Initial testing for a font viewer for desktop, using Jetpack Compose - Skaldebane.

main.kt

import androidx.compose.desktop.Window
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.*
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.items
import androidx.compose.material.*
import androidx.compose.runtime.*
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.text.font.FontFamily
import androidx.compose.ui.text.platform.Font
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import java.io.File
import kotlin.math.pow

fun main() = Window {
    var text by remember { mutableStateOf("Hello, World!") }
    var cwd by remember { mutableStateOf(File(System.getProperty("user.home"))) }
    var fontFamily: FontFamily by remember { mutableStateOf(FontFamily.Default) }
    var fontSize by remember { mutableStateOf(14.sp) }

    MaterialTheme {
        Row {
            Column(modifier = Modifier.weight(1f, true)) {
                OutlinedTextField(
                    value = text,
                    onValueChange = {
                        text = it
                    },
                    label = { Text("Test your font:") },
                    textStyle = TextStyle(
                        fontFamily = fontFamily,
                        fontSize = fontSize
                    ),
                    modifier = Modifier
                        .padding(12.dp),
                    maxLines = 5
                )
                Slider(
                    value = fontSize.value,
                    onValueChange = {
                        fontSize = it.sp
                    },
                    valueRange = 1f..100f,
                    modifier = Modifier
                )
            }
            Divider(
                modifier = Modifier
                    .padding(12.dp)
                    .fillMaxHeight()
                    .width(1.dp),
                color = Color.LightGray
            )
            Column(modifier = Modifier.weight(1f, true)) {
                Text(cwd.path)
                LazyColumn(Modifier.fillMaxWidth()) {
                    item {
                        Text(
                            text = "..",
                            modifier = Modifier
                                .fillMaxWidth()
                                .padding(8.dp)
                                .clickable {
                                    cwd = cwd.parentFile
                                }
                        )
                    }
                    items(cwd.listFiles()!!.requireNoNulls()) { file ->
                        Row(
                            modifier = Modifier.clickable {
                                if (file.isDirectory) {
                                    cwd = file
                                } else {
                                    fontFamily = FontFamily(Font(file))
                                }
                            }
                        ) {
                            Text(
                                text = file.name,
                                modifier = Modifier
                                    .padding(8.dp)
                                    .weight(1f)
                            )
                            Text(
                                text = if (file.isFile) file.size() else "",
                                modifier = Modifier.padding(8.dp)
                            )
                        }
                    }
                }
            }
        }
    }
}

fun File.size(): String {
    val bytes = this.length();
    return when {
        bytes <= 1024 ->
            "$bytes b"
        bytes <= 1024f.pow(2) ->
            "${(bytes/1024f)} Mb"
        bytes <= 1024f.pow(3) ->
            "${bytes/1024f.pow(2)} Gb"
        else ->
            "${bytes/1024f.pow(3)} Tb"
    }
}