SurfaceScope
Known direct subclasses
SurfaceCoroutineScope

SurfaceCoroutineScope is a scoped environment provided by AndroidExternalSurface and AndroidEmbeddedExternalSurface when a new Surface is created.

SurfaceScope is a scoped environment provided by AndroidExternalSurface and AndroidEmbeddedExternalSurface to handle Surface lifecycle events.

import androidx.compose.foundation.AndroidExternalSurface
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.runtime.withFrameNanos
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.lerp
import androidx.compose.ui.graphics.toArgb
import androidx.compose.ui.unit.dp

AndroidExternalSurface(modifier = Modifier.fillMaxWidth().height(400.dp)) {
    // Resources can be initialized/cached here

    // A surface is available, we can start rendering
    onSurface { surface, width, height ->
        var w = width
        var h = height

        // Initial draw to avoid a black frame
        surface.lockCanvas(Rect(0, 0, w, h)).apply {
            drawColor(Color.Blue.toArgb())
            surface.unlockCanvasAndPost(this)
        }

        // React to surface dimension changes
        surface.onChanged { newWidth, newHeight ->
            w = newWidth
            h = newHeight
        }

        // Cleanup if needed
        surface.onDestroyed {}

        // Render loop, automatically cancelled on surface destruction
        while (true) {
            withFrameNanos { time ->
                surface.lockCanvas(Rect(0, 0, w, h)).apply {
                    val timeMs = time / 1_000_000L
                    val t = 0.5f + 0.5f * sin(timeMs / 1_000.0f)
                    drawColor(lerp(Color.Blue, Color.Green, t).toArgb())
                    surface.unlockCanvasAndPost(this)
                }
            }
        }
    }
}

Summary

Public functions
Unit
Surface.onChanged(onChanged: Surface.(width: Int, height: Int) -> Unit)

Invokes onChanged when the surface's geometry (width and height) changes.
android
Unit
Surface.onDestroyed(onDestroyed: Surface.() -> Unit)

Invokes onDestroyed when the surface is destroyed.
android

Public functions

onChanged

android 
fun Surface.onChanged(onChanged: Surface.(width: Int, height: Int) -> Unit): Unit

Invokes onChanged when the surface's geometry (width and height) changes. Always invoked on the main thread.

onDestroyed

android 
fun Surface.onDestroyed(onDestroyed: Surface.() -> Unit): Unit

Invokes onDestroyed when the surface is destroyed. All rendering into the surface should stop immediately after onDestroyed is invoked. Always invoked on the main thread.