Merge pull request #1 from wieslawsoltes/feat/upstream-pretext-sync

feat: port upstream keep-all word breaking and rich-inline helpers

Author: wieslawsoltes

.gitignore

@@ -65,6 +65,7 @@ BenchmarkDotNet.Artifacts/
 project.lock.json
 project.fragment.lock.json
 artifacts/
+plan/
 
 # Tye
 .tye/

Directory.Packages.props

@@ -6,6 +6,7 @@
     See https://aka.platform.uno/using-uno-sdk#implicit-packages for more information regarding the Implicit Packages.
   -->
   <ItemGroup>
+    <PackageVersion Include="Markdig" Version="0.43.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
     <PackageVersion Include="SkiaSharp" Version="3.119.1" />

README.md

@@ -21,6 +21,7 @@ Key documentation:
 - [Choosing an API](https://wieslawsoltes.github.io/PretextSharp/articles/getting-started/choosing-an-api/)
 - [Prepared Text Lifecycle](https://wieslawsoltes.github.io/PretextSharp/articles/concepts/prepared-text-lifecycle/)
 - [Public Types and Operations](https://wieslawsoltes.github.io/PretextSharp/articles/reference/public-types-and-operations/)
+- [Rich Inline API](https://wieslawsoltes.github.io/PretextSharp/articles/reference/rich-inline-api/)
 - [Pretext.Uno Helpers](https://wieslawsoltes.github.io/PretextSharp/articles/reference/pretext-uno-helpers/)
 
 ## NuGet Packages
@@ -34,12 +35,16 @@ Key documentation:
 
 - Prepare text once and reuse the result across repeated layout passes with `Prepare` and `PrepareWithSegments`.
 - Compute fast aggregate metrics with `Layout`, or materialize full line data with `LayoutWithLines`.
-- Stream line geometry incrementally with `LayoutNextLine` and `WalkLineRanges` for custom layout engines.
+- Stream line geometry incrementally with `LayoutNextLine`, `LayoutNextLineRange`, and `WalkLineRanges` for custom layout engines.
+- Re-materialize text lazily with `MaterializeLineRange` after cheap geometry-only probing.
+- Measure widest-line geometry without allocating text via `MeasureLineStats` and `MeasureNaturalWidth`.
 - Handle ordinary spaces, preserved spaces, tabs, hard breaks, non-breaking spaces, zero-width breaks, and soft hyphens.
+- Support `WordBreakMode.KeepAll` for CJK-focused no-space wrapping behavior.
+- Build rich inline flows with `PrepareRichInline`, `WalkRichInlineLineRanges`, and `MaterializeRichInlineLineRange`.
 - Support multilingual text with locale-aware segmentation on desktop targets and bidi-aware segment levels.
 - Depend only on `SkiaSharp` in the core library so the package can be used outside Uno as well.
 - Ship with a published `Pretext.Uno` companion library for reusable Uno host controls and obstacle-aware flow helpers.
-- Ship with deterministic parity tests and a Uno sample app that demonstrates bubbles, masonry, editorial, and justification layouts.
+- Ship with deterministic parity tests and a Uno sample app that demonstrates bubbles, masonry, editorial, justification, rich-inline, and virtualized markdown chat layouts.
 
 ## Core API
 
@@ -50,7 +55,15 @@ Key documentation:
 | `Layout` | Return line count and total height for a given width and line height. |
 | `LayoutWithLines` | Return materialized line text and line widths. |
 | `LayoutNextLine` | Stream the next line from a given cursor for custom layout flows. |
+| `LayoutNextLineRange` | Stream geometry-only line ranges without materializing text. |
+| `MaterializeLineRange` | Turn a `LayoutLineRange` back into a materialized `LayoutLine`. |
 | `WalkLineRanges` | Iterate line geometry without allocating full line text. |
+| `MeasureLineStats` | Return line count plus widest line width for a prepared block. |
+| `MeasureNaturalWidth` | Return the widest unwrapped line width for prepared text. |
+| `PrepareRichInline` | Prepare multi-item inline flow with collapsed boundary whitespace and atomic items. |
+| `WalkRichInlineLineRanges` | Stream rich-inline line ranges without materializing fragment text. |
+| `MaterializeRichInlineLineRange` | Materialize one streamed rich-inline line when you actually need fragment text. |
+| `MeasureRichInlineStats` | Measure rich-inline line count and max line width. |
 | `ProfilePrepare` | Measure preparation cost for profiling and diagnostics. |
 | `SetLocale` | Override locale-sensitive segmentation behavior when needed. |
 | `ClearCache` | Reset cached font state and prepared segment text caches. |
@@ -63,6 +76,7 @@ Key documentation:
 | Actual line text and widths | `PrepareWithSegments` + `LayoutWithLines` |
 | One line at a time in a custom loop | `PrepareWithSegments` + `LayoutNextLine` |
 | Geometry only, fewer allocations | `PrepareWithSegments` + `WalkLineRanges` |
+| Rich inline fragments with atomic chips or badges | `PrepareRichInline` + `WalkRichInlineLineRanges` |
 | Preparation cost diagnostics | `ProfilePrepare` |
 
