added text alignment options to tokenized strings and paragraphs

Demos/UiDemo.cs

@@ -6,6 +6,7 @@ using Microsoft.Xna.Framework;
 using Microsoft.Xna.Framework.Graphics;
 using MLEM.Extensions;
 using MLEM.Font;
+using MLEM.Formatting;
 using MLEM.Formatting.Codes;
 using MLEM.Misc;
 using MLEM.Startup;
@@ -191,6 +192,14 @@ namespace Demos {
             this.root.AddChild(new VerticalSpace(3));
             this.root.AddChild(new Button(Anchor.AutoLeft, new Vector2(1, 10), "Disabled button", "This button can't be clicked or moved to using automatic navigation") {IsDisabled = true}).PositionOffset = new Vector2(0, 1);
 
+            const string alignText = "Paragraphs can have <c CornflowerBlue><l Left>left</l></c> aligned text, <c CornflowerBlue><l Right>right</l></c> aligned text and <c CornflowerBlue><l Center>center</l></c> aligned text.";
+            this.root.AddChild(new VerticalSpace(3));
+            var alignPar = this.root.AddChild(new Paragraph(Anchor.AutoLeft, 1, alignText));
+            alignPar.LinkAction = (l, c) => {
+                if (Enum.TryParse<TextAlignment>(c.Match.Groups[1].Value, out var alignment))
+                    alignPar.Alignment = alignment;
+            };
+
             this.root.AddChild(new VerticalSpace(3));
             this.root.AddChild(new Paragraph(Anchor.AutoLeft, 1, "The code for this demo contains some examples for how to query element data. This is the output of that:"));
 

MLEM.Ui/Elements/Paragraph.cs

@@ -16,7 +16,6 @@ namespace MLEM.Ui.Elements {
     /// </summary>
     public class Paragraph : Element {
 
-        private string text;
         /// <summary>
         /// The font that this paragraph draws text with.
         /// To set its bold and italic font, use <see cref="GenericFont.Bold"/> and <see cref="GenericFont.Italic"/>.
@@ -84,6 +83,20 @@ namespace MLEM.Ui.Elements {
         /// By default, <see cref="MlemPlatform.OpenLinkOrFile"/> is executed.
         /// </summary>
         public Action<Link, LinkCode> LinkAction;
+        /// <summary>
+        /// The <see cref="TextAlignment"/> that this paragraph's text should be rendered with
+        /// </summary>
+        public TextAlignment Alignment {
+            get => this.alignment;
+            set {
+                this.alignment = value;
+                this.SetAreaDirty();
+                this.TokenizedText = null;
+            }
+        }
+
+        private string text;
+        private TextAlignment alignment;
 
         /// <summary>
         /// Creates a new paragraph with the given settings.
@@ -128,10 +141,10 @@ namespace MLEM.Ui.Elements {
 
         /// <inheritdoc />
         public override void Draw(GameTime time, SpriteBatch batch, float alpha, BlendState blendState, SamplerState samplerState, Matrix matrix) {
-            var pos = this.DisplayArea.Location;
+            var pos = this.DisplayArea.Location + new Vector2(GetAlignmentOffset(), 0);
             var sc = this.TextScale * this.TextScaleMultiplier * this.Scale;
             var color = this.TextColor.OrDefault(Color.White) * alpha;
-            this.TokenizedText.Draw(time, batch, pos, this.RegularFont, color, sc, 0);
+            this.TokenizedText.Draw(time, batch, pos, this.RegularFont, color, sc, 0, this.Alignment);
             base.Draw(time, batch, alpha, blendState, samplerState, matrix);
         }
 
@@ -151,7 +164,7 @@ namespace MLEM.Ui.Elements {
         protected virtual void ParseText(Vector2 size) {
             if (this.TokenizedText == null) {
                 // tokenize the text
-                this.TokenizedText = this.System.TextFormatter.Tokenize(this.RegularFont, this.Text);
+                this.TokenizedText = this.System.TextFormatter.Tokenize(this.RegularFont, this.Text, this.Alignment);
 
