Barcode Selection Kmp

Barcode Selection KMP Skill

Critical: Do Not Trust Internal Knowledge

Scandit's Kotlin Multiplatform (KMP) SDK is new, shipping in 8.6. Your training data almost certainly predates it and contains zero reliable knowledge of its API — do not pattern-match it against the Android or iOS native SDKs you may know, and do not pattern-match it against the barcode-capture-kmp skill either: BarcodeSelection diverges from BarcodeCapture in several specific ways even within the same KMP SDK. The API packages are com.kmp.datacapture.* (NOT com.scandit.datacapture.*).

Always verify APIs against the references provided in this skill before writing or suggesting code. Do not rely on memorized method signatures, parameters, or property names from any other Scandit platform or mode. If you cannot find an API in the provided references, fetch the relevant documentation page before responding.

KMP-specific gotchas worth flagging:

• Import root is com.kmp.datacapture.barcode.selection.* for the mode/settings/session/listener/overlay, com.kmp.datacapture.barcode.data.* for Symbology/Barcode/CapturePreset. Never write com.scandit.datacapture.* in KMP code.
• BarcodeSelectionSettings has no public constructor — use the factory BarcodeSelectionSettings.barcodeSelectionSettings(), or BarcodeSelectionSettings.barcodeSelectionSettings(capturePresets: Set<CapturePreset>) to pre-tune for a vertical (CapturePreset.RETAIL, .LOGISTICS, .TRANSPORT, .HEALTHCARE, .MANUFACTURING). Writing BarcodeSelectionSettings() is a compile error.
• The mode factory is BarcodeSelection.forContext(dataCaptureContext, settings) — not forDataCaptureContext (Android-native) and not a raw constructor.
• settings.selectionType takes a BarcodeSelectionType built from a factory, not a constructor: BarcodeSelectionTapSelection.tapSelection() or BarcodeSelectionAimerSelection.aimerSelection(). Defaults to tap selection.
• Switching between Tap-to-Select and Aim-to-Select at runtime does not require recreating BarcodeSelection: mutate settings.selectionType and call barcodeSelection.applySettings(settings) (synchronous on KMP — there is no async/Task-returning overload here, unlike some other platforms).
• Aimer selection has its own selectionStrategy (BarcodeSelectionAutoSelectionStrategy() — auto-selects once the algorithm understands intent — or BarcodeSelectionManualSelectionStrategy() — requires aiming + a tap/selectAimedBarcode() call — defaults to manual) and its own aimerBehavior (BarcodeSelectionAimerBehavior.TOGGLE_SELECTION / .REPEAT_SELECTION, defaults to REPEAT_SELECTION). Tap selection instead has freezeBehavior (BarcodeSelectionFreezeBehavior.MANUAL / .MANUAL_AND_AUTOMATIC) and tapBehavior (BarcodeSelectionTapBehavior.TOGGLE_SELECTION / .REPEAT_SELECTION).
• The listener interface is BarcodeSelectionListener with onSelectionUpdated(barcodeSelection, session, frameData) and onSessionUpdated(barcodeSelection, session, frameData) as the two methods you must implement (onObservationStarted/onObservationStopped have empty default bodies and are optional). Note the parameter is frameData: FrameData? — nullable (it is null when the camera is frozen and the selection changes) — unlike BarcodeCaptureListener's non-null data: FrameData.
• Read newly selected/unselected barcodes from session.newlySelectedBarcodes / session.newlyUnselectedBarcodes (both List<Barcode>, not a single nullable barcode like BarcodeCapture's newlyRecognizedBarcode). Use session.getCount(barcode) to read how many times a barcode has been selected (relevant with BarcodeSelectionTapBehavior.REPEAT_SELECTION / BarcodeSelectionAimerBehavior.REPEAT_SELECTION, where re-selecting bumps a counter instead of toggling off).
• BarcodeSelection.createRecommendedCameraSettings() is a companion function on BarcodeSelection itself (same shape as BarcodeCapture).
• barcodeSelection.freezeCamera() / barcodeSelection.unfreezeCamera() freeze/resume the live preview so users can carefully tap multiple codes without them moving; barcodeSelection.selectUnselectedBarcodes() selects everything currently tracked; barcodeSelection.selectAimedBarcode() is for manual aimer selection only; barcodeSelection.reset() clears the selection history (counts) without touching enabled/camera state.
• BarcodeSelectionBasicOverlay has two factories: withBarcodeSelectionForView(barcodeSelection, view) — binds to a specific DataCaptureView, adds itself automatically — and withBarcodeSelection(barcodeSelection) (no view binding, used by the Compose composable's declarative overlays list).
• The overlay exposes four brush properties, not one: trackedBrush (barcode recognized but not yet selected/aimed), aimedBrush (currently aimed at, aimer mode only), selectingBrush (transient, during the moment of selection), and selectedBrush (currently selected). Get style defaults via BarcodeSelectionBasicOverlay.defaultTrackedBrushForStyle(style) / defaultAimedBrushForStyle(style) / defaultSelectedBrushForStyle(style) / defaultSelectingBrushForStyle(style), where style is BarcodeSelectionBasicOverlayStyle.FRAME (default) or .DOT.
• The overlay's viewfinder property is read-only (val, not var) — unlike BarcodeCaptureOverlay.viewfinder, you cannot assign a different Viewfinder instance. It is only visible when selectionType is BarcodeSelectionAimerSelection. Style it through the overlay's own hint/brush setters instead of swapping the viewfinder.
• barcodeSelection.setFeedback(soundEnabled: Boolean, vibrationEnabled: Boolean) is a KMP convenience method for the common case; for finer control assign a BarcodeSelectionFeedback instance to barcodeSelection.feedback (its selection: Feedback property holds the actual sound/vibration).
• Building the camera preview view (DataCaptureView) is platform-divergent by construction signature, same as every other KMP mode: Android's constructor takes (context: android.content.Context, dataCaptureContext: DataCaptureContext?); iOS's takes only (dataCaptureContext: DataCaptureContext?). Shared commonMain code cannot construct a DataCaptureView directly — each platform host constructs it and hands it to a shared setup function.
• To embed the native view: Android uses view.toAndroidView(): View inside a Compose AndroidView factory; iOS uses view.toUIView(): UIView inside a UIViewRepresentable. These are the only supported bridges — never call toNative() from application code (it is public only because Kotlin's internal cannot span the multi-module KMP SDK).
• Teardown order matters and there is no onDestroy: barcodeSelection.isEnabled = false → barcodeSelection.removeListener(this) → dataCaptureContext.removeMode(barcodeSelection) → camera?.switchToDesiredState(FrameSourceState.OFF). Skipping removeMode leaves the mode attached to the shared context across screen visits.
• BarcodeSelection requires the MatrixScan add-on entitlement on the license (per the platform-agnostic API doc). If a user's license lacks it, BarcodeSelection will not function — this is a licensing question, not a code bug.
• The license key placeholder is exactly -- ENTER YOUR SCANDIT LICENSE KEY HERE -- (matches the canonical sample). Use this exact string, not a different placeholder.
• On Compose Multiplatform, BarcodeSelection has no dedicated -compose composable. Use the base core-compose DataCaptureView composable with overlays = listOf(overlay) — do not look for a BarcodeSelectionView composable, it does not exist.
• Compose overlay instances must be remember-ed. The core-compose DataCaptureView composable diffs overlays by content/reference equality every recomposition; a fresh BarcodeSelectionBasicOverlay built inline on every recomposition causes constant remove/re-add churn (visible flicker).
• Request the CAMERA permission at runtime on Android before starting the camera (the manifest declaration alone is not sufficient). On iOS, NSCameraUsageDescription in Info.plist triggers the OS permission prompt automatically on first camera use.

