feat: add price popup

lib/ui/add_page/widgets/price_popup.dart

@@ -0,0 +1,65 @@
+import 'package:flutter/material.dart';
+
+class PricePopup extends StatefulWidget {
+  const PricePopup({
+    super.key,
+    required this.exitPopup,
+    required this.setPrice,
+  });
+
+  final Function(BuildContext) exitPopup;
+  final Function(num) setPrice;
+
+  @override
+  State<PricePopup> createState() => _PricePopupState();
+}
+
+class _PricePopupState extends State<PricePopup> {
+  final GlobalKey<FormState> _formKey = GlobalKey<FormState>();
+  num? price;
+  @override
+  Widget build(BuildContext context) {
+    return AlertDialog(
+      title: Text("Prix"),
+      content: Form(
+        key: _formKey,
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            TextFormField(
+              decoration: InputDecoration(
+                labelText: "Prix",
+                border: OutlineInputBorder(),
+                suffixText: "€",
+              ),
+              keyboardType: TextInputType.number,
+              validator: (value) {
+                if (value == null || value.isEmpty) {
+                  return "Indiquez un prix";
+                } else if (num.tryParse(value) == null) {
+                  return "Le prix doit être un nombre";
+                }
+                return null;
+              },
+              onSaved: (newValue) {
+                price = num.parse(newValue!);
+              },
+            ),
+          ],
+        ),
+      ),
+      actions: [
+        TextButton(
+          onPressed: () {
+            if (_formKey.currentState!.validate()) {
+              _formKey.currentState!.save();
+              widget.setPrice(price!);
+              widget.exitPopup(context);
+            }
+          },
+          child: Text("Valider"),
+        ),
+      ],
+    );
+  }
+}