PDF/.ai import: a file whose type all comes from its text document opens without its PDF part

A PDF-compatible .ai (or a PDF saved with the editing data) now opens from its layers without its PDF part being imported, and without being compared with its page, when: - its text document makes the type of every text object, hidden ones included, at least one text object shows, and none is drawn by the appearance of the layer or group it is in; - its layers hold no unread object, no placed file with a second placement and no live envelope with drawn art to fall back on, and no image too large to read; - it declares no large canvas, and its artboards are its pages' trim boxes one for one, in points or in the first page's UserUnit. A file whose layers draw differently from its page then opens from its layers instead of its PDF part. The bleed comes from the pages' bleed boxes. The check runs only when no pages are picked, layers and the editing data are on, the crop box is asked for and type comes in as text. Files saved without PDF compatibility, files whose PDF part draws only type or nothing, and files whose PDF part's content can't be read take the same path when they qualify: their bleed comes from the pages' bleed boxes, pages in units larger than a point draw them at their size in points, and the note that the PDF part couldn't be read is not given, since its content is not read. Files that don't qualify open as before, and the editing data decoded and read for the check is reused after the PDF part is imported (layered_ai_from). When a file whose PDF part can't be read is scaled up to its size in points, its text wraps are now laid out again at that size, and the default graphic styles of a file without graphic styles of its own are no longer scaled. The same applies on the new path.
2026-11-11 02:19:56 -06:00 · 2026-11-04 19:41:56 +07:00
parent 3f9545c962
commit 9275b902a9
13 changed files with 404 additions and 56 deletions
@@ -165,18 +165,18 @@ pub fn load(name: &str, bytes: &[u8]) -> Result<Loaded> {
 /// of its art, which it carries: its layers and hidden objects as they were, and the art outside
 /// its artboard (its PDF part has only what is on the artboards), as an EPS of the editor is read.
 /// Anything else as it was. `unit`: the size in points of a unit of the PDF part's user space (its
-/// first page's `UserUnit`) → (document, warnings, whether its layers were read). `private`: the
-/// editor's copy ([`editing_copy`]).
+/// first page's `UserUnit`) → (document, warnings, whether its layers were read). `layers`: the
+/// editor's copy ([`editing_copy`]), as far as it was decoded and read.
 fn through_editing_data(
-    private: Option<&[u8]>,
+    layers: Option<vectorcraft_eps::AiLayers>,
    opts: &LoadOptions,
    doc: Document,
    warnings: Vec<String>,
    unit: f64,
 ) -> (Document, Vec<String>, bool) {
-    let Some(private) = private else { return (doc, warnings, false) };
+    let Some(layers) = layers else { return (doc, warnings, false) };
    let outlined = opts.text_as == vectorcraft_pdf::TextAs::Outlines;
-    let (doc, mut warnings, read) = vectorcraft_eps::layered_ai(private, doc, warnings, outlined, opts.trust_editing_data, unit);
+    let (doc, mut warnings, read) = vectorcraft_eps::layered_ai_from(layers, doc, warnings, outlined, opts.trust_editing_data, unit);
    // The layers weren't read (or couldn't be): the notes of reading the PDF part still hold.
    if !read {
        return (doc, warnings, false);
@@ -216,6 +216,14 @@ fn reads_editing_copy(opts: &LoadOptions) -> bool {
    opts.pages.is_none() && opts.layers && opts.editing_data
 }

+/// May a file opened with `opts` open from the editor's own copy of its art without its PDF part
+/// being imported ([`vectorcraft_eps::ai_layers_alone`]): it reads the editor's copy, on the pages'
+/// trim boxes (the crop box asked for, as a file with the editor's copy opens on them), with its
+/// type as text?
+fn reads_layers_alone(opts: &LoadOptions) -> bool {
+    reads_editing_copy(opts) && opts.crop == vectorcraft_pdf::CropTo::Crop && opts.text_as != vectorcraft_pdf::TextAs::Outlines
+}
+
 /// The editor's own copy of its art that `opened` carries (as [`vectorcraft_pdf::illustrator_data`]
 /// reads it), when `opts` read it ([`reads_editing_copy`]).
 fn editing_copy(opened: &vectorcraft_pdf::Opened, opts: &LoadOptions) -> Option<Vec<u8>> {
@@ -365,41 +373,68 @@ pub fn load_with(name: &str, bytes: &[u8], opts: &LoadOptions) -> Result<Loaded>
                Ok(o) => super::pdfimport::import(bytes, o, opts, format.id != "pdf"),
                Err(e) => Err(err(e)),
            };
-            let read = restore_or_import(editing, || match imported() {
-                Ok(r) => {
-                    // The editor's copy, read once the import is done with the pages.
-                    let private = opened.as_ref().ok().and_then(|o| editing_copy(o, opts));
-                    // Pages of text alone: the editing copy alone where it reads, as for a file
-                    // saved without its PDF part (#1387: else the page, which is the art). So too
-                    // pages that draw nothing at all: there is no page art to check the layers
-                    // against, and the empty page would lose all of it.
-                    // A page is empty only when nothing on it was skipped (an image that can't be
-                    // decoded draws nothing either): its notes are at most the page's own.
-                    let empty = draws_nothing(&r.document) && r.warnings.iter().all(|w| is_page_note(w));
-                    let alone = (r.only_text || empty)
-                        .then(|| private.as_deref().map(editing_copy_alone))
-                        .flatten()
-                        .and_then(|read| read.ok())
-                        .map(|(doc, warnings)| outlined_if_asked(doc, warnings, opts));
-                    let (doc, warnings, read) = match alone {
-                        Some((doc, warnings)) => (doc, warnings, true),
-                        None => through_editing_data(private.as_deref(), opts, r.document, r.warnings, r.user_unit),
-                    };
-                    editing_data = read;
-                    Ok((doc, warnings))
+            let read = restore_or_import(editing, || {
+                // Type all from the text document and nothing that needs the PDF part: the layers
+                // alone, the PDF part not imported. Else what was read of the layers is kept for
+                // reading them with the PDF part.
+                let mut layers = None;
+                if let Some((o, private)) = opened.as_ref().ok().filter(|_| reads_layers_alone(opts)).and_then(|o| Some((o, editing_copy(o, opts)?)))
+                {
+                    let pages = o.trim_pages();
+                    match vectorcraft_eps::ai_layers_alone(&private, &pages.sizes, pages.user_unit) {
+                        Ok((mut doc, warnings)) => {
+                            doc.setup.bleed = pages.bleed;
+                            editing_data = true;
+                            return Ok((doc, warnings));
+                        }
+                        Err(read) => layers = Some(read),
+                    }
+                }
+                match imported() {
+                    Ok(r) => {
+                        // The editor's copy, read once the import is done with the pages, unless
+                        // its layers were read before it.
+                        let private = layers.is_none().then(|| opened.as_ref().ok().and_then(|o| editing_copy(o, opts))).flatten();
+                        // Pages of text alone: the editing copy alone where it reads, as for a file
+                        // saved without its PDF part (#1387: else the page, which is the art). So too
+                        // pages that draw nothing at all: there is no page art to check the layers
+                        // against, and the empty page would lose all of it.
+                        // A page is empty only when nothing on it was skipped (an image that can't be
+                        // decoded draws nothing either): its notes are at most the page's own.
+                        let empty = draws_nothing(&r.document) && r.warnings.iter().all(|w| is_page_note(w));
+                        let copy_alone = || match &private {
+                            Some(private) => Some(editing_copy_alone(private)),
+                            None if layers.is_some() => opened.as_ref().ok().and_then(|o| editing_copy(o, opts)).map(|p| editing_copy_alone(&p)),
+                            None => None,
+                        };
+                        let alone = (r.only_text || empty)
+                            .then(copy_alone)
+                            .flatten()
+                            .and_then(|read| read.ok())
+                            .map(|(doc, warnings)| outlined_if_asked(doc, warnings, opts));
+                        let (doc, warnings, read) = match alone {
+                            Some((doc, warnings)) => (doc, warnings, true),
+                            None => {
+                                let layers = layers.or_else(|| private.as_deref().map(vectorcraft_eps::AiLayers::decode));
+                                through_editing_data(layers, opts, r.document, r.warnings, r.user_unit)
+                            }
+                        };
+                        editing_data = read;
+                        Ok((doc, warnings))
+                    }
+                    // Saved without its PDF part: the editing copy is all the file has (`pages` that
+                    // name every page read it as the whole file).
+                    Err(e) if is_placeholder(&e) => opened
+                        .as_ref()
+                        .ok()
+                        .and_then(|o| from_editing_data_alone(o, opts))
+                        .unwrap_or(Err(e))
+                        .map(|(doc, warnings)| outlined_if_asked(doc, warnings, opts))
+                        .inspect(|_| editing_data = true),
+                    // A PDF part that can't be read (a stream the import refuses): the editing copy
+                    // alone where it reads, else the error.
