v0.3.0 — floating threat-circle overlay (chat-bubble style)

A 140dp draggable bubble shows the same map / tier scrim / user dot / ALPR dots that the in-app circle does, on top of any other app, while scanning is on. Tap = brings the host app forward; drag = repositions. - Manifest: add SYSTEM_ALERT_WINDOW (special-access — granted via system Settings page, not the runtime prompt). - Settings: add overlayEnabled flag (default off) + a "Display over other apps" section in SettingsScreen. Flipping the toggle to on fires Settings.ACTION_MANAGE_OVERLAY_PERMISSION so the user can grant via the system page; if they deny or revoke, the OverlayMgr re-checks canDrawOverlays() at every show() call and silently no-ops, no crash. - New OverlayManager: owns the WindowManager view at TYPE_APPLICATION_OVERLAY with FLAG_NOT_FOCUSABLE | FLAG_NOT_TOUCH_MODAL so touches outside the bubble pass through and the bubble never steals IME focus. Custom OverlayOwner implementing LifecycleOwner + SavedStateRegistryOwner since LifecycleService doesn't satisfy SSR (Compose's ComposeView requires both via the view tree). - Drag/tap handler at the View layer: rawX/rawY math for the drag, TAP_SLOP_PX guard to discriminate tap from drag, tap launches MainActivity (FLAG_ACTIVITY_NEW_TASK | SINGLE_TOP). - New OverlayBubble composable: smaller (140dp) self-contained version of the in-app threat circle that pulls running/threat/location/ mapPoints/proximity from the same companion StateFlows. Shared dot-drawable helper extracted into ui/MarkerIcons.kt. - DetectionService observes settings.overlayEnabled in beginScanning and toggles the overlay; endScanning hides it.
2026-05-07 23:24:56 -04:00
parent 42f657bc0a
commit 0841a0a33f
9 changed files with 451 additions and 28 deletions
@@ -12,8 +12,8 @@ android {
        applicationId = "org.soulstone.overwatch"
        minSdk = 26
        targetSdk = 35
-        versionCode = 11
-        versionName = "0.2.2"
+        versionCode = 12
+        versionName = "0.3.0"
    }

    buildTypes {
@@ -38,6 +38,12 @@
    <!-- Vibration on threat-tier escalation -->
    <uses-permission android:name="android.permission.VIBRATE" />

+    <!-- Floating threat-circle overlay (chat-bubble style). Special-access
+         permission — user grants via system Settings page, not the runtime
+         prompt. Only consumed when the user opts in to the bubble in app
+         Settings; otherwise dormant. -->
+    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
+
    <uses-feature android:name="android.hardware.bluetooth_le" android:required="true" />

    <!-- Allow Intent.setPackage("com.google.android.apps.maps") on Android 11+
@@ -53,6 +53,9 @@ class Settings private constructor(private val prefs: SharedPreferences) {
    private val _vibrateOnAlert = MutableStateFlow(prefs.getBoolean(KEY_VIBRATE, true))
    val vibrateOnAlert: StateFlow<Boolean> = _vibrateOnAlert.asStateFlow()

+    private val _overlayEnabled = MutableStateFlow(prefs.getBoolean(KEY_OVERLAY, false))
+    val overlayEnabled: StateFlow<Boolean> = _overlayEnabled.asStateFlow()
+
    fun setBleEnabled(v: Boolean) { prefs.edit { putBoolean(KEY_BLE, v) }; _bleEnabled.value = v }
    fun setWifiEnabled(v: Boolean) { prefs.edit { putBoolean(KEY_WIFI, v) }; _wifiEnabled.value = v }
    fun setDeflockEnabled(v: Boolean) { prefs.edit { putBoolean(KEY_DEFLOCK, v) }; _deflockEnabled.value = v }
@@ -81,6 +84,11 @@ class Settings private constructor(private val prefs: SharedPreferences) {
        _vibrateOnAlert.value = v
    }

