Add configurable JSON indent size to demo UI

Introduces a numeric up/down control in the demo form to allow users to set the number of spaces per indentation level for pretty-printed JSON (0-16, default 2). Updates the logger and sink configuration to use the selected indent size. Also changes the default indent from 4 to 2 in the sink options and extension method.

Author: vonhoff

Demo/Form1.Designer.cs

@@ -36,6 +36,8 @@ public partial class Form1 : Form
         private RichTextBoxSink? _sink;
         private bool _toolbarsVisible = true;
         private bool _prettyPrintJson = false;
+        private int _spacesPerIndent = 2;
+        private bool _updatingIndent = false;
 
         public Form1()
         {
@@ -49,7 +51,8 @@ private void Initialize()
                 theme: ThemePresets.Literate,
                 outputTemplate: "[{Timestamp:HH:mm:ss} {Level:u3}] {Message:l}{NewLine}{Exception}",
                 formatProvider: new CultureInfo("en-US"),
-                prettyPrintJson: _prettyPrintJson);
+                prettyPrintJson: _prettyPrintJson,
+                spacesPerIndent: _spacesPerIndent);
 
             _sink = new RichTextBoxSink(richTextBox1, _options);
             Log.Logger = new LoggerConfiguration()
@@ -80,6 +83,14 @@ private void Initialize()
             Log.Debug("Started logger.");
             btnDispose.Enabled = true;
             btnPrettyPrint.Text = _prettyPrintJson ? "Disable Pretty Print" : "Enable Pretty Print";
+            
+            // Update the numeric up/down control without triggering events
+            _updatingIndent = true;
+            if (numericUpDownSpacesPerIndent.Value != _spacesPerIndent)
+            {
+                numericUpDownSpacesPerIndent.Value = _spacesPerIndent;
+            }
+            _updatingIndent = false;
         }
 
         private void Form1_Load(object sender, EventArgs e)
@@ -365,6 +376,29 @@ private void btnPrettyPrint_Click(object sender, EventArgs e)
             Log.Information("Pretty print JSON: {PrettyPrint}", _prettyPrintJson);
         }
 
+        private void numericUpDownSpacesPerIndent_ValueChanged(object sender, EventArgs e)
+        {
+            // Prevent recursive calls when we're updating the value programmatically
+            if (_updatingIndent)
+            {
+                return;
+            }
+
+            var newValue = (int)numericUpDownSpacesPerIndent.Value;
+            if (newValue == _spacesPerIndent)
+            {
+                return;
+            }
+
+            _spacesPerIndent = newValue;
+
+            // Recreate the sink and logger with new indent size
+            CloseAndFlush();
+            Initialize();
+
+            Log.Information("Spaces per indent changed to: {SpacesPerIndent}", _spacesPerIndent);
+        }
+
         private void Form1_KeyDown(object sender, KeyEventArgs e)
         {
             if (e.Control && e.KeyCode == Keys.T)

Demo/Form1.cs

@@ -46,7 +46,7 @@ public static class RichTextBoxSinkLoggerConfigurationExtensions
         /// <param name="minimumLogEventLevel">Minimum log level for events to be written.</param>
         /// <param name="levelSwitch">Optional switch to change the minimum log level at runtime.</param>
         /// <param name="prettyPrintJson">If <c>true</c>, formats JSON values with indentation and line breaks. Defaults to <c>false</c>.</param>
-        /// <param name="spacesPerIndent">Number of spaces per indentation level when pretty printing JSON. Defaults to 4. Must be between 1 and 16.</param>
+        /// <param name="spacesPerIndent">Number of spaces per indentation level when pretty printing JSON. Defaults to 2.</param>
         /// <returns>The logger configuration, for chaining.</returns>
         public static LoggerConfiguration RichTextBox(
             this LoggerSinkConfiguration sinkConfiguration,
@@ -60,7 +60,7 @@ public static LoggerConfiguration RichTextBox(
             LogEventLevel minimumLogEventLevel = LogEventLevel.Verbose,
             LoggingLevelSwitch? levelSwitch = null,
             bool prettyPrintJson = false,
-            int spacesPerIndent = 4)
+            int spacesPerIndent = 2)
         {
             var appliedTheme = theme ?? ThemePresets.Literate;
             var appliedFormatProvider = formatProvider ?? CultureInfo.InvariantCulture;

Serilog.Sinks.RichTextBox.WinForms.Colored/RichTextBoxSinkLoggerConfigurationExtensions.cs

@@ -38,15 +38,15 @@ public class RichTextBoxSinkOptions
         /// <param name="outputTemplate">Serilog output template that controls textual formatting of each log event.</param>
         /// <param name="formatProvider">Optional culture-specific or custom formatting provider used when rendering scalar values; <c>null</c> for the invariant culture.</param>
         /// <param name="prettyPrintJson">When <c>true</c>, formats JSON values with indentation and line breaks for better readability. Defaults to <c>false</c>.</param>
-        /// <param name="spacesPerIndent">Number of spaces per indentation level when pretty printing JSON. Defaults to 4. Must be between 1 and 16.</param>
+        /// <param name="spacesPerIndent">Number of spaces per indentation level when pretty printing JSON. Defaults to 2.</param>
         public RichTextBoxSinkOptions(
             Theme theme,
             bool autoScroll = true,
             int maxLogLines = 256,
             string outputTemplate = DefaultOutputTemplate,
             IFormatProvider? formatProvider = null,
             bool prettyPrintJson = false,
-            int spacesPerIndent = 4)
+            int spacesPerIndent = 2)
         {
             AutoScroll = autoScroll;
             Theme = theme;
@@ -83,7 +83,7 @@ public int SpacesPerIndent
             get => _spacesPerIndent;
             private set => _spacesPerIndent = value switch
             {
-                < 1 => 1,
+                < 0 => 0,
                 > 16 => 16,
                 _ => value
             };