Add part to sales order via barcode scan (#461)

* Add part to sales order via barcode scan

* Update release notes

* Remove unused imports

lib/barcode/purchase_order.dart

@@ -188,7 +188,6 @@ class POAllocateBarcodeHandler extends BarcodeHandler {
       context,
       L10().lineItemAdd,
       fields: fields,
-      onSuccess: (data) async {},
     );
   }
 

lib/barcode/sales_order.dart

@@ -0,0 +1,81 @@
+import "package:flutter/material.dart";
+
+import "package:inventree/inventree/part.dart";
+import "package:inventree/inventree/sales_order.dart";
+import "package:one_context/one_context.dart";
+
+import "package:inventree/l10.dart";
+
+import "package:inventree/barcode/handler.dart";
+import "package:inventree/barcode/tones.dart";
+
+import "package:inventree/widget/snacks.dart";
+
+
+/*
+ * Barcode handler class for scanning a new part into a SalesOrder
+ */
+
+class SOAddItemBarcodeHandler extends BarcodeHandler {
+
+  SOAddItemBarcodeHandler({this.salesOrder});
+
+  InvenTreeSalesOrder? salesOrder;
+
+  @override
+  String getOverlayText(BuildContext context) => L10().barcodeScanPart;
+
+  @override
+  Future<void> onBarcodeMatched(Map<String, dynamic> data) async {
+
+    // Extract the part ID from the returned data
+    int part_id = -1;
+
+    if (data.containsKey("part")) {
+      part_id = (data["part"] ?? {} as Map<String, dynamic>)["pk"] as int;
+    }
+
+    if (part_id <= 0) {
+      return onBarcodeUnknown(data);
+    }
+
+    // Request the part from the server
+    var part = await InvenTreePart().get(part_id);
+
+    if (part is InvenTreePart) {
+
+      if (part.isSalable) {
+        // Dispose of the barcode scanner
+        if (OneContext.hasContext) {
+          OneContext().pop();
+        }
+
+        final context = OneContext().context!;
+
+        var fields = InvenTreeSOLineItem().formFields();
+
+        fields["order"]?["value"] = salesOrder!.pk;
+        fields["order"]?["hidden"] = true;
+
+        fields["part"]?["value"] = part.pk;
+        fields["part"]?["hidden"] = false;
+
+        InvenTreeSOLineItem().createForm(
+          context,
+          L10().lineItemAdd,
+          fields: fields,
+        );
+
+      } else {
+        barcodeFailureTone();
+        showSnackIcon(L10().partNotSalable, success: false);
+      }
+
+    } else {
+      // Failed to fetch part
+      return onBarcodeUnknown(data);
+    }
+
+  }
+
+}