+    fun setOverlayEnabled(v: Boolean) {
+        prefs.edit { putBoolean(KEY_OVERLAY, v) }
+        _overlayEnabled.value = v
+    }
+
    companion object {
        private const val PREFS = "overwatch_settings"
        private const val KEY_BLE = "src_ble"
@@ -92,6 +100,7 @@ class Settings private constructor(private val prefs: SharedPreferences) {
        private const val KEY_CITIZEN_PROX = "citizen_proximity_m"
        private const val KEY_THEME = "theme_mode"
        private const val KEY_VIBRATE = "vibrate_on_alert"
+        private const val KEY_OVERLAY = "overlay_enabled"

        const val DEFAULT_DEFLOCK_PROX = 200
        const val DEFAULT_CITIZEN_PROX = 500
@@ -105,12 +105,14 @@ class DetectionService : LifecycleService() {
    private lateinit var locationProvider: LocationProvider
    private lateinit var deflockScanner: DeflockScanner
    private lateinit var citizenScanner: CitizenScanner
+    private lateinit var overlayManager: OverlayManager
    private var pruneJob: Job? = null
    private var observerJob: Job? = null
    private var mapPointsJob: Job? = null
    private var locationJob: Job? = null
    private var deflockProxJob: Job? = null
    private var citizenProxJob: Job? = null
+    private var overlayJob: Job? = null
    private var bleStarted = false
    private var wifiStarted = false
    private var deflockStarted = false
@@ -132,6 +134,7 @@ class DetectionService : LifecycleService() {
            store, locationProvider,
            proximityMeters = { settings.citizenProximityM.value.toFloat() }
        )
+        overlayManager = OverlayManager(this)
        createNotificationChannel()
    }

@@ -248,6 +251,16 @@ class DetectionService : LifecycleService() {
                settings.citizenProximityM.drop(1).collect { citizenScanner.refresh() }
            }
        }
+
+        // Floating threat-circle overlay — observe the toggle and show/hide
+        // accordingly. The OverlayManager re-checks SYSTEM_ALERT_WINDOW each
+        // show() so a denied/revoked permission silently no-ops.
+        overlayJob?.cancel()
+        overlayJob = lifecycleScope.launch {
+            settings.overlayEnabled.collect { enabled ->
+                if (enabled) overlayManager.show() else overlayManager.hide()
+            }
+        }
    }

