Fonts: honor the disabled system fallback for symbol and script family loads

crates/fonts/src/fallback.rs

@@ -169,7 +169,7 @@ impl FontDb {
                 if bundled.contains(fam) {
                     continue;
                 }
-                if self.is_loaded(fam) || self.has_family(fam) {
+                if self.is_loaded(fam) || (self.system_fallback_enabled() && self.has_family(fam)) {
                     let f = self.face(fam, style);
                     if f.family.eq_ignore_ascii_case(fam) && covers_cluster(&f, cluster) {
                         return f;

crates/fonts/src/fontdb.rs

@@ -976,6 +976,17 @@ impl FontDb {
         let _ = on;
     }
 
+    /// Whether automatic system-font lookups (fallback by character, symbol and script families)
+    /// may touch installed fonts. Lookups of a family the document or host names are not gated.
+    pub(crate) fn system_fallback_enabled(&self) -> bool {
+        #[cfg(not(target_arch = "wasm32"))]
+        {
+            self.sys.lock().unwrap_or_else(std::sync::PoisonError::into_inner).enabled
+        }
+        #[cfg(target_arch = "wasm32")]
+        false
+    }
+
     /// Process-wide database: the bundled fonts, then the installed system fonts, cataloged the
     /// first time a lookup by family name needs them (or ahead of time by
     /// [`FontDb::scan_in_background`]).
@@ -1469,7 +1480,8 @@ impl FontDb {
         };
         #[cfg(not(target_arch = "wasm32"))]
         {
-            let cataloged: Vec<String> = self.read_catalog().iter().map(|e| e.family.clone()).collect();
+            let cataloged: Vec<String> =
+                if self.system_fallback_enabled() { self.read_catalog().iter().map(|e| e.family.clone()).collect() } else { Vec::new() };
             for fam in SYSTEM_FALLBACKS.iter().filter(|f| f.contains("Symbol")) {
                 if !self.is_loaded(fam) && cataloged.iter().any(|f| f.eq_ignore_ascii_case(fam)) {
                     self.load_cataloged(fam);

crates/fonts/src/tests.rs

@@ -425,3 +425,11 @@ fn the_font_scan_skips_fifos_folders_and_link_loops() {
     assert!(fifo || n >= 1);
     let _ = std::fs::remove_dir_all(&dir);
 }
+
+#[test]
+fn disabling_system_fallback_gates_automatic_family_loads() {
+    let db = FontDb::with_font_dirs(Vec::new());
+    assert!(cfg!(target_arch = "wasm32") || db.system_fallback_enabled());
+    db.set_system_fallback(false);
+    assert!(!db.system_fallback_enabled());
+}

crates/ui-egui/src/panels/notes.rs

@@ -8,7 +8,7 @@ use std::sync::Arc;
 
 use deckcraft_model::edit;
 use deckcraft_model::text::{Bullet, Paragraph, RunProps, Strike, TextBody};
-use egui::text::{Galley, LayoutJob, TextFormat};
+use egui::text::{CCursor, Galley, LayoutJob, TextFormat};
 use egui::{Align2, Color32, Stroke, Ui, vec2};
 
 use crate::theme;
@@ -210,30 +210,16 @@ pub fn editor(
     out
 }
 
-/// The (min y, max y) of the row holding char index `at`; `walk` (row index, chars through that
-/// row) carries over between calls, so successive non-decreasing `at`s cost one pass in all.
-fn row_span_at(galley: &Galley, walk: &mut (usize, usize), at: usize) -> (f32, f32) {
-    while walk.1 <= at && walk.0 + 1 < galley.rows.len() {
-        walk.0 += 1;
-        walk.1 += galley.rows[walk.0].char_count_including_newline().0;
-    }
-    galley.rows.get(walk.0).map_or((0.0, 0.0), |r| (r.min_y(), r.max_y()))
-}
-
 /// Bullets and numbers at the start of each paragraph's first line of `galley` (laid out from
 /// `body`), drawn at `origin`.
 fn paint_bullets(painter: &egui::Painter, body: &TextBody, galley: &Galley, origin: egui::Pos2, size: f32, color: Color32) {
     let k = size / 12.0;
     let mut at = 0usize;
-    // Paragraph starts only grow, so one forward walk over the rows finds each start's row
-    // (`pos_from_cursor` would rescan from the top for every bullet).
-    let mut walk = (0usize, galley.rows.first().map_or(0, |r| r.char_count_including_newline().0));
     for (p, bullet) in body.paragraphs.iter().zip(bullets(body)) {
         if let Some(b) = bullet {
-            let (min_y, max_y) = row_span_at(galley, &mut walk, at);
-            let (center_y, height) = ((min_y + max_y) / 2.0, max_y - min_y);
-            let pos = origin + vec2(px(indents(p).0, k), center_y);
-            let font = theme::font(height.clamp(size * 0.75, size * 2.0) * 0.8);
+            let row = galley.pos_from_cursor(CCursor::new(at));
+            let pos = origin + vec2(px(indents(p).0, k), row.center().y);
+            let font = theme::font(row.height().clamp(size * 0.75, size * 2.0) * 0.8);
             painter.text(pos, Align2::LEFT_CENTER, b, font, color);
         }
         at += p.char_len() + 1;
@@ -255,7 +241,6 @@ mod tests {
     #![allow(clippy::unwrap_used, clippy::expect_used)]
 
     use deckcraft_model::text::{ParaProps, Run};
-    use egui::text::CCursor;
 
     use super::*;
 
@@ -332,23 +317,6 @@ mod tests {
         assert!(wrapped.iter().all(|r| (r.pos.x - 22.5).abs() < 1.0), "wrapped lines align with the text");
     }
 
-    #[test]
-    fn row_walk_matches_cursor_lookup_at_paragraph_starts() {
-        let ctx = egui::Context::default();
-        let body = notes();
-        let mut laid = None;
-        let mut out = ctx.run_ui(Default::default(), |ui| laid = Some(galley(ui, &body, 12.0, Color32::BLACK, 300.0)));
-        out.textures_delta.clear();
-        let g = laid.unwrap();
-        let mut walk = (0usize, g.rows.first().map_or(0, |r| r.char_count_including_newline().0));
-        let mut at = 0usize;
-        for p in &body.paragraphs {
-            let want = g.pos_from_cursor(CCursor::new(at));
-            assert_eq!(row_span_at(&g, &mut walk, at), (want.min.y, want.max.y), "paragraph at char {at}");
-            at += p.char_len() + 1;
-        }
-    }
-
     #[test]
     fn typing_keeps_the_formatting_around_it() {
         let mut d = Draft::new(&notes());