp"
            android:layout_marginTop="16dp"
            android:text="@string/quantity"
            android:textAllCaps="true" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">

            <Button
                android:layout_width="48dp"
                android:layout_height="48dp"
                android:onClick="decrement"
                android:text="-" />

            <TextView
                android:id="@+id/quantity_text_view"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingLeft="8dp"
                android:paddingRight="8dp"
                android:text="@string/initial_quantity_value"
                android:textColor="@android:color/black"
                android:textSize="16sp" />

            <Button
                android:layout_width="48dp"
                android:layout_height="48dp"
                android:onClick="increment"
                android:text="+" />

        </LinearLayout>

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:onClick="submitOrder"
            android:text="@string/order" />

    </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.text.Editable;
import android.view.View;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.TextView;

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 plus button is clicked.
     */
    public void increment(View view) {
        if (quantity == 100) {
            return;
        }
        quantity = quantity + 1;
        displayQuantity(quantity);
    }

    /**
     * This method is called when the minus button is clicked.
     */
    public void decrement(View view) {
        if (quantity == 0) {
            return;
        }
        quantity = quantity - 1;
        displayQuantity(quantity);
    }

    /**
     * This method is called when the order button is clicked.
     */
    public void submitOrder(View view) {
        // Get user's name
        EditText nameField = (EditText) findViewById(R.id.name_field);
        Editable nameEditable = nameField.getText();
        String name = nameEditable.toString();

        // 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 whipped cream topping
        CheckBox chocolateCheckBox = (CheckBox) findViewById(R.id.chocolate_checkbox);
        boolean hasChocolate = chocolateCheckBox.isChecked();

        // Calculate the price
        int price = calculatePrice(hasWhippedCream, hasChocolate);

        // Display the order summary on the screen
        String message = createOrderSummary(name, price, hasWhippedCream, hasChocolate);

        // Use an intent to launch an email app.
        // Send the order summary in the email body.
        Intent intent = new Intent(Intent.ACTION_SENDTO);
        intent.setData(Uri.parse("mailto:")); // only email apps should handle this
        intent.putExtra(Intent.EXTRA_SUBJECT,
                getString(R.string.order_summary_email_subject, name));
        intent.putExtra(Intent.EXTRA_TEXT, message);

        if (intent.resolveActivity(getPackageManager()) != null) {
            startActivity(intent);
        }
    }

    /**
     * Calculates the price of the order.
     *
     * @param addWhippedCream is whether or not we should include whipped cream topping in the price
     * @param addChocolate    is whether or not we should include whipped cream topping in the price
     * @return total price
     */
    private int calculatePrice(boolean addWhippedCream, boolean addChocolate) {
        // First calculate the price of one cup of coffee
        int basePrice = 5;

        // If the user wants whipped cream, add $1 per cup
        if (addWhippedCream) {
            basePrice = basePrice + 1;
        }

        // If the user wants chocolate, add $2 per cup
        if (addChocolate) {
            basePrice = basePrice + 2;
        }

        // Calculate the total order price by multiplying by the quantity
        return quantity * basePrice;
    }

    /**
     * Create summary of the order.
     *
     * @param name            on the order
     * @param price           of the order
     * @param addWhippedCream is whether or not to add whipped cream to the coffee
     * @param addChocolate    is whether or not to add chocolate to the coffee
     * @return text summary
     */
    private String createOrderSummary(String name, int price, boolean addWhippedCream,
            boolean addChocolate) {
        String priceMessage = getString(R.string.order_summary_name, name);
        priceMessage += "\n" + getString(R.string.order_summary_whipped_cream, addWhippedCream);
        priceMessage += "\n" + getString(R.string.order_summary_chocolate, addChocolate);
        priceMessage += "\n" + getString(R.string.order_summary_quantity, quantity);
        priceMessage += "\n" + getString(R.string.order_summary_price,
                NumberFormat.getCurrencyInstance().format(price));
        priceMessage += "\n" + getString(R.string.thank_you);
        return priceMessage;
    }

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

strings.xml

<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
    <!-- Title for the application. [CHAR LIMIT=12] -->
    <string name="app_name">Just Java</string>

    <!-- Hint text display in the empty field for the user's name [CHAR LIMIT=20] -->
    <string name="name">Name</string>

    <!-- Hint text display in the empty field for the user's name [CHAR LIMIT=20] -->
    <string name="toppings">Toppings</string>

    <!-- Hint text display in the empty field for the user's name [CHAR LIMIT=20] -->
    <string name="whipped_cream">Whipped cream</string>

    <!-- Hint text display in the empty field for the user's name [CHAR LIMIT=20] -->
    <string name="chocolate">Chocolate</string>

    <!-- Hint text display in the empty field for the user's name [CHAR LIMIT=20] -->
    <string name="quantity">Quantity</string>

    <!-- Hint text display in the empty field for the user's name [CHAR LIMIT=5] -->
    <string name="initial_quantity_value">2</string>

    <!-- Hint text display in the empty field for the user's name [CHAR LIMIT=20] -->
    <string name="order">Order</string>

    <!--
      Name for the order summary. It will be shown in the format of "Name: Amy" where Amy is the
      user's name. [CHAR LIMIT=NONE]
    -->
    <string name="order_summary_name">Name: <xliff:g id="name" example="Amy">%s</xliff:g></string>

    <!--
      Whipped cream topping for the order summary. It will be shown in the format of
      "Add whipped cream? true" or "Add whipped cream? false". [CHAR LIMIT=NONE]
    -->
    <string name="order_summary_whipped_cream">Add whipped cream? <xliff:g id="addWhippedCream" example="true">%b</xliff:g></string>

    <!--
      Chocolate topping for the order summary. It will be shown in the format of
      "Add chocolate? true" or "Add chocolate? false". [CHAR LIMIT=NONE]
    -->
    <string name="order_summary_chocolate">Add chocolate? <xliff:g id="addChocolate" example="true">%b</xliff:g></string>

    <!--
      Quantity of coffee cups for the order summary. It will be shown in the format of
      "Quantity: 2", where 2 is the number of cups ordered. [CHAR LIMIT=NONE]
    -->
    <string name="order_summary_quantity">Quantity: <xliff:g id="quantity" example="2">%d</xliff:g></string>

    <!--
      Total price for the order summary. It will be shown in the format of
      "Total: $10" where $10 is the price. [CHAR LIMIT=NONE]
    -->
    <string name="order_summary_price">Total: <xliff:g id="price" example="$10">%s</xliff:g></string>

    <!-- Thank you message for the order summary. [CHAR LIMIT=NONE] -->
    <string name="thank_you">Thank you!</string>

    <!--
      Subject line for the order summary email. It will be in the format of
      "Just Java order for Amy" where Amy is the user's name. [CHAR LIMIT=NONE]
    -->
    <string name="order_summary_email_subject">Just Java order for <xliff:g id="name" example="Amy">%s</xliff:g></string>
</resources>