+                    Err(e) => without_pdf_part(bytes, opts, &e).inspect(|_| editing_data = true).ok_or(e),
                }
-                // Saved without its PDF part: the editing copy is all the file has (`pages` that
-                // name every page read it as the whole file).
-                Err(e) if is_placeholder(&e) => opened
-                    .as_ref()
-                    .ok()
-                    .and_then(|o| from_editing_data_alone(o, opts))
-                    .unwrap_or(Err(e))
-                    .map(|(doc, warnings)| outlined_if_asked(doc, warnings, opts))
-                    .inspect(|_| editing_data = true),
-                // A PDF part that can't be read (a stream the import refuses): the editing copy
-                // alone where it reads, else the error.
-                Err(e) => without_pdf_part(bytes, opts, &e).inspect(|_| editing_data = true).ok_or(e),
            })?;
            // The File Info of a file read from its pages or its editing copy.
            if !read.2 {
@@ -1221,10 +1221,16 @@ fn half_outlined_line(y: f64, rest: &str, mode: u8) -> String {
 /// text document (a line starting at (14, 65)), then `more` of a story the text document doesn't
 /// have. Without `story` the file has no text document.
 fn half_outlined_ai(story: Option<&str>, more: usize, type_content: &str) -> Vec<u8> {
+    half_outlined_ai_on(story, more, type_content, "", |page| page)
+}
+
+/// [`half_outlined_ai`] with the editing data's comments `head` before its art, whose page is
+/// `page_of` the 200 × 100 pt page it draws on (other boxes, more entries).
+fn half_outlined_ai_on(story: Option<&str>, more: usize, type_content: &str, head: &str, page_of: impl FnOnce(PdfPage) -> PdfPage) -> Vec<u8> {
    let text = |story: u32| format!("/AI11Text :\n0 /FreeUndo ,\n0 /FrameIndex ,\n{story} /StoryIndex ,\n;\n");
    let texts: String = std::iter::once(text(0)).chain((0..more).map(|_| text(99))).collect();
    let mut body =
-        format!("%AI3_TemplateBox: 100 50 100 50\n{}", ai::layer("Art", &format!("0.5 g\n{}f\n{texts}", ai::rect(120.0, 20.0, 160.0, 60.0))));
+        format!("{head}%AI3_TemplateBox: 100 50 100 50\n{}", ai::layer("Art", &format!("0.5 g\n{}f\n{texts}", ai::rect(120.0, 20.0, 160.0, 60.0))));
    if let Some(story) = story {
        // The story's one line starts at the canvas center (8191.5, the template box's center) moved
        // to (14, 65): its y runs down the page.
@@ -1255,7 +1261,7 @@ fn half_outlined_ai(story: Option<&str>, more: usize, type_content: &str) -> Vec
    };
    let cmap = "begincmap\n1 begincodespacerange\n<00> <FF>\nendcodespacerange\n1 beginbfchar\n<41> <FFFD>\nendbfchar\nendcmap\n";
    pdf_with(
-        &[page],
+        &[page_of(page)],
        &[&format!("<< /Length {} >>\nstream\n{data}\nendstream", data.len()), &format!("<< /Length {} >>\nstream\n{cmap}endstream", cmap.len())],
        None,
    )
@@ -1287,6 +1293,12 @@ fn texts(s: &Session) -> Vec<String> {
 /// (art x 10 to 90 and 110 to 190, y 10 to 90), then a band across the first frame (y 30 to 70),
 /// made a wrap object with no offset when `wrap` is set.
 fn wrapped_thread_ai(wrap: bool) -> Vec<u8> {
+    ai::ai(&wrapped_thread_data(wrap.then_some(0.0)), PLACEHOLDER)
+}
+
+/// The editing data of [`wrapped_thread_ai`], compressed, with the band a wrap object of `offset`
+/// when one is given.
+fn wrapped_thread_data(offset: Option<f64>) -> Vec<u8> {
    // The template box is centred at (100, 50), the canvas centre 8191.5: y runs down the canvas.
    let canvas = |x: f64, y: f64| (x + 8091.5, 8241.5 - y);
    let rect = |x0: f64, y0: f64, x1: f64, y1: f64| {
@@ -1306,14 +1318,47 @@ fn wrapped_thread_ai(wrap: bool) -> Vec<u8> {
    );
    let lines: Vec<String> = ascii85(document.as_bytes()).as_bytes().chunks(60).map(|c| format!("%{}", String::from_utf8_lossy(c))).collect();
    let frame = |f: u32| format!("/AI11Text :\n0 /FreeUndo ,\n{f} /FrameIndex ,\n0 /StoryIndex ,\n;\n");
-    let dict = if wrap { "%_/ArtDictionary :\n%_0 /Real (AI11TextWrapOffset) ,\n%_0 /Bool (AI11TextWrapInvert) ,\n%_;\n%_\n" } else { "" };
+    let dict = offset
+        .map(|o| format!("%_/ArtDictionary :\n%_{o} /Real (AI11TextWrapOffset) ,\n%_0 /Bool (AI11TextWrapInvert) ,\n%_;\n%_\n"))
+        .unwrap_or_default();
    let art = format!("{}{}0.5 g\n{}f\n{dict}", frame(0), frame(1), ai::rect(10.0, 30.0, 90.0, 70.0));
    let body = format!(
        "%AI3_TemplateBox: 100 50 100 50\n{}%AI11_BeginTextDocument\n/AI11TextDocument : /ASCII85Decode ,\n{}\n%AI11_EndTextDocument\n",
        ai::layer("Art", &art),
        lines.join("\n")
    );
-    ai::ai(&compressed(ai::editing_data(200.0, 100.0, &body).as_bytes()), PLACEHOLDER)
+    compressed(ai::editing_data(200.0, 100.0, &body).as_bytes())
+}
+
+/// The wrap offset of the first frame of `doc`'s threaded type, as its text resolves it.
+fn first_frame_wrap_offset(doc: &vectorcraft_doc::Document) -> f64 {
+    match &doc.node(doc.text_threads[0][0]).unwrap().kind {
+        NodeKind::Text(t) => t.wrap[0].wrap.offset,
+        _ => panic!("area type"),
+    }
+}
+
+/// A `.ai` in units of 10 points whose threaded area type flows around a wrap object of a 2 unit
+/// offset opens with the type flowing round it 20 pt off, its PDF part read or not, and when its
+/// PDF part can't be read. The default graphic styles of a file without its own aren't scaled.
+#[test]
+fn wrapped_type_in_units_of_ten_points_flows_round_the_wrap_at_its_size_in_points() {
+    let private = wrapped_thread_data(Some(2.0));
+    let page = "0.5 g 10 30 80 40 re f";
+    let refused = ai::ai_with_entries_and_content(&private, page, "/UserUnit 10", REFUSED_CONTENT);
+    // On the trim boxes the PDF part is imported, and the refused stream stops it.
+    let trim = LoadOptions { crop: vectorcraft_pdf::CropTo::Trim, ..Default::default() };
+    let files = [(ai::ai_with(&private, page, "/UserUnit 10"), LoadOptions::default()), (refused, trim)];
+    for (file, opts) in &files {
+        let loaded = load_with("thread.ai", file, opts).unwrap();
+        assert!(loaded.editing_data, "{:?}", loaded.warnings);
+        assert!((first_frame_wrap_offset(&loaded.doc) - 20.0).abs() < 0.01, "{:?}", loaded.warnings);
+    }
+    let loaded = load_with("thread.ai", &files[1].0, &files[1].1).unwrap();
+    assert!(loaded.warnings.iter().any(|w| w.starts_with("the PDF part couldn't be read")), "{:?}", loaded.warnings);
+    // The file has no graphic styles of its own: the default ones aren't scaled either way.
+    let read = load_with("thread.ai", &files[0].0, &files[0].1).unwrap();
+    assert_eq!(loaded.doc.graphic_styles, read.doc.graphic_styles);
 }

