dart_pdf_editor_assets

Optional bundled assets for dart_pdf_editor: the six editor fonts offered by the font menu (and used as composite-text fallbacks), the metric-compatible substitute faces for unembedded standard-14 text, and the prebuilt web render worker.

These assets add roughly 3.5 MB to a build (fonts plus the web worker, compressed). They live in this separate package - not in dart_pdf_editor - so an app that only views PDFs never bundles them: Flutter includes a package's declared assets on every build target, so the only way to make these opt-in is to keep them out of the package every consumer depends on.

Substitute faces for the standard 14

A PDF that names one of the standard 14 fonts carries no font program: the viewer draws the text, and the advances come from the AFM tables the page was typeset against. This package bundles URW's metric-compatible clones of those fonts - TeX Gyre Heros (Helvetica, Arial), Termes (Times), Cursor (Courier) and Adventor (Century Gothic, Avant Garde) - and the renderer names them ahead of anything the host has installed, so such a page is drawn with the advances it was written for on every platform.

That matters more than the shapes: the renderer places every character at the PDF's own pen offset, so that selection, search and hit boxes land on the ink. A substitute whose glyphs are narrower than the table says therefore opens white space inside words - DejaVu Sans, the fallback without this package, draws J at 295/1000 em where Helvetica's table reserves 500, which put about 2.7pt of air after every capital J at 12pt. test/substitute_metrics_test.dart checks every bundled file against the AFM tables, and CI runs it.

Without this package the renderer falls back to whatever metric-compatible face the host has (Arial, Liberation Sans, Nimbus Sans and their serif/mono equivalents), then to any sans at all - text still renders, it just may not be spaced as the page intended.

Full-featured editor (the historical default)

Add both packages and register the assets once at startup, before opening a viewer:

dependencies:
  dart_pdf_editor: ^2.1.0
  dart_pdf_editor_assets: ^2.1.0

import 'package:dart_pdf_editor_assets/dart_pdf_editor_assets.dart';

void main() {
  registerBundledEditorAssets();
  runApp(const MyApp());
}

That restores exactly what a dart_pdf_editor app got before the split: the bundled font catalogue in every font menu, DejaVu fallbacks for composite-text editing, and the off-main-thread web worker.

Size-minimal viewer

Depend on dart_pdf_editor only and skip the registration call. The font menu still offers the base-14 families, the fonts already embedded in the open document, host/platform fonts, and any custom font the app loads; the web worker falls back to main-thread rendering (or an app-supplied worker URL). See the capability → asset matrix in the dart_pdf_editor README.

Selective registration

registerBundledEditorAssets(fonts: false) or webWorker: false registers only one group - e.g. a web app that wants the worker but supplies its own font catalogue, or a native app that wants the fonts but no worker asset.

Licences

The font licences are in assets/fonts/*-LICENSE.txt. DejaVu is a permissive Bitstream Vera / Arev licence; Fira Sans, Spectral and Lobster are the SIL Open Font Licence; the TeX Gyre families (Heros, Termes, Cursor, Adventor) use the GUST Font License and ship unmodified.