Remove BarcodeScanner duplicate scan suppression (#903)

Co-authored-by: Vetle Finstad <finstad@Vetles-MacBook-Pro-2.local>

Author: Vetle444

CHANGELOG.md

@@ -1,3 +1,6 @@
+## [61.0.0]
+- [BarcodeScanner] **BREAKING**: Removed `BarcodeScannerStartOptions.DuplicateScanCooldown`. Repeated scans of the same barcode are no longer suppressed after the scanner resumes.
+
 ## [60.5.0] 
 - Resources was updated from DIPS.Mobile.DesignTokens
 

src/library/DIPS.Mobile.UI/API/Camera/BarcodeScanning/BarcodeScanner.cs

@@ -7,8 +7,6 @@ namespace DIPS.Mobile.UI.API.Camera.BarcodeScanning;
 
 public partial class BarcodeScanner : ICameraUseCase
 {
-    private const int CooldownTimeout = 500;
-
     // Session lifecycle
     private BarcodeScannerStartOptions m_currentStartOptions = new();
     private BarcodeScanSession? m_scanSession;
@@ -18,11 +16,8 @@ public partial class BarcodeScanner : ICameraUseCase
     private bool m_isDisposed;
     private bool m_isPlatformStarted;
 
-    // Detection pipeline & cooldown
+    // Detection pipeline
     private readonly BarcodeDetectionAggregator m_detectionAggregator = new();
-    private readonly HashSet<string> m_confirmedBarcodeValues = new(StringComparer.Ordinal);
-    private bool m_isCoolingDown;
-    private Timer? m_cooldownTimer;
     private CancellationTokenSource? m_automaticHintCts;
     private bool m_hasCompletedAutomaticHint;
 
@@ -70,9 +65,7 @@ public async Task Start(BarcodeScannerStartOptions startOptions)
         m_confirmationHandler?.Dispose();
         m_confirmationHandler = null;
         ResetScanState();
-        DisposeCooldownTimer();
         m_hasCompletedAutomaticHint = false;
-        m_confirmedBarcodeValues.Clear();
 
         m_scanSession?.Dispose();
         m_scanSession = new BarcodeScanSession(m_currentStartOptions, StopPlatformIfNeededAsync);
@@ -182,9 +175,7 @@ public void PauseScanning(bool resetOverlay = true)
             EndCurrentScanRun();
             m_scanSession?.PauseScanning();
             ResetBarcodeConfirmationState(resetOverlay);
-            DisposeCooldownTimer();
             StopAutomaticHint();
-            m_confirmedBarcodeValues.Clear();
         }
         catch (Exception e)
         {
@@ -205,8 +196,6 @@ public void ResumeScanning()
             BeginNewScanRun();
             ResetScanState();
             m_confirmationHandler?.Reset();
-            DisposeCooldownTimer();
-            m_confirmedBarcodeValues.Clear();
             m_scanSession?.ResumeScanning();
             RestartAutomaticHintTimer();
         }
@@ -237,7 +226,6 @@ private void StopScanningCore(bool resetOverlay)
         EndCurrentScanRun();
         StopPlatformIfNeeded();
         ResetBarcodeConfirmationState(resetOverlay);
-        DisposeCooldownTimer();
         StopAutomaticHint();
         m_confirmationHandler?.Dispose();
         m_confirmationHandler = null;
@@ -267,15 +255,6 @@ internal void InvokeBarcodeFound(Barcode barcode, RectF? overlayBounds = null, i
 
         StopAutomaticHint();
 
-        if (m_confirmedBarcodeValues.Contains(barcodeKey))
-        {
-            m_confirmationHandler?.OnConfirmedBarcodeRedetected();
-            return;
-        }
-
-        if (m_isCoolingDown)
-            return;
-
         m_detectionAggregator.AddObservation(barcode);
 
         m_confirmationHandler?.OnBarcodeDetected(overlayBounds);
@@ -319,11 +298,6 @@ private void ReportMostDetectedBarcode(int scanRunId)
         }
 
         Log($"The most detected bar code: {mostDetectedBarcodeObservation.Barcode}");
-        foreach (var obs in orderedObservations)
-        {
-            m_confirmedBarcodeValues.Add(BarcodeDetectionAggregator.GetBarcodeKey(obs.Barcode));
-        }
-
         ResetBarcodeConfirmationState(resetOverlay: false);
 
         var barcodeScanResult = new BarcodeScanResult(mostDetectedBarcodeObservation.Barcode,
@@ -375,42 +349,11 @@ private void OnBarcodeLostByHandler()
         if (!IsSessionActive)
             return;
 
-        m_confirmedBarcodeValues.Clear();
         ResetScanState();
         m_scanRectangleOverlay?.ResetBarcodeDetection();
         RestartAutomaticHintTimer();
     }
 
