To Lecture Notes

IT 372 -- Apr 1, 2024

Course Documents

• Announcements, Table of Contents, Professor Information, Syllabus, Lecture Notes, Documents, Exam Info, Projects, Exam Info, D2L

Course Prerequisites

• (IT 313 or IT CSC 300) and (IT 240 or CSC 355)

Course Textbook

• The course textbook is Griffiths and Griffiths, Head First Android Development, A Brain-Friendly Guide, 2nd Edition, O'Reilly, 2017.

Course Topics

1. Brief History of Mobile Computing
2. Review of Java
3. Android Studio
4. Activities
5. XML files
6. LinearLayout
7. The Activity Lifecycle
8. Intents and multiactivity apps
9. ConstraintLayout and other layouts
10. Widgits: toggle button, switch, radio button, spinner, scroll view, toast, image view
11. Using sqlite in Apps
12. Other topics

Brief History of Mobile Computing

Android API Versions

• Android API versions are named after sweets/deserts.
• First Android version was version 1.5: Cupcake, API 2, released in 2009.
• Most recent version is version 9.0: Pie, API 29, released in 2018.
• Read this article
  Android versions: A living history from 1.0 to 11
  Some of the questions in Quiz1 will be based on this article.
• Recent Android Studio versions are named after animals:
  

  Version	Month	Animal
  2020.3.1	July	Arctic Fox
  2021.1.1	January	Bumble Bee
  2021.2.1	May	Chipmunk
  2021.3.1	September	Dolphin
  2022.1.1	January	Electric Eel
  2022.2.1	April	Flamingo
  2022.3.1	July	Giraffe
  2023.1.1	November	Hedgehog
  2023.2.1	February	Iguana
  2022.3.1	TBA	Giraffe
  2022.3.2	TBA	Koala

Android Development

• The Android Developer Portal provides resources for Android developers.
  
  • URL: developer.android.com
  • Provides tutorials, API documentation, sample code.
• Before 2015, an Eclipse plugin was available for Android development.
• Now Android deveopment is usually done using Android Studio.
• Android Studio is built on top of IntelliJ, Google's Java editor.
• We use Android Studio in this class.
• Download Android Studio from developer.android.com

Java Review Quiz

1. What is the size in bytes of each of these datatypes?
   

   int  double  char  boolean
   

2. Write a for loop that prints the odd numbers from 99 to 1 in descending order.
3. How does a switch statement work? Show how to translate this else..if statement into a switch statement:
   

   String word;
   if (n == 1) {
       word = "one";
   }
   else if (n == 2) {
       word = "two";
   }
   else {
       word = "many";
   }
   

Create a First Android App

• TextDisplay Example

Android Studio Folder Structure

• Find these folders in the Android Studio project TextDisplay:
  

  app  src  main  java  res
  

• Find these files in the Android Studio project TextDisplay:
  

  MainActivity.java  activity_main.xml
  

  Ans: Here are the paths to each of these folders:
  

  TextDisplay/app/src/main/java/it372/smiths/textdisplay/MainActivity.java
  TextDisplay/app/src/main/res/layout/activity_main.xml
  

Project 1

• To install Android Studio on your own machine, see the Android Developer site for the download link. See the Announcements Page for the announcement about Intel Virtualization if you have an older Windows machine.
• Look at the Project 1a.

Android Class Documentation

• Look up the documentation for these classes:
  

  View  TextView  Button  LinearLayout
  

• On the AndroidDeveloper Website:
  Docs >> Reference >> Android Platform
• Search for documentation on specific classes.

Create New Class

• Create a new class named TempDesc to be used later in an Android app. This class should input a Fahrenheit temperature, then output a descriptor that describes the temperature. For example: 123 might output "hot", -34 might output "frigid", 70 might output "perfect".
• Question: (1) what should be the class methods? (2) Should these methods be static or instance? Ans:
  

  public class TempDesc {
      
      public static String getDescriptor(int temp) {
          if (temp < 0.0) {
              return "frigid";
          }
          else if (temp < 45.0) {
              return "cold";
          }
          else if (temp < 65.0) {
              return "chilly";
          }
          else if (temp < 75.0) {
              return "perfect";
          }        
          else if (temp < 90.0) {
              return "warm";
          }
          else {
              return "hot";
          }
      }
  
      public static void main(String[ ] args) {
          int t = 88;
          System.out.println(TempDesc.getDescriptor(t));
      }
  }
  

• Rewrite the TempDescriptor class to so that it can instantiate objects. Use this UML diagram:
  

  +------------------------------+
  |        TempDescriptor        |
  +------------------------------+
  | - temperature                |
  +------------------------------+
  | + TempDescriptor(temp : int) |
  | + getTemperature( ) : int    |
  | + getDescriptor( ) : String  |
  +------------------------------+