Allow to scan labels anywhere on the page

assets/controllers/helpers/scan_special_char_controller.js

@@ -0,0 +1,136 @@
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2026 Jan Böhmer (https://github.com/jbtronics)
+ *
+ *  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/>.
+ */
+
+import { Controller } from "@hotwired/stimulus"
+
+/**
+ * This controller listens for a special non-printable character (SOH / ASCII 1) to be entered anywhere on the page,
+ * which is then used as a trigger to submit the following characters as a barcode / scan input.
+ */
+export default class extends Controller {
+    connect() {
+        // Optional: Log to confirm global attachment
+        console.log("Scanner listener active")
+
+        this.isCapturing = false
+        this.buffer = ""
+
+        window.addEventListener("keypress", this.handleKeydown.bind(this))
+    }
+
+    initialize() {
+        this.isCapturing = false
+        this.buffer = ""
+        this.timeoutId = null
+    }
+
+    handleKeydown(event) {
+
+        // Ignore if the user is typing in a form field
+        const isInput = ["INPUT", "TEXTAREA", "SELECT"].includes(event.target.tagName) ||
+            event.target.isContentEditable;
+        if (isInput) return
+
+        // 1. Detect Start of Header (SOH / Ctrl+A)
+        if (event.key === "\x01" || event.keyCode === 1) {
+            this.startCapturing(event)
+            return
+        }
+
+        // 2. Process characters if in capture mode
+        if (this.isCapturing) {
+            this.resetTimeout() // Push the expiration back with every keypress
+
+            if (event.key === "Enter" || event.keyCode === 13) {
+
+                this.finishCapturing(event)
+            } else if (event.key.length === 1) {
+                this.buffer += event.key
+            }
+        }
+    }
+
+    startCapturing(event) {
+        this.isCapturing = true
+        this.buffer = ""
+        this.resetTimeout()
+        event.preventDefault()
+        console.debug("Scan character detected. Capture started...")
+    }
+
+    finishCapturing(event) {
+        event.preventDefault()
+        const data = this.buffer;
+        this.stopCapturing()
+        this.processCapture(data)
+    }
+
+    stopCapturing() {
+        this.isCapturing = false
+        this.buffer = ""
+        if (this.timeoutId) clearTimeout(this.timeoutId)
+        console.debug("Capture cleared/finished.")
+    }
+
+    resetTimeout() {
+        if (this.timeoutId) clearTimeout(this.timeoutId)
+
+        this.timeoutId = setTimeout(() => {
+            if (this.isCapturing) {
+                console.warn("Capture timed out. Resetting buffer.")
+                this.stopCapturing()
+            }
+        }, 500)
+    }
+
+    processCapture(data) {
+        if (!data) return
+
+        console.debug("Captured scan data: " + data)
+
+        const scanInput = document.getElementById("scan_dialog_input");
+        if (scanInput) { //When we are on the scan dialog page, submit the form there
+            this._submitScanForm(data);
+        } else {  //Otherwise use our own form (e.g. on the part list page)
+            this.element.querySelector("input[name='input']").value = data;
+            this.element.requestSubmit();
+        }
+
+
+    }
+
+    _submitScanForm(data) {
+        const scanInput = document.getElementById("scan_dialog_input");
+        if (!scanInput) {
+            console.error("Scan input field not found!")
+            return;
+        }
+
+        scanInput.value = data;
+        scanInput.dispatchEvent(new Event('input', { bubbles: true }));
+
+        const form = document.getElementById("scan_dialog_form");
+        if (!form) {
+            console.error("Scan form not found!")
+            return;
+        }
+
+        form.requestSubmit();
+    }
+}