Android Programming · The Big Nerd Ranch Guide, 4th Edition by Marsicano, Kristin -- Read -- Imperial Library of Trantor

Screen Pixel Densities Running on a Device Challenge: Add a Listener to the TextView Challenge: Add a Previous Button Challenge: From Button to ImageButton

3. The Activity Lifecycle

Rotating GeoQuiz Activity States and Lifecycle Callbacks Logging the Activity Lifecycle

Making log messages Using Logcat

Exploring How the Activity Lifecycle Responds to User Actions

Temporarily leaving an activity Finishing an activity Rotating an activity

Device Configuration Changes and the Activity Lifecycle

Creating a landscape layout

For the More Curious: UI Updates and Multi-Window Mode For the More Curious: Log Levels Challenge: Preventing Repeat Answers Challenge: Graded Quiz

4. Persisting UI State

Including the ViewModel Dependency Adding a ViewModel

ViewModel lifecycle and ViewModelProvider Add data to your ViewModel

Saving Data Across Process Death

Overriding onSaveInstanceState(Bundle) Saved instance state and activity records

ViewModel vs Saved Instance State For the More Curious: Jetpack, AndroidX, and Architecture Components For the More Curious: Avoiding a Half-Baked Solution

5. Debugging Android Apps

Exceptions and Stack Traces

Diagnosing misbehaviors Logging stack traces Setting breakpoints

Android-Specific Debugging

Using Android Lint Issues with the R class

Challenge: Exploring the Layout Inspector Challenge: Exploring the Profiler

6. Your Second Activity

Setting Up a Second Activity

Creating a new activity A new activity subclass Declaring activities in the manifest Adding a cheat button to MainActivity

Starting an Activity

Communicating with intents

Explicit and implicit intents

Passing Data Between Activities

Using intent extras Getting a result back from a child activity

Setting a result Sending back an intent Handling a result

How Android Sees Your Activities Challenge: Closing Loopholes for Cheaters Challenge: Tracking Cheat Status by Question

7. Android SDK Versions and Compatibility

Android SDK Versions Compatibility and Android Programming

A sane minimum Minimum SDK version Target SDK version Compile SDK version Adding code from later APIs safely Jetpack libraries

Using the Android Developer Documentation Challenge: Reporting the Device’s Android Version Challenge: Limited Cheats

8. UI Fragments and the Fragment Manager

The Need for UI Flexibility Introducing Fragments Starting CriminalIntent

Creating a new project

Creating a Data Class Creating a UI Fragment

Defining CrimeFragment’s layout Creating the CrimeFragment class

Different types of fragments Implementing fragment lifecycle functions Wiring up widgets in a fragment

Hosting a UI Fragment

Defining a container view Adding a UI fragment to the FragmentManager

Fragment transactions The FragmentManager and the fragment lifecycle

Application Architecture with Fragments

Deciding whether to use fragments

9. Displaying Lists with RecyclerView

Adding a New Fragment and ViewModel

ViewModel lifecycle with fragments

Adding a RecyclerView Creating an Item View Layout Implementing a ViewHolder Implementing an Adapter to Populate the RecyclerView

Setting the RecyclerView’s adapter

Recycling Views Cleaning Up Binding List Items Responding to Presses For the More Curious: ListView and GridView Challenge: RecyclerView ViewTypes

10. Creating User Interfaces with Layouts and Widgets

Introducing ConstraintLayout Introducing the Graphical Layout Editor Using ConstraintLayout

Making room Adding widgets ConstraintLayout’s inner workings Editing properties Making list items dynamic

More on Layout Attributes

Styles, themes, and theme attributes

For the More Curious: Margins vs Padding For the More Curious: New Developments in ConstraintLayout Challenge: Formatting the Date

11. Databases and the Room Library

Room Architecture Component Library Creating a Database

Defining entities Creating a database class

Creating a type converter

Defining a Data Access Object Accessing the Database Using the Repository Pattern Testing Queries

Uploading test data

Application Threads

Background threads

Using LiveData

Observing LiveData

Challenge: Addressing the Schema Warning For the More Curious: Singletons

12. Fragment Navigation

Single Activity: Fragment Boss

Fragment callback interfaces Replacing a fragment

Fragment Arguments

Attaching arguments to a fragment Retrieving arguments

Using LiveData Transformations Updating the Database

Using an executor Tying database writes to the fragment lifecycle

For the More Curious: Why Use Fragment Arguments? For the More Curious: Navigation Architecture Component Library Challenge: Efficient RecyclerView Reloading

13. Dialogs

Creating a DialogFragment

Showing a DialogFragment

Passing Data Between Two Fragments

Passing data to DatePickerFragment Returning data to CrimeFragment

Setting a target fragment Sending data to the target fragment

Challenge: More Dialogs

14. The App Bar

AppCompat Default App Bar Menus

Defining a menu in XML

The app namespace

Creating the menu Responding to menu selections

Using the Android Asset Studio For the More Curious: App Bar vs Action Bar vs Toolbar For the More Curious: Accessing the AppCompat App Bar Challenge: An Empty View for the RecyclerView

15. Implicit Intents

Adding Buttons Adding a Suspect to the Model Layer Using a Format String Using Implicit Intents

Parts of an implicit intent Sending a crime report Asking Android for a contact

Getting data from the contacts list Contacts permissions

Checking for responding activities

Challenge: Another Implicit Intent

16. Taking Pictures with Intents

A Place for Your Photo File Storage

Using FileProvider Designating a picture location

Using a Camera Intent

Firing the intent

Scaling and Displaying Bitmaps Declaring Features Challenge: Detail Display Challenge: Efficient Thumbnail Load

