# LayoutSplat development plan

Approved October 13, 2026. LayoutSplat is SplatWorks' browser publication-design application: precise pages, editable templates, reusable branding, personalized publications, and dependable export. It uses `/splatworks/layoutsplat/` alongside WriteSplat, ShowSplat, GridSplat, and ListSplat.

The user subsequently authorized continuing through all milestones and requested maximum compatibility with other layout applications. JSON save/open must be explicit. Add editable SVG, InDesign IDML, Scribus SLA packages, HTML/PDF exchange, and documented conversion paths for proprietary formats. Preserve a lossless native payload in supported exchange files where possible, and report converted or unsupported features. Bold, italic, and underline belong in both the rich-text editor and ordinary formatting controls.

Additional approved scope: broad local image/video decoding and conversion, printable video posters, object-specific context menus (right-click, Mac Control/Command-click, keyboard), text import into an existing frame, media replacement without changing frame geometry, and a large original template library inspired by the publication types/industry breadth of StockLayouts. The user explicitly requested native `.pub` import and subsequently required browser-contained decoding without LibreOffice. This supersedes the earlier desktop-bridge proposal. v0.2 bundles libmspub as WebAssembly with editable conversion and source retention. Import/export native content from WriteSplat, ShowSplat, GridSplat, and ListSplat as well as routing files to their original applications. Clearly distinguish editable native imports from PDF backgrounds and preserve/report conversion limitations. Update README/wiki/release documentation, commit, push, deploy the next substantial update, and verify production.

## Current checkpoint — v0.7.0, October 16, 2026

Implementation and independent acceptance evidence are in [verification](../../docs/layoutsplat-verification.md) and [progress](PROGRESS.md). Completed items describe tested behavior, not proprietary-format or print certification.

- [x] Original ebook templates, EPUB 2/3 import and reflowable/fixed-layout EPUB 3 export.
- [x] Metadata, searchable outline, heading navigation, reading themes/size and visual editing.
- [x] XHTML/CSS and visual source chapters, retained supported fonts, links, footnotes/endnotes, nonlinear chapters and EPUB 3 navigation; source-book export.
- [x] Independent Sigil/PageEdit edit/save/reopen and EPUBCheck proofs.
- [x] Local English automatic hyphenation, manual/off controls and alpha-contour picture wrapping, including rotated/cropped/master pictures.
- [x] Explicit linked-story frame sequencing controls, with undo/native persistence. Original Publisher text IDs and reusable masters remain supported.
- [x] Richer WriteSplat round trips: font files, custom tabs, hard breaks and semantic nested list numbering.
- [x] Independent Scribus opening/editing/rendering of SLA and IDML; corrected frame paths, page geometry and desktop font identifiers.
- [x] Additional pinned Publisher malformed-input robustness fixtures.
- [x] Dynamic master fields, broader 120-page image-heavy/multi-story/master workload with CPU slowdown, and existing 500-page cache/100-page print checks.
- [x] Coated/uncoated profile conversion and independent font/color/transparency/page-box structural checks.
- [x] Native `.pub` export and the user-confirmed Google Drive upload/download/reopen workflow.

## Remaining external acceptance and unsupported scope

- [ ] Actual Microsoft Publisher and Adobe InDesign acceptance require those applications; neither is available here. Scribus and LibreOffice results cannot close these checks.
- [ ] Real commercial-printer approval/physical proof and exhaustive independent ISO PDF/X certification require the target printer and validation workflow.
- [ ] Private-reference Publisher paragraph/line-break parity needs the original documents and matching fonts. Those files are unavailable in this workspace; automatic source chain inference remains limited. Manual sequencing can correct the frame order.
- [ ] Native modern Pages IWA, QuarkXPress 5+ and INDD decoding remains unsupported after feasibility review; verified interchange routes are documented.
- [ ] Annotation databases, synchronized media-overlay editing and accessibility certification remain additional ebook scope. Existing supported note XHTML is retained.

Source/page editions are independent and clearly identified at export. Scripts and network resources are excluded. Existing printer preparation tools and tests do not establish production-printer acceptance. Record future evidence in [PROGRESS.md](PROGRESS.md).

## Interface and language

Reuse SplatWorks purple (`#7c3aed`), orange (`#ff9f2f`), white panels, dark text (`#1f2937`), pale purple surfaces (`#f7f4ff`), and subtle borders (`#d8d2ff`). Follow the existing system-font stack and line-icon vocabulary. Publication pages remain white against a quiet workspace. Left-align controls; reserve strong color for selection and primary actions.

The header contains the application identity, publication title, save/undo/redo, Apps launcher, and language picker. Menus provide File, Home, Insert, Page layout, Arrange, Mail merge, View, and Help as those capabilities ship. A contextual toolbar changes with selection. Page thumbnails, masters, templates, and assets occupy the left panel; rulers and a central page occupy the workspace; properties, layers, and design checking occupy the right panel. The status bar shows page number, saving status, units, guides, zoom, and preview.

The File workspace offers New, Open, Save, Save as template, Print, Share, Export, and Pack and Go. Place Share below Print. Smaller displays use collapsible panels and touch controls without changing page geometry.

Reuse `assets/js/widget-i18n.js` and the `drawsplat.language` preference. Match the original six choices: English, Español, Tiếng Việt, العربية, 中文, and हिन्दी / اردو (`uh`, the suite's current combined option). Translate menus, dialogs, tooltips, errors, accessibility labels, and design-check findings. Arabic mirrors the interface. Publication language/direction is separate from interface language; switching the interface never rewrites document content or moves objects. Provide script-appropriate fonts and deliberate translated template editions.

