Implement Biometric Authentication in Android Apps

Biometric authentication provides a secure and user-friendly way to validate a user’s identity using fingerprint, face, or iris recognition. Android’s Biometric API simplifies this process, ensuring compatibility across devices. This blog will guide you through implementing biometric authentication in an Android app using Kotlin, with step-by-step instructions and code examples.. Before we dive into the implementation, ensure your project meets the following requirements:. Add the Biometric API dependency to your app-level build.gradle file:. Before implementing biometric authentication, check if the device supports biometrics:. To display the biometric authentication dialog, use BiometricPrompt. It requires three components:. Invoke the showBiometricPrompt() method when needed. For example, you could tie it to a button click in your app:. Check if Biometric available or not:. Prompt the user to enroll biometric credentials:. Here’s the complete implementation in an Activity:. Jetpack Compose makes it simple and elegant to build modern Android UIs. By integrating biometric authentication, you can enhance your app’s security and provide a seamless user experience..

Using Lint pre-commit hook in Android project

If you work in a team you will surely have felt the pain of not being all on the same page when it comes to code style and formatting. Code style and formatting are important for many reasons.. In this post, you will learn how to automate Ktlint and Detekt checks with a pre-commit Git hook in your Android project to run code-style checks before you commit your change list.. Using pre-commit hooks in your Android project can be beneficial as they help maintain code quality, enforce coding standards, and prevent common mistakes from being committed.. For example, you can use pre-commit hooks to run code formatting checks, static code analysis, unit tests, or any other custom validations that you deem necessary for your project.. There are several Kotlin linters available for Android projects. Some of the popular ones but in our example we are going to use Ktlint and Detekt.. In general Android projects case, Once the pre-commit hook is set up, it will execute the ktlint and detekt tasks when you try to make a commit.. If there are any code style or quality issues identified by the linter, the commit will be aborted, and an error message will be displayed. You will need to fix the issues indicated by the linter before you can successfully commit your changes.. Now navigate to the root directory of your Android project repository. And create directories as scripts and sub-directory under scripts/pre-commit.. Also, create a shell script file named pre-commit (without any file extension) intoscripts/pre-commit the directory. Here is the shell script file content:. If you have any doubts or issues, see the final created directory with file content in the working example on the below link:. :shared:preBuild : example project module task that will start after installGitHooks task completed.. Once the pre-commit hook is in place, it will be executed automatically before each commit. If the hook script exits with a non-zero status, the commit will be aborted, allowing you to fix any issues before proceeding. Let's see how in the next section!. To verify if a Git hook is successfully validating code using ktlint in the Git console, you can follow these steps now:. Now, there are a couple of possible outcomes:. If you need to check more about git hook, please check my GitHub repo.. Congratulations…. That was pretty cool, right? This is all the stuff you need to know about integrated Kotlin linting tools using git hooks in your Android project.. Before wrapping up, I want to take a moment to tell thank you for reading this article. Your continued support, comments, and engagement have been truly inspiring.. Don’t forget to clap👏/recommend as much as you can and also share📤 with your friends. It means a lot to me.. Linting tools:. Git hook docs:.

Jetpack Compose Preview like a pro!

Let’s discuss a smarter way to use Jetpack Compose Preview while app development!. Hey Androiders 👋, this is a blog where we’ll discuss how we can use JetpackCompose @Preview in a different way to make our app development more productive!. Before starting of JetpackCompose @Preview let's discuss how we can enable Android projects with required dependencies. We need to add tooling dependencies which will support @Preview annotation in the app:. Create a new Composable using @Composable annotation:. and create a preview for the above Composable annotated with @Composable and @Preview to show a preview in the Android studio window:. Composable preview in the design window:. Now let’s discuss this differently Preview parameters and use cases where we can update our Preview annotation and make the preview more useful.. Output:. specs:. Using MultiPreview, we can define multiple @Preview annotations and create a defined annotation that we can reuse instead of writing multiple Preview annotations every time. For example, you can use this annotation to preview multiple devices, font sizes, or themes simultaneously without repeating those definitions for every single composable.. See the example code below for how I created MultiPreview class to define reusable DevicePreviews annotation that we can reuse every time where we want multiple device preview. Using @DevicePreviews class:. Output:. You can combine multiple multipreview annotations and normal preview annotations, to create a complete set of previews. Combining multipreview annotations doesn’t mean all the different combinations are shown. Instead, each multipreview annotation acts independently and renders only its variants.. So, that was pretty cool, right? This is all the stuff related to JetpackCompose Preview.. More you can learn at Android Studio support for Compose:.

