guided scan zone

ROADMAP.md

@@ -21,6 +21,15 @@
 - [x] Live readability feedback in camera
 - Show real-time hint when a code is visible vs readable.
 
+- [x] Scan stability hardening
+- Temporal box stabilization (smoothing + short persistence) and same-code holdoff to reduce repeat scans.
+
+- [x] Guided scan zone
+- Only accept live camera scans when the readable code is inside the center aiming frame.
+
+- [x] Advanced gallery preview
+- Open selected image in full focus mode, support pinch zoom/pan, and run live re-detection with overlay markers linked to list entries.
+
 ## Mid-size Features (3-7 days)
 
 1. Import history
@@ -54,4 +63,4 @@
 ## Suggested Next 2
 
 1. Import history (CSV/JSON restore + merge policy)
-2. Favorites / pin scans
+2. Tagging (tags/folders + filter chips)

app/src/main/java/com/clean/scanner/ui/ScannerViewModel.kt

@@ -30,18 +30,27 @@ class ScannerViewModel(
     private val saveScan: suspend (content: String, type: String) -> Unit,
     private val nowProvider: () -> Long = { System.currentTimeMillis() }
 ) : ViewModel() {
+    private companion object {
+        const val GENERAL_DEBOUNCE_MS = 800L
+        const val SAME_CODE_HOLDOFF_MS = 2500L
+    }
+
     private val _uiState = MutableStateFlow(ScannerUiState())
     val uiState: StateFlow<ScannerUiState> = _uiState.asStateFlow()
     private val recentScanKeySet = LinkedHashSet<String>(200)
     private val batchKeySet = LinkedHashSet<String>(100)
+    private var lastAcceptedKey: String? = null
+    private var lastAcceptedTimestamp: Long = 0L
 
     fun onScan(result: ScanResult) {
         val now = nowProvider()
         val current = _uiState.value
         if (!current.analysisEnabled) return
-        if (now - current.lastScanTimestamp < 800) return
 
         val key = "${result.type}|${result.content}"
+        if (now - current.lastScanTimestamp < GENERAL_DEBOUNCE_MS) return
+        if (key == lastAcceptedKey && now - lastAcceptedTimestamp < SAME_CODE_HOLDOFF_MS) return
+
         val isDuplicate = key in recentScanKeySet
         recentScanKeySet.remove(key)
         recentScanKeySet.add(key)
@@ -49,6 +58,8 @@ class ScannerViewModel(
             recentScanKeySet.remove(recentScanKeySet.first())
         }
         val updatedRecent = recentScanKeySet.toList().asReversed()
+        lastAcceptedKey = key
+        lastAcceptedTimestamp = now
 
         _uiState.value = if (current.batchMode) {
             val updatedBatch = if (key in batchKeySet) {

app/src/main/java/com/clean/scanner/ui/screens/ScannerScreen.kt

@@ -6,6 +6,7 @@ import android.content.Intent
 import android.graphics.Bitmap
 import android.graphics.BitmapFactory
 import android.graphics.ImageDecoder
+import android.graphics.Paint
 import android.media.AudioManager
 import android.media.ToneGenerator
 import android.net.Uri
@@ -17,6 +18,7 @@ import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.foundation.Canvas
 import androidx.compose.foundation.Image
 import androidx.compose.foundation.background
+import androidx.compose.foundation.gestures.detectTransformGestures
 import androidx.compose.foundation.horizontalScroll
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
@@ -59,11 +61,17 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.CornerRadius
+import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.Path
 import androidx.compose.ui.graphics.asImageBitmap
+import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.graphics.nativeCanvas
 import androidx.compose.ui.graphics.drawscope.Stroke
 import androidx.compose.ui.hapticfeedback.HapticFeedbackType
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.layout.onSizeChanged
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.platform.LocalHapticFeedback
@@ -71,6 +79,7 @@ import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.IntSize
 import androidx.compose.ui.unit.dp
 import androidx.core.app.ActivityCompat
 import androidx.core.content.ContextCompat
@@ -89,8 +98,11 @@ import com.google.mlkit.vision.barcode.common.Barcode
 import com.google.mlkit.vision.common.InputImage
 import java.text.DateFormat
 import java.util.Date
+import kotlin.coroutines.resume
+import kotlin.coroutines.resumeWithException
 import kotlin.math.max
-import kotlin.math.min
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.suspendCancellableCoroutine
 