## Publication features

| Area | Target behavior |
| --- | --- |
| Templates | Flyers, brochures, newsletters, business cards, catalogs, and greeting cards; editable school/community/business examples; filter by type, language, size, and orientation. |
| Page setup | Letter, Legal, A4, A5, custom sizes, orientation, facing pages, margins, bleed, safe areas, and fold/panel guidance. |
| Rulers | Independent horizontal/vertical rulers; inches, centimeters, picas, points, pixels; adaptive ticks; configurable origin. |
| Guides | Margins, columns, rows, baselines, and draggable custom guides; lock/hide/copy; snap edges and centers. |
| Placement | Numeric X/Y, width/height, rotation, anchor; align/distribute to page, guides, and other objects. |
| Text | Rich text, paragraph/character styles, font/spacing/tracking, columns, bullets, tables, drop caps, format painter. |
| Stories | Continuous text through linked frames across pages; visible overflow and connections; shrink with a minimum size, grow frame, or continue into another frame. |
| Graphics | Paths, arrows, built-in/custom shapes, image fitting/cropping, transparency, watermarks, border art, and WordArt-style effects. |
| Objects | Layers, nested grouping, locks, duplication, stacking, alignment, reusable styles. |
| Masters | Reusable backgrounds/logos/headers/footers/page numbers/guides; selected-page application; explicit overrides; facing-page variants. |
| Mail merge | Local Excel/CSV input, worksheet selection, field mapping, filters, record previews, personalized publications, labels/cards/catalogs. |
| Design checker | Overflow, fonts/assets, effective image resolution, safe-area/bleed issues, unresolved fields, broken links; select the affected object and explain a fix. |

## Saving and outputs

The final native `.layoutsplat` format is a versioned ZIP containing the publication, assets, styles, masters, previews, and redistributable font assets. Early development may use an embedded-asset `.layoutsplat.json` interchange format; support migrations explicitly. Provide local autosave, recovery snapshots, undo/redo, and downloadable project saves.

PDF export preserves dimensions, text, font appearance, vector objects, page ranges, and optional bleed/crop marks. The first proof uses browser print-to-PDF from the same rendered pages; label it honestly and test the resulting PDF. Dedicated downloadable PDF output follows only when text shaping and font embedding are verified.

Photo exports offer PNG/JPEG with explicit pixel dimensions and 150/300/600 ppi choices. HTML offers a fixed-layout edition first, then an accessible reading edition with an explicit reading order. Pack and Go gathers the project, assets, permitted fonts, PDF proof, color information, instructions, and design-check report into a ZIP.

Share offers the current page, PDF, project, and HTML package. Detect device share support and fall back to download. Email preview shows content/attachments. Email delivery, if added later, is explicit and separate from preparing a document. Imported merge data stays on the device.

Commercial print preparation includes printer profiles, page boxes, bleed, font embedding, and preflight. Claim PDF/X compliance only after independent validation against printer requirements. PDF/X-4 requires an embedded output-intent profile: [PDF Association requirements](https://pdfa.org/technical-side-and-requirements-of-pdfx/). Browser sharing requires feature detection and generally HTTPS: [MDN Web Share API](https://developer.mozilla.org/en-US/docs/Web/API/Web_Share_API).

## Technical foundation

Store all geometry in points. Ruler units, screen pixels, and zoom are conversions; they never mutate the publication geometry. Use a versioned model for pages, objects, continuous text stories, styles, masters, assets, and merge fields. Keep layout computation separate from controls. Editing and export consume the same computed layout.

Reuse suitable ProseMirror components from WriteSplat for rich editing; custom frame flow/pagination remains LayoutSplat's responsibility. [ProseMirror's structured document/transaction model](https://prosemirror.net/docs/guide/) does not itself provide a desktop publication engine. The first proof can use plain-text story editing and browser-shaped lines, preserving a migration path to rich stories. Evaluate font metrics, multilingual shaping, line breaking, and print consistency before advanced typography.

Basic editing, ordinary exports, and merge work run locally. Bundle runtime assets for district use. Integrate the Apps launcher, component registry, file handoff, documentation, and installer inventory. Publisher `.pub` import is browser interchange: supported objects become editable, while advanced fidelity requires comparison with the source. Retain original bytes and include source/build/license notices for the bundled decoder.

## Milestones and acceptance

1. **Prove layout fidelity.** Two pages with linked text, images, guides, English and Arabic samples. Editing/resizing reflows stories without losing words. Print-to-PDF preserves measured geometry, selectable text, and script appearance. Save/reopen, undo/redo, language changes, and keyboard movement work.
2. **First usable release.** Six template categories, page management, five ruler units, guides, core text/images/shapes/tables, grouping, recovery, checking, PDF and image export. A user creates, saves, reopens, and prints a publication.
3. **Publishing tools.** Masters, facing pages, drop caps, baseline alignment, advanced wrapping, WordArt, borders, format painter, folding, expanded templates. A branded newsletter flows stories across pages.
4. **Personalization and sharing.** Excel/CSV, labels, record previews, catalogs, HTML, Email preview, share, Pack and Go. Check every generated record for overflow and unresolved fields.
5. **Commercial print preparation.** Printer profiles, advanced preflight, validated PDF/X, printer handoffs, larger-document performance, and district release packaging.

Verification covers unit conversion, snapping, linked-story changes, font shaping, master overrides, archive validation, save/reopen fidelity, merge accuracy, keyboard/touch operation, language changes, offline resource loading, and exported geometry. Test meaningful user workflows and independent PDF measurements. Record deployment evidence and remaining milestones in PROGRESS.md.