import android.graphics.Bitmap
import android.os.Environment
import androidx.compose.runtime.Composable
import androidx.compose.runtime.remember
import androidx.compose.ui.graphics.asImageBitmap
import androidx.compose.ui.graphics.drawscope.CanvasDrawScope
import androidx.compose.ui.graphics.nativeCanvas
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.unit.IntSize
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.withContext
import java.io.File
import java.io.FileOutputStream

@Composable
fun CaptureAndSaveComposable(
    composable: @Composable () -> Unit,
    size: IntSize,
    filename: String
) {
    val context = LocalContext.current
    val bitmap = remember { captureComposableAsBitmap(composable, size) }

    // Ideally, you'd use a coroutine to save the file asynchronously
    // so you don't block the main thread.
    // Here's an example with kotlinx.coroutines:
    /*
    LaunchedEffect(bitmap) {
        withContext(Dispatchers.IO) {
            saveBitmapAsPNG(bitmap, filename, context)
        }
    }
    */
}

fun captureComposableAsBitmap(composable: @Composable () -> Unit, size: IntSize): Bitmap {
    val bitmap = Bitmap.createBitmap(size.width, size.height, Bitmap.Config.ARGB_8888)
    val canvas = CanvasDrawScope()
    canvas.drawInto(Canvas(android.graphics.Canvas(bitmap))) {
        composable()
    }
    return bitmap
}

fun saveBitmapAsPNG(bitmap: Bitmap, filename: String, context: Context) {
    val file = File(context.getExternalFilesDir(Environment.DIRECTORY_PICTURES), "$filename.png")
    val out = FileOutputStream(file)
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, out)
    out.flush()
    out.close()
}

Kotlin online compiler

Write, Run & Share Kotlin code online using OneCompiler’s Kotlin online compiler for free. It’s a modern and fast online playground for Kotlin, supporting the latest version and ideal for learning, experimenting, and sharing code instantly.

About Kotlin

Kotlin is a statically typed, modern programming language developed by JetBrains. It runs on the JVM and is fully interoperable with Java. Kotlin is concise, expressive, and safe, and it’s officially supported by Google for Android app development.

Sample Code

The following is a simple Kotlin program that prints a greeting:

fun main() {
    println("Hello, OneCompiler!")
}

Taking inputs (stdin)

OneCompiler’s Kotlin editor supports stdin. You can provide input using the I/O tab. Here's a sample program that reads a line of input and prints a greeting:

fun main() {
    print("Enter your name: ")
    val name = readLine()
    println("Hello, $name")
}

Syntax Basics

Variables

val name: String = "OneCompiler"  // Immutable
var age: Int = 25                 // Mutable

Kotlin supports type inference, so explicit types are optional:

val city = "Hyderabad"
var count = 10

Conditionals

val score = 85
if (score >= 50) {
    println("Pass")
} else {
    println("Fail")
}

Loops

For loop

for (i in 1..5) {
    println(i)
}

While loop

var i = 1
while (i <= 5) {
    println(i)
    i++
}

Do-While loop

var j = 1
do {
    println(j)
    j++
} while (j <= 5)

Functions

fun add(a: Int, b: Int): Int {
    return a + b
}

fun greet(name: String) = "Hello, $name"

Collections

val items = listOf("apple", "banana", "cherry")
for (item in items) {
    println(item)
}

This guide provides a quick reference to Kotlin programming syntax and features. Start coding in Kotlin using OneCompiler’s Kotlin online compiler today!