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Summary: This tutorial provides guidance on how to integrate email and password authentication for Android applications built with QuickBlox. Gain the skills to implement a secure and widely recognized login system, enhancing your app’s functionality.

Table of Contents

Introduction

Building an engaging Android application often hinges on seamless user experience. A crucial aspect of this experience is secure and convenient user login. Ensuring the security of user data and maintaining user privacy are paramount concerns in app development. Authentication, the process of verifying the identity of users, plays a crucial role in addressing these concerns. Authentication mechanisms not only safeguard sensitive user information but also provide a seamless and secure user experience. Email and password authentication stand out as one of the most widely used and user-friendly approaches

This tutorial will demonstrate how to integrate this authentication method using QuickBlox, a robust platform for real-time communication and data management. It will explain the role of the Authorization Server in the authentication process and provide insights into integrating authentication mechanisms using QuickBlox. By following this guide, you’ll equip your app with a robust authentication system that fosters trust and encourages user retention.

Looking for an alternative authentication method? Check out, A Guide to Phone Number Authentication for Android Apps

Let’s Get Started!

1. Create a New Project in Android Studio

The initial step in crafting your mobile application involves creating an Android project. This foundational process establishes the groundwork for integrating various functionalities, including authentication.

As the official Integrated Development Environment (IDE) for Android, Android Studio provides all the necessary tools for application development.
Here’s a step-by-step guide to creating a new project in Android Studio:

  1. Open Android Studio on your computer.
  2. Click on “New Project” from the welcome screen.
  3. Choose the “Empty Activity” template and click “Next.”
  4. Enter the name of your application, the package name (e.g., com.example.myapp), and the location to save your project.
  5. Select the language (Java or Kotlin) and the minimum SDK version for your app.
  6. Click “Finish” to create your project.

2. Create a project in the QuickBlox admin panel

Next you’ll need to use your QuickBlox Account and initiate a project so that you can access QuickBlox real-time communication functionality for your application.

  1. Sign-up for a QuickBlox account if you don’t already have one. You can sign in with either your Google or GitHub account.
  2. To create an app, click the ‘New app‘ button.
  3. Input the necessary information about your organization into the corresponding fields and click ‘Add‘.
  4. To get your Application ID, Authorization Key, Authorization Secret, and Account Key go to the ‘Overview‘ section of your app in the Dashboard. Don’t forget to ensure that you securely store your app credentials for future utilization within your application.

For a more detailed description of getting started on QuickBlox, read our official documentation.

3. Integration with Authorization Server

The authorization server is a specialized server responsible for verifying user credentials,such as email and password, and granting permissions to access the application. It plays a pivotal role in ensuring security and safeguarding data, overseeing the user authentication process, and providing access only to authorized users.

For detailed information on its functionality and the integration process, check out our Authorization Server implementation documentation.

3.1 Integrating OkHttp with the Authorization Server

You’ll now need to integrate OkHttp with the authorization server. OkHttp is a popular open-source library for Java and Android applications that simplifies making HTTP requests and handling responses. In other words, it helps your app talk to web servers efficiently.

Leveraging libraries such OkHttp provides a handy methodology to interface with the Authorization Server and facilitate data exchange.

The following example demonstrates how the OkHttp library can be integrated with the Authorization Server.

In the RestSource class, there’s a method called getQBTokenFromAuthServer, which is designed to send a request to the Authorization Server to obtain a QuickBlox token based on the provided email and password.

The buildRequestBody method is responsible for creating the request body, which includes the email and password in JSON format. Then, the buildAuthorizationRequest function constructs a Request object for the Authorization Server, specifying the URL and content type.

Additionally, the buildClient method creates an OkHttp client with timeout configurations.

After receiving a response from the Authorization Server, the b function is called to extract the QuickBlox token from the JSON response.

This example demonstrates a simple way to interact with an Authorization Server using OkHttp in Kotlin.

class RestSource {
   fun getQBTokenFromAuthServer(email: String, password: String): String {
       try {
           val requestBody = buildRequestBody(email, password)
           val request = buildAuthServerRequest(requestBody)

           val response = buildClient().newCall(request).execute()

           val isNotSuccessfulResponse = response.isSuccessful
           if (isNotSuccessfulResponse) {
              // Handle error
           }

           val body = response.body?.string()
           if (body?.isBlank() == true) {
               throw Exception("The response without answer content")
           }

           return parseAnswerFrom(body!!)
       } catch (exception: Exception) {
           throw Exception("${exception.message}")
       }
   }

   private fun buildRequestBody(email: String, password: String): RequestBody {
       val requestJsonObject = JSONObject()
       requestJsonObject.put("email", email)
       requestJsonObject.put("password", password)

       val body: RequestBody = requestJsonObject.toString().toRequestBody()

       return body
   }

   private fun buildAuthServerRequest(requestBody: RequestBody): Request {
       val request = Request.Builder().url("https://api-url/session/email")
           .addHeader("Content-Type", "application/json")
       request.post(requestBody)

       return request.build()
   }

   private fun buildClient(): OkHttpClient {
       val clientBuilder: OkHttpClient.Builder =
           OkHttpClient.Builder()
                  .connectTimeout(20,TimeUnit.SECONDS)
                  .writeTimeout(20, TimeUnit.SECONDS)
                  .readTimeout(20, TimeUnit.SECONDS)


       return clientBuilder.build()
   }


   private fun parseAnswerFrom(body: String): String {
       val json = JSONObject(body)
       val session = (json.get("session") as JSONObject)
       val token = session.get("token")

       val result = token.toString()

       return result
   }
}

4. Authorization in QuickBlox

Once the QuickBlox token is obtained from the Authorization Server, the subsequent step involves its utilization for authentication within the QuickBlox Android SDK. To accomplish this task, developers can employ the signInToQuickBloxWithEmailAndPassword method. This method facilitates authentication by accepting the user’s email and password as parameters and delivers a QuickBlox session object upon successful authentication.

private fun signInToQuickBloxWithEmailAndPassword(email: String, password: String): QBSession? {
    try {
        // Obtaining the QuickBlox token from the auth server
        val qbToken = RestSource().getQBTokenFromAuthServer(email, password)
        
        // Authenticating in QuickBlox using the obtained token
        return QBAuth.startSessionWithToken(qbToken).perform()
    } catch (exception: Exception) {
        // Handling possible errors
        return null
    }
}

The signInToQuickBloxWithEmailAndPassword method operates by initiating a request to the Authorization Server, transmitting the user’s email and password to obtain the QuickBlox token. Subsequently, this token is utilized for authentication within the QuickBlox ecosystem. Upon successful authentication, the method furnishes a QuickBlox session object, empowering seamless interaction with the QuickBlox API.

In the event of any encountered errors during the authentication process, the method implements error handling mechanisms to effectively manage and address them. This ensures the reliability and robustness of the authentication workflow, thereby enhancing the overall user experience and application performance.

Conclusion

Implementing authentication for QuickBlox Android apps using email and password offers a secure and user-friendly approach to safeguarding user data and ensuring privacy. By integrating email and password authentication mechanisms, developers can enhance the security of their applications while providing users with a familiar and accessible login experience.

If you build mobile applications for the Android platform then you are no doubt already familiar with Android Studio, a popular tool and the official Integrated Development Environment (IDE) for Android app development.

Equally, you’ve likely heard of Github and Git. Git is a free and open-source, distributed version control system that lets you manage and track changes in files used in programming. GitHub, is one of many cloud-based hosting services that allows you to manage your Git repositories. Github enables collaborative project development, as multiple programmers can work on project code together. Developers can track and control code changes made by others and, if necessary, return to a state of code before any given change was made, making it an extremely helpful tool.

Android Studio has a user interface that makes it incredibly easy to work with Git without any additional software. In this article, we will show how to clone a repository and work with it using Android Studio and basic Git commands.