 /// Threaded area type below a wrap object flows around it when the file opens: the text the wrap
@@ -1358,6 +1403,77 @@ fn type_from_the_text_document_opens_without_the_pdf_parts_note_on_outlines() {
    assert!(!r["warnings"].as_array().unwrap().contains(&without_outlines_note(1)), "{r}");
 }

+/// A `.ai` whose text document makes all of its type, with nothing unread, opens from its layers
+/// without its PDF part being imported: a page that draws more than the layers isn't compared with
+/// them. On its trim box it takes the pages' bleed, and pages in units of 10 points draw it ten
+/// times as large, as when its PDF part is imported. With type the text document can't make,
+/// editing data on a large canvas, its type asked for as outlines, another box or pages picked, the
+/// PDF part is imported as before.
+#[test]
+fn type_all_from_the_text_document_opens_without_importing_the_pdf_part() {
+    let line = half_outlined_line(65.0, "rst draft", 0);
+    // The page draws a red square the layers don't have.
+    let differs = half_outlined_ai(Some("first draft"), 0, &format!("{line} 1 0 0 rg 20 20 30 30 re f"));
+    let mut s = Session::new();
+    let before = vectorcraft_pdf::imports_of(&differs);
+    let loaded = load_with("draft.ai", &differs, &LoadOptions::default()).unwrap();
+    assert_eq!(vectorcraft_pdf::imports_of(&differs), before, "{:?}", loaded.warnings);
+    assert!(loaded.editing_data, "{:?}", loaded.warnings);
+    assert!(!loaded.warnings.iter().any(|w| w.contains("differently")), "{:?}", loaded.warnings);
+    let r = open(&mut s, "draft.ai", &differs, json!({})).unwrap();
+    assert_eq!(names(&s.doc().unwrap().doc.layers), ["Art"], "{r}");
+    assert_eq!(texts(&s), ["first draft"], "{r}");
+    assert_eq!(s.doc().unwrap().doc.layers[0].children().unwrap().len(), 2, "the square and the type, without the page's red square: {r}");
+    // A 10 pt bleed round the trim box, the art drawn in the trim box.
+    let bled = half_outlined_ai_on(Some("first draft"), 0, &line, "", |p| PdfPage {
+        media: [0.0, 0.0, 220.0, 120.0],
+        bleed: Some([0.0, 0.0, 220.0, 120.0]),
+        trim: Some([10.0, 10.0, 210.0, 110.0]),
+        content: format!("1 0 0 1 10 10 cm {}", p.content),
+        ..p
+    });
+    let before = vectorcraft_pdf::imports_of(&bled);
+    let loaded = load_with("bled.ai", &bled, &LoadOptions::default()).unwrap();
+    assert_eq!(vectorcraft_pdf::imports_of(&bled), before);
+    assert_eq!(loaded.doc.setup.bleed, [10.0; 4]);
+    // Pages of 10 pt units.
+    let large = half_outlined_ai_on(Some("first draft"), 0, &line, "", |p| PdfPage { entries: format!("{} /UserUnit 10", p.entries), ..p });
+    let before = vectorcraft_pdf::imports_of(&large);
+    let loaded = load_with("large.ai", &large, &LoadOptions::default()).unwrap();
+    assert_eq!(vectorcraft_pdf::imports_of(&large), before);
+    let board = loaded.doc.artboards[0].rect;
+    assert!((board.width() - 2000.0).abs() < 0.01 && (board.height() - 1000.0).abs() < 0.01, "{board:?}");
+    // Opened on the trim boxes with the PDF part imported and compared, as before, both files have
+    // the same artboards and bleed.
+    for file in [&bled, &large] {
+        let alone = load_with("draft.ai", file, &LoadOptions::default()).unwrap();
+        let compared = load_with("draft.ai", file, &LoadOptions { crop: vectorcraft_pdf::CropTo::Trim, ..Default::default() }).unwrap();
+        assert!(compared.editing_data, "{:?}", compared.warnings);
+        let boards = |d: &vectorcraft_doc::Document| d.artboards.iter().map(|a| a.rect).collect::<Vec<_>>();
+        assert_eq!(boards(&alone.doc), boards(&compared.doc));
+        assert_eq!(alone.doc.setup.bleed, compared.doc.setup.bleed);
+        assert_eq!(names(&alone.doc.layers), names(&compared.doc.layers));
+        // The file has no graphic styles of its own: the default ones aren't scaled.
+        assert_eq!(alone.doc.graphic_styles, compared.doc.graphic_styles);
+    }
+    // The PDF part is imported, once.
+    let unmade = half_outlined_ai(Some("first draft"), 1, &line);
+    // Editing data on a large canvas reads at its own scale when the file has no PDF part.
+    let canvas = half_outlined_ai_on(Some("first draft"), 0, &line, "%AI24_LargeCanvasScale: 2\n", |p| p);
+    let cases = [
+        (&unmade, LoadOptions::default()),
+        (&canvas, LoadOptions::default()),
+        (&differs, LoadOptions { text_as: vectorcraft_pdf::TextAs::Outlines, ..Default::default() }),
+        (&differs, LoadOptions { crop: vectorcraft_pdf::CropTo::Trim, ..Default::default() }),
+        (&differs, LoadOptions { pages: Some("1".into()), ..Default::default() }),
+    ];
+    for (file, opts) in cases {
+        let before = vectorcraft_pdf::imports_of(file);
+        load_with("draft.ai", file, &opts).unwrap();
+        assert_eq!(vectorcraft_pdf::imports_of(file) - before, 1, "{opts:?}");
+    }
+}
+
 /// A text object that takes the page's type lacks the glyphs next to it that the page kept as
 /// outlines: a note counts such objects, in place of the PDF part's notes. Stroked glyphs that
 /// come in with the stroked type keep the PDF part's notes.
@@ -71,7 +71,7 @@ use interp::{Fault, Interp};
 use obj::PsError;

