Option A

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    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"
    tools:context=".MainActivity">

New method in MainActivity.java

/**
 * This method displays the given price on the screen.
 */
private void displayPrice(int number) {
       TextView priceTextView = (TextView) findViewById(R.id.price_text_view);
       priceTextView.setText(NumberFormat.getCurrencyInstance().format(number));
}

New method in MainActivity.java

/**
 * This method displays the given text on the screen.
 */
private void displayMessage(String message) {
    TextView priceTextView = (TextView) findViewById(R.id.price_text_view);
    priceTextView.setText(message);
}

MainActivity.java

package com.example.android.justjava;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.TextView;

import java.text.NumberFormat;

/**

udacityandroid

private String createCalendarEventReminder(String eventName, String location, int minutesAway) {
    String reminder = "You have an upcoming event in " + minutesAway + " minutes.";
    reminder = reminder + " It is " + eventName + " held at " + location + ".";
    return reminder;
}

udacityandroid

/**
 * Calculates the price of the order based on the current quantity.
 *
 * @return the price
 */
private int calculate price(int quantity {
    int price = quantity * 5;
    return price;
}

udacityandroid

/**
 * Calculates the price of the order.
 * 
 * @param quantity is the number of cups of coffee ordered
 */
private void calculatePrice(int quantity) {
    int price = quantity * 5;
}

udacityandroid

/**
 * Get the email account name.
 * 
 * @return the name of the account.
 */
private String getAccountName() {
    return "android@gmail.com";
    return "droid@gmail.com";
}

udacityandroid

/**
 * Displays text to the user.
 */
public class TextView extends View {
 
    // String value
    private String mText;
 
    // Text color of the text
    private int mTextColor;

udacityandroid

/**
 * Displays an image, such as an icon.
 */
public class ImageView extends View {
 
    // Resource ID for the source image that should be displayed in the ImageView.
    private int mImageId;
 
    // Context of the app
    private Context mContext;