Make sure you have a Github account and Android Studio installed and then read on to discover the best way to work with these tools.

Glossary

Before we get started, here are some useful terms worth understanding:

Branch – Branches allow you to work on new features, fix bugs, or develop new ideas in an isolated space within your repository. Branches are needed to isolate development work, so that other branches in the repository are not affected. The existence of branches means that developers can work together on a project and not interfere with each other’s work.

Commit – A commit is like a snapshot (copy) of your repository at specific times. Commits include metadata in addition to the contents and message, like the author, timestamp, and more. The commit history allows you to track changes and if a mistake was made, you can easily find and return to the commit where it happened.

Repository – A repository is a central location where data for your project is stored and managed. A repository contains all of your project’s files and tracks and saves a history of all changes made to files in a project.

The local repository exists on the local machine and can be seen only by the local user.

The remote repository is stored in the cloud, and its local copies are located on the computers of developers. When a developer makes changes to the local version, it can be synchronized with the remote one.

Step 1: Cloning a repository

First you need to open Android Studio.

  1. Press the More Actions command (3-dot icon) on the top row.
  2. Select from the drop-down list “Get from Version Control.”
cloning a repository with Android Studio

Then you need to copy the repository URL that you wish to use from Github.

Go to GitHub and select the project you want to clone and copy the repository URL. For example GitHub – QuickBlox Android Samples. QuickBlox code samples for Android provide an efficient way to add chat or video calling functionality to your application, saving you time from having to code from scratch.

cloning a repository in Android Studio
  1. Press the “Code” button.
  2. Press the Copy URL icon button.

Now return to Android Studio to clone the repository.

cloning a repository with Android Studio
  1. Insert the URL of the repository that you want to clone.
  2. Select the directory where the repository will be cloned.
  3. Press the “Clone” button.

Step 2. Create A New Branch

Now you need to create a new branch where you will work on the code. This is a copy of your workspace in which you can fully work and make changes without affecting the code in the branch from which the copy was made. This allows you to isolate the workflow and not interfere with other developers working on this project.

Create a new branch using Android Studio
  1. Press “Git.”
  2. Select from the drop-down list “Branches.”

This window contains a list of all local and remote branches.

Create a new branch using Android Studio

Press “New Branch

create new branch using Android Studio
  1. Enter the name of the new branch.
  2. Press the “Create” button.

After that, Android Studio will automatically switch to the new branch.

Step 3. Switch branches

To switch between branches you need to go to the window with the list of branches.

Create a new branch using Android Studio
  1. Press the “Git” button.
  2. Select from the drop-down list “Branches.”
switch branches using Android Studio
  1. Select a branch from the list and click on it.
  2. Select “Checkout” from the drop-down list.

This allows you to change the workspace to the branch of your choice.

Step 4. The Commit Command

This is the command to write indexed changes to a Git repository. It saves (writes) states of the branch on the Git project timeline. The “Commit” command should be used after changing something in the project. For example, we have added a new file with the name “Example.java”, and after that, we can save changes to the local repository branch with the commit command.

use commit command in Android Studio
  1. Press the Commit command (green tick icon) on the toolbar.
  2. Provide a brief summary of the changes that were added to this commit.
  3. Press the “Commit” button.

Step 5. The Push Command

The “Push” command will send the local repository branch to the remote repository. It should be used after changes have been committed to a local repository branch. The “push” command can send one or more commits.

Storing data in a remote repository allows you to access content from any computer and other developers who are working on the project can download and apply the actual code to their local repository and stay in sync with the team.

use Push command in Android Studio
  1. Press the Push command (green arrow icon) on the toolbar.
  2. Press the “Push” button.

Step 6. The Pull Command

The “Pull” command is used to retrieve and download content from a remote repository branch and update the local repository branch with that content. This command can be used, for example, if another developer has made changes to the branch code and pushed the changes to a remote repository. For you to have the actual code locally, you need to synchronize your local repository branch with the remote repository branch. After the “Pull” command, the local repository branch will be the same as on the remote.

use the Pull command in Android Studio
  1. Press the Update Project command (blue arrow icon) on the toolbar.
  2. Select “Merge incoming changes into the current branch.”
  3. Press the “OK” button.

Step 7. Using the Log

You can see the history of commits by pressing on the Git in the lower left-hand corner. Here you can find when and by whom the commit was made and what changes were made.

using the log in Android Studio

Conclusion

Android Studio has native integration with Git and GitHub to allow most actions via the Android Studio UI. This makes it much easier to track and manage your Git work, which saves development time. We hope that this article will help you learn how to use basic Git commands with Android Studio so that you can clone a repository and work easily with Git. Happy coding!

Flutter Travel App. Ideal template for listing, social media, and e-commerce applications.

Creating a travel app UI using Flutter involves designing screens like the home screen, destination details, booking screens, and more. Below is an example of how you can start building a simple travel app UI in Flutter.

Prerequisites

Ensure you have Flutter installed and set up on your machine. You can follow the official Flutter installation guide to get started.

Step 1: Setting Up the Project

  1. Create a new Flutter project: flutter create travel_app cd travel_app
  2. Open the project in your preferred IDE (e.g., VSCode, Android Studio).

Step 2: Designing the Home Screen

Let’s start with a basic home screen that displays a list of popular destinations.

lib/main.dart:

import 'package:flutter/material.dart';

void main() {
  runApp(TravelApp());
}

class TravelApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Travel App',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: HomeScreen(),
    );
  }
}

class HomeScreen extends StatelessWidget {
  final List<Map<String, String>> destinations = [
    {
      'name': 'Paris',
      'image': 'https://example.com/paris.jpg',
    },
    {
      'name': 'New York',
      'image': 'https://example.com/newyork.jpg',
    },
    {
      'name': 'Tokyo',
      'image': 'https://example.com/tokyo.jpg',
    },
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Travel App'),
      ),
      body: ListView.builder(
        itemCount: destinations.length,
        itemBuilder: (context, index) {
          return DestinationCard(
            name: destinations[index]['name']!,
            image: destinations[index]['image']!,
          );
        },
      ),
    );
  }
}

class DestinationCard extends StatelessWidget {
  final String name;
  final String image;

  DestinationCard({required this.name, required this.image});

  @override
  Widget build(BuildContext context) {
    return Card(
      margin: EdgeInsets.all(10),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Image.network(
            image,
            height: 200,
            fit: BoxFit.cover,
          ),
          Padding(
            padding: EdgeInsets.all(10),
            child: Text(
              name,
              style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
            ),
          ),
        ],
      ),
    );
  }
}

Step 3: Adding Navigation to Detail Screen

Now, let’s add navigation to a detail screen when a destination is tapped.

lib/main.dart (continued):

import 'package:flutter/material.dart';

void main() {
  runApp(TravelApp());
}

class TravelApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Travel App',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: HomeScreen(),
    );
  }
}

class HomeScreen extends StatelessWidget {
  final List<Map<String, String>> destinations = [
    {
      'name': 'Paris',
      'image': 'https://example.com/paris.jpg',
      'description': 'The City of Light.',
    },
    {
      'name': 'New York',
      'image': 'https://example.com/newyork.jpg',
      'description': 'The Big Apple.',
    },
    {
      'name': 'Tokyo',
      'image': 'https://example.com/tokyo.jpg',
      'description': 'The heart of Japan.',
    },
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Travel App'),
      ),
      body: ListView.builder(
        itemCount: destinations.length,
        itemBuilder: (context, index) {
          return GestureDetector(
            onTap: () {
              Navigator.push(
                context,
                MaterialPageRoute(
                  builder: (context) => DetailScreen(
                    name: destinations[index]['name']!,
                    image: destinations[index]['image']!,
                    description: destinations[index]['description']!,
                  ),
                ),
              );
            },
            child: DestinationCard(
              name: destinations[index]['name']!,
              image: destinations[index]['image']!,
            ),
          );
        },
      ),
    );
  }
}

class DestinationCard extends StatelessWidget {
  final String name;
  final String image;