 pub(crate) use native::scale_document;
-pub use native::{ai_alone, ai_alone_on_page, is_loss, layered_ai};
+pub use native::{AiLayers, ai_alone, ai_alone_on_page, ai_layers_alone, is_loss, layered_ai, layered_ai_from};
 pub use text::family_style;

 /// The page of a PostScript file without a bounding box (US Letter).
@@ -23,7 +23,9 @@
 //! before; on a layer that doesn't show it is left out of that layer, with a warning. The page is
 //! also the safety net: when the layers' art looks different from it (one draws an object the
 //! other doesn't, or much of it differs; an EPS whose page is its art's box has nothing printed
-//! outside it), the page is used.
+//! outside it), the page is used. A `.ai` whose text document makes all of its type, with no
+//! object unread and nothing else that the page would decide, opens from its layers without its
+//! PDF part being imported, so nothing is compared ([`ai_layers_alone`]).
 //!
 //! Where a file doesn't match what this module expects, it is left alone and its page is imported.

@@ -52,7 +54,7 @@ use build::{Frame, MADE, prune_unseen};
 use compare::{
    MAX_DIFFERENCE, MAX_SOLID_DIFFERENCE, PageView, Shares, compare, compared, comparison_render, comparison_samples, differ, differ_in_colour,
 };
-pub use layers::{ai_alone, ai_alone_on_page, layered_ai};
+pub use layers::{AiLayers, ai_alone, ai_alone_on_page, ai_layers_alone, layered_ai, layered_ai_from};
 pub(super) use layers::{layered, program_alone};
 pub use slots::is_loss;
 #[cfg(test)]
@@ -76,14 +76,98 @@ pub(super) fn build_on_page(data: &[u8], page: (f64, f64), unit: f64) -> Result<
    };
    let in_units = |r: Option<Rect>, k: f64| k.is_finite() && k > 1.0 && fits(r, k) && !fits(r, 1.0);
    let scale = [unit, structure.canvas_scale].into_iter().find(|&k| in_units(board, k) || (!fits(board, 1.0) && in_units(art, k)));
+    let styles = structure.styles_read;
    let (mut doc, notes) = build_from(structure, data, None, Page::Artboard, false, false, 1.0)?;
    if let Some(k) = scale {
-        // The graphic styles here are all the file's, drawn in its units too.
-        scale_document(&mut doc, k, true);
+        // The graphic styles read from the file are drawn in its units too.
+        scale_document(&mut doc, k, styles);
+        relayout_wrapped(&mut doc);
    }
    Ok((doc, notes))
 }