 private data class GalleryScanCandidate(
     val result: ScanResult,
@@ -133,7 +145,6 @@ fun ScannerScreen(
     var showRiskWarning by remember { mutableStateOf(false) }
     var pendingOpenUrl by remember { mutableStateOf<String?>(null) }
     var showImageScanFailed by remember { mutableStateOf(false) }
-    var showNoCodeInImage by remember { mutableStateOf(false) }
     var imageScanCandidates by remember { mutableStateOf<List<GalleryScanCandidate>>(emptyList()) }
     var imageScanPreviewUri by remember { mutableStateOf<Uri?>(null) }
     var hasPotentialInView by remember { mutableStateOf(false) }
@@ -173,6 +184,8 @@ fun ScannerScreen(
             showImageScanFailed = true
             return@rememberLauncherForActivityResult
         }
+        imageScanPreviewUri = uri
+        imageScanCandidates = emptyList()
 
         imageScanner.process(image)
             .addOnSuccessListener { barcodes ->
@@ -198,14 +211,7 @@ fun ScannerScreen(
                         box = normalizedBox
                     )
                 }.distinctBy { "${it.result.type}|${it.result.content}" }
-
+                imageScanCandidates = candidates
-                when (candidates.size) {
-                    0 -> showNoCodeInImage = true
-                    else -> {
-                        imageScanPreviewUri = uri
-                        imageScanCandidates = candidates
-                    }
-                }
             }
             .addOnFailureListener {
                 showImageScanFailed = true
@@ -252,6 +258,7 @@ fun ScannerScreen(
         val density = LocalDensity.current
         val viewW = with(density) { maxWidth.toPx() }
         val viewH = with(density) { maxHeight.toPx() }
+        val galleryOpen = imageScanPreviewUri != null
         val aimW = viewW * 0.62f
         val aimH = with(density) { 200.dp.toPx() }
         val aimLeft = (viewW - aimW) / 2f
@@ -259,7 +266,7 @@ fun ScannerScreen(
         val aimRight = aimLeft + aimW
         val aimBottom = aimTop + aimH
 
-        if (cameraGranted) {
+        if (cameraGranted && !galleryOpen) {
             CameraPreview(
                 modifier = Modifier.fillMaxSize(),
                 analysisEnabled = analysisEnabled,
@@ -443,7 +450,7 @@ fun ScannerScreen(
                     .align(Alignment.BottomCenter)
                     .padding(bottom = if (batchMode) 12.dp else 80.dp)
             )
-        } else {
+        } else if (!galleryOpen) {
             PermissionContent(
                 showSettingsHint = showSettingsHint,
                 onRequestPermission = { permissionLauncher.launch(Manifest.permission.CAMERA) },
@@ -455,6 +462,12 @@ fun ScannerScreen(
                     context.startActivity(intent)
                 }
             )
+        } else {
+            Box(
+                modifier = Modifier
+                    .fillMaxSize()
+                    .background(Color.Black)
+            )
         }
 
         if (lastResult != null && !batchMode) {
@@ -567,19 +580,7 @@ fun ScannerScreen(
             )
         }
 
-        if (showNoCodeInImage) {
+        if (imageScanPreviewUri != null) {
-            AlertDialog(
-                onDismissRequest = { showNoCodeInImage = false },
-                text = { Text(stringResource(R.string.no_code_found_in_image)) },
-                confirmButton = {
-                    TextButton(onClick = { showNoCodeInImage = false }) {
-                        Text(stringResource(R.string.confirm))
-                    }
-                }
-            )
-        }
-
-        if (imageScanCandidates.isNotEmpty()) {
             GalleryScanPreviewDialog(
                 imageUri = imageScanPreviewUri,
                 candidates = imageScanCandidates,
@@ -733,128 +734,6 @@ private fun buildBatchExport(results: List<BatchScanRecord>): String {
     }
 }
 