  DestinationCard({required this.name, required this.image});

  @override
  Widget build(BuildContext context) {
    return Card(
      margin: EdgeInsets.all(10),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Image.network(
            image,
            height: 200,
            fit: BoxFit.cover,
          ),
          Padding(
            padding: EdgeInsets.all(10),
            child: Text(
              name,
              style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
            ),
          ),
        ],
      ),
    );
  }
}

class DetailScreen extends StatelessWidget {
  final String name;
  final String image;
  final String description;

  DetailScreen({required this.name, required this.image, required this.description});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(name),
      ),
      body: SingleChildScrollView(
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Image.network(
              image,
              height: 300,
              fit: BoxFit.cover,
            ),
            Padding(
              padding: EdgeInsets.all(16),
              child: Text(
                description,
                style: TextStyle(fontSize: 18),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

Step 4: Adding Some Styling

To make the app more visually appealing, you can enhance the styling of the components.

lib/main.dart (continued with styling):

“`dart
import ‘package:flutter/material.dart’;

void main() {
runApp(TravelApp());
}

class TravelApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Travel App',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: HomeScreen(),
);
}
}

class HomeScreen extends StatelessWidget {
final List> destinations = [
{
'name': 'Paris',
'image': 'https://example.com/paris.jpg',
'description': 'The City of Light.',
},
{
'name': 'New York',
'image': 'https://example.com/newyork.jpg',
'description': 'The Big Apple.',
},
{
'name': 'Tokyo',
'image': 'https://example.com/tokyo.jpg',
'description': 'The heart of Japan.',
},
];

@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Travel App'),
),
body: ListView.builder(
itemCount: destinations.length,
itemBuilder: (context, index) {
return GestureDetector(
onTap: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => DetailScreen(
name: destinations[index]['name']!,
image: destinations[index]['image']!,
description: destinations[index]['description']!,
),
),
);
},
child: DestinationCard(
name: destinations[index]['name']!,
image: destinations[index]['image']!,
),
);
},
),
);
}
}

class DestinationCard extends StatelessWidget {
final String name;
final String image;

DestinationCard({required this.name, required this.image});

@override
Widget build(BuildContext context) {
return Card(
margin: EdgeInsets.all(10),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(15),
),
elevation: 5,
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
ClipRRect(
borderRadius: BorderRadius.vertical(top: Radius.circular(15)),
child: Image.network(
image,
height: 200,
fit: BoxFit.cover,
),
),
Padding(
padding: EdgeInsets.all(10),
child: Text(
name,
style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
),
),
],
),
);
}
}

class DetailScreen extends StatelessWidget {
final String name;
final String image;
final String description;

DetailScreen({required this.name, required this.image, required this.description});

@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(name),
),
body: SingleChildScrollView(
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
Image.network(
image,
height: 300,
fit: BoxFit.cover,
),
Padding(
padding: EdgeInsets.all(16),
child: Text(
description,
style: TextStyle(font

Explanation

  1. Main Function and App Entry Point: The main function runs the TravelApp widget, which is the root of the app.
  2. MaterialApp: Sets up the app with a title, theme, and home screen.
  3. HomeScreen: A stateless widget that displays the home screen with a list of destinations in a grid view.
  4. Destination Model: A simple class representing a travel destination with a name, image URL, and description.
  5. DestinationCard: A stateless widget to display each destination in a card with an image, name, and description.
  6. Sample Data: A list of sample destinations with dummy data.

You can expand this example by adding more screens (e.g., details screen, profile screen), navigation, and other features. This code provides a starting point for a travel app with a modern and clean UI using Flutter.

Generative AI has opened the floodgates to so many new innovations and AI tools. From AI image generation to AI coding assistants, there is so much to unpack, and we are still learning about new applications day after day. In this article, we’re going to specifically talk about AI coding tools that can help you with software development. You can use the AI coding tools listed below to generate code, fix bugs, explain code snippets, write unit tests, and much more. On that note, let’s go through the list.

1. GitHub Copilot X

If you are a developer and looking for the best AI coding tool, I highly recommend GitHub Copilot X. It’s an AI assistant that can help you with code completion, code explanation, debugging, and more. GitHub Copilot X is powered by the GPT-4 model, which is arguably one of the best general-purpose AI models out there. It’s even better than the purpose-built OpenAI Codex model, a descendant of the GPT-3 series.

Coming to features, GitHub Copilot X is intended to be your helpful AI pair rather than your replacement. It can integrate with every part of your workflow, offer contextual suggestions, fix a piece of code, translate code, write unit tests, and much more. You don’t even need to read the whole documentation. Copilot X can give personalized answers to your queries from the documentation.

github copilot x demo
Source: GitHub

It also keeps track of your pull requests and suggests descriptions around code changes to generate a comprehensive update of all the code merges. You can use Copilot X in your favorite Terminal or IDEs like VS Code, Visual Studio, JetBrains, Neovim, and more. Moreover, Copilot X supports several programming languages, including C, C++, C#, Go, Java, JavaScript, PHP, Python, Ruby, Scala, TypeScript, and more.

To quote some figures from Microsoft’s in-house research, Copilot X helped 74% of the developers focus more on satisfying work and 88% of developers felt more productive. In addition, for repetitive coding tasks, 96% of users were able to achieve them much faster with the help of Copilot X.

In summation, GitHub Copilot X can be your best AI coding assistant to tackle coding challenges. That said, keep in mind that Copilot X is not available to everyone currently. Individual users or businesses who already have GitHub Copilot can join the waitlist for Copilot X. Future pricing has not been decided yet, but Copilot costs $10 per month.

Check out GitHub Copilot X

2. CodeGPT

If you use VS Code extensively for programming, then you can take a look at CodeGPT. It’s a third-party extension developed by Daniel San for VS Code. You can add your own API key to access ChatGPT models, including GPT-4 in CodeGPT, and start using the extension in your codebase. I have personally used the extension, and it’s one of the best AI coding tools for developers.

codegpt features

You can ask CodeGPT any coding-related questions and it will answer your queries right away. In addition, you can generate code, select a code snippet and ask CodeGPT to explain the function, find problems and solutions, refactor the code, document it, and much more. You can also write unit tests for various functions.

It supports 16 programming languages and other than OpenAI’s ChatGPT models, you can also add API keys from other AI services such as Cohere, Anthropic, AI21 Labs, HuggingFace, etc. If you have not got access to Copilot X, you should very well check out CodeGPT.

Check out CodeGPT

3. Codey and Studio Bot by Google

In case you are unaware, Google has also entered the AI coding assistant fray with Codey and Studio Bot. You can use Codey, a coding AI assistant on Google Colab. It’s similar to GitHub Copilot X and offers in-line code suggestions, code generation, autocomplete, debugging, and much more. That said, the feature is not live for everyone yet and only users in the US can get the first access.

google colab AI demo
Source: Google

Codey is built on Google’s PaLM 2 model and supports only Python as of now. You can open Google Colab, launch a notebook, and check if a “Generate” button appears on top. The best part is that it’s free to use, however, paid Colab users will be first in line to get access.

https://youtube.com/watch?v=kfbXQbt7TBg%3Ffeature%3Doembed

Moving to Studio Bot, Google announced a similar AI companion for Android developers. You can use Studio Bot in Android Studio for developing Android apps. Again, the feature is rolled out to US developers first and other countries will get it gradually. Google says the technology is experimental, and it will slowly add new capabilities to the Bot. As for now, you can ask it to generate code, create test cases and update APIs for better compliance.

