Beyond Java, Exploring the Modern Android Development

Dive into the Future of App Development: Master Kotlin, Jetpack Compose, and Production-Ready Techniques!

Transcript

1. Bhoomi Gadhiya 📱Android Developer Beyond Java: Exploring the Modern Android Development @bhoomigadhiya GDSC PPSU
2. About me 󰟲 • Android Developer • Technical Author in DroidCon Academy • Technical Blogger : Medium @bhoomigadhiya • Technical Speaker in community • Empowering Women In Tech
3. Agenda • Kotlin • Jetpack Compose • Production-level apps • Hands-on Experience • Quiz • Q&A time
4. XML + Java XML + Kotlin Jetpack Compose In Kotlin Evolution Of Android Development
5. What is Kotlin?
6. • Developed By Jetbrains JetBrains is a software development company that creates intelligent development tools for software developers and project managers.
7. • Open-source (https://github.com/Jetbrains/kotlin) • First commit in 2010
8. • 2016 - Kotlin 1.0 released • 2017 - Android announced Official support for Kotlin
9. Kotlin Features Concise
10. Data Classes public class User { String name; int age; public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } } data class User(var name:String,var age:Int) KOTLIN JAVA
11. Concise Null-safety Kotlin Features
12. Tony’s $1B Mistake “I call it my billion-dollar mistake. It was the invention of the null reference in 1965…This has led to innumerable errors, vulnerabilities, and system crashes,” - Tony Hoare
13. Null-Safety ./No Compiler Error String name = null; ./Compiler Error var name:String = null KOTLIN JAVA ./No Compiler Error var name:String? = null ./Compiler Error on line 2 var nameLength = name.length ./Runtime Error int nameLength = name.length()
14. Kotlin Features Concise Null-safety Functional
15. Functional Programming • Immutable Data • High-Order functions • Lambda Expressions • Extension function • And much more!
16. Kotlin Features Concise Null-safety Functional Interoperability
17. Kotlin is 100% interoperable with Java
18. Kotlin Features Concise Null-safety Functional Interoperability Tool-friendly
19. Want to learn Kotlin? • kotlinlang.org • developer.android.com/kotlin • codecademy.com/learn/learn-kotlin • youtube.com/@CheezyCode
20. What is Jetpack Compose?
21. Imperative Explicit step-by-step instruction System is stupid & You are smart😎
23. Describe what you want System is smart & You don’t care😉 Declarative
25. Jetpack Compose? • Modern UI toolkit for building native UI
26. Jetpack Compose? • Modern UI toolkit for building native UI • Entirely built in Kotlin
27. Jetpack Compose? • Modern UI toolkit for building native UI • Entirely built in Kotlin • Do more with Less Code
28. Jetpack Compose? • Modern UI toolkit for building native UI • Entirely built in Kotlin • Do more with Less Code • Intuitive Kotlin APIs
29. Jetpack Compose? • Modern UI toolkit for building native UI • Entirely built in Kotlin • Do more with Less Code • Intuitive Kotlin APIs • Accelerate Development
30. Jetpack Compose? • Modern UI toolkit for building native UI • Entirely built in Kotlin • Do more with Less Code • Intuitive Kotlin APIs • Accelerate Development • Powerful Tool
32. Everything is ‘fun’ in Compose
33. Composable • A function that is used to create a UI element in Jetpack Compose. • Focuses on “What” rather “How”
34. Jetpack Compose View ./MainActivity.kt class MainActivity : Activity() { override fun onCreate(...) { setContentView(R.layout.activity_main) } } ./activity_main.xml <LinearLayout...> <TextView ... android:text="Hello World" .> ./LinearLayout> ./MainActivity.kt class MainActivity : Activity() { override fun onCreate(...) { setContent{ Greeting() } } } @Composable fun Greeting(){ Text("Hello World") }
35. Jetpack Compose View MainActivity.kt activity_main.xml MainActivity.kt Composable Screen 1 Composable Screen N
36. Setting Up Project
37. Start composing…
38. Text Hello Surat! @Composable fun Demo(name: String){ Text(text = "Hello $name!") } // Demo(name = “Surat”)