+/// A document read from the editing copy and its notes, or why it can't be read.
+pub(super) type Built = Result<(Document, Vec<String>), String>;
+
+/// [`build`] of a `.ai` without importing its PDF part, whose pages (each its trim box in points,
+/// width and height) are `pages` and are in units of `unit` points: the document read from
+/// `structure` (the editing copy `data` read) with nothing compared with the pages, when the file's
+/// text document makes the type of every text object (at least one shows, and none is type that a
+/// look draws), no object is unread or has another placement or drawn art that the page would
+/// choose, and its artboards are the pages, one for one and of their size, in points or in the pages'
+/// units ([`page_scale_alone`]). The document is drawn at that scale. Else `Err(structure)`, for
+/// [`build_from`] with the page.
+pub(super) fn build_without_page(structure: Structure, data: &[u8], pages: &[(f64, f64)], unit: f64) -> Result<Built, Box<Structure>> {
+    let Some(scale) = page_scale_alone(&structure, pages, unit).filter(|_| nothing_waits_on_page(&structure) && type_all_made(&structure, data))
+    else {
+        return Err(Box::new(structure));
+    };
+    let styles = structure.styles_read;
+    let built = build_from(structure, data, None, Page::Artboard, false, false, 1.0).map(|(mut doc, notes)| {
+        if scale != 1.0 {
+            // The graphic styles read from the file are drawn in its units too.
+            scale_document(&mut doc, scale, styles);
+            relayout_wrapped(&mut doc);
+        }
+        (doc, notes)
+    });
+    Ok(built)
+}
+
+/// Is nothing in `structure` waiting on the page: no object unread (the page's art takes its
+/// place), no placed file with another placement, no live envelope with the drawn art it replaced
+/// (the comparison with the page chooses between them)?
+fn nothing_waits_on_page(structure: &Structure) -> bool {
+    structure.unread.is_empty()
+        && structure.unread_elsewhere.is_empty()
+        && structure.placed_elsewhere.is_empty()
+        && structure.envelopes_drawn.is_empty()
+}
+
+/// Does the text document of `data` (read as `structure`) make the type of every text object, those
+/// that don't show included, with at least one that shows, and none of them type that a look draws?
+fn type_all_made(structure: &Structure, data: &[u8]) -> bool {
+    let mut infos = vec![];
+    collect_slots(&structure.doc.layers, true, &mut infos);
+    if !infos.iter().any(|i| i.shown) || infos.iter().any(|i| i.look.is_some()) {
+        return false;
+    }
+    let frames = ai::text_frames(data);
+    for info in &mut infos {
+        info.art_path = info.story.and_then(|s| frames.get(&(s, info.frame))).map(|p| PathData::from_bezpath(&(structure.to_doc * p.clone())));
+    }
+    let Some(texts) = Texts::read(data) else { return false };
+    let mut read: std::collections::BTreeMap<u32, Option<Arc<Story>>> = Default::default();
+    let stories: Vec<Option<Arc<Story>>> = infos
+        .iter()
+        .map(|i| {
+            let n = i.story?;
+            read.entry(n).or_insert_with(|| texts.story(n as usize).map(Arc::new)).clone()
+        })
+        .collect();
+    // A slot without its story is made from nothing; past the text `build_from` reads, nothing is
+    // made either: it refuses the file.
+    if stories.iter().any(Option::is_none) || stories.iter().flatten().map(|s| s.len()).sum::<usize>() > MAX_TEXT {
+        return false;
+    }
+    let template = structure.template.map(|t| ((t[0] + t[2]) / 2.0, (t[1] + t[3]) / 2.0));
+    make_slots(&infos, &stories, template, structure.to_doc, &mut vec![]).iter().all(Option::is_some)
+}
+
+/// The scale at which the artboards of `structure` are the pages `pages` (each its width and height
+/// in points), one for one and in order, each within half a point: 1 when they are in points, else
+/// `unit` (the pages' `UserUnit`) when they are in those units, as [`page_scale`] finds it with the
+/// page. `None` when they aren't the pages, and for a file that declares a large canvas scale (a
+/// `.ai` saved without its PDF part reads one at that scale, [`super::ai_alone`]).
+fn page_scale_alone(structure: &Structure, pages: &[(f64, f64)], unit: f64) -> Option<f64> {
+    let boards = &structure.doc.artboards;
+    if boards.is_empty() || boards.len() != pages.len() || structure.canvas_scale != 1.0 {
+        return None;
+    }
+    let fits = |k: f64| boards.iter().zip(pages).all(|(b, (w, h))| (b.rect.width() - w / k).abs() <= 0.5 && (b.rect.height() - h / k).abs() <= 0.5);
+    [1.0, unit].into_iter().find(|&k| k.is_finite() && k >= 1.0 && fits(k))
+}
+
 /// [`build`] from `structure`, the editing copy `data` already read.
 pub(super) fn build_from(
    structure: Structure,
@@ -1,4 +1,4 @@
-use super::build::{PAGE_MOVE, Page, build, build_from, build_on_page};
+use super::build::{PAGE_MOVE, Page, build, build_from, build_on_page, build_without_page};
 use super::slots::LAYERS_UNREAD;
 use super::{Affine, Arc, Cow, Document, Imported, Node, NodeKind, PathData, Rect, Vec2, ai};

