Class: LetraTagPrinter

PrinterAdapter for the LT-200B over Web Bluetooth.

Constructed indirectly via requestPrinter() / requestPrinters(); the constructor is exported so the harness can inject a MockTransport with a real device entry, mirroring the labelmanager-web / labelwriter-web shape.

Status has a single real source: the printer emits a 3-byte [1B 52 code] reply after each print job, parsed via parseStatus. The driver stores this as the last-known status and fans it out to onStatus subscribers. The LT-200B exposes no battery, cassette, or live-status telemetry over BLE — there is no out-of-job status channel.

Implements

• PrinterAdapter

Constructors

Constructor

new LetraTagPrinter(device: LetraTagDevice, transport: Transport): LetraTagPrinter;

Parameters

Parameter	Type
device	LetraTagDevice
transport	Transport

Returns

LetraTagPrinter

Properties

device

readonly device: LetraTagDevice;

The device entry for the connected printer.

Useful for logging, diagnostics, and displaying VID/PID. Undefined if the connection was established without device matching (e.g. a raw TCP connection to a known IP).

Implementation of

PrinterAdapter.device

---

family

readonly family: "letratag" = 'letratag';

Driver family identifier, e.g. 'brother-ql' or 'labelwriter'.

Implementation of

PrinterAdapter.family

Accessors

connected

Get Signature

get connected(): boolean;

Whether the printer is currently connected.

Returns

boolean

Implementation of

PrinterAdapter.connected

---

model

Get Signature

get model(): string;

Human-readable model name from the driver's device registry.

Returns

string

Implementation of

PrinterAdapter.model

Methods

close()

close(): Promise<void>;

Close the connection. Always call in finally blocks.

Returns

Promise<void>

Implementation of

PrinterAdapter.close

---

createPreview()

createPreview(image: RawImageData, options?: PreviewOptions): Promise<PreviewResult>;

Generate a preview showing how this printer would reproduce the design on the given media. Returns separated 1bpp planes with display colours.

The driver uses its own colour-splitting logic (the same code that print() uses internally) to produce the planes. The consuming app renders whatever planes come back without needing to know the splitting rules.

For offline preview without a live connection, use the static createPreviewOffline() function exported from the driver's *-core package instead.

Parameters

Parameter	Type	Description
image	RawImageData	— full RGBA, typically from designer.render().
options?	PreviewOptions	— optional media override. If media is omitted, uses detected media from the last getStatus(). If no status is available, the driver defaults to single-colour at the printer's native head width and sets PreviewResult.assumed = true.

Returns

Promise<PreviewResult>

Implementation of

PrinterAdapter.createPreview

---

getStatus()

getStatus(): Promise<PrinterStatus>;

Return the printer's last-known status — the most recent post-print notification, or a default empty status before the first print. The LT-200B has no out-of-job status channel.

Returns

Promise<PrinterStatus>

Implementation of

PrinterAdapter.getStatus

---

onStatus()

onStatus(cb: (status: PrinterStatus) => void): () => void;

Subscribe to status updates. The single real push source is the post-print notification — the 3-byte [1B 52 code] reply on the RX characteristic at the end of each print job, parsed via parseStatus.

The current cached status is replayed immediately on subscribe so the harness shell's status pill resolves quickly without waiting for the next event. Returns an unsubscribe function.

Per plan 11 §onStatus parity + §Letratag specifics — letratag has real push so this is not a polling shim.

Parameters

Parameter	Type
cb	(status: PrinterStatus) => void

Returns

() => void

Implementation of

PrinterAdapter.onStatus

---

print()

print(
   image: RawImageData, 
   media?: MediaDescriptor, 
options?: LetraTagPrintOptions): Promise<void>;

Print from a full-colour RGBA image.

The driver converts to its native format internally:

• Single-colour media (media.palette undefined) — threshold/dither RGBA to a single 1bpp plane via renderImage.
• Multi-ink media (media.palette defined) — split into planes via renderMultiPlaneImage using that palette.

Orientation: drivers compute the rotation via pickRotation (see ./orientation.ts) — the input image is treated as the intended visual; the driver auto-rotates landscape input on media tagged defaultOrientation: 'horizontal'.

Multi-ink splitting: the palette on the media descriptor names every ink the driver should classify pixels into; the contracts package does not pick "red" or "black" — those facts live with the media entry.

Batch printing: call print() once per label. The driver handles job framing internally (e.g. Brother QL page-break commands between sequential print() calls within the same session).

Parameters

Parameter	Type	Description
image	RawImageData	— full RGBA, typically from designer.render().
media?	MediaDescriptor	— which media to print on. Determines dimensions, margins, and colour mode. If omitted, uses detected media from the last getStatus().
options?	LetraTagPrintOptions	— per-call options (copies, density, etc.).

Returns

Promise<void>

Throws

MediaNotSpecifiedError if no media is known.

Implementation of

PrinterAdapter.print