Color parsing improvements

- Added ColorHelper.TryFromHexString, a non-throwing version of FromHexString
- Stopped the text formatter from throwing if a color can't be parsed

CHANGELOG.md

@@ -19,6 +19,10 @@ Additions
 - Added Zero, One, Linear and Clamp to Easings
 - Added GetRandomEntry and GetRandomWeightedEntry to SingleRandom
 - Added the ability to draw single corners of AutoTiling's extended auto tiles
+- Added ColorHelper.TryFromHexString, a non-throwing version of FromHexString
+
+Improvements
+- Stopped the text formatter throwing if a color can't be parsed
 
 Fixes
 - Fixed TextInput not working correctly when using surrogate pairs

MLEM.Extended/Tiled/TiledExtensions.cs

@@ -44,7 +44,8 @@ namespace MLEM.Extended.Tiled {
         /// <param name="key">The key by which to get a property</param>
         /// <returns>The color property</returns>
         public static Color GetColor(this TiledMapProperties properties, string key) {
-            return ColorHelper.FromHexString(properties.Get(key));
+            ColorHelper.TryFromHexString(properties.Get(key), out var val);
+            return val;
         }
 
         /// <summary>

MLEM/Extensions/ColorExtensions.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Globalization;
 using Microsoft.Xna.Framework;
 
@@ -64,16 +65,34 @@ namespace MLEM.Extensions {
         }
 
         /// <summary>
-        /// Parses a hexadecimal string into a color.
+        /// Parses a hexadecimal string into a color and throws a <see cref="FormatException"/> if parsing fails.
         /// The string can either be formatted as RRGGBB or AARRGGBB and can optionally start with a <c>#</c>.
         /// </summary>
         /// <param name="value">The string to parse.</param>
         /// <returns>The resulting color.</returns>
+        /// <exception cref="FormatException">Thrown if parsing fails.</exception>
         public static Color FromHexString(string value) {
+            if (!ColorHelper.TryFromHexString(value, out var val))
+                throw new FormatException($"Cannot parse hex string {value}");
+            return val;
+        }
+
+        /// <summary>
+        /// Tries to parse a hexadecimal string into a color and returns whether a color was successfully parsed.
+        /// The string can either be formatted as RRGGBB or AARRGGBB and can optionally start with a <c>#</c>.
+        /// </summary>
+        /// <param name="value">The string to parse.</param>
+        /// <param name="color">The resulting color.</param>
+        /// <returns>Whether parsing was successful.</returns>
+        public static bool TryFromHexString(string value, out Color color) {
             if (value.StartsWith("#"))
                 value = value.Substring(1);
-            var val = int.Parse(value, NumberStyles.HexNumber);
+            if (int.TryParse(value, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out var val)) {
-            return value.Length > 6 ? ColorHelper.FromHexRgba(val) : ColorHelper.FromHexRgb(val);
+                color = value.Length > 6 ? ColorHelper.FromHexRgba(val) : ColorHelper.FromHexRgb(val);
+                return true;
+            }
+            color = default;
+            return false;
         }
 
     }

MLEM/Formatting/TextFormatter.cs

@@ -102,7 +102,7 @@ namespace MLEM.Formatting {
                 this.Codes.Add(new Regex("<b>"), (f, m, r) => new FontCode(m, r, fnt => fnt.Bold));
                 this.Codes.Add(new Regex("<i>"), (f, m, r) => new FontCode(m, r, fnt => fnt.Italic));
                 this.Codes.Add(new Regex(@"<s(?: #([0-9\w]{6,8}) (([+-.0-9]*)))?>"), (f, m, r) => new ShadowCode(m, r,
-                    m.Groups[1].Success ? ColorHelper.FromHexString(m.Groups[1].Value) : this.DefaultShadowColor,
+                    ColorHelper.TryFromHexString(m.Groups[1].Value, out var color) ? color : this.DefaultShadowColor,
                     float.TryParse(m.Groups[2].Value, NumberStyles.Number, CultureInfo.InvariantCulture, out var offset) ? new Vector2(offset) : this.DefaultShadowOffset));
                 this.Codes.Add(new Regex("<u>"), (f, m, r) => new UnderlineCode(m, r, this.LineThickness, this.UnderlineOffset));
                 this.Codes.Add(new Regex("<st>"), (f, m, r) => new UnderlineCode(m, r, this.LineThickness, this.StrikethroughOffset));
@@ -111,7 +111,7 @@ namespace MLEM.Formatting {
                 this.Codes.Add(new Regex(@"<sup(?: ([+-.0-9]+))?>"), (f, m, r) => new SubSupCode(m, r,
                     float.TryParse(m.Groups[1].Value, NumberStyles.Number, CultureInfo.InvariantCulture, out var off) ? -off : this.DefaultSupOffset));
                 this.Codes.Add(new Regex(@"<o(?: #([0-9\w]{6,8}) (([+-.0-9]*)))?>"), (f, m, r) => new OutlineCode(m, r,
-                    m.Groups[1].Success ? ColorHelper.FromHexString(m.Groups[1].Value) : this.DefaultOutlineColor,
+                    ColorHelper.TryFromHexString(m.Groups[1].Value, out var color) ? color : this.DefaultOutlineColor,
                     float.TryParse(m.Groups[2].Value, NumberStyles.Number, CultureInfo.InvariantCulture, out var thickness) ? thickness : this.DefaultOutlineThickness,
                     this.OutlineDiagonals));
             }
@@ -124,12 +124,13 @@ namespace MLEM.Formatting {
                         this.Codes.Add(new Regex($"<c {c.Name}>"), (f, m, r) => new ColorCode(m, r, value));
                     }
                 }
-                this.Codes.Add(new Regex(@"<c #([0-9\w]{6,8})>"), (f, m, r) => new ColorCode(m, r, ColorHelper.FromHexString(m.Groups[1].Value)));
+                this.Codes.Add(new Regex(@"<c #([0-9\w]{6,8})>"), (f, m, r) => new ColorCode(m, r,
+                    ColorHelper.TryFromHexString(m.Groups[1].Value, out var color) ? color : Color.Red));
             }
 
             // animation codes
             if (hasAnimations) {
-                this.Codes.Add(new Regex(@"<a wobbly(?: ([+-.0-9]*) ([+-.0-9]*))?>"), (f, m, r) => new WobblyCode(m, r,
+                this.Codes.Add(new Regex("<a wobbly(?: ([+-.0-9]*) ([+-.0-9]*))?>"), (f, m, r) => new WobblyCode(m, r,
                     float.TryParse(m.Groups[1].Value, NumberStyles.Number, CultureInfo.InvariantCulture, out var mod) ? mod : this.DefaultWobblyModifier,
                     float.TryParse(m.Groups[2].Value, NumberStyles.Number, CultureInfo.InvariantCulture, out var heightMod) ? heightMod : this.DefaultWobblyHeight));
             }