valentinfernandez1 · Oct 9, 2026 · Oct 7, 2026 · Oct 7, 2026 · Oct 7, 2026 · Oct 7, 2026
@@ -328,8 +328,9 @@ withdrawn before it reaches the host, the absence of any permission prompt, and
 host failures.
 
 `Scanner` (`scan`) opens the host's own QR and barcode viewfinder (RFC
-"Host-drawn scanner"). Both CLI host roles answer it from `TRUAPI_SCAN_TEXT`,
-or with a dismissal when it is unset, so the battery runs it. The playground's
+"Host-drawn scanner"). The Android app draws it. Both CLI host roles answer
+it from `TRUAPI_SCAN_TEXT`, or with a dismissal when it is unset, so the
+battery runs it. The playground's
 Diagnosis skips it, since dot.li has no viewfinder and answers `Unsupported`.
 
 To run the playground locally in a plain browser tab, against a signing host on

@@ -106,6 +106,22 @@ class ProductsNavigator @Inject constructor(
         performNavigation(R.id.action_global_to_truapiContactPickBottomSheet)
     }
 
+    override suspend fun closeTrUAPIContactPick() = closeIfShowing(R.id.truapiContactPickBottomSheet)
+
+    override suspend fun openTrUAPIProductScan() = withContext(dispatchers.main) {
+        performNavigation(R.id.action_global_to_truapiProductScanBottomSheet)
+    }
+
+    override suspend fun closeTrUAPIProductScan() = closeIfShowing(R.id.truapiProductScanBottomSheet)
+
+    /**
+     * Closes the prompt only when it is on top, so a sheet over it stays. A prompt under another
+     * sheet closes itself when it is shown again, because its answer is already given.
+     */
+    private suspend fun closeIfShowing(destinationId: Int) = withContext(dispatchers.main) {
+        if (isCurrentDestination(destinationId)) back()
+    }
+
     override fun openPocketAddCard(payload: PocketAddCardPayload) = performNavigation(
         actionId = R.id.action_global_to_pocketAddCardBottomSheet,
         args = payload.toPayloadBundle(),

@@ -366,6 +366,14 @@
         android:id="@+id/action_global_to_truapiContactPickBottomSheet"
         app:destination="@id/truapiContactPickBottomSheet" />
 
+    <dialog
+        android:id="@+id/truapiProductScanBottomSheet"
+        android:name="io.paritytech.polkadotapp.feature_products_impl.presentation.truapiProductScan.TrUAPIProductScanBottomSheet" />
+
+    <action
+        android:id="@+id/action_global_to_truapiProductScanBottomSheet"
+        app:destination="@id/truapiProductScanBottomSheet" />
+
     <action
         android:id="@+id/action_global_to_resourceAllocationRequestBottomSheet"
         app:destination="@id/resourceAllocationRequestBottomSheet" />

@@ -10,7 +10,15 @@ import com.google.mlkit.vision.barcode.ZoomSuggestionOptions
 import com.google.mlkit.vision.barcode.common.Barcode
 import com.google.mlkit.vision.common.InputImage
 
-class QrCodeAnalyzer(private val listener: (String) -> Unit) : ImageAnalysis.Analyzer, AutoCloseable {
+/** Decodes [formats] (ML Kit `Barcode.FORMAT_*`) and reports every code in a frame with its format. */
+class QrCodeAnalyzer(
+    private val formats: List<Int>,
+    private val listener: (codes: List<Pair<Int, String>>) -> Unit,
+) : ImageAnalysis.Analyzer, AutoCloseable {
+    constructor(listener: (String) -> Unit) : this(listOf(Barcode.FORMAT_QR_CODE), { codes ->
+        codes.firstOrNull()?.let { (_, text) -> listener(text) }
+    })
+
     private var camera: Camera? = null
     private var scanner: BarcodeScanner? = null
 
@@ -35,10 +43,8 @@ class QrCodeAnalyzer(private val listener: (String) -> Unit) : ImageAnalysis.Ana
 
         scanner.process(image)
             .addOnSuccessListener {
-                val data = it.firstOrNull()?.rawValue
-                if (data != null) {
-                    listener.invoke(data)
-                }
+                val codes = it.mapNotNull { barcode -> barcode.rawValue?.let { text -> barcode.format to text } }
+                if (codes.isNotEmpty()) listener(codes)
             }
             .addOnCompleteListener {
                 imageProxy.close()
@@ -47,7 +53,7 @@ class QrCodeAnalyzer(private val listener: (String) -> Unit) : ImageAnalysis.Ana
 
     private fun createScanner(): BarcodeScanner {
         val optionsBuilder = BarcodeScannerOptions.Builder()
-            .setBarcodeFormats(Barcode.FORMAT_QR_CODE)
+            .setBarcodeFormats(formats.first(), *formats.drop(1).toIntArray())
 
         zoomSuggestionOptions()?.let(optionsBuilder::setZoomSuggestionOptions)
 

