Notepad Viewer Plus

Offline, view-only multi-format preview for Notepad++ with a native WebView2 shell and a TypeScript viewer registry.

Implemented foundation

• Dockable native Win32/WebView2 panel lifecycle with protocol-v2, generation-aware updates.
• Public identity NotepadViewerPlus / “Notepad Viewer Plus”, fresh WebView2 data directory, renamed panel class, and migration from MarkdownPreviewPlus.ini to NotepadViewerPlus.ini.
• Explicit text versus opaque exact-file source modes. PDF and image bytes never pass through the JSON bridge or SCI_GETTEXT.
• Cryptographically random, generation-bound exact-file tokens with revocation, MIME allowlisting, response headers, and bounded HTTP ranges.
• Viewer shell and registry with Markdown, standalone Mermaid/PlantUML, HTML sandbox, sanitized SVG, JSON/YAML/XML trees, CSV/TSV virtualization, image controls, safe plain-text fallback, and a view-only PDF resource viewer.
• Format-aware light/dark/system theming: native dark UI where supported, effective-theme rendering for Mermaid/PlantUML/KaTeX/code, compatibility canvases for authored or third-party content, and selectable image/SVG artboards.
• Offline-by-default navigation/resource policy, strict CSP, standalone/generated SVG sanitization, same-document OpenAPI $ref validation, and bounded parser/rendering limits.
• Pinned dependencies, license inventory, size report, fixtures, and unit/security tests.
• Phase 3 native UX: a theme-aware Toggle Preview toolbar button and an About Notepad Viewer Plus dialog with the canonical release version and author homepage.
• Reproducible version.json release identity, synchronized renderer metadata, x64/x86 structural package validation, export/PE/version checks, and validator-backed Plugin Admin entry generation.

See PHASE-2-MULTI-FORMAT-PLAN.md, docs/syntax-support.md, docs/security-model.md, and docs/architecture-decisions/ADR-0002-phase2-isolation.md.

The preview starts hidden unless Notepad++ restores a panel left open. Use Ctrl+Alt+P, Plugins → Notepad Viewer Plus → Toggle Preview, or the toolbar button to show or hide the same docked panel. Plugins → Notepad Viewer Plus → About Notepad Viewer Plus opens a native dialog that does not depend on WebView2.

Project folder identity

Use notepad-viewer-plus for the checkout folder. To finish migrating an existing old-name checkout, close Pi/IDEs and run Rename-ProjectFolder.ps1 from an external PowerShell window. It preserves Git history, source, dependencies, and release ZIPs, invalidates verified native build caches, and refreshes current-version package reports. See docs/project-name-migration.md for rebuild commands and intentional legacy references.

Clone setup

Clone the source repository with its pinned Notepad++ SDK gitlink, then generate the ignored versioned installer wrapper before the first build:

git clone --recurse-submodules https://github.com/Duclevn/notepad-viewer-plus.git
cd notepad-viewer-plus
node packaging/sync-version.mjs --write

If the repository was cloned without --recurse-submodules, run git submodule update --init --recursive. The repository includes the WebView2 headers and x64/x86 static loader libraries required for fresh native builds; other generated SDK build files remain ignored.

OneDrive / another computer

Start with New computer setup for the complete download, tooling, build/test, installation, and runtime checklist.

For the transition from Pi to interactive Codex development, read Codex handover. It records the current computer's validated build/install, the missing-square-root rendering defect, and the remaining visual checks.

From any notepad-viewer-plus checkout, use Build-Development.ps1: it resolves the checkout automatically, validates the renderer, and creates fresh x64/x86 native builds outside OneDrive under %LOCALAPPDATA%. On a new Windows computer, install the development tools, finish downloading the folder, then run:

powershell -NoProfile -ExecutionPolicy Bypass -File .\Build-Development.ps1 -InstallDependencies

See OneDrive development for prerequisites, local package paths, and safe computer-switching rules. .gitignore does not control OneDrive syncing; do not work on the synced checkout concurrently from two computers.

Renderer development

node packaging/sync-version.mjs --check
cd renderer
npm ci
npm run lint
npm test
npm run build
npm run size:strict
npm run licenses

To run the browser smoke page, build and serve renderer/dist with a local static server, then open /?demo=1. The development-only demo is not used by the Notepad++ host.

Native build

For this synced checkout, prefer Build-Development.ps1 as described above. The following in-checkout build commands are for a non-synced checkout only. Install the official Notepad++ plugin SDK, WebView2 Win32 SDK, and Visual Studio Build Tools, then configure:

cmake -S . -B build -G "Visual Studio 17 2022" -A x64 \
  -DNPP_SDK_DIR="C:/path/to/plugintemplate" \
  -DWEBVIEW2_SDK_DIR="C:/path/to/Microsoft.Web.WebView2"
cmake --build build --config Release
ctest --test-dir build -C Release --output-on-failure
cpack --config build/CPackConfig.cmake -C Release

This produces an architecture-specific ZIP with NotepadViewerPlus.dll at the archive root, which is the layout required by Notepad++ Plugin Admin. See packaging/plugin-admin/README.md for manual installation and Plugin Admin metadata.

For a local x64 install, close Notepad++, then double-click Install-NotepadViewerPlus-0.4.0.cmd in the project root. The launcher starts Windows PowerShell with the required execution-policy override, finds the matching ZIP in the checkout or the machine-local package directory created by Build-Development.ps1 -Package, and keeps the result visible until you press a key. The installer validates the essential payload, requests administrator permission when needed, and keeps the previous plugin directory as a rollback backup. For a portable/custom installation, run the .cmd launcher with -ZipPath, -NotepadRoot "C:\path\to\Notepad++", or -TargetDir "C:\path\to\plugins\NotepadViewerPlus".

Build Win32 separately for 32-bit Notepad++. Release candidates support x64 and x86; ARM64 is not supported. Notepad++ 8.0+ is the API compatibility baseline because the plugin uses the dark-mode toolbar API, but the final Plugin Admin compatibility range remains pending the recorded manual smoke matrix. The Microsoft Edge WebView2 Evergreen Runtime and the supported Microsoft Visual C++ v14 Redistributable matching the plugin architecture are required.

Current validation limits

The built-in WebView2 PDF path, toolbar modes/DPI, and Notepad++ clean-install/upgrade/Plugin Admin matrix still require manual smoke testing on supported WebView2/Notepad++ versions. Swagger/OpenAPI uses a locally bundled lazy UI chunk in documentation-only mode and rejects remote or cross-file $ref values; no network-backed Swagger configuration is used. The user explicitly authorized the primary session on 2026-10-02 to push this source snapshot to the private repository https://github.com/Duclevn/notepad-viewer-plus; public release upload remains blocked until publication rights, a project source/binary license, and the required manual release validation are approved.