Check out Codey on Google Colab
Check out Studio Bot for Android Studio

4. Replit Ghostwriter

Replit has also announced its AI coding tool named Ghostwriter. It’s backed by their in-house large language model, which is trained on publicly available code and further tuned by Replit. It supports code completion, code generation, transformation, enhancement, explanation, chat, debugging, and more. According to Replit, it factors in the context of your project and gives a relevant response. It can also automatically detect issues in your code and suggest a fix.

replit ghostwriter debugging
Source: Replit

The best part is that Replit supports a growing list of 16 programming languages, including Bash, C, C#, C++, CSS, Go, JavaScript, Java, PHP, Perl, Python, Ruby, and more. You can dive into an unfamiliar codebase and get started with different frameworks, APIs, and languages using this tool.

Having said that, Replit Ghostwriter is not free to access. You need to subscribe to the Pro plan, which costs $20 per month. In addition to AI coding assistance, you will also get a fast workspace, high resource limits, unlimited private Repls, SSH, and more. To sum up, Replit Ghostwriter is a great way to get started with programming with the help of AI. The ability to run your code in an online IDE simultaneously is an added benefit.

Check out Replit Ghostwriter

5. Amazon CodeWhisperer

In the AI race, Amazon is not far behind and bringing powerful large language models for specific use cases. Amazon CodeWhisperer is a coding-specific LLM that can help you with programming in multiple languages. According to Amazon, CodeWhisperer has been trained on billions of lines of code, and it can generate in-line code similar to Copilot X. You can simply write a comment, and it can generate complete functions based on your existing code.

Amazon CodeWhisperer demo
Source: Amazon

It also has the ability to identify code that resembles open-source training code, allowing you to further tag the code and attribute it with a license. CodeWhisperer comes with built-in code security as well. It can scan and analyze your code to find vulnerabilities and loopholes so you can fix them immediately.

The best part is that Amazon CodeWhisperer can be used in many IDEs including VS Code, IntelliJ IDEA, PyCharm, etc., and supports multiple languages like Python, Java, Javascript, Typescript, C#, and more. Finally, you can use it for free with unlimited code suggestions. That’s pretty awesome, right? So go ahead and check out Amazon CodeWhisperer for the best AI coding assistance.

Check out Amazon CodeWhisperer

6. GPT Engineer

GPT Engineer is a new open-source project that has quickly gained popularity among developers and is one of the best AI coding tools in 2023. It has received 11K stars on GitHub in a few days and continues to receive more features and updates from various contributors. GPT Engineer is an AI Agent similar to Auto-GPT, but it’s meant specifically for building the entire codebase for your project.

gpt engineer terminal demo

You need to tell the agent what you want to build. Then GPT Engineer asks you several questions for clarification and then it starts building it. Unlike Auto-GPT, GPT Engineer has a high success rate and developers have been able to build a full codebase using this project. It goes without saying that you need an OpenAI API, preferably a GPT-4 API. So if you are a coder, go ahead and test out GPT Engineer and check if it works for you.

Check out GPT Engineer

7. ChatGPT 4

While ChatGPT is a general-purpose AI chatbot, it’s vastly powerful at coding as well. After all, the OpenAI GPT-4 model powers most of the AI coding assistants in the market, including Copilot X and CodeGPT listed above. If you have subscribed to ChatGPT Plus ($20 per month), you can access the GPT-4 model and use ChatGPT to write code. I suggest using the GPT-4 model for programming because it’s accurate and usually responds with an error-free code.

chatgpt generates code

In the HumanEval Python coding tasks, GPT-4 scored 67% with zero-shot prompting. That’s the highest an LLM has performed on the HumanEval benchmark. If you use some expert-level prompts on ChatGPT, you are likely to get even better answers. I personally use ChatGPT for coding-related questions, and it does a fantastic job of explaining, generating, and fixing the code.

So if you are a developer or a beginner in programming and looking for the best AI coding tool, I would strongly suggest using ChatGPT 4 for all your coding questions.

Check out ChatGPT 4

8. Google Bard

Google Bard is again a general-purpose AI chatbot, but it’s pretty good at coding, and with newer updates, it has gotten really better at programming. Google has built Google Bard on the PaLM 2 model, which is capable in different various programming languages. It also supports more than 20 programming languages, including C, C++, Python, C#, Javascript, and more.

google bard generated code

You can also use Google Bard to translate code from one language to another. And with a new technique called Implicit Code Execution, Bard is able to run the code in the background to accurately show output. According to Google, the new technique improved Bard’s accuracy by 30% in computation-based prompts. Moreover, you can export the code directly in Google Colab and test the output. To sum up, Google Bard can prove to be one of the best coding AI tools, and you should definitely use it to your advantage.

This article is an implementation of an intro showcase to highlights different features of the app using Jetpack Compose. The implementation is inspired by the TapTargetView which is useful for legacy views.

The implementation is also available as a standalone library Intro-showcase-view on github which you can directly add as a gradle dependency in your project.

I have divided the implementation into byte size steps. Feel free to skip the steps that you understand or jump directly to the step you are interested in. The final implementation will look like above GIF.

Alright, let’s start coding!!

Step 1: Add a feature and draw circles on Canvas

First, let’s add an email fab button aligned to the bottom of the screen.

@Composable
fun ShowcaseExample() {
val context = LocalContext.current
Box {
FloatingActionButton(
onClick = {
Toast.makeText(
context,
"Fab Clicked",
Toast.LENGTH_SHORT
).show()
},
modifier = Modifier
.align(Alignment.BottomEnd)
.padding(bottom = 16.dp, end = 16.dp),
backgroundColor = ThemeColor,
contentColor = Color.White,
elevation = FloatingActionButtonDefaults.elevation(6.dp)
) {
Icon(
Icons.Filled.Email,
contentDescription = "Email"
)
}

IntroShowCase()
}
}

Then, we’ll create two circles. We’ll use Canvas API to draw our circle.

@Composable
fun IntroShowCase() {
Canvas(
modifier = Modifier
.fillMaxSize()
) {
drawCircle(
color = Color.Black
)
drawCircle(
color = Color.White,
radius = 150f
)
}
}

Pretty Simple…

But, that’s not what we want.

Step 2: Find LayoutCoordinates of a fab button and recenter circle.

We have to set a circle offset to highlight our Fab button. And for that, we need a position of our fab button. We’ll use OnGloballyPositionedModifier property of Modifier we’ll have view’s LayoutCoordinates in a callback.

A modifier whose onGlobalyPositioned is called with the final LayoutCoordinates of the Layout when the global position of the content may have changed. Note that it will be called after a composition when the coordinates are finalized.

Let’s modify the modifier of fab button to get its coordinates.

@Composable
fun showcaseExample() {

var target by remember {
mutableStateOf<LayoutCoordinates?>(null)
}
val
context = LocalContext.current

Box {
FloatingActionButton(
....
modifier = Modifier
.align(Alignment.BottomEnd)
.onGloballyPositioned { coordinates ->
target = coordinates
}
....

) {
....

}

target?.let {
IntroShowCase(it)
}
}
}

Now let’s use this coordinate to recenter our circle. Here’s how,

@Composable
fun IntroShowCase(targetCords: LayoutCoordinates) {
val targetRect = targetCords.boundsInRoot()

Canvas(
modifier = Modifier
.fillMaxSize()
) {
drawCircle(
color = Color.Black,
center = targetRect.center
)
drawCircle(
color = Color.White,
radius = 150f,
center = targetRect.center
)
}
}

We have used our target view Rect’s center offset to center our circle.

Oops!!, Where’s our fab button?. Our fab button is overlapped by circles.

Step 3: Blend the overlapped circle to set transparency

We have to set transparency where both circles are overlapped. We’ll use BlendMode to fix this and also let’s fix the radius of the inner circle based on our target view dimension.

BlendMode.Clear : Drop both the source and destination images, leaving nothing.

