jetpack compose - Spring animation

MainActivity.kt

package com.cfsuman.jetpackcompose

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import androidx.activity.compose.setContent
import androidx.compose.animation.*
import androidx.compose.animation.core.*
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.*
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.material.*
import androidx.compose.runtime.Composable
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.text.font.FontFamily
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContent {
            MainContent()
        }
    }


    @Composable
    fun MainContent(){
        val shortText = "This is a short text."
        val longtext = "Lorem Ipsum is simply dummy text of the printing" +
                " and typesetting industry. Lorem Ipsum has been the" +
                " industry's standard dummy text ever since the 1500s," +
                " when an unknown printer took a galley of type and" +
                " scrambled it to make a type specimen book."

        val isShortText = remember { mutableStateOf(true) }
        val result = remember { mutableStateOf("")}

        Column(
            modifier = Modifier
                .fillMaxSize()
                .background(Color(0xFFBCD4E6))
                .padding(16.dp),
            verticalArrangement = Arrangement.spacedBy(16.dp),
            horizontalAlignment = Alignment.CenterHorizontally
        ) {
            Button(
                onClick = { isShortText.value = !isShortText.value },
                colors = ButtonDefaults.buttonColors(
                    Color(0xFF2D383A), Color(0xCCFFFFFF)
                )
            ) {
                Text(
                    text = "Animate Content Size",
                    modifier = Modifier.padding(12.dp)
                )
            }

            Box(
                modifier = Modifier
                    .clip(RoundedCornerShape(16.dp))
                    .background(Color(0xFF4F42B5))
                    .padding(16.dp)
                    .fillMaxWidth()
                    .animateContentSize(
                        // spring creates a physics-based animation
                        // between start and end values.
                        animationSpec = spring(
                            // dampingRatio defines how bouncy the spring should be.
                            dampingRatio = Spring.DampingRatioHighBouncy,
                            // stiffness defines how fast the spring should
                            // move toward the end value.
                            stiffness = Spring.StiffnessLow
                        ),
                        finishedListener = { initialSize,endSize ->
                            result.value = "Form ($initialSize) \nTo ($endSize)"
                        }
                    )
            ) {
                Text(
                    text = if (isShortText.value) shortText else longtext,
                    fontSize = 30.sp,
                    fontWeight = FontWeight.Bold,
                    textAlign = TextAlign.Center,
                    fontFamily = FontFamily.Cursive,
                    color = Color(0xFFA4DDED)
                )
            }

            Text(
                text = result.value,
                fontSize = 20.sp,
                fontFamily = FontFamily.Serif
            )
        }
    }



    @Preview
    @Composable
    fun ComposablePreview(){
        //MainContent()
    }
}