    private fun endScanning() {
@@ -268,6 +281,8 @@ class DetectionService : LifecycleService() {
        locationJob?.cancel(); locationJob = null
        deflockProxJob?.cancel(); deflockProxJob = null
        citizenProxJob?.cancel(); citizenProxJob = null
+        overlayJob?.cancel(); overlayJob = null
+        overlayManager.hide()
        _mapPoints.value = emptyList()
        _location.value = null
        lastNotifiedTier = ThreatLevel.GREEN
@@ -0,0 +1,193 @@
+package org.soulstone.overwatch.service
+
+import android.content.Context
+import android.content.Intent
+import android.graphics.PixelFormat
+import android.provider.Settings
+import android.util.Log
+import android.view.Gravity
+import android.view.MotionEvent
+import android.view.View
+import android.view.WindowManager
+import androidx.compose.ui.platform.ComposeView
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.LifecycleOwner
+import androidx.lifecycle.LifecycleRegistry
+import androidx.lifecycle.setViewTreeLifecycleOwner
+import androidx.savedstate.SavedStateRegistry
+import androidx.savedstate.SavedStateRegistryController
+import androidx.savedstate.SavedStateRegistryOwner
+import androidx.savedstate.setViewTreeSavedStateRegistryOwner
+import kotlin.math.abs
+import org.soulstone.overwatch.MainActivity
+import org.soulstone.overwatch.ui.OverlayBubble
+
+/**
+ * Owns the floating threat-circle bubble — a [ComposeView] hosted in a
+ * [WindowManager] window at TYPE_APPLICATION_OVERLAY.
+ *
+ * Lifecycle:
+ *  - [show] is idempotent. Silently no-ops if SYSTEM_ALERT_WINDOW isn't
+ *    granted, so flipping the setting doesn't crash on a denied permission.
+ *  - [hide] removes the view and tears down the owner.
+ *  - The DetectionService calls [show] / [hide] based on the running ×
+ *    overlayEnabled product. Permission revocation between show calls is
+ *    handled silently — the bubble just doesn't appear.
+ *
+ * Touch model:
+ *  - The window flag set lets touches outside the bubble pass through to
+ *    whatever app is underneath (FLAG_NOT_TOUCH_MODAL) and never steals IME
+ *    focus (FLAG_NOT_FOCUSABLE).
+ *  - Touches *inside* the bubble are intercepted at the View layer for drag
+ *    and tap-to-open. Compose doesn't see them — the bubble is a render-only
+ *    visualization.
+ */
+class OverlayManager(private val context: Context) {
+
+    private companion object {
+        private const val TAG = "OverlayManager"
+        private const val INITIAL_X = 60
+        private const val INITIAL_Y = 240
+        private const val TAP_SLOP_PX = 12
+    }
+
+    private val wm: WindowManager =
+        context.getSystemService(Context.WINDOW_SERVICE) as WindowManager
+
+    private var view: ComposeView? = null
+    private var owner: OverlayOwner? = null
+    private var params: WindowManager.LayoutParams? = null
+
+    fun show() {
+        if (view != null) return
+        if (!Settings.canDrawOverlays(context)) {
+            Log.i(TAG, "Overlay permission not granted; skipping show()")
+            return
+        }
+
+        val newOwner = OverlayOwner()
+        val composeView = ComposeView(context).apply {
+            setViewTreeLifecycleOwner(newOwner)
+            setViewTreeSavedStateRegistryOwner(newOwner)
+            setContent { OverlayBubble() }
+        }
+
+        val lp = WindowManager.LayoutParams(
+            WindowManager.LayoutParams.WRAP_CONTENT,
+            WindowManager.LayoutParams.WRAP_CONTENT,
+            WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY,
+            WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE or
+                WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL,
+            PixelFormat.TRANSLUCENT
+        ).apply {
+            gravity = Gravity.TOP or Gravity.START
+            x = INITIAL_X
+            y = INITIAL_Y
+        }
+
+        composeView.setOnTouchListener(DragHandler(lp))
+
+        try {
+            wm.addView(composeView, lp)
+            view = composeView
+            owner = newOwner
+            params = lp
+            Log.i(TAG, "Overlay bubble attached")
+        } catch (e: Exception) {
+            // Most common: WindowManager$BadTokenException if perm was revoked
+            // between the canDrawOverlays check and addView. Tear down and
+            // bail; service can retry on next state flip.
+            Log.w(TAG, "Failed to attach overlay: ${e.message}")
+            newOwner.destroy()
+        }
+    }
+
+    fun hide() {
+        val v = view ?: return
+        try {
+            wm.removeView(v)
+        } catch (e: Exception) {
+            Log.w(TAG, "removeView failed: ${e.message}")
+        }
+        owner?.destroy()
+        view = null
+        owner = null
+        params = null
+        Log.i(TAG, "Overlay bubble detached")
+    }
+
+    /** Drag with raw coords, tap if movement stayed under [TAP_SLOP_PX]. */
+    private inner class DragHandler(private val lp: WindowManager.LayoutParams) :
+        View.OnTouchListener {
+
+        private var startX = 0
+        private var startY = 0
+        private var touchDownX = 0f
+        private var touchDownY = 0f
+        private var moved = false
+
+        override fun onTouch(v: View, ev: MotionEvent): Boolean {
+            return when (ev.action) {
+                MotionEvent.ACTION_DOWN -> {
+                    startX = lp.x
+                    startY = lp.y
+                    touchDownX = ev.rawX
+                    touchDownY = ev.rawY
+                    moved = false
+                    true
+                }
+                MotionEvent.ACTION_MOVE -> {
+                    val dx = ev.rawX - touchDownX
+                    val dy = ev.rawY - touchDownY
+                    if (abs(dx) > TAP_SLOP_PX || abs(dy) > TAP_SLOP_PX) {
+                        moved = true
+                    }
+                    if (moved) {
+                        lp.x = startX + dx.toInt()
+                        lp.y = startY + dy.toInt()
+                        try { wm.updateViewLayout(v, lp) } catch (_: Exception) {}
+                    }
+                    true
+                }
+                MotionEvent.ACTION_UP -> {
+                    if (!moved) {
+                        // Tap → bring the host app forward.
+                        val intent = Intent(context, MainActivity::class.java).apply {
+                            flags = Intent.FLAG_ACTIVITY_NEW_TASK or
+                                Intent.FLAG_ACTIVITY_SINGLE_TOP
+                        }
+                        try { context.startActivity(intent) } catch (_: Exception) {}
+                    }
+                    true
+                }
+                else -> false
+            }
+        }
+    }
+
+    /**
+     * Compose's [ComposeView] requires both a [LifecycleOwner] and a
+     * [SavedStateRegistryOwner] in its view tree. A bare [android.app.Service]
+     * isn't an SSR owner, so we synthesize one bound to the bubble's lifetime.
+     * The lifecycle is forced to RESUMED on construction (Compose only renders
+     * at STARTED+) and DESTROYED on [destroy].
+     */
+    private class OverlayOwner : SavedStateRegistryOwner {
+        private val lifecycleReg = LifecycleRegistry(this)
+        private val ssrController = SavedStateRegistryController.create(this)
+
+        init {
+            ssrController.performAttach()
+            ssrController.performRestore(null)
+            lifecycleReg.currentState = Lifecycle.State.RESUMED
+        }
+
+        override val lifecycle: Lifecycle get() = lifecycleReg
+        override val savedStateRegistry: SavedStateRegistry
+            get() = ssrController.savedStateRegistry
+
+        fun destroy() {
+            lifecycleReg.currentState = Lifecycle.State.DESTROYED
+        }
+    }
+}
@@ -224,30 +224,6 @@ fun MainScreen(
    }
 }