                 // add links to the paragraph
                 this.RemoveChildren(c => c is Link);
@@ -162,9 +175,9 @@ namespace MLEM.Ui.Elements {
             var width = size.X - this.ScaledPadding.Width;
             var scale = this.TextScale * this.TextScaleMultiplier * this.Scale;
             if (this.TruncateIfLong) {
-                this.TokenizedText.Truncate(this.RegularFont, width, scale, this.Ellipsis);
+                this.TokenizedText.Truncate(this.RegularFont, width, scale, this.Ellipsis, this.Alignment);
             } else {
-                this.TokenizedText.Split(this.RegularFont, width, scale);
+                this.TokenizedText.Split(this.RegularFont, width, scale, this.Alignment);
             }
         }
 
@@ -173,6 +186,16 @@ namespace MLEM.Ui.Elements {
                 this.Text = this.GetTextCallback(this);
         }
 
+        private float GetAlignmentOffset() {
+            switch (this.Alignment) {
+                case TextAlignment.Center:
+                    return this.DisplayArea.Width / 2;
+                case TextAlignment.Right:
+                    return this.DisplayArea.Width;
+            }
+            return 0;
+        }
+
         /// <summary>
         /// A delegate method used for <see cref="Paragraph.GetTextCallback"/>
         /// </summary>
@@ -214,7 +237,7 @@ namespace MLEM.Ui.Elements {
             public override void ForceUpdateArea() {
                 // set the position offset and size to the token's first area
                 var area = this.Token.GetArea(Vector2.Zero, this.textScale).First();
-                this.PositionOffset = area.Location;
+                this.PositionOffset = area.Location + new Vector2(((Paragraph) this.Parent).GetAlignmentOffset() / this.Parent.Scale, 0);
                 this.Size = area.Size;
                 base.ForceUpdateArea();
             }

MLEM/Font/GenericFont.cs

@@ -70,13 +70,13 @@ namespace MLEM.Font {
         }
 
         ///<inheritdoc cref="SpriteFont.MeasureString(string)"/>
-        public Vector2 MeasureString(string text) {
+        public Vector2 MeasureString(string text, bool ignoreTrailingSpaces = false) {
             var size = Vector2.Zero;
             if (text.Length <= 0)
                 return size;
             var xOffset = 0F;
-            foreach (var c in text) {
+            for (var i = 0; i < text.Length; i++) {
-                switch (c) {
+                switch (text[i]) {
                     case '\n':
                         xOffset = 0;
                         size.Y += this.LineHeight;
@@ -90,8 +90,16 @@ namespace MLEM.Font {
                     case Zwsp:
                         // don't add width for a zero-width space
                         break;
+                    case ' ':
+                        if (ignoreTrailingSpaces && IsTrailingSpace(text, i)) {
+                            // if this is a trailing space, we can skip remaining spaces too
+                            i = text.Length - 1;
+                            break;
+                        }
+                        xOffset += this.MeasureChar(' ').X;
+                        break;
                     default:
-                        xOffset += this.MeasureChar(c).X;
+                        xOffset += this.MeasureChar(text[i]).X;
                         break;
                 }
                 // increase x size if this line is the longest
@@ -186,5 +194,13 @@ namespace MLEM.Font {
             return ret.ToString();
         }
 
+        private static bool IsTrailingSpace(string s, int index) {
+            for (var i = index + 1; i < s.Length; i++) {
+                if (s[i] != ' ')
+                    return false;
+            }
+            return true;
+        }
+
     }
 }

MLEM/Formatting/TextAlignment.cs

@@ -0,0 +1,22 @@
+namespace MLEM.Formatting {
+    /// <summary>
+    /// An enumeration that represents a set of alignment options for <see cref="TokenizedString"/> objects and MLEM.Ui paragraphs.
+    /// </summary>
+    public enum TextAlignment {
+
+        /// <summary>
+        /// Left alignment, which is also the default value
+        /// </summary>
+        Left,
+        /// <summary>
+        /// Center alignment
+        /// </summary>
+        Center,
+        /// <summary>
+        /// Right alignment.
+        /// In this alignment option, trailing spaces are ignored to ensure that visual alignment is consistent.
+        /// </summary>
+        Right
+
+    }
+}

MLEM/Formatting/TextFormatter.cs

@@ -67,8 +67,9 @@ namespace MLEM.Formatting {
         /// </summary>
         /// <param name="font">The font to use for tokenization. Note that this font needs to be the same that will later be used for splitting, measuring and/or drawing.</param>
         /// <param name="s">The string to tokenize</param>
+        /// <param name="alignment">The text alignment that should be used. Note that this alignment needs to be the same that will later be used for splitting, measuring and/or drawing.</param>
         /// <returns></returns>
-        public TokenizedString Tokenize(GenericFont font, string s) {
+        public TokenizedString Tokenize(GenericFont font, string s, TextAlignment alignment = TextAlignment.Left) {
             // resolve macros
             s = this.ResolveMacros(s);
             var tokens = new List<Token>();
@@ -101,7 +102,7 @@ namespace MLEM.Formatting {
                 codes.RemoveAll(c => c.EndsHere(next));
                 codes.Add(next);
             }
-            return new TokenizedString(font, s, StripFormatting(font, s, tokens.SelectMany(t => t.AppliedCodes)), tokens.ToArray());
+            return new TokenizedString(font, alignment, s, StripFormatting(font, s, tokens.SelectMany(t => t.AppliedCodes)), tokens.ToArray());
         }
 
         /// <summary>

MLEM/Formatting/Token.cs

@@ -33,6 +33,10 @@ namespace MLEM.Formatting {
         /// </summary>
         public string DisplayString => this.ModifiedSubstring ?? this.Substring;
         /// <summary>
+        /// The <see cref="DisplayString"/>, but split at newline characters
+        /// </summary>
+        public string[] SplitDisplayString { get; internal set; }
+        /// <summary>
         /// The substring that this token contains, without the formatting codes removed.
         /// </summary>
         public readonly string RawSubstring;

MLEM/Formatting/TokenizedString.cs

@@ -38,13 +38,13 @@ namespace MLEM.Formatting {
         public readonly Code[] AllCodes;
         private string modifiedString;
 
-        internal TokenizedString(GenericFont font, string rawString, string strg, Token[] tokens) {
+        internal TokenizedString(GenericFont font, TextAlignment alignment, string rawString, string strg, Token[] tokens) {
             this.RawString = rawString;
             this.String = strg;
             this.Tokens = tokens;
             // since a code can be present in multiple tokens, we use Distinct here
             this.AllCodes = tokens.SelectMany(t => t.AppliedCodes).Distinct().ToArray();
-            this.CalculateTokenAreas(font);
+            this.RecalculateTokenData(font, alignment);
         }
 
         /// <summary>
@@ -55,10 +55,11 @@ namespace MLEM.Formatting {
         /// <param name="font">The font to use for width calculations</param>
         /// <param name="width">The maximum width, in display pixels based on the font and scale</param>
         /// <param name="scale">The scale to use for width measurements</param>
-        public void Split(GenericFont font, float width, float scale) {
+        /// <param name="alignment">The text alignment that should be used for width calculations</param>
+        public void Split(GenericFont font, float width, float scale, TextAlignment alignment = TextAlignment.Left) {
             // a split string has the same character count as the input string but with newline characters added
             this.modifiedString = font.SplitString(this.String, width, scale);
-            this.StoreModifiedSubstrings(font);
+            this.StoreModifiedSubstrings(font, alignment);
         }
 
         /// <summary>
@@ -70,12 +71,13 @@ namespace MLEM.Formatting {
         /// <param name="width">The maximum width, in display pixels based on the font and scale</param>
         /// <param name="scale">The scale to use for width measurements</param>
         /// <param name="ellipsis">The characters to add to the end of the string if it is too long</param>
-        public void Truncate(GenericFont font, float width, float scale, string ellipsis = "") {
+        /// <param name="alignment">The text alignment that should be used for width calculations</param>
+        public void Truncate(GenericFont font, float width, float scale, string ellipsis = "", TextAlignment alignment = TextAlignment.Left) {
             this.modifiedString = font.TruncateString(this.String, width, scale, false, ellipsis);
-            this.StoreModifiedSubstrings(font);
+            this.StoreModifiedSubstrings(font, alignment);
         }
 
-        /// <inheritdoc cref="GenericFont.MeasureString(string)"/>
+        /// <inheritdoc cref="GenericFont.MeasureString(string,bool)"/>
         public Vector2 Measure(GenericFont font) {
             return font.MeasureString(this.DisplayString);
         }
@@ -102,77 +104,116 @@ namespace MLEM.Formatting {
         }
 
         /// <inheritdoc cref="GenericFont.DrawString(SpriteBatch,string,Vector2,Color,float,Vector2,float,SpriteEffects,float)"/>
-        public void Draw(GameTime time, SpriteBatch batch, Vector2 pos, GenericFont font, Color color, float scale, float depth) {
+        public void Draw(GameTime time, SpriteBatch batch, Vector2 pos, GenericFont font, Color color, float scale, float depth, TextAlignment alignment = TextAlignment.Left) {
-            var innerOffset = new Vector2();
+            var innerOffset = new Vector2(this.GetInnerOffsetX(font, 0, 0, scale, alignment), 0);
-            foreach (var token in this.Tokens) {
+            for (var t = 0; t < this.Tokens.Length; t++) {
+                var token = this.Tokens[t];
                 var drawFont = token.GetFont(font) ?? font;
                 var drawColor = token.GetColor(color) ?? color;
-                for (var i = 0; i < token.DisplayString.Length; i++) {
+                for (var l = 0; l < token.SplitDisplayString.Length; l++) {
-                    var c = token.DisplayString[i];
+                    var line = token.SplitDisplayString[l];
-                    if (c == '\n') {
+                    for (var i = 0; i < line.Length; i++) {
-                        innerOffset.X = 0;
+                        var c = line[i];
+                        if (i == 0)
+                            token.DrawSelf(time, batch, pos + innerOffset, font, color, scale, depth);
+
+                        var cString = c.ToCachedString();
+                        token.DrawCharacter(time, batch, c, cString, i, pos + innerOffset, drawFont, drawColor, scale, depth);
+                        innerOffset.X += font.MeasureString(cString).X * scale;
+                    }
+                    // only split at a new line, not between tokens!
+                    if (l < token.SplitDisplayString.Length - 1) {
+                        innerOffset.X = this.GetInnerOffsetX(font, t, l + 1, scale, alignment);
                         innerOffset.Y += font.LineHeight * scale;
                     }
-                    if (i == 0)
-                        token.DrawSelf(time, batch, pos + innerOffset, font, color, scale, depth);
-
-                    var cString = c.ToCachedString();
-                    token.DrawCharacter(time, batch, c, cString, i, pos + innerOffset, drawFont, drawColor, scale, depth);
-                    innerOffset.X += font.MeasureString(cString).X * scale;
                 }
             }
         }
 
-        private void StoreModifiedSubstrings(GenericFont font) {
+        private void StoreModifiedSubstrings(GenericFont font, TextAlignment alignment) {
-            // skip substring logic for unformatted text
             if (this.Tokens.Length == 1) {
+                // skip substring logic for unformatted text
                 this.Tokens[0].ModifiedSubstring = this.modifiedString;
-                return;
+            } else {
+                // this is basically a substring function that ignores added newlines for indexing
+                var index = 0;
+                var currToken = 0;
+                var splitIndex = 0;
+                var ret = new StringBuilder();
+                while (splitIndex < this.modifiedString.Length && currToken < this.Tokens.Length) {
+                    var token = this.Tokens[currToken];
+                    if (token.Substring.Length > 0) {
+                        ret.Append(this.modifiedString[splitIndex]);
+                        // if the current char is not an added newline, we simulate length increase
+                        if (this.modifiedString[splitIndex] != '\n' || this.String[index] == '\n')
+                            index++;
+                        splitIndex++;
+                    }
+                    // move on to the next token if we reached its end
+                    if (index >= token.Index + token.Substring.Length) {
+                        token.ModifiedSubstring = ret.ToString();
+                        ret.Clear();
+                        currToken++;
+                    }
+                }
+                // set additional token contents beyond our string in case we truncated
+                if (ret.Length > 0)
+                    this.Tokens[currToken++].ModifiedSubstring = ret.ToString();
+                while (currToken < this.Tokens.Length)
+                    this.Tokens[currToken++].ModifiedSubstring = string.Empty;
             }
 
