unified_esc_pos_printer 3.4.0

Unified ESC/POS thermal printer package for Flutter. Supports USB, Bluetooth Classic, BLE, and Network connections with a single PrinterManager API

3.4.0

• Fix PrintColumn(style: PrintTextStyle(bold: true)) being ignored inside ticket.row() (#23). Style was already emitted, but many clone printers ignore mid-line ESC E after absolute positioning (ESC $). Bold columns now reinforce emphasis with a CR overstrike; mode flags in setStyles are emitted after font/size.
• Fix garbled characters on large BLE jobs (e.g. full demos with multilingual textRaster). BleConnector paces writes on the Dart side (default 128-byte chunks at ~6 KB/s) and sends ESC @ on connect. Tune via BleConnector(chunkSize:, bytesPerSecond:, interChunkDelay:).
• Fix truncated prints when disconnect() is called right after printTicket() (#17). On Bluetooth Classic, BLE write-without-response, and USB serial, a completed write only means the data reached an OS/stack buffer; closing the link immediately discarded whatever was still queued. disconnect() now waits for that buffer to drain before tearing the connection down, so no caller-side delay is needed anymore.
• Add PrinterManager.waitWriteComplete() (also available on every connector) for an explicit write barrier without disconnecting. The drain time is estimated from the amount of data written and a conservative link throughput; when a write was flow-controlled, the real throughput is measured from the write duration instead. Tunable per connector via BluetoothConnector(drainBytesPerSecond:, maxDrainWait:) and BleConnector(writeWithoutResponseDrainDelay:).
• Add Swift Package Manager (SPM) support for iOS. The plugin now ships with a Package.swift manifest alongside the existing CocoaPods podspec. SPM is used automatically on Flutter 3.44+ (or opt in earlier via flutter config --enable-swift-package-manager); CocoaPods continues to work unchanged. No source code changes, the same Swift files are shared between both systems.
• Fix a native crash (abort() has been called) during BLE scanning on Windows. The advertisement handler blocked on a WinRT async call to resolve device names, which aborts the process when the event is delivered on an STA thread; it also read the advertisement payload without a null check and watcher.Start() could throw uncaught. Name resolution now runs on a worker thread (devices appear immediately with the address as a placeholder and the name upgrades once resolved), the handler no longer lets exceptions escape, and scan start failures surface as a PrinterScanException instead of crashing.
• Compile on web. Browsers expose no raw TCP, SPP, or USB access, so no connection type is functional there, but multi-platform apps that target web alongside mobile/desktop can now share code: scanPrinters() finds no devices and connect() throws PrinterConnectionException on web.
• Widen dependency constraints: network_info_plus now allows 8.x (>=7.0.0 <9.0.0) and libserialport_plus allows 1.x (>=0.1.1 <2.0.0, resolved per the consumer's SDK; 1.x needs Dart 3.10+).
• Migrate the Android build to Flutter's built-in Kotlin support (AGP 9+ / Flutter 3.44+), keeping compatibility with older versions via a conditional Kotlin plugin apply.
• Fix concurrent print jobs interrupting each other (#21). PrinterManager now serializes its operations, so a connect() issued while another job is printing waits for that job instead of disconnecting mid-print, and connect() to the already-connected device is a no-op. Print jobs are handed to the platform as a single atomic write; the native side still chunks and paces the transfer (BLE via chunkSize / bytesPerSecond; Bluetooth Classic in chunkSize blocks with a small interChunkDelay so slow printer modules are not overflowed by large jobs). On Android, the Bluetooth Classic, BLE, and USB printer-class connections are now shared process-wide with lease counting and serialized native operations, so background isolates (e.g. notification handlers) reuse the live connection and queue behind an in-progress job instead of tearing it down; connecting to a different printer while another isolate holds the connection fails with PRINTER_BUSY.

