[kamilkaczmareksolutions]

What changed?

One WinUI 3 window opens a local .md or .markdown file and renders it offline. The build copies Sources/PreviewMD/Resources/Renderer/ unchanged and checks every file against ports/windows/renderer.sha256. Relative images stay inside the open document's folder. http, https, and mailto links open with Launcher.LaunchUriAsync.

The first screen is empty, with Open and Showcase. The window title is PreviewMD (Windows experiment). A file can also be dropped from Explorer. Ctrl+O opens the picker. Ctrl+W closes the document. Opened files appear in the taskbar Recent list.

Why this approach?

Issue 22 names WinUI 3 and WebView2. The renderer already rewrites local images to previewmd-local-image, so the shell registers that scheme and serves the bytes. A second virtual host that rewrites img.src after render would race the diagram pass.

An unpackaged build copies the Windows App SDK next to the executable, so dotnet run does not need a separate runtime install. -p:WindowsPackageType=MSIX selects the package build. That package expects the Windows App Runtime.

How was it tested?

• dotnet test ports/windows/PreviewMD.Windows.sln passed, 17 tests, 0 failed
• dotnet build ports/windows/PreviewMD.Windows.sln passed, 0 warnings
• swift test — this change does not touch the macOS app
• python3 -m unittest discover -s site -p 'test_*.py' — the site is unchanged
• ./scripts/build-app.sh — packaging of the macOS app is unchanged
• Manual run of PreviewMD.Windows.exe on Windows 11

The empty window showed Open and Showcase. A local note showed a relative image, a KaTeX formula, and a highlighted Swift block. A second note drew a Mermaid flowchart with no network. Showcase loaded the bundled welcome.md, including its badge images. Open chose a file. A drag from Explorer opened another file. An https link opened Brave on Example Domain. The taskbar Recent list showed the opened names.

Visual evidence

The runs above were on this machine. Screenshots stayed local. They are not in the branch.

Contributor checklist

• The change is focused and does not rewrite unrelated code.
• New behavior has tests or an explanation of why a test is impractical.
• Offline rendering and document privacy remain intact.
• Third-party code includes source, version, license, and notices.
• No credentials, private documents, subscriber data, or local paths were added.
• Every commit has a DCO Signed-off-by line (git commit -s).
• Public use of the PreviewMD name/icon follows TRADEMARKS.md.

Follow-ups or limitations

Tabs and Ctrl+Tab stay out. This issue leaves a TabView until after the slice works.

A directory junction inside the document folder can still point outside it. Path.GetFullPath does not resolve that.

The MSIX was produced and not installed. The running build was unpackaged, with the same copied renderer.

Fixes #22

[kamilkaczmareksolutions]

Pushed feat(windows): close a document, drop a file, and remember it.

Ctrl+W returned the window to the empty screen. A local note still renders. Clicking the http link in the document opened Brave on Example Domain.

dotnet publish -p:WindowsPackageType=MSIX produced PreviewMD.Windows_1.0.0.0_x64.msix. That package is not committed and was not installed.

Tabs and Ctrl+Tab stay out, as the issue leaves tabs until after this slice.

[kamilkaczmareksolutions]

The three remaining checks are now visible on a running window.

• Open chose picker.md. The window showed “Opened from the picker”.
• A drag from Explorer of explorer.md opened that file. The window showed “Dropped from Explorer”.
• A right-click on the taskbar button showed Recent: explorer.md, picker.md, link.md, and opened.md.

[ashtree74]

Thank you for the WinUI 3 experiment and the Windows smoke-test results. The macOS fixes have now landed in #29; this port remains separate and #22 stays open until the Windows slice is ready to merge.

Before merging:

1. Sync with current main and refresh the renderer manifest with deterministic checkout line endings. I compared all 77 entries: 15 pins match CRLF-converted text rather than the Git blob bytes, and editor.js, renderer.css and renderer.js have changed in 1.8. The checksum checks must continue to verify the actual current renderer.
2. Address the resource-confinement limitation already documented in the PR/README, with a Windows regression test matching the document-folder restriction promised in #22.
3. Re-run the Windows tests/build on the updated branch and verify installation/launch of the MSIX, which is currently recorded as produced but not installed. Update the README's excluded-feature list, which still excludes drag/drop and the Jump List even though this PR implements them.

This is a source review and checksum comparison; I have not independently run WinUI/MSIX on Windows. No CI checks were returned for this revision, so the existing macOS release validation does not validate this port.

[kamilkaczmareksolutions]

Thanks for the review. Follow-up is on tip 38598fa (also mirrored on fork draft kamilkaczmareksolutions#2). The head of this PR (port/windows-winui) is now at that tip.

1. Sync + pins. Current upstream main is merged (incl. 1.8/1.9 renderer from #29+). ports/windows/renderer.sha256 is regenerated from Git blob bytes; text renderer files check out LF (.gitattributes). python3 ports/windows/pin-renderer.py exits 1 if the work tree differs from HEAD. Checksum gate stays on. On Windows, dotnet test and verify-renderer.ps1 pass; the build log shows Renderer checksum shell is pwsh.

2. Confinement. ImagePolicy follows the final target of a symlink/junction, then applies the document-folder prefix check. DocumentFolderAllowsARelativeImageAndRefusesEscape passed on Win11 with mklink /J. Volume-root ResolveLinkTarget(@"C:\") throwing DirectoryNotFoundException is treated as identity (not InvalidRequest), so relative images under the document folder work again.

3. Build / MSIX / README. dotnet build and unpackaged Release launch succeed on Win11 (window title PreviewMD (Windows experiment)). MSIX package builds; sideload of the unsigned test package fails with 0x800B0100 (needs a signing cert — same on prior tip). README no longer lists drag/drop or Jump List as excluded.

Happy to rebase onto #28’s head / adjust signing if you want a different packaging path.