@Composable
fun IntroShowCase(targetCords: LayoutCoordinates) {
val targetRect = targetCords.boundsInRoot()
val targetRadius = targetRect.maxDimension / 2f + 40f
// 40f extra traget spacing

Canvas(
modifier = Modifier
.fillMaxSize().graphicsLayer (alpha = 0.99f)
) {
drawCircle(
color = Color.Black,
center = targetRect.center
)
drawCircle(
color = Color.White,
radius = targetRadius,
center = targetRect.center,
blendMode = BlendMode.Clear
)
}
}

Perfect!! Isn’t it?

Step: 4 Add circle reveals animation to highlight target

Now, Let’s add an animation around our target view

val animationSpec = infiniteRepeatable<Float>(
animation = tween(2000, easing = FastOutLinearInEasing),
repeatMode = RepeatMode.Restart,
)
val animatables = listOf(
remember { Animatable(0f) },
remember { Animatable(0f) }
)

animatables.forEachIndexed { index, animatable ->
LaunchedEffect(animatable) {
delay(index * 1000L)
animatable.animateTo(
targetValue = 1f, animationSpec = animationSpec
)
}
}

val
dys = animatables.map { it.value }Canvas(
...
) {
...


dys.forEach { dy ->
drawCircle(
color = Color.White,
radius = targetRect.maxDimension * dy * 2f,
center = targetRect.center,
alpha = 1 - dy
)
}
...
}

Let’s try to understand this, We have used infiniteRepeatable , as we want our animation to run infinitely.

animatables is the array of Animatable, We have set up the initial delay for the second wave, We can not use delayMillis as that is considered for repeat animation as well. We just want to delay the initial animation, and then continue the loop without any delay.

we created an animation that will animate between 0 to 1 infinitely. Based on that, we have set up a radius and animated alpha between 1 to 0, which will make waves disappear at the end of an animation.

Let’s see what it look likes,

Step 5: Add texts to describe the feature

Let’s create a data class that holds the value of our targets coordinates, title, subtitle, colors, etc.

data class ShowcaseProperty(
val index: Int,
val coordinates: LayoutCoordinates,
val title: String, val subTitle: String,
val titleColor: Color = Color.White,
val subTitleColor: Color = Color.White,
)

Okay, for now, let’s ignore index field, we’ll use it later to manage the order of when we have multiple features. Let’s refactor our composable a bit.

@Composable
fun IntroShowCase(target: ShowcaseProperty) {
val targetRect = target.coordinates.boundsInRoot()
val targetRadius = targetRect.maxDimension / 2f + 40f

val animationSpec = infiniteRepeatable<Float>(
animation = tween(2000, easing = FastOutLinearInEasing),
repeatMode = RepeatMode.Restart,
)
val animatables = listOf(
remember { Animatable(0f) },
remember { Animatable(0f) }
)

animatables.forEachIndexed { index, animatable ->
LaunchedEffect(animatable) {
delay(index * 1000L)
animatable.animateTo(
targetValue = 1f, animationSpec = animationSpec
)
}
}

val
dys = animatables.map { it.value }

Box {

Canvas(
modifier = Modifier
.fillMaxSize()
.graphicsLayer(alpha = 0.99f)
) {
drawCircle(
color = Color.Black,
center = targetRect.center
)

dys.forEach { dy ->
drawCircle(
color = Color.White,
radius = targetRect.maxDimension * dy * 2f,
center = targetRect.center,
alpha = 1 - dy
)
}

drawCircle(
color = Color.White,
radius = targetRadius,
center = targetRect.center,
blendMode = BlendMode.Clear
)
}

ShowCaseText(
currentTarget = target
)
}
}@Composable
private fun ShowCaseText(
currentTarget: ShowcaseProperty,
) {

Column(modifier = Modifier
.padding(16.dp)
)
{
Text(
text = currentTarget.title,
fontSize = 24.sp,
color = currentTarget.subTitleColor,
fontWeight = FontWeight.Bold
)
Text(text = currentTarget.subTitle, fontSize = 16.sp, color = currentTarget.subTitleColor)
}
}

We just have added two Text for title and subtitle, let’s see the output.

But that’s not even near to our circles.

Step 6: Set offset of Texts

Here we need to check the top and bottom space to set up our text in free space. So we’re going to do it in onGloballyPositioned we’ll calculate the Y offset of our Text, based on total text height and the center of our target. Here’s how.

@Composable
fun IntroShowCaseEx(target: ShowcaseProperty){
....
val targetRect = target.coordinates.boundsInRoot()
val targetRadius = targetRect.maxDimension / 2f + 40f
Box {
ShowCaseText(target, targetRect, targetRadius)
}
....
}
@Composable
private fun ShowCaseText(
currentTarget: ShowcaseProperty,
targetRect: Rect,
targetRadius: Float
) {

var txtOffsetY by remember {
mutableStateOf(0f)
}

Column(modifier = Modifier
.offset(y = with(LocalDensity.current) {
txtOffsetY.toDp()
})
.onGloballyPositioned {
val
textHeight = it.size.height

val
possibleTop =
targetRect.center.y - targetRadius - textHeight

txtOffsetY = if (possibleTop > 0) {
possibleTop
} else {
targetRect.center.y + targetRadius
}
}
.padding(16.dp)
)
{
Text(
text = currentTarget.title,
fontSize = 24.sp,
color = currentTarget.subTitleColor,
fontWeight = FontWeight.Bold
)
Text(text = currentTarget.subTitle, fontSize = 16.sp, color = currentTarget.subTitleColor)
}

}

And here’s the result.

But, the Text is not in the radius of our circle.

Step 7: Calculate outer circle radius

We have to estimate the rectangle which includes our text, and our target view including its spacing.

fun getOuterRadius(textRect: Rect, targetRect: Rect): Float {

val topLeftX = min(textRect.topLeft.x, targetRect.topLeft.x)
val topLeftY = min(textRect.topLeft.y, targetRect.topLeft.y)
val bottomRightX = max(textRect.bottomRight.x, targetRect.bottomRight.x)
val bottomRightY = max(textRect.bottomRight.y, targetRect.bottomRight.y)

val expandedBounds = Rect(topLeftX, topLeftY, bottomRightX, bottomRightY)

val d = sqrt(
expandedBounds.height.toDouble().pow(2.0)
+ expandedBounds.width.toDouble().pow(2.0)
).toFloat()

return (d / 2f)
}

Okay, we just have found the rectangle of our content, and from that, we got the radius.

var textCoordinate: LayoutCoordinates? by remember {
mutableStateOf(null)
}
var
outerRadius by remember {
mutableStateOf(0f)
}
textCoordinate?.let { textCoords ->
val
textRect = textCoords.boundsInRoot()
outerRadius = getOuterRadius(textRect, targetRect) + targetRadius
}Box {
Canvas(
modifier = Modifier
.fillMaxSize()
.graphicsLayer(alpha = 0.99f)
) {
drawCircle(
color = Color.Black,
center = targetRect.center,
radius = outerRadius,
alpha = 0.9f
)

dys.forEach { dy ->
drawCircle(
color = Color.White,
radius = targetRect.maxDimension * dy * 2f,
center = targetRect.center,
alpha = 1 - dy
)
}

drawCircle(
color = Color.White,
radius = targetRadius,
center = targetRect.center,
blendMode = BlendMode.Clear
)
}

ShowCaseText(
currentTarget = target,
targetRect = targetRect,
targetRadius = targetRadius
) {
textCoordinate = it
}
}

Let’s see the result.

Nope, That’s not enough to cover the whole content.

