Animating Circle Drawing in Android using Jetpack Compose

In Android, we can create animations of our choice for displaying an entry, in-transit, or exit of an element or a view. The most commonly inbuilt animation is of Circular ProgressBar, where an animator sweeps out a circle indicating the progress of the executed task. A sample video is given below to get an idea about what we are going to do in this article. 

In this article, we will show you how you could create such an animation in Android using Jetpack Compose. Follow the below steps once the IDE is ready.

Step by Step Implementation

Step 1: Create a New Project in Android Studio

To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. While choosing the template, select Empty Compose Activity. If you do not find this template, try upgrading the Android Studio to the latest version. We demonstrated the application in Kotlin, so make sure you select Kotlin as the primary language while creating a New Project.

Step 2: Working with the MainActivity.kt file

Go to the MainActivity.kt file and refer to the following code. Below is the code for the MainActivity.kt file. Comments are added inside the code to understand the code in more detail.

Kotlin

package com.geeksforgeeks.jccirclecompleteanimation

import android.annotation.SuppressLint
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.animation.core.Animatable
import androidx.compose.animation.core.LinearEasing
import androidx.compose.animation.core.tween
import androidx.compose.foundation.Canvas
import androidx.compose.foundation.layout.*
import androidx.compose.material.*
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.geometry.Size
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.drawscope.Stroke
import androidx.compose.ui.unit.dp

class MainActivity : ComponentActivity() {
    @SuppressLint("RememberReturnType")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {

            // Creating a Simple Scaffold
            // Layout for the application
            Scaffold(

                // Creating a Top Bar
                topBar = { TopAppBar(title = { Text("GFG | Circle Animation", color = Color.White) }, backgroundColor = Color(0xff0f9d58)) },

                // Creating Content
                content = {

                    // Creating a Column Layout
                    Column(Modifier.fillMaxSize(), horizontalAlignment = Alignment.CenterHorizontally, verticalArrangement = Arrangement.Center) {

                        // Declaring circle radius
                        val radius = 200f

                        // Creating animation
                        val animateFloat = remember { Animatable(0f) }
                        LaunchedEffect(animateFloat) {
                            animateFloat.animateTo(
                                targetValue = 1f,
                                animationSpec = tween(durationMillis = 3000, easing = LinearEasing))
                        }

                        // Creating Arc with useCenter as True
                        Row{
                            Canvas(modifier = Modifier.width(100.dp).height(100.dp)){
                                drawArc(
                                    color = Color.Black,
                                    startAngle = 0f,
                                    sweepAngle = 360f * animateFloat.value,
                                    useCenter = true,
                                    size = Size(radius * 2 , radius * 2),
                                    style = Stroke(2.0f)
                                )
                            }
                        }

                        // Adding a Space of height 100dp
                        Spacer(modifier = Modifier.height(100.dp))

                        // Creating Arc with useCenter as False
                        Row{
                            Canvas(modifier = Modifier.width(100.dp).height(100.dp)){
                                drawArc(
                                    color = Color.Black,
                                    startAngle = 0f,
                                    sweepAngle = 360f * animateFloat.value,
                                    useCenter = false,
                                    size = Size(radius * 2 , radius * 2),
                                    style = Stroke(2.0f)
                                )
                            }
                        }
                    }
                }
            )
        }
    }
}

Output:

You can see that we are able to create an animation that sweeps out a circle.