The Android guy

Searchable Fragments with the Paging Library

This post is inspired by @EpicPandaForce¬†answer in StackOverflow. I faced the same problem which I didn’t know how to solve: How to perform search when you are using a Paging Library (or how the hell to refresh after I reperform Rooms query)? Let’s suppose we have this scenario: I have a list of data, which are shown in the Fragment by LiveData observation, which are retrieved by the ViewModel through LiveDataPagedListBuilder().

Prepopulate Room with data.

There are times, when we just need the data when the app starts, and all the functionality is just a matter of work. Or we just need the app to be independent from the network and we have the data. A simple dog-race database or cat-race database doesn’t actually need online interaction at all (if there are not too many data of course). So, Room comes with a nice solution about this.

Fragments ‚̧ ViewPager2

The ViewPager2 is a pretty nice rework of the ViewPager API. Some new features you may find with the ViewPager2 are: 1- Vertical scrolling. You can simply enable it by adding: android:orientation="vertical” in the tag in your xml file. 2- Right to left support: you can set the android:layoutDirection="rtl” to enable this. 3- Support for DiffUtil, because it is based on RecyclerView. 4 - Fragments improved support, which we will talk about below.

Setting up Gradle with Kotlin DSL, a simple guide

Kotlin is a very a pretty nice adoptive language and user friendly. It really replaced Java from my everyday programming. However, it was not enough. We all know that groovy runs on JVM. So, why do I even need a new language just for my builds? Can’t it be Java? So Java is the basic language for the JVM, Kotlin runs on JVM, Groovy runs on JVM and my build system has a separated language from my business logic system.

Conditional navigation and single event LiveData

Conditional navigation is a little tricky when it comes to Navigation Architecture. There are plenty of nice articles and solutions about it, but I’m sharing the way I solve this important problem. So let’s consider this use case: If you don’t put HomeFragment as a start destination, you will have some serious trouble with the fragment back stack and you would need to write the onBackPressDispatcher in every fragment.

Are service locators in Android actually simple?

This week, I’ve been playing with service locators in Android. I made this repo with 3 different branches. One of them is using Dagger as a DI tool, the other branches are implementation with KodeIn and Koin. The app is pretty simple, just retrieves some data from a Cat API, saves them to a local Room persistence and then renders them to the screen: The screen renders just a the list of cats retrieved by the database after the data are fetched from a remote API.