Step 8: change the offset of our outer circle

Now, let’s find the center offset of the outer circle which includes our target and texts.

var outerOffset by remember {
mutableStateOf(Offset(0f, 0f))
}textCoordinate?.let { textCoords ->
val
textRect = textCoords.boundsInRoot()
val textHeight = textCoords.size.height

outerOffset = getOuterCircleCenter(
targetRect, textRect, targetRadius, textHeight
)

outerRadius = getOuterRadius(textRect, targetRect) + targetRadius
}Box {
Canvas(
modifier = Modifier
.fillMaxSize()
.graphicsLayer(alpha = 0.99f)
) {
drawCircle(
color = Color.Black,
center = outerOffset,
radius = outerRadius,
alpha = 0.9f
)

dys.forEach { dy ->
drawCircle(
color = Color.White,
radius = targetRect.maxDimension * dy * 2f,
center = targetRect.center,
alpha = 1 - dy
)
}

drawCircle(
color = Color.White,
radius = targetRadius,
center = targetRect.center,
blendMode = BlendMode.Clear
)
}

ShowCaseText(
currentTarget = target,
targetRect = targetRect,
targetRadius = targetRadius
) {
textCoordinate = it
}
}
fun getOuterCircleCenter(
targetBound: Rect,
textBound: Rect,
targetRadius: Float,
textHeight: Int,
): Offset {
var outerCenterX: Float
var outerCenterY: Float

val onTop =
targetBound.center.y - targetRadius - textHeight > 0

val left = min(
textBound.left,
targetBound.left - targetRadius
)
val right = max(
textBound.right,
targetBound.right + targetRadius
)

val centerY =
if (onTop) targetBound.center.y - targetRadius - textHeight
else targetBound.center.y + targetRadius + textHeight

outerCenterY = centerY
outerCenterX = (left + right) / 2

return Offset(outerCenterX, outerCenterY)
}

Looks cool!!

But what if our target is in a toolbar or bottom bar? Let’s see by changing the alignment of our fab button to TopEnd .

Not so perfect!!.

Step 9: Fix the outer circle center point for the Top and Bottom bar.

We have to recheck our center point of an outer circle when our target is in the toolbar or at the bottom of the screen.

Here’s how

val topArea = 88.dp
val screenHeight = LocalConfiguration.current.screenHeightDp
val
yOffset = with(LocalDensity.current) {
target.coordinates.positionInRoot().y.toDp()
}var outerOffset by remember {
mutableStateOf(Offset(0f, 0f))
}textCoordinate?.let { textCoords ->
val
textRect = textCoords.boundsInRoot()
val textHeight = textCoords.size.height
val
isInGutter = topArea > yOffset || yOffset > screenHeight.dp.minus(topArea)

outerOffset = getOuterCircleCenter(
targetRect, textRect, targetRadius, textHeight, isInGutter
)

outerRadius = getOuterRadius(textRect, targetRect) + targetRadius
}....fun getOuterCircleCenter(
targetBound: Rect,
textBound: Rect,
targetRadius: Float,
textHeight: Int,
isInGutter: Boolean,
): Offset {
var outerCenterX: Float
var outerCenterY: Float

val onTop =
targetBound.center.y - targetRadius - textHeight > 0

val left = min(
textBound.left,
targetBound.left - targetRadius
)
val right = max(
textBound.right,
targetBound.right + targetRadius
)

val centerY =
if (onTop) targetBound.center.y - targetRadius - textHeight
else targetBound.center.y + targetRadius + textHeight

outerCenterY = centerY
outerCenterX = (left + right) / 2

if (isInGutter) {
outerCenterY = targetBound.center.y
}

return Offset(outerCenterX, outerCenterY)
}

If our target is in Gutter we just set targetBound.center.y to outerCenterY and our outerCenterX would be the same as the center X of our content rectangle in both cases.

Let’s check the output now.

Perfect!!

And last but not least…

Step 10: Add circle reveals animation to our outer circle.

val outerAnimatable = remember { Animatable(0.6f) }

LaunchedEffect(target) {
outerAnimatable.snapTo(0.6f)

outerAnimatable.animateTo(
targetValue = 1f,
animationSpec = tween(
durationMillis = 500,
easing = FastOutSlowInEasing,
),
)
}

We have created Animatable with initial value 0.6 as we don’t want our circle to scale from 0.0. If you notice, we have used target here as a key of LaunchedEffect , this will only trigger the inner block when a key changes. Whenever key changes we have reset the current value to the initial value 0.6f using snapTo. Let’s use Animatable value with our outer circle radius.

Box {
Canvas(
modifier = Modifier
.fillMaxSize()
.graphicsLayer(alpha = 0.99f)
) {
drawCircle(
color = Color.Black,
center = outerOffset,
radius = outerRadius * outerAnimatable.value,
alpha = 0.9f
)
}
}

Okay, here’s the result

That’s it!!

Now let’s integrate it with multiple feature showcases. We’re not going to cover all the basic details.onGloballyPositioned may call multiple times so we’ll use an mutableStateMapOf of ShowcaseProperty to avoid duplications.

@Composable
fun ShowcaseSample() {
val targets = remember {
mutableStateMapOf<String, ShowcaseProperty>()
}

Box {
FloatingActionButton(
onClick = {},
modifier = Modifier
.padding(16.dp)
.align(Alignment.BottomEnd)
.onGloballyPositioned { coordinates ->
targets["email"] = ShowcaseProperty(
1, coordinates,
"Check emails", "Click here to check/send emails"
)
},
backgroundColor = ThemeColor,
contentColor = Color.White,
elevation = FloatingActionButtonDefaults.elevation(6.dp)
) {
Icon(
Icons.Filled.Email,
contentDescription = "Email"
)
}
Button(
onClick = {},
modifier = Modifier
.align(Alignment.BottomStart)
.padding(start = 16.dp, bottom = 16.dp)
.onGloballyPositioned { coordinates ->
targets["follow"] = ShowcaseProperty(
2, coordinates,
"Follow me", "Click here to follow"
)
}
) {
Text(text = "Follow")
}


IntroShowCase(targets)
}
}

And Here’s our Intro showcase view

@Composable
fun IntroShowCase(
targets: SnapshotStateMap<String, ShowcaseProperty>,
backgroundColor: Color = Color.Black,
onShowcaseCompleted: () -> Unit
) {
val uniqueTargets = targets.values.sortedBy { it.index }
var
currentTargetIndex by remember { mutableStateOf(0) }

val
currentTarget =
if (uniqueTargets.isNotEmpty() && currentTargetIndex < uniqueTargets.size) uniqueTargets[currentTargetIndex] else null


currentTarget?.let {
TargetContent(it, backgroundColor) {
if
(++currentTargetIndex >= uniqueTargets.size) {
onShowcaseCompleted()
}
}
}
}

Pretty simple!!

Similarly, you can add rest of the views as aShowcaseProperty to make it look like the video shown at the beginning of the article. Full source code is available here.

As I mentioned earlier, the implementation is also available as a library, which you can integrate easily. Feel free to use it in your app and if you want to customize it you’re free to fork.

Creating an entire Android project from scratch here would be too extensive, but I can provide you with a basic outline and code snippets to implement a QR code/barcode scanner in an Android application using Java. We’ll use the ZXing library, which is a popular library for scanning QR codes and barcodes in Android.

Step 1: Set Up Your Android Project
Start by creating a new Android project in Android Studio.

