new handheld scanner function

assets/controllers/pages/handheld_scan_controller.js

@@ -0,0 +1,135 @@
+import {Controller} from "@hotwired/stimulus";
+/**
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ * Copyright (C) 2024 Alex Barclay (https://github.com/barclaac)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/* stimulusFetch: 'lazy' */
+export default class extends Controller {
+
+    _scanner = null;
+
+    constructor() {
+	super()
+	_scanner = new ScannerSerial()
+    }
+
+    connect(event) {
+	console.log('Controller connected')
+
+	if (_scanner.isConnected()) {
+	    console.log('already connected')
+	    document.getElementById('handheld_scanner_dialog_connect').style.display='none'
+	    document.getElementById('handheld_scanner_dialog_disconnect').style.display=''
+	}
+    }
+
+    async onConnectScanner(event) {
+	console.log('Connect to barcode reader')
+
+	if (!_scanner.isConnected()) {
+	    await _scanner.connect(async (reader) => {
+		decoder = new TextDecoder();
+		var barcodeBuffer = '';
+		while (true) {
+		    const { value, done } = await reader.read();
+		    if (done) {
+			console.log('releasing reader')
+			reader.releaseLock();
+			reader = null;
+			break;
+		    }
+		    console.log(value);
+		    console.log(decoder.decode(value));
+		    partial = decoder.decode(value);
+		    barcodeBuffer += partial
+		    end = false
+		    endidx = partial.indexOf('\x1e\x04');
+		    if (endidx != -1) {
+			end = true;
+		    } else {
+			endidx = partial.indexOf('\r');
+			if (endidx != -1) {
+			    end = true;
+			}
+		    }
+
+		    if (end) {
+			// Decode the barcode
+			console.log(barcodeBuffer)
+			start = barcodeBuffer.indexOf('[)>')
+			if (start == -1) {
+			    console.log('badly formed barcode')
+			} else {
+			    // Post this back to the server
+			    document.getElementById('handheld_scanner_dialog_barcode').value = barcodeBuffer;
+			    form = document.getElementById('handheld_dialog_form');
+			    form.requestSubmit();
+			}
+			barcodeBuffer = '';
+		    }
+		}
+	    })
+	    document.getElementById('handheld_scanner_dialog_connect').style.display='none'
+	    document.getElementById('handheld_scanner_dialog_disconnect').style.display=''
+
+	}
+    }
+
+    async onDisconnectScanner(event) {
+	console.log('Disconnect called')
+	if (_scanner.isConnected) {
+	    _scanner.disconnect()
+	    document.getElementById('handheld_scanner_dialog_connect').style.display=''
+	    document.getElementById('handheld_scanner_dialog_disconnect').style.display='none'
+	}
+    }
+}
+
+class ScannerSerial {
+    device = null
+    reader = null
+
+    constructor() {
+	if (ScannerSerial.instance) {
+	    return ScannerSerial.instance;
+	}
+	ScannerSerial.instance = this;
+    }
+
+    async connect(readHandler) {
+	this.device = await navigator.serial.requestPort({ filters: [{ usbVendorId: 0x03f0, usbDeviceId: 0x0339 }] })
+	await this.device.open({baudRate: 9600})
+
+	console.log(this.device)
+	this.reader = this.device.readable.getReader()
+	readHandler(this.reader)
+    }
+
+    async disconnect() {
+	await this.reader.cancel()
+	this.reader = null
+	this.device.close()
+    }
+
+    isConnected() {
+	if (this.reader == null) {
+	    return false;
+	}
+	return true
+    }
+}