only use nbsp in image codes if the font supports it

MLEM.Extended/Font/GenericBitmapFont.cs

@@ -78,6 +78,11 @@ namespace MLEM.Extended.Font {
             batch.DrawString(this.Font, text, position, color, rotation, origin, scale, effects, layerDepth);
         }
 
+        /// <inheritdoc />
+        public override bool HasCharacter(char c) {
+            return this.Font.GetCharacterRegion(c) != null;
+        }
+
         // this fixes an issue with BitmapFonts where, if only given a single character,
         // only the width of the character itself (disregarding spacing) is returned
         private bool SingleCharacterWidthFix(string text, out Vector2 size) {

MLEM.Ui/Style/UntexturedStyle.cs

@@ -74,6 +74,10 @@ namespace MLEM.Ui.Style {
             public override void DrawString(SpriteBatch batch, StringBuilder text, Vector2 position, Color color, float rotation, Vector2 origin, Vector2 scale, SpriteEffects effects, float layerDepth) {
             }
 
+            public override bool HasCharacter(char c) {
+                return false;
+            }
+
         }
 
     }

MLEM/Font/GenericFont.cs

@@ -48,6 +48,13 @@ namespace MLEM.Font {
         ///<inheritdoc cref="SpriteBatch.DrawString(SpriteFont,string,Vector2,Color,float,Vector2,float,SpriteEffects,float)"/>
         public abstract void DrawString(SpriteBatch batch, StringBuilder text, Vector2 position, Color color, float rotation, Vector2 origin, Vector2 scale, SpriteEffects effects, float layerDepth);
 
+        /// <summary>
+        /// Returns whether this generic font supports the given character 
+        /// </summary>
+        /// <param name="c">The character</param>
+        /// <returns>Whether this generic font supports the character</returns>
+        public abstract bool HasCharacter(char c);
+
         /// <summary>
         /// Draws a string with the given text alignment.
         /// </summary>

MLEM/Font/GenericSpriteFont.cs

@@ -72,5 +72,10 @@ namespace MLEM.Font {
             batch.DrawString(this.Font, text, position, color, rotation, origin, scale, effects, layerDepth);
         }
 
+        /// <inheritdoc />
+        public override bool HasCharacter(char c) {
+            return this.Font.Characters.Contains(c);
+        }
+
     }
 }

MLEM/Formatting/Codes/ImageCode.cs

@@ -29,7 +29,9 @@ namespace MLEM.Formatting.Codes {
         /// <inheritdoc />
         public override string GetReplacementString(GenericFont font) {
             if (this.replacement == null) {
-                this.replacement = font.GetWidthString(font.LineHeight);
+                // use non-breaking space so that the image won't be line-splitted
+                var strg = font.GetWidthString(font.LineHeight, font.HasCharacter('\u00A0') ? '\u00A0' : ' ');
+                this.replacement = strg.Remove(strg.Length - 1) + ' ';
                 this.gapSize = font.MeasureString(this.replacement).X;
             }
             return this.replacement;