-    private void StartCooldown()
-    {
-        m_isCoolingDown = true;
-        m_cooldownTimer?.Dispose();
-        var scanRunId = CurrentScanRunId;
-        m_cooldownTimer = new Timer(_ => MainThread.BeginInvokeOnMainThread(() => FinishCooldown(scanRunId)),
-            null, (int)Math.Max(m_currentStartOptions.DuplicateScanCooldown.TotalMilliseconds, CooldownTimeout), Timeout.Infinite);
-    }
-
-    private void FinishCooldown(int scanRunId)
-    {
-        if (scanRunId != CurrentScanRunId)
-            return;
-
-        m_isCoolingDown = false;
-        if (m_scanRectangleOverlay is null)
-        {
-            m_confirmedBarcodeValues.Clear();
-        }
-        m_cooldownTimer?.Dispose();
-        m_cooldownTimer = null;
-    }
-
-    private void DisposeCooldownTimer()
-    {
-        m_cooldownTimer?.Dispose();
-        m_cooldownTimer = null;
-        m_isCoolingDown = false;
-    }
-
     private void RestartAutomaticHintTimer()
     {
         StopAutomaticHint();
@@ -553,7 +496,6 @@ private void ResumeScanningAfterAnimation()
         if (!CanResumeSession)
             return;
 
-        StartCooldown();
         m_scanSession?.ResumeScanning();
         RestartAutomaticHintTimer();
     }

src/library/DIPS.Mobile.UI/API/Camera/BarcodeScanning/BarcodeScannerStartOptions.cs

@@ -50,9 +50,4 @@ public class BarcodeScannerStartOptions
     /// Gets or sets automatic hint options for scan rectangle barcode scanner sessions.
     /// </summary>
     public BarcodeScannerHintOptions Hint { get; set; } = new();
-
-    /// <summary>
-    /// Gets or sets the cooldown applied after a scan has been accepted or rejected.
-    /// </summary>
-    public TimeSpan DuplicateScanCooldown { get; set; } = TimeSpan.FromMilliseconds(800);
 }

src/library/DIPS.Mobile.UI/API/Camera/BarcodeScanning/IBarcodeConfirmationHandler.cs

@@ -8,16 +8,10 @@ namespace DIPS.Mobile.UI.API.Camera.BarcodeScanning;
 internal interface IBarcodeConfirmationHandler : IDisposable
 {
     /// <summary>
-    /// Called when a new (unconfirmed, non-cooldown) barcode observation has been recorded.
+    /// Called when a barcode observation has been recorded.
     /// </summary>
     void OnBarcodeDetected(RectF? overlayBounds);
 
-    /// <summary>
-    /// Called when an already-confirmed barcode is detected again.
-    /// Keeps the overlay barcode-lost timer alive in overlay mode; no-op in timer mode.
-    /// </summary>
-    void OnConfirmedBarcodeRedetected();
-
     /// <summary>
     /// Resets transient tracking state (e.g. bracket animation flags) without disposing timers.
     /// </summary>

src/library/DIPS.Mobile.UI/API/Camera/BarcodeScanning/OverlayBarcodeConfirmationHandler.cs

@@ -77,11 +77,6 @@ public void OnBarcodeDetected(RectF? overlayBounds)
         }
     }
 
-    public void OnConfirmedBarcodeRedetected()
-    {
-        ResetBarcodeLostTimer();
-    }
-
     public void ResetTrackingState()
     {
         m_isTrackingBarcode = false;

src/library/DIPS.Mobile.UI/API/Camera/BarcodeScanning/TimerBarcodeConfirmationHandler.cs

@@ -36,11 +36,6 @@ public void OnBarcodeDetected(RectF? overlayBounds)
             null, m_detectionTime, Timeout.InfiniteTimeSpan);
     }
 
-    public void OnConfirmedBarcodeRedetected()
-    {
-        // No barcode-lost tracking in timer mode.
-    }
-
     public void ResetTrackingState()
     {
         // No transient tracking state in timer mode.

wiki/Media/Camera.md

@@ -71,7 +71,7 @@ protected override void OnAppearing()
 > Notice that `CameraPreview` is the code behind reference from the preview guide.
 
 ## Validate barcodes before accepting them
-Use `ValidateBarcodeAsync` when the scanner should ask your app whether a detected barcode belongs in the current workflow before playing the success animation. If validation returns invalid, the scanner plays the failure animation, does not increment the progress counter, and resumes scanning after a short cooldown.
+Use `ValidateBarcodeAsync` when the scanner should ask your app whether a detected barcode belongs in the current workflow before playing the success animation. If validation returns invalid, the scanner plays the failure animation, does not increment the progress counter, and then resumes scanning. Repeated scans of the same barcode are processed like any other scan; reject already-scanned values in `ValidateBarcodeAsync` when your workflow needs that behavior.
 
 ```csharp
 private readonly BarcodeScanner m_scanner = new();