 ## Quick Start
@@ -95,6 +109,8 @@ foreach (var line in lines.Lines)
 }
 ```
 
+If the prepared text is empty after normalization, `Layout` returns `new LayoutResult(0, 0)`. If a container in your UI must still reserve one visual row, clamp with `Math.Max(1, metrics.LineCount)` in the caller instead of expecting `Pretext` to synthesize a blank line.
+
 The core package exposes the `Pretext` namespace and is not tied to Uno. Use it anywhere you use SkiaSharp.
 
 The `font` argument is a CSS-like subset such as `16px Inter`, `italic 16px Georgia`, or `700 18px "IBM Plex Sans"`. Line height is supplied separately to layout calls.
@@ -108,6 +124,32 @@ var prepared = PretextLayout.PrepareWithSegments(
     new PrepareOptions(WhiteSpaceMode.PreWrap));
 ```
 
+Use `WordBreakMode.KeepAll` when CJK-heavy text should avoid ordinary intra-run breaks:
+
+```csharp
+var prepared = PretextLayout.PrepareWithSegments(
+    "日本語foo-bar",
+    "16px Inter",
+    new PrepareOptions(WordBreak: WordBreakMode.KeepAll));
+```
+
+Use the rich-inline helper when paragraph text and atomic inline boxes must share one flow:
+
+```csharp
+var flow = PretextLayout.PrepareRichInline(
+[
+    new RichInlineItem("Ship ", "16px Inter"),
+    new RichInlineItem("@maya", "700 12px Inter", RichInlineBreakMode.Never, extraWidth: 18),
+    new RichInlineItem("'s note wraps cleanly.", "16px Inter"),
+]);
+
+PretextLayout.WalkRichInlineLineRanges(flow, 180, line =>
+{
+    var materialized = PretextLayout.MaterializeRichInlineLineRange(flow, line);
+    Console.WriteLine(string.Join("", materialized.Fragments.Select(f => f.Text)));
+});
+```
+
 ## Uno Companion
 
 Install the Uno companion package when you want the reusable Uno-specific helpers on top of the core engine:
@@ -134,6 +176,7 @@ The sample app lives in `samples/PretextSamples` and demonstrates the library in
 - Bubbles
 - Masonry
 - Rich Text
+- Markdown Chat
 - Dynamic Layout
 - Editorial Engine
 - Justification Comparison

samples/PretextSamples/Assets/shower_thoughts.json

@@ -17,6 +17,7 @@
         <NavigationViewItem Content="Bubbles" Tag="bubbles" Icon="Comment" />
         <NavigationViewItem Content="Masonry" Tag="masonry" Icon="Library" />
         <NavigationViewItem Content="Rich Text" Tag="rich" Icon="Document" />
+        <NavigationViewItem Content="Markdown Chat" Tag="markdown-chat" Icon="Comment" />
         <NavigationViewItem Content="Dynamic Layout" Tag="dynamic" Icon="Pictures" />
         <NavigationViewItem Content="Editorial Engine" Tag="editorial" Icon="Play" />
         <NavigationViewItem Content="Justification Comparison" Tag="justification" Icon="Document" />

samples/PretextSamples/MainPage.xaml

@@ -12,6 +12,7 @@ public sealed partial class MainPage : Page
         ["bubbles"] = static () => new BubblesSampleView(),
         ["masonry"] = static () => new MasonrySampleView(),
         ["rich"] = static () => new RichNoteSampleView(),
+        ["markdown-chat"] = static () => new MarkdownChatSampleView(),
         ["dynamic"] = static () => new DynamicLayoutSampleView(),
         ["editorial"] = static () => new EditorialEngineSampleView(),
         ["justification"] = static () => new JustificationComparisonSampleView(),

samples/PretextSamples/MainPage.xaml.cs

@@ -1,5 +1,6 @@
 <Project Sdk="Uno.Sdk">
   <ItemGroup>
+    <PackageReference Include="Markdig" />
     <ProjectReference Include="..\..\src\Pretext.Uno\Pretext.Uno.csproj" />
     <PackageReference Include="Tmds.DBus.Protocol" />
   </ItemGroup>