jetc.dev Newsletter Issue #58
beta03 is out, and it is as boring as was
So, instead, we focus on modifier ordering, along with evergreen topics like themes and navigation. We also peek at using Compose UI on foldable/dual-screen devices, give our composables major motion, and see what Google’s Chris Banes has been up to recently. Plus, I encourage you to “eat your vegetables” and get your app architecture in a good place before diving seriously into Compose.
Reviewing the release notes for the latest Jetpack Compose update!
As with past beta releases, there are relatively few changes to the API exposed
beta03. You might want to review the release notes if you are using:
Otherwise, you should encounter few modifications, if any.
One Off the Stack, One Off the Slack
You’ve got questions. That’s understandable!
Compose UI offers automatic layout orientation based on LTR/RTL languages.
However, what if you want to override that for a particular composable?
Learn how to use
for that in this week’s highlighted Stack Overflow question!
The order of modifiers matters. Each modifier basically creates a composable that
wraps the preceding composable, and so a chain of modifiers creates a chain of
wrapped composables. Sometimes the order will appear to have no impact, and sometimes
the order will result in UI artifacts, as we see in
this week’s highlighted Kotlinlang
#compose Slack thread.
Posts, videos, and other new information related to Jetpack Compose!
Igor Escodro is back, this time looking at how to integrate Compose UI with
a common system feature: the
Notification. Igor shows how to use Navigation
for Compose and deep links to get a
Notification to not only launch your
activity but to show a specific composable from your nav graph.
Maia Grotepass delivered a presentation to GDG Johannesburg, with an introduction to Compose and Compose UI, including a walkthrough of many of the steps in the Jetpack Compose basics codelab.
Thomas Künneth continues an exploration of portrait and landscape modes and how they work with Compose UI. In this case, though, Thomas focuses on a different scenario: foldables. In particular, Thomas explores how to adapt a landscape-style UI to cases where the hardware, more so than your app, dictates where the UI split should occur, courtesy of a fold or hinge.
Microsoft and Joy Liu agree with Thomas Künneth, that foldables are important. I am sure that the fact that Microsoft sells a dual-screen Android device is purely a coincidence. 😁 In this post, Joy expands upon an earlier post to look at various UI design patterns for foldable/dual-screen devices and how to implement them using Compose UI.
Other Interesting Links
- Prime Table Generator in Jetpack Compose
- Building UI with Jetpack Compose. Part 1: Bottom Sheet Implementation
- How much can we share in Kotlin MultiPlatform
- Jetpack Compose Ep:11 — Switch App
- Writing List Views for lazy android developers
100% pure code!
accompanist series of libraries is now An Official Google Thing™ 🎉
In addition to the image loaders, theme adapters, and system UI libraries from
before, it now adds a composable pager (akin to
ViewPager) and a flexbox-style
The Material Design spec has a specific motion system.
GitHub user fornewid has created a library of composables that implements several
of those motion system specifications (e.g.,
FadeThrough()), plus a
composable to allow you to easily apply different motions based on app state.
GitHub user Tlaster is back with another library, this one offering Kotlin/Common
code for navigation, viewmodels, and a
LiveData equivalent. The objective is to
allow you to write more of your app logic in
commonMain of your Kotlin/Multiplatform
project, by replacing Jetpack dependencies with intrinsic Android ties.
Other Interesting Links
- Gist: warting / ZoomableImage.kt
- GitHub: manueldidonna / undo-redo-animation
- GitHub: theapache64 / klokk
- GitHub: tylerbwong / stack
- GitHub: Madonahs / The-Sports-DB
…And One More Thing
Jetpack Compose is crazysexycool.
(presumably, you agree — otherwise… this might be the wrong newsletter for you)
However, be careful not to sacrifice other essential concerns of your app development while chasing the cool.
In particular, before you embark on a serious migration of an app to Compose UI, consider first whether your app architecture is in a good place. Trying to change your architecture along with the UI rendering is likely to be a massive undertaking. Of the two, dealing with the architecture now, while Compose is still in beta, likely is a better option than is worrying about Compose now and “kicking the can down the road” on architecture concerns.
Besides, a lot of what we are aiming for in architecture will simplify any Compose migration. A key objective of modern Android app architecture is to get all non-essential code out of your activities and fragments and into other things: viewmodels, use cases, repositories, data sources, etc. Partly, all of this is good for long-term maintainability and testing. But it also limits the excess “mental noise” that you will have to deal with as you migrate your UI from views to composables.
So, take a tour of your app code, and if you have things unrelated to UI presentation or system navigation… see if you can move it somewhere else:
Network I/O (TCP/IP,
Peripheral I/O (Bluetooth, BLE, NFC, printing, USB, etc.)
Sensor readings (GPS, accelerometer, etc.)
Non-presentation aspects of camera integration
And so on
The more of that you can get out of your activities and fragments, the more likely it is that you will be able to swap in composables cleanly as replacements for your layouts and views.
- 2021-07-20: rc02! Preview and ViewModel, together again! Coil supports Compose! MVI! @dequesystems on accessibility! Screenshots of composables! D-pad support! And... Context code smells?!?
- 2021-07-13: Focus! Viewports! Navigation! @divyajain2405 talks about architecture! Screenshot testing! Sliders! Reorderable lists!
- 2021-07-06: RC01! Navigation! Phones *and* tablets! Cards! Timers! Barcodes! And... the