-            // this is basically a substring function that ignores added newlines for indexing
+            this.RecalculateTokenData(font, alignment);
-            var index = 0;
-            var currToken = 0;
-            var splitIndex = 0;
-            var ret = new StringBuilder();
-            while (splitIndex < this.modifiedString.Length && currToken < this.Tokens.Length) {
-                var token = this.Tokens[currToken];
-                if (token.Substring.Length > 0) {
-                    ret.Append(this.modifiedString[splitIndex]);
-                    // if the current char is not an added newline, we simulate length increase
-                    if (this.modifiedString[splitIndex] != '\n' || this.String[index] == '\n')
-                        index++;
-                    splitIndex++;
-                }
-                // move on to the next token if we reached its end
-                if (index >= token.Index + token.Substring.Length) {
-                    token.ModifiedSubstring = ret.ToString();
-                    ret.Clear();
-                    currToken++;
-                }
-            }
-            // set additional token contents beyond our string in case we truncated
-            if (ret.Length > 0)
-                this.Tokens[currToken++].ModifiedSubstring = ret.ToString();
-            while (currToken < this.Tokens.Length)
-                this.Tokens[currToken++].ModifiedSubstring = string.Empty;
-
-            this.CalculateTokenAreas(font);
         }
 
-        private void CalculateTokenAreas(GenericFont font) {
+        private float GetInnerOffsetX(GenericFont font, int tokenIndex, int lineIndex, float scale, TextAlignment alignment) {
-            var innerOffset = new Vector2();
+            if (alignment > TextAlignment.Left) {
-            foreach (var token in this.Tokens) {
+                var rest = this.GetRestOfLineLength(font, tokenIndex, lineIndex) * scale;
+                if (alignment == TextAlignment.Center)
+                    rest /= 2;
+                return -rest;
+            }
+            return 0;
+        }
+
+        private float GetRestOfLineLength(GenericFont font, int tokenIndex, int lineIndex) {
+            var token = this.Tokens[tokenIndex];
+            var ret = font.MeasureString(token.SplitDisplayString[lineIndex], true).X;
+            if (lineIndex >= token.SplitDisplayString.Length - 1) {
+                // the line ends somewhere in or after the next token
+                for (var i = tokenIndex + 1; i < this.Tokens.Length; i++) {
+                    var other = this.Tokens[i];
+                    if (other.SplitDisplayString.Length > 1) {
+                        // the line ends in this token
+                        ret += font.MeasureString(other.SplitDisplayString[0]).X;
+                        break;
+                    } else {
+                        // the line doesn't end in this token, so add it fully
+                        ret += font.MeasureString(other.DisplayString).X;
+                    }
+                }
+            }
+            return ret;
+        }
+
+        private void RecalculateTokenData(GenericFont font, TextAlignment alignment) {
+            // split display strings
+            foreach (var token in this.Tokens)
+                token.SplitDisplayString = token.DisplayString.Split('\n');
+
+            // token areas
+            var innerOffset = new Vector2(this.GetInnerOffsetX(font, 0, 0, 1, alignment), 0);
+            for (var t = 0; t < this.Tokens.Length; t++) {
+                var token = this.Tokens[t];
                 var area = new List<RectangleF>();
-                var split = token.DisplayString.Split('\n');
+                for (var l = 0; l < token.SplitDisplayString.Length; l++) {
-                for (var i = 0; i < split.Length; i++) {
+                    var size = font.MeasureString(token.SplitDisplayString[l]);
-                    var size = font.MeasureString(split[i]);
                     var rect = new RectangleF(innerOffset, size);
                     if (!rect.IsEmpty)
                         area.Add(rect);
 
-                    if (i < split.Length - 1) {
+                    if (l < token.SplitDisplayString.Length - 1) {
-                        innerOffset.X = 0;
+                        innerOffset.X = this.GetInnerOffsetX(font, t, l + 1, 1, alignment);
                         innerOffset.Y += font.LineHeight;
                     } else {
                         innerOffset.X += size.X;