Intent Routing

Based on the user's request, load the appropriate reference file before responding:

• Integrating BarcodeSelection from scratch, choosing tap vs aimer selection, configuring selection strategies, handling selections and per-barcode counts, freezing/unfreezing the camera, customizing overlay brushes, wiring the Compose Multiplatform view, or troubleshooting selection behavior (e.g. "add BarcodeSelection to my KMP app", "let users tap to select barcodes", "switch to aim-to-select", "how many times was this barcode selected", "freeze the camera while selecting", "use BarcodeSelection with Compose Multiplatform") → read references/integration.md and follow the instructions there.

API Usage Policy

Only use APIs that are explicitly documented in the Scandit references below. Do not invent or guess method signatures, parameters, or property names — and never carry over a signature from BarcodeCapture, or from the Android-native/iOS-native SDKs, without verifying it also holds for KMP BarcodeSelection. If unsure whether an API exists or how it is called — or if a compile error occurs — fetch the relevant reference page before responding. Do not tell the user to check the docs themselves. After answering, always include the relevant link so the user can explore further.

Never construct or guess documentation URLs. When you need a specific class or property's API page:

1. First check whether the page you already fetched contains a direct hyperlink to it — topic pages link directly to relevant API symbols. Always request links alongside content in your fetch prompt.
2. If no direct link was found, fetch the API index (see Full API reference in the table below), extract the actual link from it, and follow that.

URL structures can vary and guessing will lead to 404s.

References

Direct users to the right resource based on their question: