using Bloxstrap.UI.ViewModels; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Markup; using System.Windows; using Markdig.Syntax; using Markdig.Syntax.Inlines; using Markdig; using System.Windows.Media; namespace Bloxstrap.UI.Elements.Controls { /// /// TextBlock with markdown support. /// [ContentProperty("MarkdownText")] [Localizability(LocalizationCategory.Text)] class MarkdownTextBlock : TextBlock { private static MarkdownPipeline _markdownPipeline; public static readonly DependencyProperty MarkdownTextProperty = DependencyProperty.Register(nameof(MarkdownText), typeof(string), typeof(MarkdownTextBlock), new FrameworkPropertyMetadata(string.Empty, FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender, OnTextMarkdownChanged)); [Localizability(LocalizationCategory.Text)] public string MarkdownText { get => (string)GetValue(MarkdownTextProperty); set => SetValue(MarkdownTextProperty, value); } private static System.Windows.Documents.Inline? GetWpfInlineFromMarkdownInline(Markdig.Syntax.Inlines.Inline? inline) { if (inline is LiteralInline literalInline) { return new Run(literalInline.ToString()); } else if (inline is EmphasisInline emphasisInline) { switch (emphasisInline.DelimiterChar) { case '*': case '_': { if (emphasisInline.DelimiterCount == 1) // 1 = italic { var childInline = new Italic(GetWpfInlineFromMarkdownInline(emphasisInline.FirstChild)); return childInline; } else // 2 = bold { var childInline = new Bold(GetWpfInlineFromMarkdownInline(emphasisInline.FirstChild)); return childInline; } } case '=': // marked { var childInline = new Span(GetWpfInlineFromMarkdownInline(emphasisInline.FirstChild)); childInline.Background = new SolidColorBrush(Color.FromArgb(50, 255, 255, 255)); // TODO: better colour? return childInline; } } } else if (inline is LinkInline linkInline) { string? url = linkInline.Url; var textInline = linkInline.FirstChild; if (string.IsNullOrEmpty(url)) { return GetWpfInlineFromMarkdownInline(textInline); } var childInline = GetWpfInlineFromMarkdownInline(textInline); return new Hyperlink(childInline) { Command = GlobalViewModel.OpenWebpageCommand, CommandParameter = url }; } return null; } private void AddMarkdownInline(Markdig.Syntax.Inlines.Inline? inline) { var wpfInline = GetWpfInlineFromMarkdownInline(inline); if (wpfInline != null) Inlines.Add(wpfInline); } private static void OnTextMarkdownChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs dependencyPropertyChangedEventArgs) { if (dependencyObject is not MarkdownTextBlock markdownTextBlock) return; if (dependencyPropertyChangedEventArgs.NewValue is not string rawDocument) return; MarkdownDocument document = Markdown.Parse(rawDocument, _markdownPipeline); markdownTextBlock.Inlines.Clear(); if (document.FirstOrDefault() is not ParagraphBlock paragraphBlock || paragraphBlock.Inline == null) return; for (int i = 0; i < paragraphBlock.Inline.Count(); i++) { var inline = paragraphBlock.Inline.ElementAt(i); markdownTextBlock.AddMarkdownInline(inline); } } static MarkdownTextBlock() { _markdownPipeline = new MarkdownPipelineBuilder() .UseEmphasisExtras(Markdig.Extensions.EmphasisExtras.EmphasisExtraOptions.Marked) // enable '==' support .Build(); } } }