Add product list

lib/app.dart

@@ -1,5 +1,5 @@
 import 'package:flutter/material.dart';
-import 'package:thesis_shop/screens/product_list/ProductListScreen.dart';
+import 'package:thesis_shop/screens/product_list/product_list_screen.dart';
 
 class ThesisShopApp extends StatelessWidget {
   const ThesisShopApp({Key? key}) : super(key: key);

lib/models/product.dart

@@ -0,0 +1,11 @@
+import 'package:flutter/foundation.dart';
+
+@immutable
+class Product {
+  final String title;
+  final double price;
+
+  String get priceAsString => price.toStringAsFixed(2);
+
+  const Product({required this.title, required this.price});
+}

lib/screens/product_list/ProductListScreen.dart

@@ -1,12 +0,0 @@
-import 'package:flutter/material.dart';
-
-class ProductListScreen extends StatelessWidget {
-  const ProductListScreen({Key? key}) : super(key: key);
-
-  @override
-  Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(title: const Text('Thesis Shop')),
-    );
-  }
-}

lib/screens/product_list/product_item.dart

@@ -0,0 +1,16 @@
+import 'package:flutter/material.dart';
+import 'package:thesis_shop/models/product.dart';
+import 'package:thesis_shop/widgets/number_picker.dart';
+
+class ProductItem extends StatelessWidget {
+  final Product product;
+  const ProductItem({Key? key, required this.product}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return ListTile(
+      title: Text('${product.title} (${product.priceAsString}€/Stück)'),
+      trailing: NumberPicker(value: 5, onUp: () {}, onDown: () {}),
+    );
+  }
+}

lib/screens/product_list/product_list_screen.dart

@@ -0,0 +1,27 @@
+import 'package:flutter/material.dart';
+import 'package:thesis_shop/models/product.dart';
+import 'package:thesis_shop/screens/product_list/product_item.dart';
+
+const _productPlaceholder = [
+  Product(title: 'Bananen', price: 3),
+  Product(title: 'Äpfel', price: 2),
+  Product(title: 'Birnen', price: 2.5),
+  Product(title: 'Kirschen', price: 1.2),
+];
+
+class ProductListScreen extends StatelessWidget {
+  const ProductListScreen({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    const products = _productPlaceholder;
+    return Scaffold(
+      appBar: AppBar(title: const Text('Thesis Shop')),
+      body: ListView.separated(
+        itemCount: products.length,
+        itemBuilder: (context, index) => ProductItem(product: products[index]),
+        separatorBuilder: (context, _) => const Divider(),
+      ),
+    );
+  }
+}

lib/widgets/number_picker.dart

@@ -0,0 +1,52 @@
+import 'package:flutter/material.dart';
+
+class NumberPicker extends StatelessWidget {
+  final int value;
+  final VoidCallback onUp;
+  final VoidCallback onDown;
+  final int minValue;
+  final int maxValue;
+  const NumberPicker({
+    Key? key,
+    required this.value,
+    required this.onUp,
+    required this.onDown,
+    this.minValue = 0,
+    this.maxValue = 100,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Row(
+      mainAxisSize: MainAxisSize.min,
+      crossAxisAlignment: CrossAxisAlignment.center,
+      children: [
+        _ConditionalIconButton(
+            enabled: value > minValue, onClick: onDown, iconData: Icons.remove),
+        Text(value.toString()),
+        _ConditionalIconButton(
+            enabled: value < maxValue, onClick: onUp, iconData: Icons.add),
+      ],
+    );
+  }
+}
+
+class _ConditionalIconButton extends StatelessWidget {
+  final bool enabled;
+  final VoidCallback onClick;
+  final IconData iconData;
+  const _ConditionalIconButton({
+    Key? key,
+    required this.enabled,
+    required this.onClick,
+    required this.iconData,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return IconButton(
+      onPressed: enabled ? onClick : null,
+      icon: Icon(iconData),
+    );
+  }
+}