How to Build a Todo List App with Java and Android Studio

Posted on by Panther

Introduction

In this tutorial, we will learn how to build a Todo List app using Java and Android Studio. A Todo List app allows users to create, edit, and manage tasks. We will cover the following topics:

  1. Setting up Android Studio and creating a new project
  2. Designing the user interface of the app
  3. Implementing the Java code for adding, editing, and deleting tasks
  4. Storing the tasks in a SQLite database
  5. Displaying the tasks in a RecyclerView

Prerequisites

To follow along with this tutorial, you will need the following:

  1. Android Studio installed on your computer
  2. Basic knowledge of Java programming language
  3. Familiarity with Android app development concepts

Step 1: Setting up Android Studio and creating a new project

First, make sure you have Android Studio installed on your computer. If not, you can download it from the official Android Studio website and follow the installation instructions.

Once you have Android Studio installed, open it and click on “Start a new Android Studio project”. Fill in the required details like project name, package name, and project location. Choose the API level you want to target and select “Empty Activity” as the template for the project.

Click “Finish” to create the project. Android Studio will generate the required files and directories for your new project.

Step 2: Designing the user interface of the app

In this step, we will design the user interface using the layout files in Android Studio.

Open the “activity_main.xml” file from the “res/layout” directory. This file represents the main layout of the app. Modify the layout according to your needs, but make sure to include the following elements:

  1. A RecyclerView to display the list of tasks
  2. An EditText to enter a new task
  3. A Button to add the task to the list

Here is an example of a simple layout:

<LinearLayout>
    <EditText
        android_id="@+id/editTextTask"
        ... />

    <Button
        android_id="@+id/buttonAdd"
        ... />

    <RecyclerView
        android_id="@+id/recyclerViewTasks"
        ... />
</LinearLayout>

Step 3: Implementing the Java code for adding, editing, and deleting tasks

In this step, we will write the Java code to handle the logic of adding, editing, and deleting tasks.

Create a new Java class called “Task” to represent a task. This class should have properties like id, title, and description. Implement the getters and setters for these properties.

Next, create another Java class called “TaskAdapter” which extends RecyclerView.Adapter. This class will be responsible for populating the RecyclerView with the list of tasks.

Inside the “TaskAdapter” class, create a ViewHolder class which extends RecyclerView.ViewHolder. This class will hold references to the UI elements of each item in the RecyclerView.

In the “TaskAdapter” class, implement the required methods like “onCreateViewHolder”, “onBindViewHolder”, and “getItemCount”. These methods will inflate the layout for each item, bind data to the UI elements, and return the number of items in the list respectively.

Step 4: Storing the tasks in a SQLite database

To store the tasks in a database, we will use the SQLite database provided by Android.

Create a new Java class called “DatabaseHelper” to handle the database operations. This class will extend the SQLiteOpenHelper class and override the required methods.

Inside the “DatabaseHelper” class, create a table called “tasks” with columns like “id”, “title”, and “description”. Implement methods to add, update, delete, and retrieve tasks from the database.

In your main activity class (MainActivity.java), create an instance of the “DatabaseHelper” class and use it to perform database operations like adding, editing, and deleting tasks.

Step 5: Displaying the tasks in a RecyclerView

In this step, we will display the tasks in the RecyclerView using the “TaskAdapter” class.

In your main activity class, create an instance of the “TaskAdapter” class and set it as the adapter for the RecyclerView. Fetch the list of tasks from the database and pass it to the adapter.

Implement the logic to add a new task when the user clicks on the “Add” button. Get the task details entered by the user from the EditText and add it to the database. Refresh the RecyclerView by notifying the adapter of the data changes.

Implement the logic to edit or delete a task when the user interacts with an item in the RecyclerView. Use the position of the item to perform the corresponding action (edit or delete) on the task.

Conclusion

Congratulations! You have successfully built a Todo List app with Java and Android Studio. You have learned how to set up Android Studio, design the user interface, implement the Java code for adding, editing, and deleting tasks, store tasks in a SQLite database, and display the tasks in a RecyclerView. You can now further enhance the app by adding features like sorting tasks, marking tasks as completed, and setting reminders for tasks.

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