Fix #1499: PDF and EPS another app copied paste as editable vector art

Paste read PDF only from the Windows clipboard and EPS nowhere, so on macOS a copied
equation or drawing pasted nothing new (the last thing copied in the app came back).
- macOS: the pasteboard's PDF, EPS and SVG are read, ahead of text and bitmaps.
- Windows: EPS is read beside PDF.
- Everywhere: an .eps file copied in a file manager pastes.
- clipboard.importEps loads an EPS into the clipboard as document.open reads one.

crates/engine/src/cmd/clipboard.rs

@@ -21,7 +21,7 @@ use vectorcraft_color::Swatch;
 use vectorcraft_doc::{Document, GraphicStyle, ImageBlob, Node, NodeId, PatternDef, Symbol, TextStyleDef};
 use vectorcraft_geom::Rect;
 
-pub use flavours::{BITMAP, EMF, FILE_HEAD, Flavour, PASTE_ORDER, PDF, PNG, SVG, TEXT, file_flavour, is_address, names_a_picture};
+pub use flavours::{BITMAP, EMF, EPS, FILE_HEAD, Flavour, PASTE_ORDER, PDF, PNG, SVG, TEXT, file_flavour, is_address, names_a_picture};
 pub(crate) use resources::SwatchChoices;
 
 use super::*;

crates/engine/src/cmd/clipboard/flavours.rs

@@ -1,5 +1,5 @@
 //! Clipboard flavours: what Copy offers other apps besides SVG (PNG, PDF and plain text) and what
-//! Paste takes from them (bitmaps, plain text, PDF and Windows metafiles).
+//! Paste takes from them (bitmaps, plain text, PDF, EPS and Windows metafiles).
 //!
 //! The UI owns the platform clipboard (`Services::system_clipboard` in the egui frontend): on Copy
 //! it publishes [`Session::clipboard_flavours`]; before a Paste it turns what another app put on
@@ -27,9 +27,12 @@ pub const BITMAP: &str = "image/*";
 /// An EMF (or WMF) picture: what Windows apps copy as vector art (the system clipboard reads it
 /// where the platform offers it).
 pub const EMF: &str = "image/emf";
+/// An EPS (or other PostScript) picture: what drawing and typesetting apps copy as vector art
+/// beside, or instead of, a PDF (#1499).
+pub const EPS: &str = "application/postscript";
 /// What Paste reads from other apps, best first: vector art before text, text before bitmaps
 /// (word processors offer a picture of copied text too).
-pub const PASTE_ORDER: [&str; 5] = [SVG, PDF, EMF, TEXT, BITMAP];
+pub const PASTE_ORDER: [&str; 6] = [SVG, PDF, EPS, EMF, TEXT, BITMAP];
 /// Is `text` only an address (a web page's, an image's, a file's)? A browser's Copy Image puts the
 /// image's address as text next to the picture: then the picture is what Paste takes (#597). An
 /// address alone pastes as text, and nothing is fetched.
@@ -67,13 +70,14 @@ fn only_images(html: &str) -> bool {
 pub const FILE_HEAD: usize = 4096;
 
 /// What a file copied in a file manager pastes as, if one of `mimes` (`image/*`: any bitmap):
-/// SVG, PDF, a Windows metafile or a bitmap (its own `image/…` type), told from its first
+/// SVG, PDF, EPS, a Windows metafile or a bitmap (its own `image/…` type), told from its first
 /// [`FILE_HEAD`] bytes and its name. The file's bytes are that flavour's data.
 pub fn file_flavour(name: &str, head: &[u8], mimes: &[&str]) -> Option<&'static str> {
     let f = fileio::detect(name, head)?;
     let (asked, mime) = match f.id {
         "svg" => (SVG, SVG),
         "pdf" => (PDF, PDF),
+        "eps" => (EPS, EPS),
         "emf" | "wmf" => (EMF, EMF),
         _ if f.raster => (BITMAP, f.mime),
         _ => return None,
@@ -167,6 +171,15 @@ pub fn specs() -> Vec<CommandSpec> {
             has_doc,
             import_emf
         ),
+        cmd!(
+            query "clipboard.importEps",
+            "Load EPS into Clipboard",
+            [],
+            None,
+            "{dataBase64 (EPS or other PostScript bytes), center?: [x, y]} replace the clipboard with the picture's objects as document.open reads an EPS (editable paths, type and images, with the images, patterns and swatches they use), centred on `center` (default: the first artboard) → {count, warnings}; then run edit.paste",
+            has_doc,
+            import_eps
+        ),
     ]
 }
 
@@ -345,10 +358,26 @@ fn import_emf(s: &mut Session, p: &Value) -> Result<Value> {
     if vectorcraft_metafile::sniff(&bytes).is_none() {
         return Err(bad(C, "the data isn't an EMF or WMF picture"));
     }
-    let loaded = fileio::load("Clipboard.emf", &bytes).map_err(|e| bad(C, e.to_string()))?;
+    import_picture(s, p, C, "Clipboard.emf", &bytes)
+}
+
+fn import_eps(s: &mut Session, p: &Value) -> Result<Value> {
+    const C: &str = "clipboard.importEps";
+    let bytes = data_param(p, C)?;
+    if !vectorcraft_pdf::is_postscript(&bytes) {
+        return Err(bad(C, "the data isn't an EPS or PostScript picture"));
+    }
+    import_picture(s, p, C, "Clipboard.eps", &bytes)
+}
+
+/// Replace the clipboard with the objects of the picture `bytes`, read as the file `name` is
+/// opened (command `cmd`).
+fn import_picture(s: &mut Session, p: &Value, cmd: &str, name: &str, bytes: &[u8]) -> Result<Value> {
+    let mut loaded = fileio::load(name, bytes).map_err(|e| bad(cmd, e.to_string()))?;
+    loaded.doc.drop_edit_modes();
     let clip = Clipboard::from_document(&loaded.doc);
     if clip.is_empty() {
-        return Err(bad(C, "the picture has no objects"));
+        return Err(bad(cmd, "the picture has no objects"));
     }
     let count = s.load_clipboard(clip, p)?;
     Ok(json!({ "count": count, "warnings": loaded.warnings }))