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You're reading from Android Studio 4.2 Development Essentials - Kotlin Edition Developing Android applications using Android Studio 4.2, Kotlin, and Android Jetpack

Product type Paperback

Published in Aug 2021

Publisher Packt

ISBN-13 9781803231549

Length 804 pages

Edition 1st Edition

Languages

Kotlin

Tools

Android

Concepts

Android Development

Author (1):

Neil Smyth

View More author details

Table of Contents (94) Chapters

1. Introduction

2. Setting up an Android Studio Development Environment FREE CHAPTER

3. Creating an Example Android App in Android Studio

4. Creating an Android Virtual Device (AVD) in Android Studio

5. Using and Configuring the Android Studio AVD Emulator

6. A Tour of the Android Studio User Interface

7. Testing Android Studio Apps on a Physical Android Device

8. The Basics of the Android Studio Code Editor

9. An Overview of the Android Architecture

10. The Anatomy of an Android Application

11. An Introduction to Kotlin

12. Kotlin Data Types,Variables and Nullability

13. Kotlin Operators and Expressions

14. Kotlin Flow Control

15. An Overview of Kotlin Functions and Lambdas

16. The Basics of Object Oriented Programming in Kotlin

17. An Introduction to Kotlin Inheritance and Subclassing

18. An Overview of Android View Binding

19. Understanding Android Application and Activity Lifecycles

20. Handling Android Activity State Changes

21. Android Activity State Changes by Example

22. Saving and Restoring the State of an Android Activity

23. Understanding Android Views, View Groups and Layouts

24. A Guide to the Android Studio Layout Editor Tool

25. A Guide to the Android ConstraintLayout

26. A Guide to Using ConstraintLayout in Android Studio

27. Working with ConstraintLayout Chains and Ratios in Android Studio

28. An Android Studio Layout Editor ConstraintLayout Tutorial

29. Manual XML Layout Design in Android Studio

30. Managing Constraints using Constraint Sets

31. An Android ConstraintSet Tutorial

32. A Guide to using Apply Changes in Android Studio

33. An Overview and Example of Android Event Handling

34. Android Touch and Multi-touch Event Handling

35. Detecting Common Gestures Using the Android Gesture Detector Class

36. Implementing Custom Gesture and Pinch Recognition on Android

37. An Introduction to Android Fragments

38. Using Fragments in Android Studio - An Example

39. Modern Android App Architecture with Jetpack

40. An Android Jetpack ViewModel Tutorial

41. An Android Jetpack LiveData Tutorial

42. An Overview of Android Jetpack Data Binding

43. An Android Jetpack Data Binding Tutorial

44. An Android ViewModel Saved State Tutorial

45. Working with Android Lifecycle-Aware Components

46. An Android Jetpack Lifecycle Awareness Tutorial

47. An Overview of the Navigation Architecture Component

48. An Android Jetpack Navigation Component Tutorial

49. An Introduction to MotionLayout

50. An Android MotionLayout Editor Tutorial

51. A MotionLayout KeyCycle Tutorial

52. Working with the Floating Action Button and Snackbar

53. Creating a Tabbed Interface using the TabLayout Component

54. Working with the RecyclerView and CardView Widgets

55. An Android RecyclerView and CardView Tutorial

56. A Layout Editor Sample Data Tutorial

57. Working with the AppBar and Collapsing Toolbar Layouts

58. An Android Studio Primary/Detail Flow Tutorial

59. An Overview of Android Intents

60. Android Explicit Intents – A Worked Example

61. Android Implicit Intents – A Worked Example

62. Android Broadcast Intents and Broadcast Receivers

63. An Introduction to Kotlin Coroutines

64. An Android Kotlin Coroutines Tutorial

65. An Overview of Android Services

66. Implementing an Android Started Service – A Worked Example

67. Android Local Bound Services – A Worked Example

68. Android Remote Bound Services – A Worked Example

69. An Android Notifications Tutorial

70. An Android Direct Reply Notification Tutorial

71. Foldable Devices and Multi-Window Support

72. An Overview of Android SQLite Databases

73. The Android Room Persistence Library

74. An Android TableLayout and TableRow Tutorial

75. An Android Room Database and Repository Tutorial

76. Accessing Cloud Storage using the Android Storage Access Framework

77. An Android Storage Access Framework Example

78. Video Playback on Android using the VideoView and MediaController Classes

79. Android Picture-in-Picture Mode

80. An Android Picture-in-Picture Tutorial

81. Making Runtime Permission Requests in Android

82. Android Audio Recording and Playback using MediaPlayer and MediaRecorder

83. Printing with the Android Printing Framework

84. An Android HTML and Web Content Printing Example

85. A Guide to Android Custom Document Printing

86. An Introduction to Android App Links

87. An Android Studio App Links Tutorial

88. A Guide to the Android Studio Profiler

89. An Android Biometric Authentication Tutorial

90. Creating, Testing and Uploading an Android App Bundle

91. An Overview of Android Dynamic Feature Modules

92. An Android Studio Dynamic Feature Tutorial

93. An Overview of Gradle in Android Studio

Index

22.4 Saving the State

The first step in extending the StateChange application is to make sure that the text entered by the user is extracted from the EditText component within the onSaveInstanceState() method of the MainActivity activity, and then saved as a key-value pair into the Bundle object.

In order to extract the text from the EditText object we first need to identify that object in the user interface. Clearly, this involves bridging the gap between the Kotlin code for the activity (contained in the MainActivity.kt source code file) and the XML representation of the user interface (contained within the activity_main.xml resource file). In order to extract the text entered into the EditText component we need to gain access to that user interface object.

Each component within a user interface has associated with it a unique identifier. By default, the Layout Editor tool constructs the id for a newly added component from the object type. If more than one view of the same...

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You're reading from Android Studio 4.2 Development Essentials - Kotlin Edition Developing Android applications using Android Studio 4.2, Kotlin, and Android Jetpack

Table of Contents (94) Chapters

Authors (1)

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You're reading from Android Studio 4.2 Development Essentials - Kotlin Edition Developing Android applications using Android Studio 4.2, Kotlin, and Android Jetpack

Table of Contents (94) Chapters

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Authors (1)

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