The Working Dev

I'm Ted Hagos. I've been coding for the better part of the last 3 decades, a code instructor for half of that, and an author for a third of that.

Recent posts

May 1, 2020
How to Handle Clicks in Android
To follow the tutorial, you’ll need to create a project or download the project file here. I created this project using Android Studio 4 (Canary version, at the time of writing). Below are the project details;

May 1, 2020
Android Studio Time Savers
What we usually mean when talking about productivity is that we want to do what we need to do in the shortest possible time; that means keyboard shortcuts, templates, snippets etc. In this section, we’ll take a peek at some of what Android Studio has to offer give our productivity a little boost. We won’t go into detail; that’s not the goal, but rather just to show you what’s available in Android Studio.

Apr 24, 2020
How to pass command line arguments to a Node app
You can pass an argument to a Node app like this

Apr 23, 2020
Event Handling in Android
The user interacts with an app by touching, clicking, swiping or typing something. The Android framework captures, stores, processes and sends these actions to the app as event objects. The diagram (figure 1) below summarizes these interactions

Jun 8, 2019
How to create a simple Random number generator in Java
If you need to generate Random numbers in your Android app (assuming you’re using Java), you can simply use the java.util.Random class.

Jun 8, 2019
How to open a file in Kotlin
Just like in Java, you use the java.io classes, like this;

Sep 29, 2018
Kotlin's function can take variable arguments
Functions in Kotlin, like in Java, can also accept an arbitrary number of arguments. The syntax is a bit different from Java, instead of using three dots after the type ... , we use the vararg keyword instead.

Sep 29, 2018
Reified Generics in Kotlin
Let’s deal with the meaning of reify first. It means to make something real, and the reason we’re using reify and generics on the same statement is because of Java’s type erasure.

Sep 28, 2018
Variance in Kotlin Generics
We’ll need to review some of our OOP basics to prepare us for a discussion on variance. Hopefully, we can jog your memory and remember some of the fundamental principles of object-oriented programming.

Sep 25, 2018
Kotlin when, switch statement on steroids
Kotlin doesn’t have a switch statement, but it has the when construct. It looks a lot like the switch but it packs a lot more punch. In its simplest form, it can be implemented like this

Sep 22, 2018
Kotlin if-then expressions
The if construct in Kotlin works almost the same as in Java.

Sep 9, 2018
Kotlin while loops
Kotlin has a while loop that looks and behaves exactly like the one in Java

Sep 8, 2018
Kotlin Exception Handling
Kotlin’s approach to exception is similar to Java. Somewhat. It uses the try-catch-finally, just like in Java. So, your knowledge about how try-catch works commutes nicely to Kotlin. The code below should be very familiar. It shows a typical code on how to open a file

Sep 6, 2018
An introduction to Kotlin functions
Kotlin functions are defined using fun keyword, followed by the name of the function, a pair of parentheses, optional parameters, the return type of function and then the body of the function, which is pair of curly braces. It’s pretty much like a Java function, except that in Java, we have no fun (pun intended) and the type of the function is written to the left of the function (in Java), while in Kotlin, the return type of the function is to the right of function name.

Sep 1, 2018
100 days ML challenge - day I
Like most challenges that I took, I know that I won’t be able to do this challenge consistently everyday. But here goes the #100dayMLchallenge. This is my day 1.

Aug 19, 2018
Using the File API to write a file in Android
The following snippet shows how to write a file in the internal storage (standard location, not cache).

Aug 11, 2018
Android architecture
The most visible part of Android, at least for developers, is its operating system (OS). An OS is a complex thing but for the most part, it is what stands between a user and the hardware. That is an oversimplification, but it will suffice for our purposes. By “user”, I don’t literally mean an end user or a person. What I mean by it is an application, a piece of code that a programmer creates, like a word processor or an email client.

Aug 9, 2018
Android AsyncTask
In previous posts (Android Jank and Android Threads, Handlers and Messages) we explored ways on how to run code in the background. Why would we want to do that? So that UI Thread is freed up to do UI stuff like creating and updating views. Coz if we burden the UI Thread with other stuff that doesn’t concern the UI, like doing I/O work or doing complex calculations, the Android runtime will reduce the framerate of our app which will cause it behave sluggishly — in short, jank.