mirror of
https://github.com/storytold/pdfcraft.git
synced 2026-10-14 19:27:04 -04:00
Márk BartalosandBrandon Thomas
fff985f30d
A stamp placed on a page with /Rotate was drawn in user space, so the label or picture turned with the page. Counterrotate the appearance so it reads upright as the page is displayed. Co-authored-by: Brandon Thomas <[email protected]>
59 lines
3.4 KiB
Markdown
59 lines
3.4 KiB
Markdown
# pdfcraft-annot
|
|
|
|
Comments (annotations), ISO 32000-2 §12.5. Layer L3, depends on `pdfcraft-cos`, `pdfcraft-fonts` and `pdfcraft-model`.
|
|
|
|
## What it does
|
|
|
|
- **Builders** for the comment types Acrobat's commenting tools create: sticky note (`Text` +
|
|
`Popup`), highlight, underline, strikethrough, squiggly, rectangle (`Square`), oval (`Circle`),
|
|
line and arrow (`Line` with `/LE`), freehand drawing (`Ink`) and text box (`FreeText`).
|
|
- **Appearance streams** (`appearance::build`) generated from the annotation dictionary, so new
|
|
and restyled comments look the same in every viewer. Highlights multiply (`/BM /Multiply`).
|
|
Note icons are PdfCraft's own drawings. Text boxes use standard Helvetica (WinAnsi), with
|
|
line breaking by approximate Helvetica proportions (no font program is bundled). Text it can't
|
|
draw (in a text box, callout, Fill & Sign text, measurement label or dynamic stamp's by-line;
|
|
`appearance::undrawable_text`) is kept as typed and drawn as `?`, and the comment is marked with
|
|
the first such character (`pdfcraft_fonts::UNDRAWN_MARK`) so the engine reports the edit and
|
|
flattening refuses to make it permanent. Two refusals (`AnnotError::Undrawable`): a redaction
|
|
mark's overlay text, which becomes page content when applied; and a restyle or resize of a
|
|
comment another program drew with a font that has those characters, whose appearance is kept
|
|
rather than redrawn with `?` (new text for it is taken).
|
|
- **Edits:** reply (`/IRT`), set review status (a `/State` reply, as Acrobat's "Set status"
|
|
does), change text, move, resize, restyle, delete (with pop-up and replies).
|
|
|
|
## API sketch
|
|
|
|
```rust
|
|
let index = add_annotation(&mut doc, &NewAnnotation { page, shape, style, contents, author }, &meta)?;
|
|
add_reply(&mut doc, page, index, "Agreed", "Ada", &meta)?;
|
|
set_review_state(&mut doc, page, index, ReviewState::Accepted, "Ada", &meta)?;
|
|
move_annotation(&mut doc, page, index, dx, dy, &meta)?;
|
|
set_style(&mut doc, page, index, Some(rgb), Some(0.5), Some(2.0), &meta)?;
|
|
delete_annotation(&mut doc, page, index)?;
|
|
signature_image(&doc, page, index)?; // embedded image XObject of Fill & Sign signature/initials
|
|
```
|
|
|
|
A comment is addressed by `(page, index in /Annots)`, the same pair
|
|
`pdfcraft_render::Annotation` reports. `Meta` carries the date and the `/NM` id so edits stay
|
|
deterministic; the engine supplies them.
|
|
|
|
## Fidelity rules
|
|
|
|
- Unknown keys are kept. Inline annotation dictionaries are promoted to indirect objects only
|
|
when an edit needs a reference to them.
|
|
- `set_style` refuses (and changes nothing) when it cannot redraw the comment, e.g. stamps,
|
|
cloudy borders or callouts, instead of leaving a stale appearance.
|
|
- Replies get the parent's `/Rect` and an empty appearance: they appear in comment lists but
|
|
never paint a second icon.
|
|
- Resizing a stamp changes its `/Rect` and preserves its original appearance and resources;
|
|
viewers scale that appearance into the new rectangle. Locked stamps refuse the edit.
|
|
- Picture stamps (a natural-size or explicit-rectangle image, a PDF page, or an image
|
|
signature) and PdfCraft's rubber stamps counterrotate their appearance on rotated pages, so
|
|
the picture or label reads upright as the page is displayed. Restyling a picture stamp keeps
|
|
that appearance matrix. The rotation is the page's `/Rotate` at placement.
|
|
|
|
## Not yet
|
|
|
|
Callouts, polygons and polylines, clouds, carets (insert/replace text), stamps, file
|
|
attachments, rich text (`/RC`, `/DS`), and the shared named-appearance cache Acrobat writes.
|