[desktop] Restore window position

src/UnforgettableMemo.WinDesktop/MainWindow.xaml.Settings.cs

@@ -0,0 +1,36 @@
+using System.IO;
+using System.Text.Json;
+
+namespace UnforgettableMemo.WinDesktop
+{
+    public partial class MainWindow
+    {
+        public class MainWindowSettings
+        {
+            public double? TopLocation { get; set; }
+            public double? LeftLocation { get; set; }
+        }
+
+        private MainWindowSettings LoadSettings()
+        {
+            string filePath = System.IO.Path.Combine(this.settingsDirectory, this.settingsFilename);
+            if (!File.Exists(filePath))
+            {
+                return new MainWindowSettings();
+            }
+            string fileText = File.ReadAllText(filePath);
+            MainWindowSettings settings = JsonSerializer.Deserialize<MainWindowSettings>(fileText);
+            return settings;
+        }
+
+        public void SaveSettings(MainWindowSettings settings)
+        {
+            Directory.CreateDirectory(this.settingsDirectory);
+            string fileText = JsonSerializer.Serialize(settings, new JsonSerializerOptions()
+            {
+                WriteIndented = true
+            });
+            File.WriteAllText(System.IO.Path.Combine(this.settingsDirectory, this.settingsFilename), fileText);
+        }
+    }
+}

src/UnforgettableMemo.WinDesktop/MainWindow.xaml.cs

@@ -27,11 +27,23 @@ public class MainWindowViewModel
             public Memo DisplayingMemo { get; set; }
         }
 
+        private readonly string settingsDirectory = "desktop";
+        private readonly string settingsFilename = "mainWindowSettings.json";
+
         private readonly MainWindowViewModel viewModel = new MainWindowViewModel();
 
         private MemoScheduler memoScheduler;
         public MainWindow()
         {
+            MainWindowSettings settings = LoadSettings();
+            if (settings.LeftLocation != null)
+            {
+                this.Left = settings.LeftLocation.Value;
+            }
+            if (settings.TopLocation != null)
+            {
+                this.Top = settings.TopLocation.Value;
+            }
             InitializeComponent();
         }
 
@@ -84,6 +96,11 @@ private void btnReview_Click(object sender, RoutedEventArgs e)
 
         private void btnExit_Click(object sender, RoutedEventArgs e)
         {
+            SaveSettings(new MainWindowSettings()
+            {
+                LeftLocation = this.Left,
+                TopLocation = this.Top
+            });
             this.Close();
         }