@@ -1,4 +1,4 @@
-package io.paritytech.polkadotapp.feature_scan_impl.presentation.scanning.compose
+package io.paritytech.polkadotapp.common.presentation.camera.compose
 
 import androidx.camera.compose.CameraXViewfinder
 import androidx.camera.core.SurfaceRequest
@@ -25,13 +25,13 @@ import kotlinx.coroutines.flow.SharedFlow
 import kotlinx.coroutines.flow.StateFlow
 import io.paritytech.polkadotapp.common.R as RCommon
 
-internal class PermissionMissingHint(
+class PermissionMissingHint(
     val missing: StateFlow<Boolean>,
     val content: @Composable (onRetry: () -> Unit) -> Unit,
 )
 
 @Composable
-internal fun QrViewfinder(
+fun QrViewfinder(
     modifier: Modifier = Modifier,
     surfaceRequestFlow: StateFlow<SurfaceRequest?>,
     invalidCodeEvent: SharedFlow<Unit>,

@@ -1633,6 +1633,8 @@ I’m attaching PDF with more information and details regarding the Tattoo Stenc
     <string name="truapi_contact_pick_body">%1$s learns only who you choose, and never your contact list.</string>
     <string name="truapi_contact_pick_unnamed">Unnamed contact</string>
     <string name="truapi_contact_pick_dismiss">Not now</string>
+    <string name="truapi_product_scan_title">Scan for %1$s</string>
+    <string name="truapi_product_scan_not_for_product">This code isn\'t for %1$s</string>
     <string name="debug_report_title">Report app issue</string>
     <string name="debug_report_what_happened">What happened?</string>
     <string name="debug_report_placeholder">Tell us about the issue you encountered</string>

@@ -71,6 +71,9 @@ dependencies {
     implementation(libs.nova.substrate.serialization)
 
     implementation(project(":bindings:truapi-host"))
+    // The app supplies ML Kit per flavor, as for :common.
+    compileOnly(libs.google.play.services.mlkit)
+    testImplementation(libs.google.play.services.mlkit)
     implementation(project(":bindings:sr25519-vrf"))
 
     implementation(project(":common"))

@@ -27,7 +27,7 @@ import javax.inject.Inject
  */
 class AppContactsHostBridge @Inject constructor(
     private val directory: ContactDirectory,
-    private val pickLauncher: TrUAPIContactPickLauncher,
+    private val picks: TrUAPIContactPicks,
 ) : ContactsHostBridge {
     private class HandleIndex(val handleKey: ByteArray, val accountsByHandle: Map<DataByteArray, ByteArray>)
 
@@ -87,7 +87,7 @@ class AppContactsHostBridge @Inject constructor(
 
         if (options.isEmpty()) return HostContactPick.NoContacts
 
-        val picked = pickLauncher.awaitPick(productId, options)
+        val picked = picks.ask(ContactPickRequest(productId, options))
             ?: return HostContactPick.Dismissed
 
         return HostContactPick.Picked(picked.account)

@@ -0,0 +1,33 @@
+package io.paritytech.polkadotapp.feature_products_impl.domain.truapi
+
+import com.google.mlkit.vision.barcode.common.Barcode
+import uniffi.truapi.CodeFormat
+
+/** Translates between the formats a product names and the ones ML Kit reads. */
+internal object ProductScanFormats {
+    private val mlKitFormats = mapOf(
+        CodeFormat.QR to listOf(Barcode.FORMAT_QR_CODE),
+        CodeFormat.AZTEC to listOf(Barcode.FORMAT_AZTEC),
+        CodeFormat.DATA_MATRIX to listOf(Barcode.FORMAT_DATA_MATRIX),
+        CodeFormat.PDF417 to listOf(Barcode.FORMAT_PDF417),
+        CodeFormat.EAN13 to listOf(Barcode.FORMAT_EAN_13, Barcode.FORMAT_UPC_A),
+        CodeFormat.EAN8 to listOf(Barcode.FORMAT_EAN_8),
+        CodeFormat.UPC_E to listOf(Barcode.FORMAT_UPC_E),
+        CodeFormat.CODE128 to listOf(Barcode.FORMAT_CODE_128),
+        CodeFormat.CODE39 to listOf(Barcode.FORMAT_CODE_39),
+        CodeFormat.CODE93 to listOf(Barcode.FORMAT_CODE_93),
+        CodeFormat.ITF to listOf(Barcode.FORMAT_ITF),
+        CodeFormat.CODABAR to listOf(Barcode.FORMAT_CODABAR),
+    )
+
+    fun mlKitFormats(formats: List<CodeFormat>): List<Int> = formats.flatMap(mlKitFormats::getValue)
+
+    /**
+     * The code as a product sees it, or null for a format no product can ask for. UPC-A is read
+     * as EAN-13 with a leading zero, which is how iOS reports it.
+     */
+    fun codeFor(mlKitFormat: Int, text: String): Pair<CodeFormat, String>? = when (mlKitFormat) {
+        Barcode.FORMAT_UPC_A -> CodeFormat.EAN13 to "0$text"
+        else -> mlKitFormats.entries.firstOrNull { mlKitFormat in it.value }?.let { it.key to text }
+    }
+}
@@ -1,10 +1,6 @@
 package io.paritytech.polkadotapp.feature_products_impl.domain.truapi
 