-@Composable
-private fun GalleryScanPreviewDialog(
-    imageUri: Uri?,
-    candidates: List<GalleryScanCandidate>,
-    onPick: (GalleryScanCandidate) -> Unit,
-    onDismiss: () -> Unit
-) {
-    val context = LocalContext.current
-    val bitmap = remember(imageUri) {
-        imageUri?.let { loadBitmapFromUri(context, it) }
-    }
-
-    AlertDialog(
-        onDismissRequest = onDismiss,
-        title = { Text(stringResource(R.string.image_scan_pick_title, candidates.size)) },
-        text = {
-            Column(
-                modifier = Modifier
-                    .fillMaxWidth()
-                    .verticalScroll(rememberScrollState()),
-                verticalArrangement = Arrangement.spacedBy(8.dp)
-            ) {
-                if (bitmap != null) {
-                    Box(
-                        modifier = Modifier
-                            .fillMaxWidth()
-                            .height(260.dp)
-                            .background(Color.Black.copy(alpha = 0.32f), RoundedCornerShape(12.dp)),
-                        contentAlignment = Alignment.Center
-                    ) {
-                        Image(
-                            bitmap = bitmap.asImageBitmap(),
-                            contentDescription = stringResource(R.string.scan_from_image),
-                            modifier = Modifier
-                                .fillMaxWidth()
-                                .height(260.dp),
-                            contentScale = androidx.compose.ui.layout.ContentScale.Fit
-                        )
-                        Canvas(
-                            modifier = Modifier
-                                .fillMaxWidth()
-                                .height(260.dp)
-                        ) {
-                            val bitmapW = bitmap.width.toFloat()
-                            val bitmapH = bitmap.height.toFloat()
-                            if (bitmapW <= 0f || bitmapH <= 0f) return@Canvas
-
-                            val scale = min(size.width / bitmapW, size.height / bitmapH)
-                            val drawW = bitmapW * scale
-                            val drawH = bitmapH * scale
-                            val offsetX = (size.width - drawW) / 2f
-                            val offsetY = (size.height - drawH) / 2f
-
-                            candidates.forEach { candidate ->
-                                val box = candidate.box ?: return@forEach
-                                val color = Color(0xFF4AE3A3).copy(alpha = 0.96f)
-                                val points = box.corners.map { p ->
-                                    androidx.compose.ui.geometry.Offset(
-                                        x = offsetX + (p.x * drawW),
-                                        y = offsetY + (p.y * drawH)
-                                    )
-                                }
-                                if (points.size >= 4) {
-                                    val path = Path().apply {
-                                        moveTo(points.first().x, points.first().y)
-                                        points.drop(1).forEach { pt -> lineTo(pt.x, pt.y) }
-                                        close()
-                                    }
-                                    drawPath(path = path, color = color, style = Stroke(width = 4f))
-                                } else {
-                                    val left = offsetX + (box.left * drawW)
-                                    val top = offsetY + (box.top * drawH)
-                                    val right = offsetX + (box.right * drawW)
-                                    val bottom = offsetY + (box.bottom * drawH)
-                                    if (right > left && bottom > top) {
-                                        drawRoundRect(
-                                            color = color,
-                                            topLeft = androidx.compose.ui.geometry.Offset(left, top),
-                                            size = androidx.compose.ui.geometry.Size(right - left, bottom - top),
-                                            cornerRadius = CornerRadius(10f, 10f),
-                                            style = Stroke(width = 4f)
-                                        )
-                                    }
-                                }
-                            }
-                        }
-                    }
-                }
-
-                Text(text = stringResource(R.string.image_scan_pick_subtitle))
-                candidates.forEach { candidate ->
-                    TextButton(
-                        onClick = { onPick(candidate) },
-                        modifier = Modifier.fillMaxWidth()
-                    ) {
-                        Column(modifier = Modifier.fillMaxWidth()) {
-                            Text(
-                                text = candidate.result.type,
-                                textAlign = TextAlign.Start,
-                                modifier = Modifier.fillMaxWidth()
-                            )
-                            Text(
-                                text = candidate.result.content,
-                                maxLines = 2,
-                                overflow = TextOverflow.Ellipsis,
-                                textAlign = TextAlign.Start,
-                                modifier = Modifier.fillMaxWidth()
-                            )
-                        }
-                    }
-                }
-            }
-        },
-        confirmButton = {},
-        dismissButton = {
-            TextButton(onClick = onDismiss) {
-                Text(stringResource(R.string.cancel))
-            }
-        }
-    )
-}
-
 private fun loadBitmapFromUri(context: android.content.Context, uri: Uri): Bitmap? {
     return try {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
@@ -870,6 +749,280 @@ private fun loadBitmapFromUri(context: android.content.Context, uri: Uri): Bitma
     }
 }
 
