Files
Stirling-PDF/frontend
Ludy f4d760b139 fix(sign): preserve PNG signature placement and page content (#7093)
# Description of Changes

This PR fixes PNG signature application issues in the PDF signing
workflow.

## What was changed

- Reworked signature application to create locked and printable PDFium
stamp annotations with dedicated appearance streams.
- Removed the use of `FPDFPage_GenerateContent()` from the signature
workflow.
- Preserved the signature's original position and dimensions when
converting from the viewer's top-left coordinate system to PDF
coordinates.
- Added CropBox-aware coordinate conversion for PDFs whose visible page
origin differs from the MediaBox origin.
- Improved signature image extraction to handle internal EmbedPDF asset
references and nested image data.
- Refactored PDFium bitmap creation so image objects can safely be
transferred to annotations.
- Corrected PDFium bitmap ownership and cleanup to prevent duplicate
destruction.
- Added a PDFium WASM integration test covering:
  - Existing page-content preservation
  - Stamp appearance generation
  - Signature coordinates and dimensions
  - Printable, read-only, and locked annotation flags
- Persisted image data taking precedence over internal asset references

## Why the change was made

Applying a PNG signature previously regenerated the complete page
content through PDFium. This could corrupt existing vector or font-based
page elements, including the university logo reported in the linked
issue.

The previous coordinate conversion also relied only on the page height
and did not account for CropBox offsets, allowing the applied signature
to move from its preview position.

Creating a PDFium stamp annotation with its own appearance stream avoids
regenerating existing page content while retaining the selected
signature position and size.


Closes #7083

---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### Translations (if applicable)

- [ ] I ran
[`scripts/counter_translation.py`](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/docs/counter_translation.md)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have run `task check` to verify linters, typechecks, and tests
pass
- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md#7-testing)
for more details.
2026-07-20 12:05:01 +00:00
..
2026-04-27 11:35:50 +01:00
2026-05-22 13:40:34 +01:00

Frontend

All frontend commands are run from the repository root using Task:

  • task frontend:dev — start Vite dev server (localhost:5173)
  • task frontend:build — production build
  • task frontend:test — run tests
  • task frontend:test:watch — run tests in watch mode
  • task frontend:lint — run ESLint + cycle detection
  • task frontend:typecheck — run TypeScript type checking
  • task frontend:check — run typecheck + lint + test
  • task frontend:install — install npm dependencies

For desktop app development, see the Tauri section below.

Layout

frontend/ is a workspace containing one or more apps. Today it holds the PDF editor under frontend/editor/; new apps (the developer portal, etc.) will sit alongside it as siblings. Shared tooling — package.json, node_modules, .storybook/, ESLint, Prettier — lives at frontend/ so every app installs once and lints with the same config.

Environment Variables

The editor's environment variables live in committed .env files at frontend/editor/:

  • .env — used by all builds (core, proprietary, and as the base for desktop/SaaS)
  • .env.desktop — additional vars loaded in desktop (Tauri) mode
  • .env.saas — additional vars loaded in SaaS mode

These files contain non-secret defaults and are checked into Git, so most dev work needs no further setup.

To override values locally (API keys, machine-specific settings), create an uncommitted sibling editor/.env.local / editor/.env.desktop.local / editor/.env.saas.local. Vite automatically layers these on top of the committed files.

Docker Setup

For Docker deployments and configuration, see the Docker README.

Tauri

All desktop tasks are available via Task. From the root of the repo:

Dev

task desktop:dev

This ensures the JLink runtime and backend JAR exist (skipping if already built), then starts Tauri in dev mode.

Build

task desktop:build

This does a full clean rebuild of the backend JAR and JLink runtime, then builds the Tauri app for production.

Platform-specific dev builds are also available:

task desktop:build:dev           # No bundling
task desktop:build:dev:mac       # macOS .app bundle
task desktop:build:dev:windows   # Windows NSIS installer
task desktop:build:dev:linux     # Linux AppImage

You can also run JLink steps individually:

task desktop:jlink          # Build JAR + create JLink runtime
task desktop:jlink:jar      # Build backend JAR only
task desktop:jlink:runtime  # Create JLink custom JRE only
task desktop:jlink:clean    # Remove JLink artifacts

Clean

task desktop:clean

Removes all desktop build artifacts including JLink runtime, bundled JARs, Cargo build, and dist/build directories.