Annotation model

Annotations are plain, JSON-serialisable objects in PDF user space. The store holds them, change events carry them and the PDF codec reads and writes them.

Common fields

Kinds

Change operations

onAnnotationsChange(list, ops) receives the new list and the operations of one undo step:

type AnnotationOp =
	| { type: 'add'; annotation: Annotation }
	| { type: 'update'; id: string; before: Annotation; after: Annotation }
	| { type: 'remove'; annotation: Annotation };

type AnnotationOp =
	| { type: 'add'; annotation: Annotation }
	| { type: 'update'; id: string; before: Annotation; after: Annotation }
	| { type: 'remove'; annotation: Annotation };

Persist the list, or apply ops to a server for collaborative or incremental saves.

Palette

defaultPalette has eight entries (yellow, green, blue, pink, purple, orange, red, gray), each with rgb (stored on the annotation), light and dark CSS colours. Pass your own with the palette prop; nearestPaletteKey(rgb) recovers a key for annotations imported from other apps.

Text box fonts

A text box’s font.family is one of FREETEXT_FONT_FAMILIES: 'Handwritten', 'Helvetica' (sans), 'Times' (serif) and 'Courier' (mono). The library ships no font files: the text box takes its typeface from a CSS custom property, so your app picks (and bundles) the faces:

:root {
	--pdf-font-handwritten: 'Shantell Sans', sans-serif; /* default: Shantell Sans if installed, else a system marker face */
	--pdf-font-sans: 'Atkinson Hyperlegible Next', sans-serif; /* default: Helvetica, Arial */
	--pdf-font-serif: Charter, serif; /* default: Times New Roman */
	--pdf-font-mono: ui-monospace, monospace; /* default: Courier New */
}

:root {
	--pdf-font-handwritten: 'Shantell Sans', sans-serif; /* default: Shantell Sans if installed, else a system marker face */
	--pdf-font-sans: 'Atkinson Hyperlegible Next', sans-serif; /* default: Helvetica, Arial */
	--pdf-font-serif: Charter, serif; /* default: Times New Roman */
	--pdf-font-mono: ui-monospace, monospace; /* default: Courier New */
}

freetextFontCss(family) returns the font-family value a text box uses (handy to show each choice in its own font); the context menu’s Font entries carry it as action.font. New text boxes get the freetextFont option (Annotations.Root prop, default 'Helvetica'); store.setFont(ids, family) changes existing ones.

In the PDF, /DA and the appearance stream use the closest standard font (standardFontOf): Helvetica for handwritten and sans, Times for serif, Courier for mono. The exact family is kept in the private data, so svelte-pdf-mini reads it back. The chosen typeface is not embedded: a subset of a handwritten face adds about 5–11 KB per font style to each PDF and needs fontkit in the export worker (about 390 KB minified, 155 KB gzipped) plus TrueType copies of the fonts (fontkit cannot read WOFF2 or variable fonts), and viewers that edit the box redraw it from /DA anyway.

Text boxes draw their text in an ink shade of their color, so pastel fills still read as text: paletteInk(entry, dark) gives the entry’s optional ink (light) or inkDark (dark) value, by default inkCss(color, dark), which keeps the hue and chroma and sets the lightness to at most 0.5 by day and at least 0.75 by night.