Merge PR #565: Files: save and open outlines as RTF

Conflicts:
crates/engine/src/cmd/file.rs: export spec keeps main's transparentBackground and adds rtf; probe_clips (main) and outline_text (PR) both kept
docs/file-format-parity.md: PR's outline row (RTF now read) with main's .md wording, main's PNG row

crates/engine/src/cmd/file.rs

@@ -37,7 +37,7 @@ pub fn specs() -> Vec<CommandSpec> {
         cmd!(noundo "file.saveAs", "Save As…", ["File"], Some("Cmd+Shift+S"), "{path, format?}", has_doc, save_as),
         cmd!(noundo "file.saveTemplate", "Save as Template…", ["File"], None, "{path}", has_doc, save_as),
         cmd!(query "file.saveBytes", "Save to Data", [], None, "{format?: deckcraft|pptx} → {data: base64}", has_doc, save_bytes_cmd),
-        cmd!(noundo "file.export", "Export…", ["File"], None, "{path, format?: png|jpeg|pptx|deckcraft|outline|pdf|gif (else by path), slide?: index, all?: bool, scale?: px per pt, layout?: slides|notes|handouts (pdf), perPage?: 1|2|3|4|6|9, paper?: letter|a4|legal|a3 (pdf), orientation?: portrait|landscape (pdf), dpi?, slides?: [index]|range (\"1-3,5\"), includeHidden?, textLayer?, frame?, transparentBackground?: bool (png: leave the slide background out), width?: px 16-3840|small|medium|large|extraLarge (gif), secondsPerSlide?: 0.1-600 (gif; 5), loop?: bool (gif; true: forever)} → {path, bytes} or {files} (png, jpeg); gif adds frames, width, height, secondsPerSlide", has_doc, export),
+        cmd!(noundo "file.export", "Export…", ["File"], None, "{path, format?: png|jpeg|pptx|deckcraft|outline|rtf|pdf|gif (else by path), slide?: index, all?: bool, scale?: px per pt, layout?: slides|notes|handouts (pdf), perPage?: 1|2|3|4|6|9, paper?: letter|a4|legal|a3 (pdf), orientation?: portrait|landscape (pdf), dpi?, slides?: [index]|range (\"1-3,5\"), includeHidden?, textLayer?, frame?, transparentBackground?: bool (png: leave the slide background out), width?: px 16-3840|small|medium|large|extraLarge (gif), secondsPerSlide?: 0.1-600 (gif; 5), loop?: bool (gif; true: forever)} → {path, bytes} or {files} (png, jpeg); gif adds frames, width, height, secondsPerSlide", has_doc, export),
         cmd!(
             query "file.info",
             "Info",
@@ -167,8 +167,10 @@ fn open_other(name: &str, bytes: &[u8]) -> Result<(Presentation, Vec<String>)> {
         return Err(EngineError::Other(format!("{name} is password-protected. DeckCraft can't open password-protected presentations yet.")));
     }
     let lower = name.to_ascii_lowercase();
-    if lower.ends_with(".txt") || lower.ends_with(".md") {
+    let rtf = deckcraft_format::rtf::sniff_rtf(bytes);
+    if rtf || lower.ends_with(".txt") || lower.ends_with(".md") {
         let text = String::from_utf8_lossy(bytes);
+        let text = if rtf { std::borrow::Cow::Owned(deckcraft_format::rtf::rtf_to_outline(&text)) } else { text };
         let mut p = defaults::blank_presentation(defaults::WIDE, Default::default(), false);
         if lower.ends_with(".md") {
             deckcraft_format::markdown_to_slides(&mut p, &text);
@@ -219,6 +221,12 @@ fn probe_clips(p: &mut Presentation) {
     }
 }
 
+/// An outline file's text: RTF is read into the tab-indented outline, anything else as UTF-8.
+pub fn outline_text(bytes: &[u8]) -> String {
+    let text = String::from_utf8_lossy(bytes);
+    if deckcraft_format::rtf::sniff_rtf(bytes) { deckcraft_format::rtf::rtf_to_outline(&text) } else { text.into_owned() }
+}
+
 pub fn add_opened(s: &mut Session, name: &str, path: Option<String>, p: Presentation) -> usize {
     let title = std::path::Path::new(name).file_stem().map(|n| n.to_string_lossy().to_string()).unwrap_or_else(|| name.to_string());
     crate::fonts::install_embedded_fonts(&p);
@@ -334,6 +342,7 @@ pub fn save_bytes(doc: &Presentation, format: &str) -> Result<Vec<u8>> {
     match format {
         f @ ("pptx" | "potx" | "ppsx") => deckcraft_pptx::export_as(doc, f).map_err(|e| EngineError::Other(e.to_string())),
         "outline" | "txt" => Ok(deckcraft_format::slides_to_outline(doc).into_bytes()),
+        "rtf" => Ok(deckcraft_format::rtf::slides_to_rtf(doc).into_bytes()),
         "pdf" => deckcraft_pdf::export(doc, &Default::default()).map_err(|e| EngineError::Other(e.to_string())),
         "gif" => gif_bytes(doc, &Value::Null),
         _ => deckcraft_format::save(doc).map_err(|e| EngineError::Other(e.to_string())),
@@ -409,7 +418,7 @@ pub fn pdf_bytes(doc: &Presentation, p: &Value) -> Result<Vec<u8>> {
 }
 
 /// The output extensions [`format_for_path`] maps to a writer of that format.
-pub const WRITABLE_EXTENSIONS: &[&str] = &["deckcraft", "pptx", "potx", "ppsx", "pdf", "png", "jpg", "jpeg", "gif", "txt", "md"];
+pub const WRITABLE_EXTENSIONS: &[&str] = &["deckcraft", "pptx", "potx", "ppsx", "pdf", "png", "jpg", "jpeg", "gif", "txt", "md", "rtf"];
 
 /// The format a file named `path` is written in, or `None` when its extension names no format
 /// DeckCraft writes (`.odp`, `.svg`, no extension …): [`format_for_path`] would save
@@ -442,6 +451,8 @@ pub fn format_for_path(path: &str) -> &'static str {
         "gif"
     } else if l.ends_with(".txt") || l.ends_with(".md") {
         "outline"
+    } else if l.ends_with(".rtf") {
+        "rtf"
     } else {
         "deckcraft"
     }
@@ -622,7 +633,7 @@ fn export(s: &mut Session, p: &Value) -> Result<Value> {
                 "secondsPerSlide": f64::from(out.delay_cs) / 100.0,
             }))
         }
-        "pptx" | "potx" | "ppsx" | "deckcraft" | "outline" | "txt" => {
+        "pptx" | "potx" | "ppsx" | "deckcraft" | "outline" | "txt" | "rtf" => {
             let bytes = save_bytes(&st.doc, &format)?;
             write_file(&path, &bytes)?;
             Ok(json!({"path": path, "bytes": bytes.len()}))