+private suspend fun detectBarcodes(
+    scanner: com.google.mlkit.vision.barcode.BarcodeScanner,
+    image: InputImage
+): List<Barcode> = suspendCancellableCoroutine { cont ->
+    scanner.process(image)
+        .addOnSuccessListener { barcodes ->
+            if (cont.isActive) cont.resume(barcodes)
+        }
+        .addOnFailureListener { error ->
+            if (cont.isActive) cont.resumeWithException(error)
+        }
+}
+
+@Composable
+private fun GalleryScanPreviewDialog(
+    imageUri: Uri?,
+    candidates: List<GalleryScanCandidate>,
+    onPick: (GalleryScanCandidate) -> Unit,
+    onDismiss: () -> Unit
+) {
+    val context = LocalContext.current
+    val bitmap = remember(imageUri) { imageUri?.let { loadBitmapFromUri(context, it) } }
+    var liveCandidates by remember(imageUri, candidates) { mutableStateOf(candidates) }
+    var zoom by remember(imageUri) { mutableStateOf(1f) }
+    var pan by remember(imageUri) { mutableStateOf(Offset.Zero) }
+    var viewportSize by remember { mutableStateOf(IntSize.Zero) }
+    var scanTick by remember { mutableStateOf(0) }
+    val markerPaint = remember {
+        Paint().apply {
+            color = android.graphics.Color.WHITE
+            textAlign = Paint.Align.CENTER
+            textSize = 34f
+            isAntiAlias = true
+            isFakeBoldText = true
+        }
+    }
+    val scanner = remember {
+        BarcodeScanning.getClient(
+            BarcodeScannerOptions.Builder()
+                .setBarcodeFormats(Barcode.FORMAT_ALL_FORMATS)
+                .enableAllPotentialBarcodes()
+                .build()
+        )
+    }
+
+    DisposableEffect(Unit) {
+        onDispose { scanner.close() }
+    }
+
+    LaunchedEffect(bitmap, viewportSize, zoom, pan, scanTick) {
+        val bmp = bitmap ?: return@LaunchedEffect
+        val vw = viewportSize.width.toFloat()
+        val vh = viewportSize.height.toFloat()
+        if (vw <= 0f || vh <= 0f) return@LaunchedEffect
+
+        delay(120)
+
+        val imgW = bmp.width.toFloat()
+        val imgH = bmp.height.toFloat()
+        if (imgW <= 1f || imgH <= 1f) return@LaunchedEffect
+
+        val baseScale = max(vw / imgW, vh / imgH)
+        val effectiveScale = (baseScale * zoom).coerceAtLeast(0.01f)
+        val cx = vw * 0.5f
+        val cy = vh * 0.5f
+
+        fun screenToImageX(screenX: Float): Float {
+            return ((screenX - cx - pan.x) / effectiveScale) + (imgW * 0.5f)
+        }
+        fun screenToImageY(screenY: Float): Float {
+            return ((screenY - cy - pan.y) / effectiveScale) + (imgH * 0.5f)
+        }
+
+        val left = screenToImageX(0f).coerceIn(0f, imgW - 1f)
+        val right = screenToImageX(vw).coerceIn(0f, imgW - 1f)
+        val top = screenToImageY(0f).coerceIn(0f, imgH - 1f)
+        val bottom = screenToImageY(vh).coerceIn(0f, imgH - 1f)
+
+        val cropLeft = minOf(left, right).toInt()
+        val cropTop = minOf(top, bottom).toInt()
+        val cropW = (kotlin.math.abs(right - left)).toInt().coerceAtLeast(8)
+        val cropH = (kotlin.math.abs(bottom - top)).toInt().coerceAtLeast(8)
+        val boundedW = cropW.coerceAtMost(bmp.width - cropLeft)
+        val boundedH = cropH.coerceAtMost(bmp.height - cropTop)
+        if (boundedW <= 4 || boundedH <= 4) return@LaunchedEffect
+
+        val cropped = Bitmap.createBitmap(bmp, cropLeft, cropTop, boundedW, boundedH)
+        val barcodes = try {
+            detectBarcodes(scanner, InputImage.fromBitmap(cropped, 0))
+        } catch (_: Exception) {
+            emptyList()
+        }
+
+        val live = barcodes.mapNotNull { barcode ->
+            val raw = barcode.rawValue?.takeIf { it.isNotBlank() } ?: return@mapNotNull null
+            val normalizedBox = barcode.boundingBox?.let { bounds ->
+                val leftN = ((bounds.left + cropLeft) / imgW).coerceIn(0f, 1f)
+                val topN = ((bounds.top + cropTop) / imgH).coerceIn(0f, 1f)
+                val rightN = ((bounds.right + cropLeft) / imgW).coerceIn(0f, 1f)
+                val bottomN = ((bounds.bottom + cropTop) / imgH).coerceIn(0f, 1f)
+                val corners = barcode.cornerPoints?.map { p ->
+                    com.clean.scanner.data.scanner.DetectionPoint(
+                        x = ((p.x + cropLeft) / imgW).coerceIn(0f, 1f),
+                        y = ((p.y + cropTop) / imgH).coerceIn(0f, 1f)
+                    )
+                } ?: emptyList()
+                DetectionBox(leftN, topN, rightN, bottomN, corners)
+            }
+            GalleryScanCandidate(
+                result = ScanResult(content = raw, type = barcode.valueType.toHumanType()),
+                box = normalizedBox
+            )
+        }.distinctBy { "${it.result.type}|${it.result.content}" }
+
+        liveCandidates = live
+    }
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text(stringResource(R.string.image_scan_pick_title, liveCandidates.size)) },
+        text = {
+            Column(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .verticalScroll(rememberScrollState()),
+                verticalArrangement = Arrangement.spacedBy(8.dp)
+            ) {
+                if (bitmap != null) {
+                    Box(
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .height(260.dp)
+                            .onSizeChanged {
+                                viewportSize = it
+                                scanTick++
+                            }
+                            .pointerInput(bitmap) {
+                                detectTransformGestures { _, panChange, zoomChange, _ ->
+                                    zoom = (zoom * zoomChange).coerceIn(1f, 6f)
+                                    pan += panChange
+                                    scanTick++
+                                }
+                            }
+                            .background(Color.Black.copy(alpha = 0.32f), RoundedCornerShape(12.dp)),
+                        contentAlignment = Alignment.Center
+                    ) {
+                        Image(
+                            bitmap = bitmap.asImageBitmap(),
+                            contentDescription = stringResource(R.string.scan_from_image),
+                            modifier = Modifier
+                                .fillMaxWidth()
+                                .height(260.dp)
+                                .graphicsLayer {
+                                    scaleX = zoom