@@ -110,11 +110,24 @@ fn layer_tree(nodes: &[Arc<Node>]) -> Vec<Arc<Node>> {
 /// units comes in `unit` times as large, and so does the artboard layout `place_pages` takes from
 /// it.
 pub fn layered_ai(private: &[u8], visible: Document, warnings: Vec<String>, outlined: bool, trust: bool, unit: f64) -> (Document, Vec<String>, bool) {
+    layered_ai_from(AiLayers::decode(private), visible, warnings, outlined, trust, unit)
+}
+
+/// [`layered_ai`] of the editing copy `layers`, as far as it was already decoded and read.
+pub fn layered_ai_from(
+    layers: AiLayers,
+    visible: Document,
+    warnings: Vec<String>,
+    outlined: bool,
+    trust: bool,
+    unit: f64,
+) -> (Document, Vec<String>, bool) {
    let unread = |mut all: Vec<String>, why: &str| {
        all.push(format!("{LAYERS_UNREAD} from its editing data ({why}): they come from its PDF part"));
        all
    };
-    let data = match ai::decode_private(private) {
+    let AiLayers { data, structure } = layers;
+    let data = match data {
        Ok(data) => data,
        Err(why) => return (visible, unread(warnings, &why), false),
    };
@@ -137,7 +150,10 @@ pub fn layered_ai(private: &[u8], visible: Document, warnings: Vec<String>, outl
        use_variables(&data, &mut visible, &mut all);
        (visible, all, false)
    };
-    match build(&data, Some(&visible), Page::Artboard, outlined, trust, unit) {
+    let built = structure
+        .unwrap_or_else(|| ai::read(&data, false).map(Box::new))
+        .and_then(|structure| build_from(*structure, &data, Some(&visible), Page::Artboard, outlined, trust, unit));
+    match built {
        // An image too large for the editing data's reader would be missing from the layers, while
        // the PDF part has it: the file comes in as its PDF part instead (#1479).
        Ok((_, notes)) if notes.iter().any(|n| n == ai::IMAGE_TOO_LARGE) => {
@@ -153,6 +169,51 @@ pub fn layered_ai(private: &[u8], visible: Document, warnings: Vec<String>, outl
    }
 }

+/// The `.ai` whose editing copy is `private` (as [`layered_ai`] takes it) from its layers alone,
+/// without its PDF part, whose pages (each its trim box in points, width and height) are `pages`
+/// and are in units of `unit` points (its first page's `UserUnit`): the document and the notes of
+/// reading it, when the file's text document makes all of its type and nothing in its layers needs
+/// the PDF part (see `build_without_page`). Nothing is compared with the PDF part. Else, as the
+/// error, what was decoded and read of the editing copy, for [`layered_ai_from`] once the PDF part
+/// is imported.
+pub fn ai_layers_alone(private: &[u8], pages: &[(f64, f64)], unit: f64) -> Result<(Document, Vec<String>), AiLayers> {
+    let data = match ai::decode_private(private) {
+        Ok(data) => data,
+        Err(why) => return Err(AiLayers { data: Err(why), structure: None }),
+    };
+    if !has_layers(&data) {
+        return Err(AiLayers { data: Ok(data), structure: None });
+    }
+    let structure = match ai::read(&data, false) {
+        Ok(structure) => structure,
+        Err(why) => return Err(AiLayers { data: Ok(data), structure: Some(Err(why)) }),
+    };
+    match build_without_page(structure, &data, pages, unit) {
+        // An image too large for the editing data's reader is missing from the layers: the PDF
+        // part has it (as in `layered_ai`).
+        Ok(Ok((doc, notes))) if !notes.iter().any(|n| n == ai::IMAGE_TOO_LARGE) => Ok((doc, notes)),
+        Ok(_) => Err(AiLayers { data: Ok(data), structure: None }),
+        Err(structure) => Err(AiLayers { data: Ok(data), structure: Some(Ok(structure)) }),
+    }
+}
+
+/// A `.ai`'s editing copy decoded, and its layers read when they were, for [`layered_ai_from`]:
+/// what [`ai_layers_alone`] read isn't decoded or read again.
+pub struct AiLayers {
+    /// The editing copy decoded, or why it can't be.
+    data: Result<Vec<u8>, String>,
+    /// Its layers read with [`ai::read`] as [`layered_ai`] reads them, or why they can't be; `None`
+    /// when they are still to be read.
+    structure: Option<Result<Box<ai::Structure>, String>>,
+}
+
+impl AiLayers {
+    /// The editing copy `private` (as [`layered_ai`] takes it), decoded.
+    pub fn decode(private: &[u8]) -> Self {
+        Self { data: ai::decode_private(private), structure: None }
+    }
+}
+
 /// `doc` (a file read as its page or PDF part, in place of its layers) with the variables, data
 /// sets, active data set and lock of the variable library of its editing data `data`, as [`build`]
 /// gives a document read from the layers, and the note about what of the library wasn't read
@@ -44,7 +44,8 @@ mod tiff;

 pub use ai_editing::{AiEditingOptions, AiEditingOutput, CREATOR_VERSION, export_ai_editing, private_data as ai_private_data};
 pub use import::{
-    Imported, POSTSCRIPT_ERRORS, ai_alone, ai_alone_on_page, family_style, import, import_trusting, import_with, is_loss, layered_ai, page,
+    AiLayers, Imported, POSTSCRIPT_ERRORS, ai_alone, ai_alone_on_page, ai_layers_alone, family_style, import, import_trusting, import_with, is_loss,
+    layered_ai, layered_ai_from, page,
 };
 pub use legacy_ai::{HiddenObjects, LegacyAiOptions, LegacyAiOutput, export_legacy_ai};
 pub use print::{PrintJob, PrintPage, print};
@@ -9,7 +9,7 @@ description = "VectorCraft PDF export and import"
 workspace = true

 [features]
-# `vectorcraft_pdf::reads_of` for other crates' tests (dev-dependencies only).
+# `vectorcraft_pdf::reads_of` and `imports_of` for other crates' tests (dev-dependencies only).
 read-count = []

 [dependencies]
@@ -38,6 +38,8 @@ mod state;