Work with Firebase Realtime database lists

Lets learn with example how we can listen list items updates in firebase realtime database. Today in this blog we are going to learn how we can read data in Firebase Realtime Database(RTDB) with use case. This might be sound like old topic, but still I want to share how we are using RTDB in our app and use realtime data changes from RTDB.. Now let’s take a look at reading data from Firebase Realtime Database. We are developing event platform and in app we have below use cases to get the realtime database, to display on event participants side which there are live in any of event using our app.. ah! lot of line I have read, time for some line of code :). Add ValueEventListener:. Remove ValueEventListener :. Then in list update the value as per received trigger, if it is for add/update(in the case if user send raise hand request) or it is for delete item(in the case if user revert raise hand request). That was pretty cool, right? This is all the stuff you need to know about how we can implement Firebase realtime database to read data in your Android app.. Let’s just take a look at the summary of what we have learned:.

Getting started with Material3 in your app

Lets learn how to integrate Material3 theming in your app. Hey Androiders 👋, this is a mini-blog where we’ll discuss about Android to the new Material 3(Material Components) system in your Android app. We are trying to learn how we will integrate new material library in our android app and how we will configure our themes that can gives us great user experiences.. So now we need to change our themes files like below that can gives you a Material3 theming support:. OK, so before confused into different theme colors name you can check how we can generate those using Material theme builder in below section.. For ex. I have added one button in my app layout and I run my app:. It will default gives us layout output as below:. So what is different compare to previously we were defining material theme?. M3: Buttons are taller at 40dp and have fully rounded corners. Button labels use sentence case.. lets take one more example like text field:. This will display inputlayout with default OutLineBox style inputbox as below:. To define explicit style we can define as below:. Let’s just take a look at the summary of what we have learned:.

Hilt — The official new DI Library for Android (Part-2)

A qualifier is an annotation used to identify a binding.. ⚠️ In this stage, while building a project you will get the DuplicateBindings error! why it is?. Now, these qualifiers must annotate the @Binds functions that provide each implementation. So the full code of LoggingModule.kt will be:. So now you can run the app and check all logs.. That was pretty cool, right? This is all the stuff you need to know about Hilt integration for your Android app.. Let’s just take a look at the summary of what we have learned:. Here is the Github repository link of the app:.

Hilt - The official new DI Library for Android (Part-1)

With the use of Hilt, our app code would be:. In this blog guide, we would learn:. Now let’s take a look at Hilt!. Using this codelab, we can learn how to use Hilt for the new app and refactor the existing app.. Here is the startup project which we are going to take as a reference to start integration of Hilt in-app:. So let’s check step by step guide…. 💡 With @AndroidEntryPoint to the LogsFragment will create a dependency container that is attached to LogsFragment's lifecycle. 2️⃣ Now we need an inject instance of different fields (like dateformatter ) in LogsFragment which we can do with @Inject annotation that will do field injection.. So now we have to remove manual initialization of logger and dateFormatter from LogFragment because now Hilt will initialize those fields for us😊 . We need to removeonAttach and populateFields methods.. Before going to learn about @Provides we need to learn modules, which tell hilt how to provide instances of different types.. Now you can see LogFragment has all the necessary information to inject. Hilt needs to be aware of the MainActivity that hosts the LogFragment in order to work. We need to annotate MainActivity with @AndroidEntryPoint.. ⚠️ Hilt Modules cannot contain both non-static and abstract binding methods, so you cannot place @Binds and @Provides annotations in the same class.. To perform best practices for the Hilt, new modules make code more organized. So let's create a new file called NavigationModule.kt in the di folder. Then, let's create a new abstract class called NavigationModule annotated with @Module :. To refactor MainActivity :. Now let's refactor ButtonFragment same as LogFragment . To make the class be field injected by Hilt, we have to:. ⚔Congratulations…. Till now we have covered major and basic things you integrated Hilt in your app including modules and different annotations.⚔. So here we are end up with our part-1 for the Hilt introduction and basics.. In the next article, we will finish this blog and ongoing example. You’ll learn how to scope instances to containers and how we can use qualifiers. See you in part 2….