+                                    scaleY = zoom
+                                    translationX = pan.x
+                                    translationY = pan.y
+                                },
+                            contentScale = ContentScale.Crop
+                        )
+                        Canvas(
+                            modifier = Modifier
+                                .fillMaxWidth()
+                                .height(260.dp)
+                        ) {
+                            val imageW = bitmap.width.toFloat()
+                            val imageH = bitmap.height.toFloat()
+                            if (imageW <= 0f || imageH <= 0f) return@Canvas
+
+                            val baseScale = max(size.width / imageW, size.height / imageH)
+                            val effectiveScale = baseScale * zoom
+                            val cx = size.width * 0.5f
+                            val cy = size.height * 0.5f
+
+                            fun imageToScreen(ix: Float, iy: Float): Offset {
+                                val sx = cx + ((ix - imageW * 0.5f) * effectiveScale) + pan.x
+                                val sy = cy + ((iy - imageH * 0.5f) * effectiveScale) + pan.y
+                                return Offset(sx, sy)
+                            }
+
+                            liveCandidates.forEachIndexed { index, candidate ->
+                                val box = candidate.box ?: return@forEachIndexed
+                                val color = Color(0xFF4AE3A3).copy(alpha = 0.96f)
+                                val points = box.corners.map { p ->
+                                    imageToScreen(p.x * imageW, p.y * imageH)
+                                }
+                                if (points.size >= 4) {
+                                    val path = Path().apply {
+                                        moveTo(points.first().x, points.first().y)
+                                        points.drop(1).forEach { pt -> lineTo(pt.x, pt.y) }
+                                        close()
+                                    }
+                                    drawPath(path = path, color = color, style = Stroke(width = 4f))
+                                } else {
+                                    val lt = imageToScreen(box.left * imageW, box.top * imageH)
+                                    val rb = imageToScreen(box.right * imageW, box.bottom * imageH)
+                                    val left = minOf(lt.x, rb.x)
+                                    val top = minOf(lt.y, rb.y)
+                                    val right = maxOf(lt.x, rb.x)
+                                    val bottom = maxOf(lt.y, rb.y)
+                                    if (right > left && bottom > top) {
+                                        drawRoundRect(
+                                            color = color,
+                                            topLeft = androidx.compose.ui.geometry.Offset(left, top),
+                                            size = androidx.compose.ui.geometry.Size(right - left, bottom - top),
+                                            cornerRadius = CornerRadius(10f, 10f),
+                                            style = Stroke(width = 4f)
+                                        )
+                                    }
+                                }
+
+                                val center = if (points.isNotEmpty()) {
+                                    val sx = points.sumOf { it.x.toDouble() }.toFloat() / points.size
+                                    val sy = points.sumOf { it.y.toDouble() }.toFloat() / points.size
+                                    Offset(sx, sy)
+                                } else {
+                                    imageToScreen(
+                                        (box.left + box.right) * 0.5f * imageW,
+                                        (box.top + box.bottom) * 0.5f * imageH
+                                    )
+                                }
+                                drawCircle(
+                                    color = Color.Black.copy(alpha = 0.65f),
+                                    radius = 16f,
+                                    center = center
+                                )
+                                drawContext.canvas.nativeCanvas.drawText(
+                                    "${index + 1}",
+                                    center.x,
+                                    center.y + 11f,
+                                    markerPaint
+                                )
+                            }
+                        }
+                    }
+                }
+
+                if (liveCandidates.isEmpty()) {
+                    Text(text = stringResource(R.string.no_code_found_in_image))
+                } else {
+                    Text(text = stringResource(R.string.image_scan_pick_subtitle))
+                    liveCandidates.forEachIndexed { index, candidate ->
+                        TextButton(
+                            onClick = { onPick(candidate) },
+                            modifier = Modifier.fillMaxWidth()
+                        ) {
+                            Column(modifier = Modifier.fillMaxWidth()) {
+                                Text(
+                                    text = "${index + 1}. ${candidate.result.type}",
+                                    textAlign = TextAlign.Start,
+                                    modifier = Modifier.fillMaxWidth()
+                                )
+                                Text(
+                                    text = candidate.result.content,
+                                    maxLines = 2,
+                                    overflow = TextOverflow.Ellipsis,
+                                    textAlign = TextAlign.Start,
+                                    modifier = Modifier.fillMaxWidth()
+                                )
+                            }
+                        }
+                    }
+                }
+            }
+        },
+        confirmButton = {},
+        dismissButton = {
+            TextButton(onClick = onDismiss) {
+                Text(stringResource(R.string.cancel))
+            }
+        }
+    )
+}
+
 @Composable
 private fun PermissionContent(
     showSettingsHint: Boolean,

