jetpack compose - Canvas inset

MainActivity.kt

package com.cfsuman.jetpackcompose

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import androidx.activity.compose.setContent
import androidx.compose.foundation.Canvas
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.*
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.geometry.Size
import androidx.compose.ui.graphics.*
import androidx.compose.ui.graphics.drawscope.inset
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.dp

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

        setContent {
            MainContent()
        }
    }


    @Composable
    fun MainContent(){
        Canvas(
            modifier = Modifier
                .fillMaxSize()
                .background(Color(0xFFDEB887))
        )
        {
            inset(
                horizontal = 50.dp.toPx(),
                vertical = 70.dp.toPx()
            ){
                drawRect(color = Color(0xFFEDEAE0))
                drawRect(
                    color = Color(0xFF915C83),
                    topLeft = Offset(
                        x = 20.dp.toPx(),
                        y = 20.dp.toPx()
                    ),
                    size = Size(
                        width = size.width - 40.dp.toPx(),
                        height = 50.dp.toPx()
                    )
                )

                drawRect(
                    color = Color(0xFFFF9966),
                    topLeft = Offset(
                        x = 20.dp.toPx(),
                        y = size.height - 70.dp.toPx()
                    ),
                    size = Size(
                        width = size.width - 40.dp.toPx(),
                        height = 50.dp.toPx()
                    )
                )
            }
        }
    }


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