use more readable colours if player has a light-backgrounded terminal (#327)

release-notes.md

@@ -4,6 +4,7 @@
 
 For players:
 * The SMAPI console is now much simpler and easier-to-read.
+* The SMAPI console now uses more readable colors in terminals with a light background.
 
 For mod developers:
 * Added API to edit XNB images & data loaded by the game (see [API reference](http://stardewvalleywiki.com/Modding:SMAPI_APIs#Content)).

src/StardewModdingAPI/Framework/Monitor.cs

@@ -25,15 +25,7 @@ namespace StardewModdingAPI.Framework
         private static readonly int MaxLevelLength = (from level in Enum.GetValues(typeof(LogLevel)).Cast<LogLevel>() select level.ToString().Length).Max();
 
         /// <summary>The console text color for each log level.</summary>
-        private static readonly Dictionary<LogLevel, ConsoleColor> Colors = new Dictionary<LogLevel, ConsoleColor>
+        private static readonly IDictionary<LogLevel, ConsoleColor> Colors = Monitor.GetConsoleColorScheme();
-        {
-            [LogLevel.Trace] = ConsoleColor.DarkGray,
-            [LogLevel.Debug] = ConsoleColor.DarkGray,
-            [LogLevel.Info] = ConsoleColor.White,
-            [LogLevel.Warn] = ConsoleColor.Yellow,
-            [LogLevel.Error] = ConsoleColor.Red,
-            [LogLevel.Alert] = ConsoleColor.Magenta
-        };
 
         /// <summary>Propagates notification that SMAPI should exit.</summary>
         private readonly CancellationTokenSource ExitTokenSource;
@@ -172,5 +164,56 @@ namespace StardewModdingAPI.Framework
             if (this.WriteToFile)
                 this.LogFile.WriteLine(fullMessage);
         }
+
+        /// <summary>Get the color scheme to use for the current console.</summary>
+        private static IDictionary<LogLevel, ConsoleColor> GetConsoleColorScheme()
+        {
+#if !SMAPI_1_x
+            // scheme for dark console background
+            if (Monitor.IsDark(Console.BackgroundColor))
+            {
+#endif
+                return new Dictionary<LogLevel, ConsoleColor>
+                {
+                    [LogLevel.Trace] = ConsoleColor.DarkGray,
+                    [LogLevel.Debug] = ConsoleColor.DarkGray,
+                    [LogLevel.Info] = ConsoleColor.White,
+                    [LogLevel.Warn] = ConsoleColor.Yellow,
+                    [LogLevel.Error] = ConsoleColor.Red,
+                    [LogLevel.Alert] = ConsoleColor.Magenta
+                };
+#if !SMAPI_1_x
+            }
+
+            // scheme for light console background
+            return new Dictionary<LogLevel, ConsoleColor>
+            {
+                [LogLevel.Trace] = ConsoleColor.DarkGray,
+                [LogLevel.Debug] = ConsoleColor.DarkGray,
+                [LogLevel.Info] = ConsoleColor.Black,
+                [LogLevel.Warn] = ConsoleColor.DarkYellow,
+                [LogLevel.Error] = ConsoleColor.Red,
+                [LogLevel.Alert] = ConsoleColor.DarkMagenta
+            };
+#endif
+        }
+
+        /// <summary>Get whether a console color should be considered dark, which is subjectively defined as 'white looks better than black on this text'.</summary>
+        /// <param name="color">The color to check.</param>
+        private static bool IsDark(ConsoleColor color)
+        {
+            switch (color)
+            {
+                case ConsoleColor.Black:
+                case ConsoleColor.Blue:
+                case ConsoleColor.DarkBlue:
+                case ConsoleColor.DarkRed:
+                case ConsoleColor.Red:
+                    return true;
+
+                default:
+                    return false;
+            }
+        }
     }
 }