Retrieving collection parts in Kotlin

Exploring Kotlin standard library extensions to retrieving parts of a kotlin collection.. This post has been also published at:. In this blog, we will deep dive into how we can retrieve specific parts of Collection. In other words, we can say we will check different extension functions that help us to retrieve Collections elements using a specific range of indices.. In addition, the Standard Library provides functions with conditions to take and drop elements. Below all functions are using predicates which use for taking or dropping the elements:. So, that was pretty cool, right? This is all the stuff you need to know about Retrieving parts from Kotlin Collections using Kotlin standard library..

Firebase App Distribution — Distributing test releases of your Android apps

CameraX — Getting started guide

Android Jetpack is a collection of Android software components which helps us in building great Android apps. It provides a series of unbundled libraries not tied to any particular version of Android, giving developers a way to support newer features on older versions of the Android operating system.. All the components of Jetpack are divided into following categories:. So in this article, we will deep dive into all the new CameraX API and features.. Thanks to Google team for working on Camera API problems and introducing a brand new library CameraX. While using CameraX, it would help us in reducing lot of boilerplate code and conditions that we need to tackle because of the vast range of android devices.. It provides a consistent and easy-to-use API surface that works across most Android devices, with backward-compatibility to Android 5.0 (API level 21).. CameraX is an addition to Jetpack that makes it easier to leverage the capabilities of Camera2 APIs. ✔️ Easy to use with capabilities of Camera2 API.. ✔️ All cameraX apis uses approaches are lifecycle aware(No need to handle lifecycle by yourself 😌).. ✔️ No need to add device-specific code in your codebase.. ✔️ Smaller APK size, more human readable code and minimal line of code.. ✔️ Fixed Front/Back camera switch crashes.. ✔️ Optimized camera closures / Fixed Incorrect Orientation / Fixed — Flash not firing.. Lets discuss how CameraX will help developers to make Camera development easy. At present, we can do following tasks by using CameraX library.. Sync your project and now our app is ready to use CameraX.. Lets design layout to achieve our different CameraX scenarios like Preview or capture. For that, Let’s update the activity_main layout file from res > layout > activity_main.xml. As we want to work with Camera we need runtime permission code for Camera and need to declare Camera Permission in our Manifest file:. Now we are ready to test our CameraX Preview case. Run your app and test your preview.. Image capture is much simpler using CameraX. User has to decide how they need image. CameraX provides Capture file and in-buffer Captured image.. We need to prepare ImageCaptureConfig for ImageCapture which we can use for photo capture:. Above code makes our capture button functional. Now you can capture an image.. In my opinion, Analysis is the best use case that cameraX does have via ImageAnalysis. We can perform image processing, computer vision, or machine learning inference on the image. Image Analysis will perform on every camera output frame.. Now run your app and You will get output like below in every second when an image is being analyzed:. CameraX extensions provide a way to access vendor-specific features like Portrait, HDR, Night, Beauty, and bokeh effects. CameraX runs a check if those features are available of the device or not. It will enable them they are available.. So, that was pretty cool, right? This is all the stuff you need to know to get started with CameraX.. Let’s just take a look at summary of what we have learned:.