-/** Builds a small filled-circle Marker icon. Used for both the user-position
- *  dot (blue) and the ALPR pins (red) — osmdroid's default teardrop marker
- *  reads as a "click me" affordance which is wrong for a non-interactive
- *  visualization, so we use simple dots instead. */
-private fun dotDrawable(
-    resources: android.content.res.Resources,
-    sizePx: Int,
-    coreColor: Int
-): android.graphics.drawable.BitmapDrawable {
-    val bitmap = android.graphics.Bitmap.createBitmap(
-        sizePx, sizePx, android.graphics.Bitmap.Config.ARGB_8888
-    )
-    val canvas = android.graphics.Canvas(bitmap)
-    val outline = android.graphics.Paint(android.graphics.Paint.ANTI_ALIAS_FLAG).apply {
-        color = 0xFFFFFFFF.toInt()
-    }
-    canvas.drawCircle(sizePx / 2f, sizePx / 2f, sizePx / 2f - 1f, outline)
-    val core = android.graphics.Paint(android.graphics.Paint.ANTI_ALIAS_FLAG).apply {
-        color = coreColor
-    }
-    canvas.drawCircle(sizePx / 2f, sizePx / 2f, sizePx / 2f - 4f, core)
-    return android.graphics.drawable.BitmapDrawable(resources, bitmap)
-}
-
@Composable
 private fun ThreatMapCircle(
    level: ThreatLevel,
@@ -324,8 +300,8 @@ private fun ThreatMapCircle(
            val ctx = LocalContext.current
            // Build the marker drawables once per Composition rather than
            // every recomposition — bitmap allocation isn't free.
-            val userDot = remember(ctx) { dotDrawable(ctx.resources, 36, 0xFF2196F3.toInt()) }
-            val flockDot = remember(ctx) { dotDrawable(ctx.resources, 26, 0xFFD7263D.toInt()) }
+            val userDot = remember(ctx) { dotDrawable(ctx.resources, 36, DOT_USER_BLUE) }
+            val flockDot = remember(ctx) { dotDrawable(ctx.resources, 26, DOT_FLOCK_RED) }
            AndroidView(
                modifier = Modifier.fillMaxSize(),
                factory = { c ->
@@ -0,0 +1,29 @@
+package org.soulstone.overwatch.ui
+
+import android.content.res.Resources
+import android.graphics.Bitmap
+import android.graphics.Canvas
+import android.graphics.Paint
+import android.graphics.drawable.BitmapDrawable
+
+/** Builds a small filled-circle Marker icon. Used for both the user-position
+ *  dot (blue) and the ALPR pins (red) — osmdroid's default teardrop marker
+ *  reads as a "click me" affordance which is wrong for a non-interactive
+ *  visualization, so we use simple dots instead. Shared by the in-app and
+ *  overlay versions of the threat circle. */
+internal fun dotDrawable(
+    resources: Resources,
+    sizePx: Int,
+    coreColor: Int
+): BitmapDrawable {
+    val bitmap = Bitmap.createBitmap(sizePx, sizePx, Bitmap.Config.ARGB_8888)
+    val canvas = Canvas(bitmap)
+    val outline = Paint(Paint.ANTI_ALIAS_FLAG).apply { color = 0xFFFFFFFF.toInt() }
+    canvas.drawCircle(sizePx / 2f, sizePx / 2f, sizePx / 2f - 1f, outline)
+    val core = Paint(Paint.ANTI_ALIAS_FLAG).apply { color = coreColor }
+    canvas.drawCircle(sizePx / 2f, sizePx / 2f, sizePx / 2f - 4f, core)
+    return BitmapDrawable(resources, bitmap)
+}
+
+internal const val DOT_USER_BLUE = 0xFF2196F3.toInt()
+internal const val DOT_FLOCK_RED = 0xFFD7263D.toInt()
@@ -0,0 +1,163 @@
+package org.soulstone.overwatch.ui
+
+import androidx.compose.animation.core.RepeatMode
+import androidx.compose.animation.core.animateFloat
+import androidx.compose.animation.core.infiniteRepeatable
+import androidx.compose.animation.core.rememberInfiniteTransition
+import androidx.compose.animation.core.tween
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Brush
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.viewinterop.AndroidView
+import kotlin.math.cos
+import kotlin.math.max
+import org.osmdroid.tileprovider.tilesource.TileSourceFactory
+import org.osmdroid.util.BoundingBox
+import org.osmdroid.util.GeoPoint
+import org.osmdroid.views.MapView
+import org.osmdroid.views.overlay.Marker
+import org.soulstone.overwatch.data.settings.Settings
+import org.soulstone.overwatch.fusion.ThreatLevel
+import org.soulstone.overwatch.service.DetectionService
+import org.soulstone.overwatch.ui.theme.ThreatColors
+
+/**
+ * Smaller "chat-bubble" version of the threat-map circle, hosted in a
+ * WindowManager overlay by [org.soulstone.overwatch.service.OverlayManager].
+ *
+ * Self-contained: pulls all of its data from the same companion-level
+ * StateFlows the in-app [MainScreen] uses (DetectionService.running / store /
+ * mapPoints / location) plus the proximity sliders from [Settings]. The
+ * caller doesn't pass any state — keeps the OverlayManager dumb.
+ *
+ * Tap and drag are handled at the View layer (OverlayManager's OnTouchListener);
+ * this composable is render-only.
+ */
+@Composable
+fun OverlayBubble() {
+    val ctx = LocalContext.current
+    val settings = remember(ctx) { Settings.get(ctx) }
+
+    val running by DetectionService.running.collectAsState()
