Barista (Just Java) App from Udacity Android Class

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@drawable/mybg"
    android:paddingTop="16dp"
    android:paddingLeft="16dp"
    tools:context="com.example.android.justjava.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="16dp"
        android:padding="4dp"
        android:textAllCaps="true"
        android:id="@+id/quantity_label"
        android:text="Quantity" />

    <LinearLayout
        android:layout_width="120dp"
        android:layout_height="wrap_content"
        android:layout_marginBottom="16dp">
        <Button
            android:id="@+id/decrease_qty"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:onClick="decrease"
            android:text="-"
            android:textColor="@color/colorAccent"
            android:textSize="18sp"
            android:textStyle="bold"
            android:typeface="monospace" />

        <TextView
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="wrap_content"
            android:textSize="16sp"
            android:textColor="@color/colorTextHeader"
            android:id="@+id/quantity_text_view"
            android:textAlignment="center"
            android:text="0" />

        <Button
            android:id="@+id/increase_qty"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:fontFamily="monospace"
            android:onClick="increase"
            android:text="+"
            android:textColor="@color/colorAccent"
            android:textSize="18sp"
            android:textStyle="bold"
            android:typeface="monospace" />
    </LinearLayout>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:textAllCaps="true"
        android:text="Price" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@android:color/black"
        android:layout_marginTop="16dp"
        android:textSize="16sp"
        android:id="@+id/price_text_view"
        android:textAlignment="center"
        android:text="$0" />

    <Button
        android:layout_width="150dp"
        android:layout_height="wrap_content"
        android:id="@+id/order_button"
        android:layout_marginTop="20dp"
        android:textColor="@color/colorAccent"
        android:text="Order"
        android:onClick="submitOrder" />
</LinearLayout>

colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorTextHeader">#000000</color>
    <color name="colorPrimaryLight">#EFEBE9</color>
    <color name="colorPrimary">#795548</color>
    <color name="colorPrimaryDark">#3E2723</color>
    <color name="colorAccent">#004D40</color>
</resources>

MainActivity.java

package com.example.android.justjava;

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

import java.text.NumberFormat;

/**
 * This app displays an order form to order coffee.
 */
public class MainActivity extends AppCompatActivity {
    int quantity=1;

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

    public void increase(View view) {
        quantity++;
        display(quantity);
    }

    public void decrease(View view) {
        quantity--;
        quantity = quantity>=0 ? quantity : 0;
        display(quantity);
    }

    public void submitOrder(View view) {
        displayPrice(quantity * 5);
    }

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

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

mybg.xml

<?xml version="1.0" encoding="utf-8"?>
<bitmap
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:src="@drawable/cafe"
    android:gravity="center"
    android:alpha="0.3"
    android:scaleType="centerCrop"
  />