Initial commit

Helpers/ChangeNotifier.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+using System.Text;
+
+namespace ReceiptPDFBuilder.Helpers
+{
+
+    // https://docs.microsoft.com/en-us/dotnet/api/system.componentmodel.inotifypropertychanged?view=netframework-4.7.2
+    class ChangeNotifier : INotifyPropertyChanged
+    {
+        public event PropertyChangedEventHandler? PropertyChanged;
+        protected void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
+        {
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+        }
+    }
+}