Jetpack Compose OverlayService. You have to have all the correct permissions granted and in your manifest, but if you do, this this will show a green box with "Hello" in it!

MyLifecycleOwner.kt

import android.os.Bundle
import androidx.lifecycle.Lifecycle
import androidx.lifecycle.LifecycleRegistry
import androidx.savedstate.SavedStateRegistry
import androidx.savedstate.SavedStateRegistryController
import androidx.savedstate.SavedStateRegistryOwner

internal class MyLifecycleOwner : SavedStateRegistryOwner {
    private var mLifecycleRegistry: LifecycleRegistry = LifecycleRegistry(this)
    private var mSavedStateRegistryController: SavedStateRegistryController = SavedStateRegistryController.create(this)

    /**
     * @return True if the Lifecycle has been initialized.
     */
    val isInitialized: Boolean
        get() = true

    override fun getLifecycle(): Lifecycle {
        return mLifecycleRegistry
    }

    fun setCurrentState(state: Lifecycle.State) {
        mLifecycleRegistry.currentState = state
    }

    fun handleLifecycleEvent(event: Lifecycle.Event) {
        mLifecycleRegistry.handleLifecycleEvent(event)
    }

    override fun getSavedStateRegistry(): SavedStateRegistry {
        return mSavedStateRegistryController.savedStateRegistry
    }

    fun performRestore(savedState: Bundle?) {
        mSavedStateRegistryController.performRestore(savedState)
    }

    fun performSave(outBundle: Bundle) {
        mSavedStateRegistryController.performSave(outBundle)
    }
}

OverlayService.kt

import android.app.AlertDialog
import android.app.Service
import android.content.Intent
import android.graphics.PixelFormat
import android.os.Build
import android.os.IBinder
import android.util.TypedValue
import android.view.Window
import android.view.WindowManager
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.wrapContentSize
import androidx.compose.material.Text
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.platform.ComposeView
import androidx.compose.ui.unit.sp
import androidx.lifecycle.Lifecycle
import androidx.lifecycle.ViewModelStore
import androidx.lifecycle.ViewTreeLifecycleOwner
import androidx.lifecycle.ViewTreeViewModelStoreOwner
import androidx.savedstate.ViewTreeSavedStateRegistryOwner
import com.viatek.fitnation.echelon_android.R


class OverlayService : Service() {

    val windowManager get() = getSystemService(WINDOW_SERVICE) as WindowManager

    override fun onCreate() {
        super.onCreate()
        setTheme(R.style.ThemeOverlay_AppCompat_Light)
        showOverlay()
    }

    private fun showOverlay() {
        val layoutFlag: Int = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY
        } else {
            WindowManager.LayoutParams.TYPE_PHONE
        }

        val params = WindowManager.LayoutParams(
            WindowManager.LayoutParams.WRAP_CONTENT,
            WindowManager.LayoutParams.WRAP_CONTENT,
            layoutFlag,
            WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE or WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN or WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
            PixelFormat.TRANSLUCENT
        )

        val composeView = ComposeView(this)
        composeView.setContent {
            Text(
                text = "Hello",
                color = Color.Black,
                fontSize = 50.sp,
                modifier = Modifier
                    .wrapContentSize()
                    .background(Color.Green)
            )
        }

        // Trick The ComposeView into thinking we are tracking lifecycle
        val viewModelStore = ViewModelStore()
        val lifecycleOwner = MyLifecycleOwner()
        lifecycleOwner.performRestore(null)
        lifecycleOwner.handleLifecycleEvent(Lifecycle.Event.ON_CREATE)
        ViewTreeLifecycleOwner.set(composeView, lifecycleOwner)
        ViewTreeViewModelStoreOwner.set(composeView) { viewModelStore }
        ViewTreeSavedStateRegistryOwner.set(composeView, lifecycleOwner)

        windowManager.addView(composeView, params)
    }

    override fun onBind(intent: Intent): IBinder? {
        return null
    }
}

I am getting error: android.view.WindowManager$BadTokenException: Unable to add window android.view.ViewRootImpl$W@6c83604 -- permission denied for window type 2038.

