more robust markdowntextblock

Bloxstrap/UI/Elements/Controls/MarkdownTextBlock.cs

@@ -6,6 +6,7 @@ using System.Windows;
 using Markdig.Syntax;
 using Markdig.Syntax.Inlines;
 using Markdig;
+using System.Windows.Media;
 
 namespace Bloxstrap.UI.Elements.Controls
 {
@@ -19,15 +20,97 @@ namespace Bloxstrap.UI.Elements.Controls
     {
         public static readonly DependencyProperty MarkdownTextProperty = 
             DependencyProperty.Register(nameof(MarkdownText), typeof(string), typeof(MarkdownTextBlock),
-                new FrameworkPropertyMetadata(string.Empty,FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender, OnTextMarkdownChanged));
+                new FrameworkPropertyMetadata(string.Empty, FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender, OnTextMarkdownChanged));
 
         [Localizability(LocalizationCategory.Text)]
         public string MarkdownText
         {
-            get => Inlines.ToString() ?? "";
+            get => (string)GetValue(MarkdownTextProperty);
             set => SetValue(MarkdownTextProperty, value);
         }
 
+        /// <returns>Span, skip</returns>
+        private static (Span, int) GetInlineUntilEndTagDetected(Markdig.Syntax.Inlines.Inline? inline, string tagName)
+        {
+            string endTag = $"<{tagName}/>"; // TODO: better way of doing this
+
+            var span = new Span();
+
+            int skip = 0;
+            var current = inline;
+            while (current is Markdig.Syntax.Inlines.Inline currentInline)
+            {
+                skip++;
+
+                if (currentInline is HtmlInline html)
+                {
+                    if (html.Tag == endTag)
+                        return (span, skip);
+                }
+
+                (var childInline, int childSkip) = GetWpfInlineFromMarkdownInline(currentInline);
+                if (childInline != null)
+                    span.Inlines.Add(childInline);
+
+                skip += childSkip;
+
+                current = currentInline.NextSibling;
+            }
+
+            throw new Exception("End tag not detected");
+        }
+
+        /// <returns>Inline, skip</returns>
+        private static (System.Windows.Documents.Inline?, int) GetWpfInlineFromMarkdownInline(Markdig.Syntax.Inlines.Inline? inline)
+        {
+            if (inline is LiteralInline literalInline)
+            {
+                return (new Run(literalInline.ToString()), 0);
+            }
+            else if (inline is LinkInline linkInline)
+            {
+                string? url = linkInline.Url;
+                var textInline = linkInline.FirstChild;
+
+                if (string.IsNullOrEmpty(url))
+                {
+                    return GetWpfInlineFromMarkdownInline(textInline);
+                }
+
+                (var childInline, int skip) = GetWpfInlineFromMarkdownInline(textInline);
+
+                return (new Hyperlink(childInline)
+                {
+                    Command = GlobalViewModel.OpenWebpageCommand,
+                    CommandParameter = url
+                }, skip);
+            }
+            else if (inline is HtmlInline htmlInline)
+            {
+                string? tag = htmlInline.Tag; // TODO: parse tag
+                var nextInline = htmlInline.NextSibling;
+
+                if (tag == "<highlight>")
+                {
+                    (var span, int skip) = GetInlineUntilEndTagDetected(nextInline, "highlight");
+                    span.Background = new SolidColorBrush(Color.FromArgb(50,255,255,255));
+                    return (span, skip);
+                }
+            }
+
+            return (null, 0);
+        }
+
+        /// <returns>Skip</returns>
+        private int AddMarkdownInline(Markdig.Syntax.Inlines.Inline? inline)
+        {
+            (var wpfInline, int skip) = GetWpfInlineFromMarkdownInline(inline);
+            if (wpfInline != null)
+                Inlines.Add(wpfInline);
+
+            return skip;
+        }
+
         private static void OnTextMarkdownChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs dependencyPropertyChangedEventArgs)
         {
             if (dependencyObject is not MarkdownTextBlock markdownTextBlock)
@@ -43,26 +126,12 @@ namespace Bloxstrap.UI.Elements.Controls
             if (document.FirstOrDefault() is not ParagraphBlock paragraphBlock || paragraphBlock.Inline == null)
                 return;
 
-            foreach (var inline in paragraphBlock.Inline)
+            for (int i = 0; i < paragraphBlock.Inline.Count(); i++)
             {
-                if (inline is LiteralInline literalInline)
+                var inline = paragraphBlock.Inline.ElementAt(i);
-                {
-                    markdownTextBlock.Inlines.Add(new Run(literalInline.ToString()));
-                }
-                else if (inline is LinkInline linkInline)
-                {
-                    string? url = linkInline.Url;
-                    string? text = linkInline.FirstChild?.ToString();
 
-                    if (string.IsNullOrEmpty(url) || string.IsNullOrEmpty(text))
+                int skip = markdownTextBlock.AddMarkdownInline(inline);
-                        continue;
+                i += skip;
-
-                    markdownTextBlock.Inlines.Add(new Hyperlink(new Run(text))
-                    {
-                        Command = GlobalViewModel.OpenWebpageCommand,
-                        CommandParameter = url
-                    });
-                }
             }
         }
     }