class MyService: FloatingBubbleService() {

        override fun setupBubble(action: FloatingBubble.Action): FloatingBubble.Builder {
            return ...
        }

        // optional, only required if you want to navigate to the expandable-view 
        override fun setupExpandableView(action: ExpandableView.Action): ExpandableView.Builder? {
            return ...
        }
    }

    val intent = Intent(context, MyService::class.java)
    
    ContextCompat.startForegroundService(this, intent)
    // or
    // startService(intent)           // for android version lower than 8.0 (android O)
    // startForegroundService(intent) // for android 8.0 and higher

class MyService : FloatingBubbleService() {

    override fun setupBubble(action: FloatingBubble.Action): FloatingBubble.Builder {

        // You can create your own view manually, or using this helper class that I specially designed for you 💖
        val v = ViewHelper.fromDrawable(this, R.drawable.ic_rounded_blue_diamond, 60, 60);

        v.setOnClickListener{ 
            action.navigateToExpandableView()
        }

        return FloatingBubble.Builder(this)

            // pass view
            .bubble(v)

            // or our sweetie, Jetpack Compose
            .bubble{
                BubbleCompose()
            }

            // set style for the bubble, fade animation by default
            .bubbleStyle(null)

            // set start location for the bubble, (x=0, y=0) is the top-left
            .startLocation(100, 100)        // in dp
            .startLocationPx(100, 100)      // in px

            // enable auto animate bubble to the left/right side when release, true by default
            .enableAnimateToEdge(true)

            // set close-bubble icon attributes, currently only drawable and bitmap are supported
            .closeBubble(R.drawable.ic_close_bubble, 60, 60)

            // set style for close-bubble, null by default
            .closeBubbleStyle(null)

            // show close-bubble, true by default
            .enableCloseBubble(true)

            // the more value (dp), the larger closeable-area
            .distanceToClose(100)

            // choose behavior of the bubbles
            // DYNAMIC_CLOSE_BUBBLE: close-bubble moving based on the bubble's location
            // FIXED_CLOSE_BUBBLE: bubble will automatically move to the close-bubble when it reaches the closable-area
            .behavior(BubbleBehavior.DYNAMIC_CLOSE_BUBBLE)

            // enable bottom background, false by default
            .bottomBackground(false)

            // add listener for the bubble
            .addFloatingBubbleListener(object : FloatingBubble.Listener {
                override fun onMove(x: Float, y: Float) {} // The location of the finger on the screen which triggers the movement of the bubble.
                override fun onUp(x: Float, y: Float) {}   // ..., when finger release from bubble
                override fun onDown(x: Float, y: Float) {} // ..., when finger tap the bubble
            })
            // set bubble's opacity
            .opacity(1f)

    }

    override fun setupExpandableView(action: ExpandableView.Action): ExpandableView.Builder? {

        val inflater = getSystemService(LAYOUT_INFLATER_SERVICE) as LayoutInflater
        val layout = inflater.inflate(R.layout.layout_view_test, null)

        layout.findViewById<View>(R.id.card_view).setOnClickListener { v: View? ->
            Toast.makeText(this, "hello from kotlin", Toast.LENGTH_SHORT).show();
            action.popToBubble()
        }

        return ExpandableView.Builder(this)

            // You should not pass both view and compose. Passing both will cause crashing. ❗💥
            // set view to expandable-view
            .view(layout)

            // You should not pass both view and compose. Passing both will cause crashing. ❗💥
            // set composable to expandable-view
            .compose {
                TestComposeView(
                    popBack = {
                        action.popToBubble()
                    }
                )
            }

            // set the amount of dimming below the view.
            .dimAmount(0.8f)

            // apply style for the expandable-view
            .expandableViewStyle(null)

            // ddd listener for the expandable-view
            .addExpandableViewListener(object : ExpandableView.Listener {
                override fun onOpenExpandableView() {}
                override fun onCloseExpandableView() {}
            })
    }
}

class MyService : FloatingBubbleService() {

    // config the initial notification for Bubble on Android 8 and up.
    // return null if you want to show the notification later.
    open fun initialNotification(): Notification? {
        return NotificationCompat.Builder(this, channelId())
            .setOngoing(true)
            .setSmallIcon(R.drawable.ic_rounded_blue_diamond)
            .setContentTitle("bubble is running")
            .setPriority(PRIORITY_MIN)
            .setCategory(Notification.CATEGORY_SERVICE)
            .setSilent(true)
            .build()
    }

    override fun channelId() = "your_channel_id"
    override fun channelName() = "your_channel_name"
    override fun notificationId() = 69
}

    override fun setupExpandableView(action: ExpandableView.Action): ExpandableView.Builder? {
        ...
        val wrapper: ViewGroup = object : FrameLayout(this) {
            override fun dispatchKeyEvent(event: KeyEvent): Boolean {
                if (event.keyCode == KeyEvent.KEYCODE_BACK) {
                    action.popToBubble()
                    return true
                }
                return super.dispatchKeyEvent(event)
            }
        }

        val layout = inflater.inflate(R.layout.layout_view_test, wrapper) // pass "wrapper" here
        ...
    }

@Composable
fun SomeComposable(){
    ...
    OverrideDispatchKeyEvent { event ->
        if (event?.keyCode == KeyEvent.KEYCODE_BACK) {
            // your code here
        }
        null
    }
}