Long-running task such as CPU intensive work, writing a file to disk or network request should NOT run on the main thread. Android, for example, will throw a NetworkOnMainThreadException if you try to perform an HTTP reqeust on the main thread. To resolve this issue, we can use Kotlin coroutine to perform long-running task on a separate thread. This post shows how to perform a non-blocking HTTP reqest using HttpUrlConnection and Kotlin coroutine.

One common task for most Android apps is connecting to the Internet. Most network-connected Android apps use HTTP to send and receive data. This article shows you how to write a simple application that connects to the Internet, send HTTP GET request & display the response using Kotlin.

ListAdapter for RecyclerView has been introduced in Revision 27.1.0 Release of Support Library. ListAdapter uses DiffUtil under the hood to compute list diffs on a background thread. This will help RecyclerView animate changes automatically with less work on the UI thread.

You can navigate between sibling screens using horizontal finger gesture. This post shows you how to build swipe views and how to add tabs to action bar offering users a familiar interfaces

How to center a view or its content e.g. TextView or Button horizontally and vertically? layout_gravity can be used to position a view in the center of its parent. While gravity attribute is used to position view’s content e.g. “text” in the center of the view.

Given an array of size N, we will find all possible combinations of k elements in that array using three different algorithms.

Creating a scrollable list of elements is a common pattern in mobile application. Using RecyclerView we can list a large data sets or frequently changing one. RecyclerView is an advanced and flexible version of ListView, addressing serveral issues with existing listing views.