flutter_markdown_stream 0.3.0

Flicker-free streaming Markdown widget for Flutter. Renders partial LLM token streams progressively, handling unclosed syntax gracefully.

Changelog

0.3.0

• StreamingTextController: programmatic playback control for MarkdownStream. Call pause(), resume(), skipToEnd(), stop(), or restart() (the latter requires a streamFactory). Exposes a StreamingState enum (idle, streaming, paused, completed, error), live currentText / chunkCount, an onStateChanged and onCompleted callback, and a speedMultiplier that compresses or stretches the effective rebuild debounce.

• StreamingTextConfig and StreamingPresets: bundle the rebuild debounce and fade settings into a single value. Named presets: chatGPT, claude, instant, typewriter, gentle, fast. Supply a preset directly:

  MarkdownStream(stream: s, config: StreamingPresets.claude)
  

• Trailing-fade effect: opt-in via config.fadeInEnabled. A bottom-edge gradient softens newly-arriving content while streaming and animates away over fadeInDuration on onDone.

• LaTeX support: supply a latexBuilder to MarkdownStream to render inline ($…$) and block ($$…$$) math expressions via your preferred renderer (e.g. flutter_math_fork). No math dependency is added to the package — bring your own. Includes LaTeXBlockSyntax, LaTeXInlineSyntax, LaTeXElementBuilder, and a new latexEnabled flag on SafeMarkdownParser.sanitize() for delimiter balancing during streaming.

• RTL / textDirection: wrap rendered output in a Directionality when textDirection is set, enabling Arabic, Hebrew, and similar right-to-left scripts without external widgets.

All additions are non-breaking and opt-in. No new pub dependencies.

0.2.0

• Breaking: Migrated from the discontinued flutter_markdown to flutter_markdown_plus (the official successor maintained by Foresight Mobile).
  • sizedImageBuilder parameter renamed to imageBuilder.
  • MarkdownSizedImageBuilder typedef replaced by MarkdownImageBuilder (signature changed from (Uri, MarkdownImageConfig) to (Uri, String?, String?)).
• Shortened package description to comply with pub.dev 60–180 character guideline.

0.1.0

Initial release of flutter_markdown_stream (formerly developed under the working name flutter_markdown_stream).

• MarkdownStream widget that renders Stream<String> of Markdown chunks progressively, with a one-frame debounce and optional cursor widget.
• Rebuilds are scoped tightly via ValueNotifier + ValueListenableBuilder; no setState in the hot path, so incoming tokens do not invalidate the outer widget subtree or restart unrelated animations.
• MarkdownStream is generic over the chunk type: MarkdownStream<T> accepts any Stream<T> with a chunkToText extractor. Stream<String> remains the default and requires no extractor.
• StreamAdapters utility with three composable converters for common non-string stream shapes: utf8Bytes (UTF-8 safe across byte splits), serverSentEvents (multi-chunk-safe SSE parser honouring [DONE]), and jsonField (nested JSON string extraction).
• SafeMarkdownParser.sanitize utility that repairs unclosed bold, italic, strikethrough, inline code, fenced code blocks, inline links, and autolinks mid-stream.
• Full MarkdownBody pass-through: styleSheet, styleSheetTheme, syntaxHighlighter, onTapLink, onTapText, imageDirectory, blockSyntaxes, inlineSyntaxes, extensionSet, sizedImageBuilder, checkboxBuilder, bulletBuilder, builders, paddingBuilders, listItemCrossAxisAlignment, fitContent, shrinkWrap, softLineBreak, selectable — anything you can do with flutter_markdown you can do with MarkdownStream.
• codeBuilder fires only for fenced (block) code, never for inline code. A builders['code'] entry takes precedence over codeBuilder if both are supplied.
• Stream errors cancel the subscription cleanly (cancelOnError: true) and are finalized through the same onDone path.
• Family of eight cursor widgets: BlinkingCursor, BarCursor, FadingCursor, PulsingCursor, TypingDotsCursor, WaveDotsCursor, SpinnerCursor, ShimmerCursor. All default to the ambient text colour, share the same customization shape (color, size, period), and dispose their tickers cleanly.
• flutter_lints-clean: zero analyzer issues. Targets Flutter >=3.27.0, Dart >=3.6.0. Uses Color.withValues(alpha:) (the withOpacity successor) and MarkdownBody.sizedImageBuilder (the imageBuilder successor) so the package stays green against current upstream APIs.
• Full unit-test coverage of the sanitizer across adversarial inputs.
• Widget tests cover stream swap, cursor lifecycle, partial code fences.
• Example app demonstrating the widget with a simulated token stream and a gallery of every cursor.