Step 2: Add ZXing Dependency
Add the ZXing library to your build.gradle file (Module: app) to include it in your project:

dependencies {
    implementation 'com.google.zxing:core:3.4.1'
    implementation 'com.journeyapps:zxing-android-embedded:3.6.0'
}

Step 3: Request Camera Permission
In the AndroidManifest.xml, add the following permission:

<uses-permission android:name="android.permission.CAMERA"/>

Step 4: Create Layout
Create your layout file (e.g., activity_main.xml) with a surface view for the camera preview and a button to start scanning:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <SurfaceView
        android:id="@+id/surfaceView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <Button
        android:id="@+id/scanButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="Scan QR Code/Barcode" />

</RelativeLayout>

Step 5: Implement Scanner Logic
In your MainActivity.java, implement the QR code/barcode scanning logic:

import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import com.google.zxing.Result;
import me.dm7.barcodescanner.zxing.ZXingScannerView;

public class MainActivity extends AppCompatActivity implements ZXingScannerView.ResultHandler {

    private static final int CAMERA_PERMISSION_REQUEST_CODE = 200;
    private ZXingScannerView scannerView;
    private Button scanButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        scannerView = new ZXingScannerView(this);
        SurfaceView surfaceView = findViewById(R.id.surfaceView);
        surfaceView.addView(scannerView);

        scanButton = findViewById(R.id.scanButton);
        scanButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                checkCameraPermission();
            }
        });
    }

    private void checkCameraPermission() {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) {
            startScanner();
        } else {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA}, CAMERA_PERMISSION_REQUEST_CODE);
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (requestCode == CAMERA_PERMISSION_REQUEST_CODE) {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                startScanner();
            } else {
                Toast.makeText(this, "Camera permission required to scan QR codes/Barcodes", Toast.LENGTH_SHORT).show();
            }
        }
    }

    private void startScanner() {
        scannerView.setResultHandler(this);
        scannerView.startCamera();
    }

    @Override
    public void handleResult(Result result) {
        // This method will be called when a QR code / Barcode is scanned.
        // You can handle the scanned data here as per your requirements.
        Toast.makeText(this, "Scanned Result: " + result.getText(), Toast.LENGTH_SHORT).show();

        // Resume scanning after a short delay to capture multiple codes if required.
        scannerView.resumeCameraPreview(this);
    }

    @Override
    protected void onPause() {
        super.onPause();
        scannerView.stopCamera();
    }
}

This code sets up a basic QR code/barcode scanner using the ZXing library. When the “Scan QR Code/Barcode” button is clicked, the app checks for camera permission, and if granted, starts the scanner. When a code is scanned, the handleResult() method is called, and the scanned data is displayed in a Toast message.

Remember to handle any exceptions or edge cases based on your specific requirements in a production application.

That’s it! With this code, you should have a functioning QR code/barcode scanner in your Android app.

Create A material Design

Step 1: Set Up Your Android Project
Start by creating a new Android project in Android Studio.

Step 2: Add Material Components Library
In your build.gradle file (Module: app), add the Material Components library as a dependency:

dependencies {
    implementation 'com.google.android.material:material:1.4.0'
}

Step 3: Apply Material Theme
In your styles.xml file (res/values/styles.xml), apply a Material theme. You can use any of the Material themes provided by Android, such as “Theme.MaterialComponents.Light” or “Theme.MaterialComponents.DayNight”:

<style name="AppTheme" parent="Theme.MaterialComponents.Light">
    <!-- Customize theme attributes here -->
</style>

Step 4: Create a Material Design Layout
Create your layout file (e.g., activity_main.xml) using Material Design components:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16dp"
    android:background="@android:color/white"
    tools:context=".MainActivity">

    <com.google.android.material.textfield.TextInputLayout
        android:id="@+id/usernameInputLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:hint="Username">

        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/usernameEditText"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

    </com.google.android.material.textfield.TextInputLayout>

    <com.google.android.material.textfield.TextInputLayout
        android:id="@+id/passwordInputLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:hint="Password">

        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/passwordEditText"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:inputType="textPassword" />

    </com.google.android.material.textfield.TextInputLayout>

    <com.google.android.material.button.MaterialButton
        android:id="@+id/loginButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="24dp"
        android:text="Login"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@id/passwordInputLayout" />

</androidx.constraintlayout.widget.ConstraintLayout>

In this example, we used the TextInputLayout and TextInputEditText for the username and password fields, along with the MaterialButton for the login button.

Step 5: Apply Material Styles (Optional)
You can further customize your Material Design elements by applying custom styles to your theme or individual components in your styles.xml file.

For example, to change the color of the floating label and the underline color of the TextInputLayout, you can add the following styles:

<style name="AppTheme" parent="Theme.MaterialComponents.Light">
    <!-- Customize theme attributes here -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
    <item name="textInputStyle">@style/MyTextInputLayoutStyle</item>
</style>

<style name="MyTextInputLayoutStyle" parent="Widget.MaterialComponents.TextInputLayout.FilledBox">
    <item name="hintTextColor">@color/colorHint</item>
    <item name="boxStrokeColor">@color/colorPrimary</item>
    <item name="boxBackgroundColor">@color/colorWhite</item>
</style>

In this example, we changed the hintTextColor, boxStrokeColor, and boxBackgroundColor attributes.

Remember to define the colors used in the styles in your colors.xml file (res/values/colors.xml).

This is just a basic example of applying Material Design to an Android app. Material Design includes many other components and design principles that you can explore to make your app look and feel modern and attractive.

I’m trying to get the URL of a file that is on my drive, knowing its name and the name of the parent folder. But the result is always null.

I’m using a service account with owner permission, I already put the correct credentials inside the project and shared the folder and file with the service account email, and still, the problem continues. When debugging the code it is possible to see that the size of List<File> folders = result.getFiles();  is 0.

Here is the complete code:

import android.content.Context;

import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpRequestInitializer;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.services.drive.Drive;
import com.google.api.services.drive.DriveScopes;
import com.google.api.services.drive.model.File;
import com.google.api.services.drive.model.FileList;
import com.google.auth.http.HttpCredentialsAdapter;
import com.google.auth.oauth2.GoogleCredentials;

import java.io.IOException;
import java.io.InputStream;
import java.security.GeneralSecurityException;
import java.util.Collections;
import java.util.List;

public class DriveAccessRunnable implements Runnable {

   private static final String APPLICATION_NAME = "School Grade";

   private static final JsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();

   private static Drive driveService;
   private final Context context;
   private final String parentFolderTitle;
   private final String fileName;
   private final DriveAccessCallback callback;

   public DriveAccessRunnable(Context context, String parentFolderTitle, String fileName, DriveAccessCallback callback) {
      this.context = context;
      this.parentFolderTitle = parentFolderTitle;
      this.fileName = fileName;
      this.callback = callback;
   }

   @Override
   public void run() {
      try {
         // Google Drive access code
         HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
         driveService = new Drive.Builder(httpTransport, JSON_FACTORY, getHttpRequestInitializer())
                 .setApplicationName(APPLICATION_NAME)
                 .build();

         // Get the URL of the file or null if not found
         String fileUrl = getFileUrl(parentFolderTitle, fileName);

        
         // Call the callback with the result
         callback.onFileUrlReceived(fileUrl);
      } catch (IOException | GeneralSecurityException e) {
         e.printStackTrace();
         // Call the callback with an error result
         callback.onError(e.getMessage());
      }

   }

   private HttpRequestInitializer getHttpRequestInitializer() throws IOException {
      InputStream credentialsStream = context.getResources().openRawResource(R.raw.credentials);

      GoogleCredentials credentials = GoogleCredentials.fromStream(credentialsStream)
              .createScoped(Collections.singletonList(DriveScopes.DRIVE_FILE));

      return new HttpCredentialsAdapter(credentials);
   }

   private String getFileUrl(String parentFolderTitle, String fileName) throws IOException {
     
       // Search parent folder by title
      FileList result = driveService.files().list()
              .setQ("mimeType='application/vnd.google-apps.folder' and trashed=false and name='" + parentFolderTitle + "'")
              .setSpaces("drive")
              .setFields("files(id)")
              .execute();

      List<File> folders = result.getFiles();

      if (!folders.isEmpty()) {
         String parentFolderId = folders.get(0).getId();

         
         // Browse files inside the parent folder
         result = driveService.files().list()
                 .setQ("'" + parentFolderId + "' in parents and trashed=false")
                 .setFields("files(name, webViewLink)")
                 .execute();

         List<File> files = result.getFiles();
         for (File file : files) {
            if (file.getName().equals(fileName)) {
               return file.getWebViewLink();
            }
         }
      }

      return null;
   }


   public interface DriveAccessCallback {
      void onFileUrlReceived(String fileUrl);
      void onError(String errorMessage);
   }
}

So I am trying to implement app links from web search to open the app and I want it to use regex to match the below URL example…

/(url-1|url-2)/

Where it can be either of those strings, but it doesn’t seem to work. Is this possible in the pattern matcher?