17. Localization

Localizing Resources

Default resources

Screen density works differently

Checking string coverage using the Translations Editor Targeting a region

Configuration Qualifiers

Prioritizing alternative resources Multiple qualifiers Finding the best-matching resources

Ruling out incompatible directories Stepping through the precedence table

Testing Alternative Resources For the More Curious: More on Determining Device Size Challenge: Localizing Dates

18. Accessibility

TalkBack

Explore by Touch Linear navigation by swiping

Making Non-Text Elements Readable by TalkBack

Adding content descriptions Making a widget focusable

Creating a Comparable Experience For the More Curious: Using Accessibility Scanner Challenge: Improving the List Challenge: Providing Enough Context for Data Entry Challenge: Announcing Events

19. Data Binding and MVVM

Different Architectures: Why Bother? MVVM View Models vs Jetpack ViewModels Creating BeatBox Implementing Simple Data Binding Importing Assets Accessing Assets Wiring Up Assets for Use Binding to Data

Creating a view model Binding to a view model Observable data

For the More Curious: More About Data Binding

Lambda expressions Syntactic sugar BindingAdapters

For the More Curious: LiveData and Data Binding

20. Unit Testing and Audio Playback

Creating a SoundPool Accessing Assets Loading Sounds Playing Sounds Test Dependencies Creating a Test Class Setting Up Your Test

Setting up the test subject

Writing Tests

Testing object interactions

Data Binding Callbacks Unloading Sounds For the More Curious: Integration Testing For the More Curious: Mocks and Testing Challenge: Playback Speed Control Challenge: Play Sound Across Rotation

21. Styles and Themes

Color Resources Styles

Style inheritance

Themes

Modifying the theme

Adding Theme Colors Overriding Theme Attributes

Theme spelunking

Modifying Button Attributes For the More Curious: More on Style Inheritance For the More Curious: Accessing Theme Attributes

22. XML Drawables

Making Uniform Buttons Shape Drawables State List Drawables Layer List Drawables For the More Curious: Why Bother with XML Drawables? For the More Curious: Mipmap Images For the More Curious: 9-Patch Images Challenge: Button Themes

23. More About Intents and Tasks

Setting Up NerdLauncher Resolving an Implicit Intent Creating Explicit Intents at Runtime Tasks and the Back Stack

Switching between tasks Starting a new task

Using NerdLauncher as a Home Screen For the More Curious: Processes vs Tasks For the More Curious: Concurrent Documents Challenge: Icons

24. HTTP and Background Tasks

Creating PhotoGallery Networking Basics with Retrofit

Defining an API interface Building the Retrofit object and creating an API instance

Adding a String converter

Executing a web request Asking permission to network Moving toward the repository pattern

Fetching JSON from Flickr

Deserializing JSON text into model objects

Networking Across Configuration Changes Displaying Results in RecyclerView For the More Curious: Alternate Parsers and Data Formats For the More Curious: Canceling Requests For the More Curious: Managing Dependencies Challenge: Adding a Custom Gson Deserializer Challenge: Paging Challenge: Dynamically Adjusting the Number of Columns

25. Loopers, Handlers, and HandlerThread

Preparing RecyclerView to Display Images Preparing to Download Bytes from a URL Downloading Lots of Small Things Assembling a Background Thread

Making your thread lifecycle aware Starting and stopping a HandlerThread

Messages and Message Handlers

Message anatomy Handler anatomy Using handlers Passing handlers

Listening to the View Lifecycle Retained Fragments

Rotation and retained fragments Whether to retain

For the More Curious: Solving the Image Downloading Problem For the More Curious: StrictMode Challenge: Observing View LifecycleOwner LiveData Challenge: Improving ThumbnailDownloader’s Lifecycle Awareness Challenge: Preloading and Caching

26. SearchView and SharedPreferences

Searching Flickr Using SearchView

Responding to SearchView user interactions

Simple Persistence with SharedPreferences Polishing Your App Editing SharedPreferences with Android KTX Challenge: Polishing Your App Some More

27. WorkManager

Creating a Worker Scheduling Work Checking for New Photos Notifying the User Providing User Control over Polling

28. Broadcast Intents

Regular Intents vs Broadcast Intents Filtering Foreground Notifications

Sending broadcast intents Creating and registering a standalone receiver Limiting broadcasts to your app using private permissions

More about protection levels

Creating and registering a dynamic receiver Passing and receiving data with ordered broadcasts

Receivers and Long-Running Tasks For the More Curious: Local Events

Using EventBus Using RxJava

For the More Curious: Limitations on Broadcast Receivers For the More Curious: Detecting the Visibility of Your Fragment

29. Browsing the Web and WebView

One Last Bit of Flickr Data The Easy Way: Implicit Intents The Harder Way: WebView

Using WebChromeClient to spruce things up

Proper Rotation with WebView

Dangers of handling configuration changes

WebView vs a Custom UI For the More Curious: Injecting JavaScript Objects For the More Curious: WebView Updates For the More Curious: Chrome Custom Tabs (Another Easy Way) Challenge: Using the Back Button for Browser History

30. Custom Views and Touch Events

Setting Up the DragAndDraw Project Creating a Custom View

Creating BoxDrawingView

Handling Touch Events

Tracking across motion events

Rendering Inside onDraw(Canvas) For the More Curious: GestureDetector Challenge: Saving State Challenge: Rotating Boxes Challenge: Accessibility Support

31. Property Animation

Building the Scene Simple Property Animation

View transformation properties Using different interpolators Color evaluation

Playing Animators Together For the More Curious: Other Animation APIs

Legacy animation tools Transitions

Challenges

32. Afterword

The Final Challenge Shameless Plugs Thank You

Index

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