ComposeWidthActivity.kt

package com.leonidivankin.draftandroid.articles.benchmark

import android.os.Bundle
import android.util.Log
import androidx.activity.compose.setContent
import androidx.appcompat.app.AppCompatActivity
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp


class ComposeWidthActivity : AppCompatActivity() {
    var time = 0L

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        title = "compose, width"
        val colors = listOf(
            0xFFF44336,
            0xFFE91E63,
            0xFF9C27B0,
            0xFF673AB7,
            0xFF3F51B5,
            0xFF2196F3,
            0xFF03A9F4,
            0xFF00BCD4,
            0xFF009688,
            0xFF4CAF50,
            0xFF8BC34A,
            0xFFCDDC39,
            0xFFFFEB3B,
            0xFFFFC107,
            0xFFFF9800,
            0xFFFF5722
        )
        time = System.currentTimeMillis()

        setContent { MyBox(colors) }
    }

    override fun onResume() {
        super.onResume()
        Log.d("Benchmark", "ComposeWidthActivity onResume: ${System.currentTimeMillis() - time}")
    }

    override fun onWindowFocusChanged(hasFocus: Boolean) {
        super.onWindowFocusChanged(hasFocus)
        if (hasFocus) {
            Log.d(
                "Benchmark",
                "ComposeWidthActivity onWindowFocusChanged: ${System.currentTimeMillis() - time}"
            )
        }
    }
}

@Composable
private fun MyBox(list: List<Long>) {
    Column {
        repeat(49) {
            Box(
                Modifier
                    .fillMaxWidth()
                    .height(8.dp)
                    .background(color = Color(list[it % list.size]))
            )
        }
    }
}