Jetpack Compose internals

Jetpack Compose is the future of Android UI. Master how it works internally and become a more efficient developer with it. You'll also find it valuable if you are not an Android dev. This book provides all the details to understand how the Compose compiler & runtime work, and how to create a client library using them. This book explores the guts of Jetpack Compose, the brand new library by Google and the Android team that will become the future of Android UI. Dedicating time now to learn about its internals in-depth will yield powerful skills to write modern and efficient Android apps in the future. If you are interested in other use cases of Jetpack Compose rather than Android, this book has got you covered also. Jetpack Compose internals is very focused on exploring the compiler and runtime from a generic perspective, making the overall experience very agnostic of the target platform. The book also provides a chapter dedicated to diverse use cases for Jetpack Compose, which exposes a few really interesting examples over code. Table of Contents Prelude Why to read this book What this book is not about What this book is about Keep the sources close Code snippets and examples 1. Composable functions The nature of Composable functions Composable function properties Calling context Idempotent Free of side effects Restartable Fast execution Positional memoization Similarities with suspend functions Composable functions are colored Composable function types 2. The Compose compiler A Kotlin compiler plugin Compose annotations Registering Compiler extensions Static analysis Kotlin Compiler version Static Checkers Call checks Type checks Declaration checks Diagnostic suppression Runtime version check Code generation The Kotlin IR Lowering Inferring class stability Enabling live literals Compose lambda memoization Injecting the Composer Comparison propagation Default parameters Control flow group generation Klib and decoy generation 3. The Compose runtime The slot table and the list of changes The slot table in depth The list of changes The Composer Feeding the Composer Modeling the Changes Optimizing when to write Writing and reading groups Remembering values Recompose scopes SideEffects in the Composer Storing CompositionLocals Storing source information Linking Compositions via CompositionContext Accessing the current State snapshot Navigating the nodes Keeping reader and writer in sync Applying the changes Performance when building the node tree How changes are applied Attaching and drawing the nodes Composition Creating a Composition The initial Composition process Applying changes after initial Composition Additional information about the Composition The Recomposer Spawning the Recomposer Recomposition process Concurrent recomposition Recomposer states 4. Compose UI 5. State snapshot system 6. Smart Recomposition 7. Effects and effect handlers Introducing side effects Side effects in Compose What we need Effect Handlers Non suspended effects Suspended effects Third party library adapters 8. The Composable lifecycle 9. Advanced Compose Runtime use cases Compose runtime vs Compose UI Composition of vector graphics Building vector image tree Integrating vector composition into Compose UI Managing DOM with Compose Standalone composition in the browser Conclusion