update invoice

lib/pages/widgets/discount_dropdown.dart

@@ -0,0 +1,69 @@
+import 'package:fcs/domain/entities/discount.dart';
+import 'package:fcs/helpers/theme.dart';
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+
+import 'local_text.dart';
+
+class DiscountDropdown<T> extends StatelessWidget {
+  final Function(T) callback;
+  final IconData iconData;
+  final T selectedValue;
+  final List<T> values;
+
+  const DiscountDropdown(
+      {Key key, this.callback, this.iconData, this.selectedValue, this.values})
+      : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.only(left: 5.0, right: 0),
+      child: Row(
+        children: [
+          Padding(
+            padding: const EdgeInsets.only(left: 0, right: 10),
+            child: Icon(iconData, color: primaryColor),
+          ),
+          Expanded(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Padding(
+                  padding: const EdgeInsets.only(right: 18.0),
+                  child: LocalText(
+                    context,
+                    "invoice.discount",
+                    color: Colors.black54,
+                    fontSize: 16,
+                  ),
+                ),
+                DropdownButton<T>(
+                  isDense: true,
+                  value: selectedValue,
+                  style: TextStyle(color: Colors.black, fontSize: 14),
+                  underline: Container(
+                    height: 1,
+                    color: primaryColor,
+                  ),
+                  onChanged: (T newValue) {
+                    callback(newValue);
+                  },
+                  isExpanded: true,
+                  items: values.map<DropdownMenuItem<T>>((T value) {
+                    return DropdownMenuItem<T>(
+                      value: value,
+                      child: Text(value == null ? "" : (value as Discount).code,
+                          overflow: TextOverflow.ellipsis,
+                          style: TextStyle(color: primaryColor)),
+                    );
+                  }).toList(),
+                ),
+              ],
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}