app/src/test/java/com/clean/scanner/ui/ScannerViewModelTest.kt

@@ -50,7 +50,7 @@ class ScannerViewModelTest {
         viewModel.onScan(result)
         viewModel.resumeScanning()
 
-        now = 2_000L
+        now = 4_000L
         viewModel.onScan(result)
         advanceUntilIdle()
 
@@ -75,7 +75,7 @@ class ScannerViewModelTest {
         now = 2_000L
         viewModel.onScan(ScanResult(content = "B", type = "Text"))
 
-        now = 3_000L
+        now = 3_600L
         viewModel.onScan(ScanResult(content = "A", type = "Text"))
         advanceUntilIdle()
 
@@ -92,4 +92,27 @@ class ScannerViewModelTest {
         assertTrue(viewModel.uiState.value.batchResults.isEmpty())
         assertEquals(3, saved.size)
     }
+
+    @Test
+    fun sameCodeWithinHoldoff_isIgnored() = runTest {
+        val saved = mutableListOf<Pair<String, String>>()
+        var now = 1_000L
+        val viewModel = ScannerViewModel(
+            saveScan = { content, type -> saved += content to type },
+            nowProvider = { now }
+        )
+
+        val result = ScanResult(content = "HOLD", type = "Text")
+        viewModel.setBatchMode(true)
+        viewModel.onScan(result)
+
+        now = 2_000L
+        viewModel.onScan(result)
+        advanceUntilIdle()
+
+        val state = viewModel.uiState.value
+        assertEquals(1, state.scanFeedbackNonce)
+        assertEquals(1, saved.size)
+        assertEquals(1, state.batchResults.size)
+    }
 }