 import io.paritytech.polkadotapp.feature_products_impl.presentation.productBotManagement.ProductsRouter
-import kotlinx.coroutines.CompletableDeferred
-import kotlinx.coroutines.sync.Mutex
-import kotlinx.coroutines.sync.withLock
-import kotlinx.coroutines.withTimeoutOrNull
 import javax.inject.Inject
 import javax.inject.Singleton
 
@@ -19,87 +15,18 @@ class ContactPickOption(
     val displayName: String?,
 )
 
-/** One in-flight pick and the choice the core is waiting on. */
-class TrUAPIContactPickContext(
+/** What the contact picker shows: who is asking, and whom they may pick. */
+class ContactPickRequest(
     val productId: String,
     val options: List<ContactPickOption>,
-) {
-    private val choice = CompletableDeferred<ContactPickOption?>()
-    private val shown = CompletableDeferred<Unit>()
-
-    /** Called by the sheet once it holds this context. */
-    fun markShown() {
-        shown.complete(Unit)
-    }
-
-    /** Whether the sheet appeared within [timeoutMs]. */
-    suspend fun awaitShown(timeoutMs: Long): Boolean = withTimeoutOrNull(timeoutMs) { shown.await() } != null
-
-    fun pick(option: ContactPickOption) {
-        choice.complete(option)
-    }
-
-    /** Also the answer for a dismissed sheet, so an abandoned pick names nobody. */
-    fun dismiss() {
-        choice.complete(null)
-    }
-
-    suspend fun await(): ContactPickOption? = choice.await()
-}
-
-/**
- * Parks the in-flight pick for the sheet to pick up.
- *
- * Mirrors [TrUAPIConfirmationContextHolder], owner-guarded clear included: the
- * sheet's ViewModel is cleared after the dismiss animation, by which time the
- * holder may already carry the next request.
- */
-@Singleton
-class TrUAPIContactPickContextHolder @Inject constructor() {
-    private var context: TrUAPIContactPickContext? = null
-
-    fun set(context: TrUAPIContactPickContext) {
-        this.context = context
-    }
-
-    fun get(): TrUAPIContactPickContext? = context
-
-    fun clear(owner: TrUAPIContactPickContext) {
-        if (context === owner) {
-            context = null
-        }
-    }
-}
+)
 
-/** Opens the contact picker for a product and awaits the person the user chose. */
-// Singleton for the same reason the confirmation launcher is: the holder carries
-// one context, and every live tab's bridge shares it.
+/** Opens the contact picker for a product and waits for the person the user chose. */
 @Singleton
-class TrUAPIContactPickLauncher @Inject constructor(
-    private val holder: TrUAPIContactPickContextHolder,
+class TrUAPIContactPicks @Inject constructor(
     private val productsRouter: ProductsRouter,
-) {
-    private val oneAtATime = Mutex()
-
-    suspend fun awaitPick(
-        productId: String,
-        options: List<ContactPickOption>,
-    ): ContactPickOption? = oneAtATime.withLock {
-        val context = TrUAPIContactPickContext(productId, options)
-        holder.set(context)
-        productsRouter.openTrUAPIContactPick()
-        // Navigation can fail silently (backgrounded, no controller, another
-        // sheet on top), and then no ViewModel ever answers. Waiting on that
-        // would hold the lock, and every later pick, forever. The context stays
-        // in the holder so a sheet that does turn up late still finds one.
-        if (!context.awaitShown(SHEET_SHOWN_TIMEOUT_MS)) {
-            context.dismiss()
-            return@withLock null
-        }
-        context.await()
-    }
+) : TrUAPIPrompts<ContactPickRequest, ContactPickOption?>(unanswered = null) {
+    override suspend fun open() = productsRouter.openTrUAPIContactPick()
 
