minor update

- Implemented a CustomMessageBox window (not used by anything yet)
- Moved WindowPositioningExtensions to VolumeControl.WPF assembly
- Moved JsonConverter attrib from EScreenCorner to relevant config props
- Added log message indicating if the config file existed at startup
- Added log message when loading config (if log is initialized)
- Included Directory.Build.props in solution files
- Simplified StringDataTemplate by removing the Grid control
- Renamed SelectValues to SelectValue in EnumerableExtensions.cs
- Inconsequential changes to ActionSettingsWindow.xaml

VolumeControl.Core/Config.cs

@@ -11,6 +11,7 @@
 using VolumeControl.Core.Structs;
 using VolumeControl.Log;
 using VolumeControl.WPF.Collections;
+using VolumeControl.WPF.Extensions;
 
 namespace VolumeControl.Core
 {
@@ -95,6 +96,12 @@ public void Save(Formatting formatting = Formatting.Indented, [CallerMemberName]
                 FLog.Trace($"Saved {nameof(Config)} (Caller: \"{callerName}\")");
             base.Save(formatting);
         }
+        public override bool Load()
+        {
+            if (FLog.IsInitialized && FLog.FilterEventType(EventType.TRACE))
+                FLog.Trace($"Loaded {nameof(Config)} from {Location}.");
+            return base.Load();
+        }
         #endregion Method Overrides
 
         #region EventHandlers
@@ -222,6 +229,7 @@ private void PropertyWithCollectionChangedEvents_CollectionChanged(object? sende
         /// <summary>
         /// Gets or sets the origin corner to use when restoring the main window's position.
         /// </summary>
+        [JsonConverter(typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
         public EScreenCorner MainWindowOriginCorner { get; set; } = EScreenCorner.TopLeft;
         /// <summary>
         /// Gets or sets the position to restore the main window to when the application starts.

VolumeControl.Core/NotificationConfigSection.cs

@@ -3,6 +3,7 @@
 using System.Windows;
 using System.Windows.Media;
 using VolumeControl.Core.Enum;
+using VolumeControl.WPF.Extensions;
 
 namespace VolumeControl.Core
 {
@@ -51,6 +52,7 @@ public class NotificationConfigSection : INotifyPropertyChanged
         /// <summary>
         /// Gets or sets the corner from which ListNotification size transform operations are rooted.
         /// </summary>
+        [JsonConverter(typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
         public EScreenCorner PositionOriginCorner { get; set; } = EScreenCorner.TopLeft;
         /// <summary>
         /// Gets or sets whether the notification window slowly fades in instead of appearing instantly.

VolumeControl.SDK/DataTemplates/DataTemplateDictionary.xaml

@@ -18,9 +18,7 @@
         x:Key="StringDataTemplate"
         DataType="{x:Type actionSettings:IActionSettingInstance}"
         ValueType="{x:Type sys:String}">
-        <Grid>
-            <TextBox Style="{StaticResource RoundedTextBoxStyle}" Text="{Binding Value, UpdateSourceTrigger=LostFocus}" />
-        </Grid>
+        <TextBox Style="{StaticResource RoundedTextBoxStyle}" Text="{Binding Value, UpdateSourceTrigger=LostFocus}" />
     </core:ActionSettingDataTemplate>
 
     <!--  Bool  -->

VolumeControl.TypeExtensions/EnumerableExtensions.cs

@@ -73,14 +73,29 @@ public static IEnumerable<TResult> SelectIf<TSource, TResult>(this IEnumerable<T
             }
         }
         /// <summary>
+        /// Selects non-<see langword="null"/> values from the enumerable.
+        /// </summary>
+        /// <typeparam name="TSource">The type of element in the enumerable.</typeparam>
+        /// <returns>The resulting elements that aren't <see langword="null"/>.</returns>
+        public static IEnumerable<TSource> SelectValues<TSource>(this IEnumerable<TSource> source)
+        {
+            foreach (var item in source)
+            {
+                if (item is TSource value)
+                {
+                    yield return value;
+                }
+            }
+        }
+        /// <summary>
         /// Selects non-<see langword="null"/> values from the enumerable using the specified <paramref name="selector"/>.
         /// </summary>
         /// <typeparam name="TSource">The type of element in the enumerable.</typeparam>
         /// <typeparam name="TResult">The type of element in the resulting enumerable.</typeparam>
         /// <param name="source">The enumerable to apply the <paramref name="selector"/> to.</param>
         /// <param name="selector">A function that accepts a parameter of type <typeparamref name="TSource"/> and returns a <typeparamref name="TResult"/> instance, or <see langword="null"/>. When this returns <see langword="null"/> the item does not appear in the resulting enumeration.</param>
         /// <returns>The resulting elements of type <typeparamref name="TResult"/> that aren't <see langword="null"/>.</returns>
-        public static IEnumerable<TResult> SelectValue<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult?> selector)
+        public static IEnumerable<TResult> SelectValues<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult?> selector)
         {
             foreach (var item in source)
             {

VolumeControl.WPF/Converters/EnumHasFlagConverter.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Globalization;
+using System.Windows.Data;
+
+namespace VolumeControl.WPF.Converters
+{
+    /// <summary>
+    /// Converts from an enum value to <see cref="bool"/> depending on the flag value specified as a converter parameter.
+    /// </summary>
+    [ValueConversion(typeof(Enum), typeof(bool))]
+    public class EnumHasFlagConverter : IValueConverter
+    {
+        #region Properties
+        /// <summary>
+        /// Gets or sets the <see cref="bool"/> value returned by Convert when the input value is <see langword="null"/>.
+        /// </summary>
+        public bool ConvertResultWhenNull { get; set; } = false;
+        #endregion Properties
+
+        #region IValueConverter
+        /// <summary>
+        /// Converts from an enum flag <paramref name="value"/> to <see cref="bool"/>.
+        /// </summary>
+        /// <remarks>
+        /// When <paramref name="value"/> is <see langword="null"/>, the value of the ConvertResultWhenNull property is returned instead.
+        /// </remarks>
+        /// <returns><see langword="true"/> when <paramref name="value"/> has the <paramref name="parameter"/> flag set; otherwise, <see langword="false"/>.</returns>
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            // Provide the enum flag value(s) to check for as the ConverterParameter
+            ArgumentNullException.ThrowIfNull(parameter);
+
+            if (value == null) return ConvertResultWhenNull;
+
+            var e_value = System.Convert.ToInt64(value);
+            var flag = System.Convert.ToInt64(parameter);
+
+            return (e_value & flag) != 0;
+        }
+        /// <summary>
+        /// Converts from <see cref="bool"/> to the specified <paramref name="targetType"/> enum.
+        /// </summary>
+        /// <returns>The <paramref name="parameter"/> value as the specified <paramref name="targetType"/>.</returns>
+        /// <exception cref="NotImplementedException"/>
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            ArgumentNullException.ThrowIfNull(value);
+            ArgumentNullException.ThrowIfNull(parameter);
+
+            long result = 0;
+            if ((bool)value)
+                result |= System.Convert.ToInt64(parameter);
+
+            return Enum.ToObject(targetType, result);
+        }
+        #endregion IValueConverter
+    }
+}