 #[cfg(test)]
 pub(crate) use cid::{CidText, font_chars, identify_glyph, unify_radical};
+#[cfg(any(test, feature = "read-count"))]
+pub use entry::imports_of;
 pub use entry::{
    INVISIBLE_TEXT_NOTE, OFF_ARTBOARD_NOTE, OUTLINED_TEXT_NOTE, PAST_PAGE_NOTE, UNMATCHED_GLYPHS_NOTE, UNNAMED_CHARACTERS_NOTE, holds_outlines,
    import, import_opened, import_with_report, is_glyph_outlines, is_outlines_note,
@@ -221,6 +221,16 @@ fn read_with_reader_options(bytes: &[u8], opts: &ImportOptions, reader: &craft_p
    read_opened(bytes, opts, reader, &original)
 }

+/// How many times each buffer's pages have been imported, by its address (tests).
+#[cfg(any(test, feature = "read-count"))]
+static IMPORTS: std::sync::Mutex<std::collections::BTreeMap<usize, usize>> = std::sync::Mutex::new(std::collections::BTreeMap::new());
+
+/// How many times the pages of `bytes`, at its address, have been imported on any thread (tests).
+#[cfg(any(test, feature = "read-count"))]
+pub fn imports_of(bytes: &[u8]) -> usize {
+    IMPORTS.lock().ok().and_then(|i| i.get(&(bytes.as_ptr() as usize)).copied()).unwrap_or(0)
+}
+
 /// [`read_with_reader_options`] of `original`, the PDF `bytes` read with `reader`.
 fn read_opened(
    bytes: &[u8],
@@ -228,6 +238,11 @@ fn read_opened(
    reader: &craft_pdf::OpenOptions,
    original: &craft_pdf::syntax::Pdf,
 ) -> Result<ImportReport, PdfError> {
+    #[cfg(any(test, feature = "read-count"))]
+    if let Ok(mut imports) = IMPORTS.lock() {
+        let n = imports.entry(bytes.as_ptr() as usize).or_default();
+        *n = n.saturating_add(1);
+    }
    let picked = crate::pages::picked(opts, original.pages().len())?;
    let mut ocgs = Ocgs::read(original);
    let route = opts.layers && !ocgs.list.is_empty();
@@ -76,6 +76,8 @@ pub use editing::{EDITING_FILE, Editing, LEGACY_EDITING_FILE, editing, editing_w
 pub use encrypt::Encryption;
 pub use export::{export, export_with_report, page_areas};
 pub use file_info::{FileInfo, file_info};
+#[cfg(any(test, feature = "read-count"))]
+pub use import::imports_of;
 pub use import::{
    INVISIBLE_TEXT_NOTE, OFF_ARTBOARD_NOTE, OUTLINED_TEXT_NOTE, PAST_PAGE_NOTE, UNMATCHED_GLYPHS_NOTE, UNNAMED_CHARACTERS_NOTE, holds_outlines,
    import, import_opened, import_with_report, is_glyph_outlines, is_outlines_note,
@@ -83,8 +85,8 @@ pub use import::{
 #[cfg(any(test, feature = "read-count"))]
 pub use pages::reads_of;
 pub use pages::{
-    IllustratorData, Opened, PageInfo, PdfInfo, has_illustrator_data, illustrator_data, illustrator_data_without_pdf_part, info, is_postscript,
-    open_pdf,
+    IllustratorData, Opened, PageInfo, PdfInfo, TrimPages, has_illustrator_data, illustrator_data, illustrator_data_without_pdf_part, info,
+    is_postscript, open_pdf,
 };
 pub use piece_info::{PRIVATE_CHUNK, PrivateData};
 pub use post::{THUMBNAIL_SIZE, Thumbnail};
@@ -280,6 +280,36 @@ impl Opened {
    pub fn page_count(&self) -> usize {
        self.pdf.pages().len()
    }
+
+    /// The pages' trim boxes and bleed, as an import of every page on its trim box takes them,
+    /// without importing any page's art.
+    pub fn trim_pages(&self) -> TrimPages {
+        let pages = self.pdf.pages();
+        let mut bleed = [0.0; 4];
+        for page in pages.iter() {
+            for (side, b) in bleed.iter_mut().zip(self::bleed(page)) {
+                *side = f64::max(*side, b);
+            }
+        }
+        TrimPages {
+            sizes: pages.iter().map(|page| frame(page, CropTo::Trim).1).map(|r| (r.width(), r.height())).collect(),
+            user_unit: pages.first().map_or(1.0, |page| f64::from(page.user_unit())),
+            bleed,
+        }
+    }
+}
+
+/// A PDF's pages as an import on their trim boxes sizes them ([`Opened::trim_pages`]).
+#[derive(Clone, Debug, PartialEq)]
+pub struct TrimPages {
+    /// Each page's trim box (its crop box when it has none) in points, rotated as the page shows:
+    /// width and height.
+    pub sizes: Vec<(f64, f64)>,
+    /// The size in points of a unit of the first page's user space (its `UserUnit`).
+    pub user_unit: f64,
+    /// The bleed of the pages, `[top, bottom, left, right]` in points: on each side, the widest
+    /// of the pages' bleed, as the import makes it the document's bleed.
+    pub bleed: [f64; 4],
 }

 /// Preserve the application's existing accepted file sizes. Ordinary stream decoding still