Anywhere exists a tool to test this, can’t seem to find any other than generic regex testers which are different to the android format here.

I’ll provide you with a sample code and explanation for creating a profile screen with a RecyclerView using Android DataBinding. Here’s a step-by-step guide:

Step 1: Set up your project
Create a new Android project in Android Studio. Make sure you have the necessary dependencies in your build.gradle file:

android {
    // ...
    dataBinding {
        enabled = true
    }
}

Step 2: Create the layout files
Create the following layout files in your project:

activity_profile.xml:

<layout xmlns:android="http://schemas.android.com/apk/res/android">
    <data>
        <variable
            name="viewModel"
            type="com.example.yourapp.ProfileViewModel" />
    </data>

    <!-- Your profile screen layout here -->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/recyclerView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:items="@{viewModel.blogItems}"
            app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
            app:itemLayout="@layout/item_blog" />
    </LinearLayout>
</layout>

item_blog.xml:

<layout xmlns:android="http://schemas.android.com/apk/res/android">
    <data>
        <variable
            name="blog"
            type="com.example.yourapp.BlogItem" />
    </data>

    <!-- Your blog item layout here -->
</layout>

Step 3: Create the ViewModel and BlogItem classes
Create the following classes in your project:

ProfileViewModel.kt:

class ProfileViewModel : ViewModel() {
    val blogItems: LiveData<List<BlogItem>> = MutableLiveData(
        listOf(
            BlogItem("Title 1", "Content 1"),
            BlogItem("Title 2", "Content 2"),
            BlogItem("Title 3", "Content 3")
        )
    )
}

class BlogItem(val title: String, val content: String)

Step 4: Create the Adapter and ViewHolder
Create the following classes in your project:

BlogAdapter.kt:

class BlogAdapter(private val blogItems: List<BlogItem>) :
    RecyclerView.Adapter<BlogAdapter.ViewHolder>() {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        val inflater = LayoutInflater.from(parent.context)
        val binding: ItemBlogBinding = DataBindingUtil.inflate(
            inflater, R.layout.item_blog, parent, false
        )
        return ViewHolder(binding)
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        holder.bind(blogItems[position])
    }

    override fun getItemCount(): Int = blogItems.size

    class ViewHolder(private val binding: ItemBlogBinding) :
        RecyclerView.ViewHolder(binding.root) {

        fun bind(blogItem: BlogItem) {
            binding.blog = blogItem
            binding.executePendingBindings()
        }
    }
}

Step 5: Connect everything in your Activity or Fragment
Update your ProfileActivity or ProfileFragment to include the following code:

ProfileActivity.kt:

class ProfileActivity : AppCompatActivity() {

    private lateinit var binding: ActivityProfileBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = DataBindingUtil.setContentView(this, R.layout.activity_profile)

        val viewModel = ViewModelProvider(this).get(ProfileViewModel::class.java)
        binding.viewModel = viewModel

        val adapter = BlogAdapter(viewModel.blogItems.value ?: emptyList())
        binding.recyclerView.adapter = adapter
    }
}

That’s it! You have now created a profile screen with a RecyclerView using Android DataBinding. Make sure to replace com.example.yourapp it with the appropriate package name in the code.

Remember to customize the layout files and the BlogItem class according to your requirements. You can also update the blog items dynamically by modifying the blogItems LiveData in the ViewModel.

Hope this helps you get started with your profile screen implementation!

Here’s an example of an Android application that allows users to choose an image from the camera or gallery and perform cropping functionality using the “Android Image Cropper” library.

Step 1: Set up the project

Start by creating a new Android project in Android Studio. Make sure you have the necessary dependencies and permissions in your project’s build.gradle file:

dependencies {
    implementation 'com.theartofdev.edmodo:android-image-cropper:2.8.+'
}

Also, make sure you have the necessary permissions in your AndroidManifest.xml file:

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.CAMERA" />

Step 2: Create the layout

Create a layout file called activity_main.xml with the following code:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="16dp"
    android:paddingTop="16dp"
    android:paddingRight="16dp"
    android:paddingBottom="16dp"
    tools:context=".MainActivity">

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:adjustViewBounds="true"
        android:scaleType="centerInside"
        android:src="@drawable/placeholder" />

    <Button
        android:id="@+id/btnChooseImage"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/imageView"
        android:text="Choose Image" />

    <Button
        android:id="@+id/btnCropImage"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/btnChooseImage"
        android:text="Crop Image"
        android:enabled="false" />

</RelativeLayout>

Step 3: Implement the functionality in the MainActivity

Open MainActivity.java and add the following code:

import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import com.theartofdev.edmodo.cropper.CropImage;
import com.theartofdev.edmodo.cropper.CropImageView;

import java.io.IOException;

public class MainActivity extends AppCompatActivity {

    private static final int REQUEST_CAMERA_PERMISSION = 200;
    private static final int REQUEST_IMAGE_CAPTURE = 100;
    private static final int REQUEST_IMAGE_GALLERY = 101;

    private ImageView imageView;
    private Button btnChooseImage;
    private Button btnCropImage;

    private Uri imageUri;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        imageView = findViewById(R.id.imageView);
        btnChooseImage = findViewById(R.id.btnChooseImage);
        btnCropImage = findViewById(R.id.btnCropImage);

        btnChooseImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                chooseImage();
            }
        });

        btnCropImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                cropImage(imageUri);
            }
        });
    }

    private void chooseImage() {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA}, REQUEST_CAMERA_PERMISSION);
        } else {
            openImageChooser();
        }
    }

    private void openImageChooser() {
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.setType("image/*");
        startActivityForResult(intent, REQUEST_IMAGE_GALLERY);
    }

    private void cropImage(Uri imageUri) {
        CropImage.activity(imageUri)
                .setGuidelines(CropImageView.Guidelines.ON)
                .setAspectRatio(1, 1)
                .start(this);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
            cropImage(imageUri);
        } else if (requestCode == REQUEST_IMAGE_GALLERY && resultCode == RESULT_OK && data != null) {
            try {
                Bitmap bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), data.getData());
                imageView.setImageBitmap(bitmap);
                imageUri = data.getData();
                btnCropImage.setEnabled(true);
            } catch (IOException e) {
                e.printStackTrace();
            }
        } else if (requestCode == CropImage.CROP_IMAGE_ACTIVITY_REQUEST_CODE) {
            CropImage.ActivityResult result = CropImage.getActivityResult(data);
            if (resultCode == RESULT_OK) {
                Uri resultUri = result.getUri();
                try {
                    Bitmap croppedBitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), resultUri);
                    imageView.setImageBitmap(croppedBitmap);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } else if (resultCode == CropImage.CROP_IMAGE_ACTIVITY_RESULT_ERROR_CODE) {
                Exception error = result.getError();
                error.printStackTrace();
            }
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == REQUEST_CAMERA_PERMISSION && grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            openImageChooser();
        }
    }
}

That’s it! Now you have an Android application that allows users to choose an image from the camera or gallery and perform cropping functionality. Remember to replace the placeholder image with an actual placeholder image of your choice.

Note: Don’t forget to add the necessary runtime permissions check in your code to handle permissions for accessing the camera and gallery.