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Nitrox.Launcher/Models/Converters/TrimConverter.cs

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+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Threading;
+
+namespace Nitrox.Launcher.Models.Converters;
+
+/// <summary>
+///     Trims the value when retrieved by code but keeps the spaces in the input field intact for improved UX.
+/// </summary>
+/// <remarks>
+///     This converter is unconventional (inverted converter) in that the value is converted for the backend.
+///     The user wants to be able to input spaces while they're typing, but we don't want to save those spaces.
+/// </remarks>
+public class TrimConverter : Converter<TrimConverter>
+{
+    private readonly Lock inOutCacheLock = new();
+    /// <summary>
+    ///     Cache to remember the last known untrimmed value (here, the value) for trimmed values (here, the key).
+    /// </summary>
+    private readonly Dictionary<string, string> inOutCache = new();
+
+    /// <summary>
+    ///     Converts trimmed value back to last known untrimmed value.
+    /// </summary>
+    public override object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+    {
+        if (value is not string strValue)
+        {
+            return value;
+        }
+        lock (inOutCacheLock)
+        {
+            if (inOutCache.TryGetValue(strValue.Trim(), out string untrimmedValue))
+            {
+                strValue = untrimmedValue;
+            }
+        }
+        return strValue;
+    }
+
+    /// <summary>
+    ///     Converts untrimmed value back to trimmed value.
+    /// </summary>
+    public override object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+    {
+        if (value is not string strValue)
+        {
+            return value;
+        }
+        if (!strValue.StartsWith(' ') && !strValue.EndsWith(' '))
+        {
+            // It's safe to reset cache now.
+            lock (inOutCacheLock)
+            {
+                inOutCache.Clear();
+            }
+            return strValue;
+        }
+        string trim = strValue.Trim();
+        lock (inOutCacheLock)
+        {
+            inOutCache[trim] = strValue;
+        }
+        return trim;
+    }
+}