+    val threat by DetectionService.store.threatLevel.collectAsState()
+    val userLocation by DetectionService.location.collectAsState()
+    val mapPoints by DetectionService.mapPoints.collectAsState()
+    val deflockProx by settings.deflockProximityM.collectAsState()
+    val citizenProx by settings.citizenProximityM.collectAsState()
+    val radius = max(deflockProx, citizenProx).toFloat()
+
+    val activeColor = when (threat) {
+        ThreatLevel.GREEN -> ThreatColors.Green
+        ThreatLevel.YELLOW -> ThreatColors.Yellow
+        ThreatLevel.ORANGE -> ThreatColors.Orange
+        ThreatLevel.RED -> ThreatColors.Red
+    }
+
+    val transition = rememberInfiniteTransition(label = "overlay-pulse")
+    val pulse by transition.animateFloat(
+        initialValue = 0.55f,
+        targetValue = 1.0f,
+        animationSpec = infiniteRepeatable(
+            animation = tween(durationMillis = 1200),
+            repeatMode = RepeatMode.Reverse
+        ),
+        label = "overlay-pulse"
+    )
+
+    val userDot = remember(ctx) { dotDrawable(ctx.resources, 30, DOT_USER_BLUE) }
+    val flockDot = remember(ctx) { dotDrawable(ctx.resources, 22, DOT_FLOCK_RED) }
+
+    Box(
+        modifier = Modifier
+            .size(140.dp)
+            .clip(CircleShape),
+        contentAlignment = Alignment.Center
+    ) {
+        // The OverlayManager only attaches the bubble while running == true,
+        // but check anyway — paranoia keeps the bubble from rendering a stale
+        // map if a future code path lets the composition outlive the service.
+        val fix = userLocation
+        if (!running || fix == null) {
+            Box(
+                modifier = Modifier
+                    .fillMaxSize()
+                    .background(
+                        Brush.radialGradient(
+                            colors = listOf(
+                                activeColor.copy(alpha = pulse),
+                                activeColor.copy(alpha = pulse * 0.6f)
+                            )
+                        )
+                    )
+            )
+        } else {
+            AndroidView(
+                modifier = Modifier.fillMaxSize(),
+                factory = { c ->
+                    MapView(c).apply {
+                        setTileSource(TileSourceFactory.MAPNIK)
+                        setMultiTouchControls(false)
+                        setBuiltInZoomControls(false)
+                        isClickable = false
+                        isFocusable = false
+                    }
+                },
+                update = { map ->
+                    map.controller.setCenter(GeoPoint(fix.latitude, fix.longitude))
+                    map.overlays.clear()
+                    for (p in mapPoints) {
+                        map.overlays.add(
+                            Marker(map).apply {
+                                position = GeoPoint(p.lat, p.lon)
+                                setAnchor(Marker.ANCHOR_CENTER, Marker.ANCHOR_CENTER)
+                                icon = flockDot
+                                title = p.operator ?: p.manufacturer ?: "ALPR"
+                                setInfoWindow(null)
+                            }
+                        )
+                    }
+                    map.overlays.add(
+                        Marker(map).apply {
+                            position = GeoPoint(fix.latitude, fix.longitude)
+                            setAnchor(Marker.ANCHOR_CENTER, Marker.ANCHOR_CENTER)
+                            icon = userDot
+                            setInfoWindow(null)
+                        }
+                    )
+                    val r = radius.toDouble().coerceAtLeast(50.0)
+                    val latDegPerMeter = 1.0 / 111_000.0
+                    val lonDegPerMeter = 1.0 /
+                        (111_000.0 * cos(Math.toRadians(fix.latitude)).coerceAtLeast(0.01))
+                    val bbox = BoundingBox(
+                        fix.latitude + r * latDegPerMeter,
+                        fix.longitude + r * lonDegPerMeter,
+                        fix.latitude - r * latDegPerMeter,
+                        fix.longitude - r * lonDegPerMeter
+                    )
+                    map.post { map.zoomToBoundingBox(bbox, false, 0) }
+                    map.invalidate()
+                },
+                onRelease = { map -> map.onDetach() }
+            )
+            // Tier scrim — same pulse alpha range as the in-app circle.
+            val scrimAlpha = (0.55f * pulse).coerceIn(0.40f, 0.65f)
+            Box(
+                modifier = Modifier
+                    .fillMaxSize()
+                    .background(activeColor.copy(alpha = scrimAlpha))
+            )
+        }
+    }
+}
@@ -1,5 +1,8 @@
 package org.soulstone.overwatch.ui

