Make the lifecycle available to the upstream Flow to skip unnecessary work — This is the second part of a series of articles about using Kotlin Flow on Android. In the first part, we described the main limitation of Kotlin Flow when used inside ViewModel classes: When a SharedFlow or StateFlow using the SharingStarted.WhileSubscribed() strategy is collected again after the user navigates back…

Yet another take on AutoClearedValue — Handling the lifecycle of Android Fragments is difficult. I already covered this topic in an article I wrote in 2017, before Google added a View-specific Lifecycle to Fragments in an attempt to solve some issues. Until now, the number one cause of memory leaks when using Fragments remains the same…

LiveData is still your friend — Loading UI data in Android applications can be challenging. The lifecycles of the various screens need to be taken into account, as well as configuration changes leading to the destruction and recreation of Activities. The individual screens of an app constantly toggle between interactive and hidden as the user navigates…

and making ViewPager2 usable — RecyclerView is one of the main building blocks of Android user interfaces today. It’s more capable and flexible than its ListView predecessor but this also leads to more complexity and new problems. One core feature of RecyclerView is the externalization of its layout engine to components called LayoutManagers, which are…

Life is too short to waste time on writing Parcelable code — Two years ago, I wrote about how you can leverage features of the Kotlin programming language to manually write your Android Parcelable implementations in the most concise and readable way. Does it mean that I always prefer writing this code manually rather than letting a library or tool generate it…

A match made in parser heaven — Moshi is a modern JSON library for Android and Java from Square. It can be considered as the successor to GSON, with a simpler and leaner API and an architecture enabling better performance through the use of the Okio library. It’s also the most Kotlin-friendly library you can use to…

I’m the happy owner of a Lenovo Ideapad laptop (model 710S-13IKB). It’s comparable to the Dell XPS 13 and runs beautifully under Linux, but one detail has always been bugging me: Lenovo only provides BIOS updates for its Ideapad laptops in the form of Windows 10 executable files. System firmware…

LiveData and the Fragment lifecycle — The new Android Architecure Components are soon to be announced as stable after a few months of public testing. A lot has already been written about the basics (starting with the very good documentation) so I won’t cover them here. Instead I would like to focus on important pitfalls that…

object has its limits — In Kotlin, the singleton pattern is used as a replacement for static members and fields that don’t exist in that programming language. A singleton is created by simply declaring an object. object SomeSingleton Contrary to a class, an object can’t have any constructor, but init blocks are allowed if some…