Today, I came across the term “Trampoline Activities”. Although it’s not an official name (or is it?), I’ve noticed it is a typical pattern and have decided to make a “How To” guide. What are Trampoline Activities? A Trampoline Activity is an Activity that launches another activity and finishes itself. It may include conditional logic to determine which activity to launch or transforming the parameters before sending it to the next Activity....
Modeling is a critical task in Software Development: good models reduce the risk of bugs, increase readability and improve maintainability. However, we can often see developers focusing on “How can I code this?”, and they are done with their task when they find a way to code it. This inherently reduces the domain modeling to the abuse of primitives and shallow design where any inconsistent state is allowed. To better explain, let’s consider the hypothetical requirements:...
Jetpack Compose hit Beta! Many teams are excited to experiment with Compose, but as you might know, since 1.0.0-alpha04, the compiler has been refactored to a new group and became incompatible with the current Android Studio (AS) 4.1 stable: Compose Version 1.0.0-alpha04 is only compatible with Android Studio 4.2 Canary 13 and later. Been forced to use a Canary version of AS is a real bummer. There are cases in which you want to explore Compose in a real-world application (e....
This post represents my personal experience while working at N26. I do not speak for the company nor by other employees. N26 Android App current codebase has a million lines of code, 280+ modules, and 30+ engineers working in 4 different countries and different timezones in a mono repository. Our modules are divided into features and libraries, and we have been using “Sample Apps” for years now as our full app build time might take up to 20 minutes....
The Android Community has long advocated that Activities and Fragments were views - but this perception has changed over time. For good. Let’s dive deep into how to design views and view models, how they wire to a LifecycleOwner, and how this can positively impact your’s app testability. To better describe how to build humble views we will be developing an elementary Sign-Up form with an email, a password text field and two buttons: a cancel that pops the user’s back stack and a sign up that creates an account and moves the user to the home screen....
When discussing Factory Methods, extension functions are often preferred in Kotlin. However, naming these functions in a discoverable way without cluttering your project’s namespace can be challenging. A great source of inspiration is Kotlin’s Standard Library, which offers numerous examples to guide function design. Wrapping an Instance If you want to take an existing instance and adapt it to a different object to meet another contract—such as creating a ViewModelProvider.Factory that internally uses a javax....