39. Button @Composable fun Demo() { Button(onClick = { ** Do Something */ }) { Text("Click Me") } }
40. Image @Composable fun Demo() { Image( painter = painterResource(R.drawable.logo), contentDescription = "Android" ) }
41. Without Layouts @Composable fun Demo() { Text("A") Text("B") Text("C") } A B C
42. Column @Composable fun Demo() { Column { Text("A") Text("B") Text("C") } } A B C
43. Row @Composable fun Demo() { Row{ Text("A") Text("B") Text("C") } } A BC
44. Box @Composable fun Demo() { Box(Modifier.size(28.dp)) { Text("A", modifier = Modifier.align(Alignment.TopStart)) Text("B", modifier = Modifier.align(Alignment.Center)) Text("C", modifier = Modifier.align(Alignment.BottomEnd)) } } A B C
45. More composable functions • LazyColumn • LazyRow • ConstraintLayout • Spacer • ... and much more
46. Modifier • Change the appearance and behavior of composables. • Example: setting background color, adding padding, making elements clickable, and more.
47. Modifier @Composable fun Demo() { Box(Modifier.background(Color.Yellow)) { Text( text = "Hello", modifier = Modifier .padding(8.dp) .background(Color.Red) ) } } Hello
48. State • State is any value in the app that can change. • Examples: a. Whether to show a button or not based on some condition. b. Result of fetching the data : Loading, Error, Success. c. Error message when user enters invalid message.
49. Recomposition • Whenever state is updated, recomposition takes place.
50. @Composable fun DisplayName(name: String) { Text(text = "Hello, $name!") } Initial Composition @Composable fun DisplayName(name: String) { Text(text = "Hello, $name!") } Name Changes ReComposition Recomposition
51. Recomposition • Whenever state is updated, recomposition takes place. • Only way to update UI, calling same composable with new argument.
52. Recomposition • Whenever state is updated, recomposition takes place. • Only way to update UI, calling same composable with new argument. • Only rebuild part of UI.
53. Remember @Composable fun Detail(name: String) { val someClass = SomeClass() Text(name) } Without Remember With Remember @Composable fun Detail(name: String) { val someClass = remember{SomeClass()} Text(name) } val someClass Composition 1 Recomposition 2 Recomposition 3 SomeClass@111 SomeClass@222 SomeClass@333 val someClass Composition 1 Recomposition 2 Recomposition 3 SomeClass@111 SomeClass@111 SomeClass@111
54. How to create State? var enabled by remember { mutableStateOf(true) } Retain the data during recomposition Store the latest value
55. Want to learn Compose? • developer.android.com/jetpack/compose • github.com/android/compose-samples • github.com/android/nowinandroid • medium.com/androiddevelopers • youtube.com/c/AndroidDevelopers/videos • composables.com • youtube.com/@CheezyCode
56. Production Level Apps API Database Architecture Pattern Backend Integration
57. Scalability Testability Complexity Maintainability Source: https://storyset.com/people
58. Architecture Patterns Separation Of Concern No Hard Dependency
59. Architecture Patterns • MVC (Model - View - Controller) • MVP (Model - View - Presenter) • MVVM (Model - View - ViewModel) • MVI (Model - View - Intent) • And some more!
60. Application Programming Interface Source: https://shorturl.at/ewAE3
61. Endpoints
62. Endpoints https://dummy.restapiexample.com/api/v1/employees
63. Retrofit • Type-safe REST Client for Android • Convert the response in POJO
64. Retrofit API Request with method GET/POST Response with JSON Format Client Server
65. Backend Integration Create your own Backend Use Firebase
66. Firebase • BAAS (Backend As A Service) • Build, improve and grow your app • No need to maintain the server!
67. Source: https://shorturl.at/lotFX
68. Then What?
69. If you’re an Android Developer, you have to keep learning!
70. Practice! Practice! Practice!💻
71. Let’s build something! #Code
72. Kudos👏 GDSC
73. The Power of Community💪
74. LinkedIn Twitter Medium @bhoomigadhiya
75. Scan here for the slides👇
76. Question & Answer Time⏲