- Android Programming for Beginners - Second Edition
- Table of Contents
- Android Programming for Beginners - Second Edition
- Contributors
- Preface
- 1. Beginning Android and Java
- 2. First Contact – Java, XML, and the UI Designer
- Examining the log output
- A note for early adopters of this book
- Exploring the project's Java code and the main layout's XML code
- Adding buttons to the main layout file
- Leaving comments in our Java code
- Coding messages to the user and the developer
- Writing our first Java code
- Frequently asked questions
- Summary
- 3. Exploring Android Studio and the Project Structure
- 4. Getting Started with Layouts and Material Design
- Material design
- Exploring Android UI design
- Layouts
- Creating the Exploring Layouts project
- Building a menu with LinearLayout
- Wiring up the UI with the Java code (part 1)
- Adding layouts within layouts
- Making the layout look pretty
- Wiring up the UI with the Java code (part 2)
- Building a precise UI with ConstraintLayout
- Laying out data with TableLayout
- Summary
- 5. Beautiful Layouts with CardView and ScrollView
- 6. The Android Lifecycle
- 7. Java Variables, Operators, and Expressions
- 8. Java Decisions and Loops
- 9. Java Methods
- 10. Object-Oriented programming
- 11. More Object-Oriented Programming
- Remember that encapsulation thing?
- Encapsulation and static methods mini-app
- OOP and inheritance
- Inheritance example app
- Polymorphism
- Frequently asked questions
- Summary
- 12. The Stack, the Heap, and the Garbage Collector
- 13. Anonymous Classes – Bringing Android Widgets to Life
- Declaring and initializing the objects
- Creating UI widgets from pure Java without XML
- Exploring the palette – part 1
- Anonymous classes
- Exploring the palette – Part 2, and more anonymous classes
- Widget exploration app
- Converting layouts to ConstraintLayout
- Summary
- 14. Android Dialog Windows
- Dialog windows
- The Note to self app
- Summary
- 15. Arrays, ArrayList, Map and Random Numbers
- A random diversion
- Handling large amounts of data with arrays
- Simple array example mini-app
- Getting dynamic with arrays
- Entering the nth dimension with Arrays
- ArrayLists
- Arrays and ArrayLists are polymorphic
- More Java Collections – Meet Java Hashmap
- The Note to Self app
- Frequently asked questions
- Summary
- 16. Adapters and Recyclers
- RecyclerView and RecyclerAdapter
- Adding RecyclerView, RecyclerAdapter, and ArrayList to the Note to Self project
- Running the app
- Frequently asked questions
- Summary
- 17. Data Persistence and Sharing
- 18. Localization
- 19. Animations and Interpolations
- 20. Drawing Graphics
- 21. Threads, and Starting the Live Drawing App
- 22. Particle Systems and Handling Screen Touches
- 23. Supporting Different Versions of Android, Sound Effects, and the Spinner Widget
- 24. Design Patterns, Multiple Layouts, and Fragments
- 25. Advanced UI with Paging and Swiping
- 26. Advanced UI with Navigation Drawer and Fragment
- 27. Android Databases
- 28. Coding a Snake Game Using Everything We Have Learned So Far
- 29. Enumerations and Finishing the Snake Game
- 30. A Quick Chat Before You Go
- Other Books You May Enjoy
- Index
In this chapter, we will discover that in Java, classes are fundamental to just about everything. We will begin to understand why the software engineers at Sun Microsystems back in the early 1990s made Java the way they did.
We have already talked about reusing other people's code, specifically the Android API, but in this chapter, we will really get to grips with how this works and learn about object-oriented programming and how to use it.
In summary, we will cover the following topics:
- What is OOP, including encapsulation, inheritance, and polymorphism
- How to write and use our first class in an app
Before we get to what exactly OOP is, a quick warning.
I'm referring to our brain's memories for a change. If you try to memorize this chapter (or the next), you will have to make a lot of room in your brain and you will probably forget something really important in its place, such as going to work or thanking the author for telling you not to try and memorize this stuff.
A good goal will be to try and just-about get it. This way, our understanding will become more rounded. You can then refer to this chapter (or the next) for a refresher when needed.
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