-    private companion object {
-        const val SHEET_SHOWN_TIMEOUT_MS = 10_000L
-    }
+    override suspend fun close() = productsRouter.closeTrUAPIContactPick()
 }
@@ -73,6 +73,7 @@ class TrUAPIHostRuntimeProvider @Inject constructor(
     private val confirmationLauncher: TrUAPIConfirmationLauncher,
     private val appLifecycleObserver: AppLifecycleObserver,
     private val contactsBridge: AppContactsHostBridge,
+    private val scannerBridge: TrUAPIProductScans,
     // Lazy: the supervisor boots workers on this runtime, and reports back through this bridge.
     private val workerSupervisor: Lazy<TrUAPIWorkerSupervisor>,
     dispatchers: CoroutineDispatchers,
@@ -121,6 +122,7 @@ class TrUAPIHostRuntimeProvider @Inject constructor(
         // Before any product execution opens, so a product never sees the
         // window where the host lists no contacts.
         runtime.setContacts(contactsBridge)
+        runtime.setScanner(scannerBridge)
         observeContactRemovals(runtime)
         chainProvider.attach(
             onResponse = runtime::notifyChainResponse,

@@ -0,0 +1,66 @@
+package io.paritytech.polkadotapp.feature_products_impl.domain.truapi
+
+import androidx.lifecycle.Lifecycle
+import io.parity.truapi.ScannerHostBridge
+import io.paritytech.polkadotapp.common.presentation.resources.ContextManager
+import io.paritytech.polkadotapp.common.utils.CoroutineDispatchers
+import io.paritytech.polkadotapp.feature_products_impl.presentation.productBotManagement.ProductsRouter
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.withContext
+import kotlinx.coroutines.withTimeoutOrNull
+import uniffi.truapi.HostScan
+import uniffi.truapi.HostScannerScanRequest
+import uniffi.truapi.ProductExecutionKind
+import javax.inject.Inject
+import javax.inject.Singleton
+import kotlin.time.Duration.Companion.milliseconds
+import kotlin.time.Duration.Companion.seconds
+
+/** What the viewfinder shows: who is asking, and what they accept. */
+class ProductScanRequest(
+    val productId: String,
+    val executionKind: ProductExecutionKind,
+    val request: HostScannerScanRequest,
+)
+
+/**
+ * Serves `scanner.scan`: opens the viewfinder for a product the user can see and waits for the
+ * code they scanned. A Worker has no page, so the app must be in front. The core already checked
+ * that its user tapped its card.
+ */
+@Singleton
+class TrUAPIProductScans @Inject constructor(
+    private val productsRouter: ProductsRouter,
+    private val visibleProducts: VisibleProducts,
+    private val contextManager: ContextManager,
+    private val dispatchers: CoroutineDispatchers,
+) : TrUAPIPrompts<ProductScanRequest, HostScan>(unanswered = HostScan.Dismissed, notShown = HostScan.NotVisible),
+    ScannerHostBridge {
+    override suspend fun scanCode(
+        productId: String,
+        executionKind: ProductExecutionKind,
+        request: HostScannerScanRequest,
+    ): HostScan = ask(ProductScanRequest(productId, executionKind, request))
+
+    override suspend fun canShow(question: ProductScanRequest): Boolean = withContext(dispatchers.main) {
+        when (question.executionKind) {
+            ProductExecutionKind.WORKER ->
+                contextManager.getActivity()?.lifecycle?.currentState?.isAtLeast(Lifecycle.State.RESUMED) == true
+            ProductExecutionKind.APP, ProductExecutionKind.WIDGET -> pageOnScreen(question.productId)
+        }
+    }
+
+    override suspend fun open() = productsRouter.openTrUAPIProductScan()
+
+    override suspend fun close() = productsRouter.closeTrUAPIProductScan()
+
+    // A host screen closing over the page, such as the last scanner, holds focus for a moment.
+    private suspend fun pageOnScreen(productId: String) = withTimeoutOrNull(FOCUS_RETURN_TIMEOUT) {
+        while (!visibleProducts.isOnScreen(productId)) delay(FOCUS_POLL_INTERVAL)
+    } != null
+
+    private companion object {
+        val FOCUS_RETURN_TIMEOUT = 1.seconds
+        val FOCUS_POLL_INTERVAL = 50.milliseconds
+    }
+}