3.3.3

• Fix iOS (and other platforms without USB support) throwing PrinterConnectionException: USB printing is not supported on this platform during a combined printer scan (#14). The stub USB connector threw synchronously from scan(), so any scanPrinters() / scanAll() that included USB (which the default set does) failed on iOS even when the caller only wanted network, BLE, or Bluetooth printers. USB scan() on unsupported platforms now yields no devices instead of throwing. connect() and writeBytes() still throw there, since explicitly using a USB printer on such a platform is a genuine error.

3.3.2

• Allow Bluetooth scan/connect from a background isolate (e.g. a Firebase Messaging background handler or WorkManager) when the required permissions were already granted in a prior foreground session (#12). The native permission handler previously returned false whenever no Activity was attached, which is always the case in a background isolate, so every scan()/connect() threw a permission error even though the OS permissions were granted. It now checks already-granted permissions against the application context (which needs no Activity) and only requires an Activity to prompt for missing ones. Background isolates still cannot show a permission prompt, and Bluetooth discovery remains unreliable there, so connect to a known device by address rather than scanning.

3.3.1

• Fix Ticket.row() / Generator.row() printing each column on its own line on many generic ESC/POS printers (#10). Each column was preceded by its own ESC a (select justification) command. Per the ESC/POS specification ESC a is only honoured at the beginning of a line, and many clone printers respond to a mid-line ESC a by flushing the buffered line and feeding — pushing every column onto a separate line. Column alignment is already achieved by the absolute print position (ESC $), so ESC a is now emitted only once per row (left justification, at the start of the line) and never per column. Output is unchanged on printers that previously rendered rows correctly.

3.3.0

• Add native Android support for USB Printer Class (interface class 0x07) devices (#5, #8). Most generic ESC/POS thermal printers expose this class instead of a CDC / serial chip and previously failed with Not an Serial device from the usb_serial package. The connector now probes each device's USB interface classes and routes Printer Class devices through a new native UsbManager + bulkTransfer path while keeping the existing usb_serial path for CDC / Virtual COM devices (FTDI, CP210x, PL2303, CH34x, USB CDC ACM). The user sees a one-time Android USB permission dialog on first connect to a Printer Class device.

3.2.1

• Remove hardcoded permissions from the package's Android manifest. The library no longer declares BLUETOOTH, BLUETOOTH_ADMIN, BLUETOOTH_SCAN, BLUETOOTH_CONNECT, ACCESS_FINE_LOCATION, or ACCESS_COARSE_LOCATION — these previously included maxSdkVersion="30" on the location entries, which the Android manifest merger propagated into consuming apps and broke apps that need location permissions on API 31+ for other features (maps, geolocation, etc.). Consumers must now declare the permissions they need in their own AndroidManifest.xml; see the updated "Android Setup" section in the README for the recommended permission set.

3.2.0

• Migrate USB serial dependency from flutter_libserialport to libserialport_plus to fix Android 16KB page size compatibility (#3)

3.1.0

• Add PrintRasterColumn class for Flutter TextStyle-based column definitions
• Add Ticket.rowRaster() method for raster-rendered table rows with full Flutter text styling, multilingual support, and RTL text direction
• Update example app with Raster Row & Columns demo

3.0.1

• Fix iOS BLE scan stream handler by using explicit BleScanStreamHandler when setting the stream handler for the BLE scan event channel (#1)

3.0.0

• BREAKING: Rename TextStyles to PrintTextStyle
• BREAKING: Rename styles parameter to style in ticket/generator APIs and PrintColumn
• BREAKING: Rename textStyle to style in Ticket.textRaster(...) and renderTextLinesAsImages(...)
• Update README and example app to use the new names

2.0.0

• BREAKING: Remove align from TextStyles
• Add explicit align parameter to Ticket.text(...) and Ticket.textEncoded(...)
• Add PrintColumn.align for row/column alignment
• Update Generator alignment flow to use explicit alignment parameters
• Update README.md and example app usage to the new alignment API

1.0.3

• Rename spaceBetweenRows to columnGap for clarity
• Only apply columnGap between columns, not after the last column
• Change default columnGap from 5 to 1

1.0.2

• Improved Pub Score

1.0.1

• Update README.md.

1.0.0

• Initial release.