+import android.content.Intent
+import android.net.Uri
+import android.provider.Settings as AndroidSettings
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
@@ -11,6 +14,7 @@ import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.foundation.shape.RoundedCornerShape
@@ -54,6 +58,8 @@ fun SettingsScreen(
    val citizenProx by settings.citizenProximityM.collectAsState()
    val theme by settings.themeMode.collectAsState()
    val vibrate by settings.vibrateOnAlert.collectAsState()
+    val overlay by settings.overlayEnabled.collectAsState()
+    val context = LocalContext.current

    Column(
        modifier = Modifier
@@ -130,6 +136,32 @@ fun SettingsScreen(
        SectionLabel("Alerts")
        SourceToggle("Vibrate on threat escalation", vibrate) { settings.setVibrateOnAlert(it) }

+        Spacer(Modifier.height(16.dp))
+        SectionLabel("Display over other apps")
+        SourceToggle("Floating threat circle", overlay) { enabled ->
+            settings.setOverlayEnabled(enabled)
+            // Special-access perm: can't be granted via runtime prompt. Bounce
+            // the user to the system settings page for this app so they can
+            // approve. The DetectionService re-checks canDrawOverlays at show()
+            // time so a denied/revoked perm just means the bubble silently
+            // doesn't appear — no crash.
+            if (enabled && !AndroidSettings.canDrawOverlays(context)) {
+                val intent = Intent(
+                    AndroidSettings.ACTION_MANAGE_OVERLAY_PERMISSION,
+                    Uri.parse("package:${context.packageName}")
+                ).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+                try { context.startActivity(intent) } catch (_: Exception) {}
+            }
+        }
+        if (overlay && !AndroidSettings.canDrawOverlays(context)) {
+            Text(
+                "Permission needed — system page should have opened. If not, grant manually under Apps → OVERWATCH → Display over other apps.",
+                fontSize = 11.sp,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.padding(vertical = 4.dp)
+            )
+        }
+
        Spacer(Modifier.height(16.dp))
        SectionLabel("Appearance")
        ThemeRadio("System default", theme == Settings.ThemeMode.SYSTEM) {