Jetpack Compose internals
Jetpack Compose internals
About the Book
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.
Jetpack Compose and Android are trademarks of Google LLC and this book is not endorsed by or affiliated with Google in any way.
About the Contributors

Software Engineer
Andrei wrote the chapter about "Advanced Compose runtime use cases", one of the most interesting chapters in the book. It showcases how to create client libraries that leverage all the power of the Compose runtime.
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
- Kotlin Compiler version
- Static analysis
- 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
- Integrating UI with the Compose runtime
- Mapping scheduled changes to actual changes to the tree
- Composition from the point of view of Compose UI
- Subcomposition from the point of view of Compose UI
- Reflecting changes in the UI
- Different types of Appliers
- Materializing a new LayoutNode
- Closing the circle
- Materializing a change to remove nodes
- Materializing a change to move nodes
- Materializing a change to clear all the nodes
- Measuring in Compose UI
- Measuring policies
- Intrinsic measurements
- Layout Constraints
- Modeling modifier chains
- Setting modifiers to the LayoutNode
- How LayoutNode ingests new modifiers
- Drawing the node tree
- Semantics in Jetpack Compose
- Notifying about semantic changes
- Merged and unmerged semantic trees
-
5. State snapshot system
- What snapshot state is
- Concurrency control systems
- Multiversion concurrency control (MCC or MVCC)
- The Snapshot
- The snapshot tree
- Snapshots and threading
- Observing reads and writes
- MutableSnapshots
- GlobalSnapshot and nested snapshots
- StateObjects and StateRecords
- Reading and writing state
- Removing or reusing obsolete records
- Change propagation
- Merging write conflicts
- 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
The Leanpub 60-day 100% Happiness Guarantee
Within 60 days of purchase you can get a 100% refund on any Leanpub purchase, in two clicks.
See full terms
Do Well. Do Good.
Authors have earned$11,714,583writing, publishing and selling on Leanpub, earning 80% royalties while saving up to 25 million pounds of CO2 and up to 46,000 trees.
Learn more about writing on Leanpub
Free Updates. DRM Free.
If you buy a Leanpub book, you get free updates for as long as the author updates the book! Many authors use Leanpub to publish their books in-progress, while they are writing them. All readers get free updates, regardless of when they bought the book or how much they paid (including free).
Most Leanpub books are available in PDF (for computers), EPUB (for phones and tablets) and MOBI (for Kindle). The formats that a book includes are shown at the top right corner of this page.
Finally, Leanpub books don't have any DRM copy-protection nonsense, so you can easily read them on any supported device.
Learn more about Leanpub's ebook formats and where to read them
Top Books
Recipes for Decoupling
Matthias NobackWrite software that survives
OpenIntro Statistics
David Diez, Christopher Barr, Mine Cetinkaya-Rundel, and OpenIntroA complete foundation for Statistics, also serving as a foundation for Data Science.
Leanpub revenue supports OpenIntro (US-based nonprofit) so we can provide free desk copies to teachers interested in using OpenIntro Statistics in the classroom and expand the project to support free textbooks in other subjects.
More resources: openintro.org.
C++20 - The Complete Guide
Nicolai M. JosuttisAll new language and library features of C++20 (for those who know previous C++ versions).
The book presents all new language and library features of C++20. Learn how this impacts day-to-day programming, to benefit in practice, to combine new features, and to avoid all new traps.
Buy early, pay less, free updates.
Other books:
CQRS by Example
Carlos Buenosvinos, Christian Soronellas, and Keyvan Akbary- Leverage your Software Architecture skills by learning everything about CQRS in detail with lots of examples
- Develop faster applications by applying CQRS and fostering Read Models and Projections
- Learn how to apply CQRS into a brownfield project from a pragmatic approach
Ansible for DevOps
Jeff GeerlingAnsible is a simple, but powerful, server and configuration management tool. Learn to use Ansible effectively, whether you manage one server—or thousands.
Maîtriser Apache JMeter
Philippe Mouawad, Bruno Demion (Milamber), and Antonio Gomes RodriguesToute la puissance d'Apache JMeter expliquée par ses commiteurs et utilisateurs experts. De l'intégration continue en passant par le Cloud, vous découvrirez comment intégrer JMeter à vos processus "Agile" et Devops.
If you're looking for the newer english version of this book, go to Master JMeter : From load testing to DevOps
Jetpack Compose internals
Jorge CastilloJetpack 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.
The PowerShell Scripting and Toolmaking Book
Don Jones and Jeff HicksLearn the patterns, practices, and details of PowerShell Scripting and Toolmaking from the industry's two most recognized experts on the subject.
Mastering STM32 - Second Edition
Carmine NovielloWith more than 1200 microcontrollers, STM32 is probably the most complete ARM Cortex-M platform on the market. This book aims to be the most complete guide around introducing the reader to this exciting MCU portfolio from ST Microelectronics and its official CubeHAL and STM32CubeIDE development environment.
Introduction to Data Science
Rafael A IrizarryThe demand for skilled data science practitioners in industry, academia, and government is rapidly growing. This book introduces concepts from probability, statistical inference, linear regression and machine learning and R programming skills. Throughout the book we demonstrate how these can help you tackle real-world data analysis challenges.
Top Bundles
- #1
Software Architecture
2 Books
"Software Architecture for Developers" is a practical and pragmatic guide to modern, lightweight software architecture, specifically aimed at developers. You'll learn:The essence of software architecture.Why the software architecture role should include coding, coaching and collaboration.The things that you really need to think about before... - #2
CCIE Service Provider Ultimate Study Bundle
2 Books
Piotr Jablonski, Lukasz Bromirski, and Nick Russo have joined forces to deliver the only CCIE Service Provider training resource you'll ever need. This bundle contains a detailed and challenging collection of workbook labs, plus an extensively detailed technical reference guide. All of us have earned the CCIE Service Provider certification... - #4
Pattern-Oriented Memory Forensics and Malware Detection
2 Books
This training bundle for security engineers and researchers, malware and memory forensics analysts includes two accelerated training courses for Windows memory dump analysis using WinDbg. It is also useful for technical support and escalation engineers who analyze memory dumps from complex software environments and need to check for possible... - #6
All the Books of The Medical Futurist
6 Books
We put together the most popular books from The Medical Futurist to provide a clear picture about the major trends shaping the future of medicine and healthcare. Digital health technologies, artificial intelligence, the future of 20 medical specialties, big pharma, data privacy, digital health investments and how technology giants such as Amazon...