Fix double relay property setting SettingsManager, docs

StabilityMatrix.Core/Models/RelayPropertyChangedEventArgs.cs

@@ -0,0 +1,15 @@
+using System.ComponentModel;
+
+namespace StabilityMatrix.Core.Models;
+
+public class RelayPropertyChangedEventArgs : PropertyChangedEventArgs
+{
+    public bool IsRelay { get; }
+
+    /// <inheritdoc />
+    public RelayPropertyChangedEventArgs(string? propertyName, bool isRelay = false)
+        : base(propertyName)
+    {
+        IsRelay = isRelay;
+    }
+}

StabilityMatrix.Core/Services/ISettingsManager.cs

@@ -16,25 +16,47 @@ public interface ISettingsManager
     DirectoryPath TagsDirectory { get; }
     
     Settings Settings { get; }
+    
+    /// <summary>
+    /// Event fired when the library directory is changed
+    /// </summary>
     event EventHandler<string>? LibraryDirChanged;
-    event EventHandler<PropertyChangedEventArgs>? SettingsPropertyChanged;
+    
+    /// <summary>
+    /// Event fired when a property of Settings is changed
+    /// </summary>
+    event EventHandler<RelayPropertyChangedEventArgs>? SettingsPropertyChanged;
 
-    /// <inheritdoc />
+    /// <summary>
+    /// Return a SettingsTransaction that can be used to modify Settings
+    /// Saves on Dispose.
+    /// </summary>
     SettingsTransaction BeginTransaction();
 
-    /// <inheritdoc />
+    /// <summary>
+    /// Execute a function that modifies Settings
+    /// Commits changes after the function returns.
+    /// </summary>
+    /// <param name="func">Function accepting Settings to modify</param>
     void Transaction(Action<Settings> func, bool ignoreMissingLibraryDir = false);
 
-    /// <inheritdoc />
+    /// <summary>
+    /// Modify a settings property by expression and commit changes.
+    /// This will notify listeners of SettingsPropertyChanged.
+    /// </summary>
     void Transaction<TValue>(Expression<Func<Settings, TValue>> expression, TValue value);
 
-    /// <inheritdoc />
+    /// <summary>
+    /// Register a source observable object and property to be relayed to Settings
+    /// </summary>
     void RelayPropertyFor<T, TValue>(
         T source, 
         Expression<Func<T, TValue>> sourceProperty,
         Expression<Func<Settings, TValue>> settingsProperty) where T : INotifyPropertyChanged;
 
-    /// <inheritdoc />
+    /// <summary>
+    /// Register an Action to be called on change of the settings property.
+    /// </summary>
     void RegisterPropertyChangedHandler<T>(
         Expression<Func<Settings, T>> settingsProperty,
         Action<T> onPropertyChanged);

StabilityMatrix.Core/Services/SettingsManager.cs

@@ -54,8 +54,8 @@ public class SettingsManager : ISettingsManager
     public Settings Settings { get; private set; } = new();
     
     public event EventHandler<string>? LibraryDirChanged; 
-    public event EventHandler<PropertyChangedEventArgs>? SettingsPropertyChanged;
-
+    public event EventHandler<RelayPropertyChangedEventArgs>? SettingsPropertyChanged;
+    
     /// <inheritdoc />
     public SettingsTransaction BeginTransaction()
     {
@@ -106,7 +106,7 @@ public class SettingsManager : ISettingsManager
         propertyInfo.SetValue(transaction.Settings, value);
         
         // Invoke property changed event
-        SettingsPropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
+        SettingsPropertyChanged?.Invoke(this, new RelayPropertyChangedEventArgs(name));
     }
 
     /// <inheritdoc />
@@ -128,7 +128,8 @@ public class SettingsManager : ISettingsManager
         // Update source when settings change
         SettingsPropertyChanged += (_, args) =>
         {
-            if (args.PropertyName != propertyName) return;
+            // Skip if event is relay, to avoid double setting
+            if (args.IsRelay || args.PropertyName != propertyName) return;
             
             Logger.Trace(
                 "[RelayPropertyFor] " +
@@ -149,10 +150,12 @@ public class SettingsManager : ISettingsManager
                 sourceTypeName, propertyName, targetPropertyName);
             
             settingsSetter(Settings, sourceGetter(source));
+            
+            // Save settings to file
             SaveSettingsAsync().SafeFireAndForget();
             
             // Invoke property changed event
-            SettingsPropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+            SettingsPropertyChanged?.Invoke(this, new RelayPropertyChangedEventArgs(propertyName, true));
         };
     }