Does anyone know how to fix?
@mairs8
You have to add the permission to use Window Manager
https://stackoverflow.com/questions/74433762/how-to-show-a-view-when-an-android-app-is-not-active-focused

That's working for me! But the shadow is missing while I show my composable. I've tried adding extra padding in the parent of my composable, or in ComposeView. The shadow works well when I put them into activities. Could anyone help me? Here is my code:

@OptIn(ExperimentalMaterialApi::class)
@Composable
fun Overlay(
    modifier: Modifier = Modifier,
    onDrag: (offsetX: Float, offsetY: Float) -> Unit,
    onClick: () -> Unit,
) {
    var offsetX by remember { mutableStateOf(0f) }
    var offsetY by remember { mutableStateOf(0f) }
    val drag = Modifier.pointerInput(Unit) {
        detectDragGestures(onDragStart = {}, onDrag = { change, dragAmount ->
            change.consume()
            offsetX += dragAmount.x
            offsetY += dragAmount.y
            onDrag(offsetX, offsetY)
        }, onDragEnd = {})
    }
    Box(
        Modifier
            .background(Color.White)
            .zIndex(0f)
            .padding(50.dp)
    ) {
        Surface(
            elevation = 10.dp,
            shape = CircleShape,
            onClick = onClick,
            modifier = modifier.then(drag),
        ) {
            Image(
                painter = painterResource(id = R.drawable.avatar_green),
                contentDescription = "assistant",
            )
        }
    }
}

@NamekMaster Have you tried to add recomposer? https://stackoverflow.com/questions/74433762/how-to-show-a-view-when-an-android-app-is-not-active-focused

Amazing works great!!

    ViewTreeLifecycleOwner.set(composeView, lifecycleOwner)
    ViewTreeViewModelStoreOwner.set(composeView) { viewModelStore }
    ViewTreeSavedStateRegistryOwner.set(composeView, lifecycleOwner)

I can not import this by lifecycle version 2.6.1. Anyone fix it ?

@tungthanhss the api changed to extension functions on View

composeView.setViewTreeLifecycleOwner(lifecycleOwner)
composeView.setViewTreeSavedStateRegistryOwner(lifecycleOwner)
composeView.setViewTreeViewModelStoreOwner(viewModelStoreOwner)

viewModelStoreOwner

thank you but how i can get viewModelStoreOwner
val viewModelStoreOwner = ViewModelStoreOwner { viewModelStore } not working now

val viewModelStore = ViewModelStore()
val viewModelStoreOwner = object : ViewModelStoreOwner {
  override val viewModelStore: ViewModelStore
    get() = viewModelStore
}

Does anyone else get the error Class 'MyLifecycleOwner' is not abstract and does not implement abstract member public abstract val lifecycle: Lifecycle defined in androidx.savedstate.SavedStateRegistryOwner with lifecycle version 2.6.1?

Does anyone else get the error Class 'MyLifecycleOwner' is not abstract and does not implement abstract member public abstract val lifecycle: Lifecycle defined in androidx.savedstate.SavedStateRegistryOwner with lifecycle version 2.6.1?

I'm having the same issue

Does anyone else get the error Class 'MyLifecycleOwner' is not abstract and does not implement abstract member public abstract val lifecycle: Lifecycle defined in androidx.savedstate.SavedStateRegistryOwner with lifecycle version 2.6.1?

I am facing the same problem with version 2.5.1. However, I have managed to resolve it by overriding the lifecycle as a variable instead of a function. Although the IDE is currently displaying an error ("lifecycle" overrides nothing), but the project can still be compiled and built without any issues.

override val lifecycle: Lifecycle get() = lifecycleRegistry

I am using this solution and it's been working fine. The only issue I got is overlay is kind of transparent no matter what I do. The content behind the overlay is visible as shown in the screenshot attached and also the button is not clickable. Any help would be appreciated.

I have found a fix to the problem. Removing FLAG_NOT_TOUCHABLE and setting alpha of params to 1f did the job. Now the button or any other views/composables are receiving click events and also the transparency is removed. Also, Thanks to @tberghuis for his excellent Floating Timer open-source code.

Does anyone else get the error Class 'MyLifecycleOwner' is not abstract and does not implement abstract member public abstract val lifecycle: Lifecycle defined in androidx.savedstate.SavedStateRegistryOwner with lifecycle version 2.6.1?

I am facing the same problem with version 2.5.1. However, I have managed to resolve it by overriding the lifecycle as a variable instead of a function. Although the IDE is currently displaying an error ("lifecycle" overrides nothing), but the project can still be compiled and built without any issues.

override val lifecycle: Lifecycle get() = lifecycleRegistry

I also ran into this problem. Follow @AhmedMousa7 's method to solve this problem,

Android Studio prompts

Class 'LifecycleOwner' is not abstract and does not implement abstract member public abstract fun getLifecycle(): Lifecycle defined in androidx.savedstate.SavedStateRegistryOwner
'lifecycle' overrides nothing

but gradle compiles and runs without problems.

I found that the version of LifecycleOwner inherited by SavedStateRegistryOwner is wrong. The dependency it uses is androidx.lifecycle:lifecycle-common:2.0.0, not the expected 2.6.1. I suspect this is the reason.

Anyone else also using androidx.lifecycle:lifecycle-common:2.0.0?