created different models

lib/constants/cooking_units.dart

@@ -0,0 +1,158 @@
+import 'package:flutter/material.dart';
+
+import '../models/unit.dart' show Unit;
+import '../src/enums.dart';
+
+abstract class CookingUnits {
+  // Fluid volume units
+  static Unit get teaspoon => Unit(
+        'teaspoon',
+        UnitType.fluid,
+        system: System.imperial,
+      );
+
+  static Unit get tablespoon => Unit(
+        'tablespoon',
+        UnitType.fluid,
+        system: System.imperial,
+      );
+
+  static Unit get fluidOunce => Unit(
+        'fluid ounce',
+        UnitType.fluid,
+        system: System.imperial,
+      );
+
+  static Unit get cup => Unit(
+        'cup',
+        UnitType.fluid,
+        system: System.imperial,
+      );
+
+  static Unit get pint => Unit(
+        'pint',
+        UnitType.fluid,
+        system: System.imperial,
+      );
+
+  static Unit get quart => Unit(
+        'quart',
+        UnitType.fluid,
+        system: System.imperial,
+      );
+
+  static Unit get gallon => Unit(
+        'gallon',
+        UnitType.fluid,
+        system: System.imperial,
+      );
+
+  static Unit get milliliter => Unit(
+        'milliliter',
+        UnitType.fluid,
+      );
+
+  static Unit get liter => Unit(
+        'liter',
+        UnitType.fluid,
+      );
+
+  // Weight units
+  static Unit get ounce => Unit(
+        'ounce',
+        UnitType.weight,
+        system: System.imperial,
+      );
+
+  static Unit get pound => Unit(
+        'pound',
+        UnitType.weight,
+        system: System.imperial,
+      );
+
+  static Unit get gram => Unit(
+        'gram',
+        UnitType.weight,
+      );
+
+  static Unit get kilogram => Unit(
+        'kilogram',
+        UnitType.weight,
+      );
+
+  // Count units
+  static Unit get piece => Unit(
+        'piece',
+        UnitType.count,
+        system: System.neutral,
+      );
+
+  static Unit get dozen => Unit(
+        'dozen',
+        UnitType.count,
+        system: System.neutral,
+      );
+
+  // Informal units
+  static Unit get pinch => Unit(
+        'pinch',
+        UnitType.count,
+        system: System.neutral,
+      );
+
+  static Unit get dash => Unit(
+        'dash',
+        UnitType.count,
+        system: System.neutral,
+      );
+
+  static Unit get drop => Unit(
+        'drop',
+        UnitType.fluid,
+        system: System.neutral,
+      );
+
+  static Unit get stick => Unit(
+        'stick',
+        UnitType.count,
+        system: System.neutral,
+      );
+
+  static Unit get can => Unit(
+        'can',
+        UnitType.count,
+        system: System.neutral,
+      );
+
+  static Unit get batch => Unit(
+        'batch',
+        UnitType.count,
+        system: System.neutral,
+      );
+
+  static Unit get handful => Unit(
+        'handful',
+        UnitType.count,
+        system: System.neutral,
+      );
+
+  /// returns english abbreviation if available, else empty String
+  static String getUnitAbbreviation(BuildContext context, Unit unit) {
+    final abbreviations = {
+      'teaspoon': 'tsp',
+      'tablespoon': 'tbsp',
+      'fluid ounce': 'fl oz',
+      'cup': 'c',
+      'pint': 'pt',
+      'quart': 'qt',
+      'gallon': 'gal',
+      'milliliter': 'ml',
+      'liter': 'l',
+      'ounce': 'oz',
+      'pound': 'lb',
+      'gram': 'g',
+      'kilogram': 'kg',
+    };
+    return abbreviations[unit.name] ?? '';
+  }
+}