Add support for Bengali text in the UI

Updated cjk.rs

crates/ui-egui/src/cjk.rs

@@ -1,8 +1,8 @@
-//! Chinese, Japanese and Korean text in the UI. egui's own fonts and Inter have no CJK glyphs, so
+//! Chinese, Japanese, Korean and Bengali text in the UI. egui's own fonts and Inter have no CJK or non-Latin glyphs, so
 //! the UI adds a face per script it needs: the UI language's, the scripts in the open file's names
 //! and comments, the language picker's and typed text. Desktop finds them among the installed
 //! fonts (the system font scan), only once one is needed, so English users load none; the web
-//! build has only the CJK faces built in from craft-fonts (`FIGCRAFT_EMBED_CJK`), else none.
+//! build has only the CJK and non-Latin faces built in from craft-fonts (`FIGCRAFT_EMBED_CJK`), else none.
 
 use std::sync::Arc;
 
@@ -12,7 +12,15 @@ pub const KANA: u8 = 1;
 pub const HANGUL: u8 = 2;
 /// Han characters (and CJK punctuation and full-width forms).
 pub const HAN: u8 = 4;
+pub const BENGALI: u8 = 8;
 
+const BENGALI_FONTS: &[&str] = &[
+    "Noto Sans Bengali",
+    "Nirmala UI",
+    "Bangla Sangam MN",
+    "Kalpurush",
+    "SolaimanLipi",
+];
 /// Japanese faces, the built-in one first: Windows, macOS, then Linux names.
 const JAPANESE: &[&str] = &[
     "BIZ UDPGothic",
@@ -46,24 +54,26 @@ const CHINESE: &[&str] = &[
     "Droid Sans Fallback",
 ];
 
-/// The CJK scripts in `s`.
+/// The CJK and Bengali scripts in `s`.
 pub fn scripts(s: &str) -> u8 {
     s.chars().fold(0, |m, c| {
         m | match u32::from(c) {
             0x3040..=0x30FF | 0x31F0..=0x31FF | 0xFF66..=0xFF9F => KANA,
             0x1100..=0x11FF | 0x3130..=0x318F | 0xA960..=0xA97F | 0xAC00..=0xD7FF | 0xFFA0..=0xFFDC => HANGUL,
             0x3000..=0x303F | 0x3400..=0x4DBF | 0x4E00..=0x9FFF | 0xF900..=0xFAFF | 0xFF01..=0xFF65 | 0x20000..=0x3FFFF => HAN,
+            0x0980..=0x09FF => BENGALI,
             _ => 0,
         }
     })
 }
 
-/// The CJK scripts a UI language (a catalog code) is written in.
+/// The scripts a UI language (a catalog code) is written in.
 pub fn language(code: &str) -> u8 {
     match code.split('-').next() {
         Some("ja") => KANA | HAN,
         Some("ko") => HANGUL,
         Some("zh") => HAN,
+        Some("bn") => BENGALI,
         _ => 0,
     }
 }
@@ -75,7 +85,9 @@ pub fn can_show(code: &str) -> bool {
     let need = language(code);
     need == 0
         || !cfg!(target_arch = "wasm32")
-        || samples(need, 0).iter().all(|(c, _)| figcraft_text::face_with_char(*c, &["BIZ UDPGothic", "Noto Sans CJK SC"]).is_some())
+        || samples(need, 0).iter().all(|(c, families)| {
+            figcraft_text::face_with_char(*c, families).is_some()
+        })
 }
 
 /// A character standing for each script in `need`, with the families to look for it in, the UI
@@ -89,10 +101,21 @@ fn samples(need: u8, ui: u8) -> Vec<(char, Vec<&'static str>)> {
         (false, HANGUL) => ('漢', [KOREAN, JAPANESE, CHINESE].concat()),
         (false, _) => ('漢', [JAPANESE, KOREAN, CHINESE].concat()),
     };
-    let mut v = vec![(KANA, ('あ', JAPANESE.to_vec())), (HAN, han), (HANGUL, ('한', KOREAN.to_vec()))];
+    let mut v = vec![
+        (KANA, ('あ', JAPANESE.to_vec())),
+        (HAN, han),
+        (HANGUL, ('한', KOREAN.to_vec())),
+        (BENGALI, ('অ', BENGALI_FONTS.to_vec())),
+    ];
     match ui {
         HANGUL => v.reverse(),
         HAN => v.swap(0, 1),
+        BENGALI => {
+            if let Some(pos) = v.iter().position(|(bit, _)| *bit == BENGALI) {
+                let item = v.remove(pos);
+                v.insert(0, item);
+            }
+        }
         _ => {}
     }
     v.into_iter().filter(|(bit, _)| need & bit != 0).map(|(_, s)| s).collect()
@@ -124,11 +147,13 @@ mod tests {
         assert_eq!(scripts("ボタン"), KANA);
         assert_eq!(scripts("버튼"), HANGUL);
         assert_eq!(scripts("按钮"), HAN);
+        assert_eq!(scripts("বাংলা"), BENGALI);
         assert_eq!(scripts("日本語のレイヤー（1）"), KANA | HAN);
         assert_eq!(language("ja"), KANA | HAN);
         assert_eq!(language("ko"), HANGUL);
         assert_eq!(language("zh-Hant"), HAN);
         assert_eq!(language("zh-Hans"), HAN);
+        assert_eq!(language("bn"), BENGALI);
         assert_eq!(language("fr"), 0);
         assert!(["en", "es", "es-419", "fr", "de", "pt-BR", "tr", "id"].iter().all(|c| can_show(c)));
     }
@@ -137,7 +162,7 @@ mod tests {
     fn the_ui_language_script_comes_first() {
         let order = |need, ui| samples(need, ui).into_iter().map(|(c, _)| c).collect::<String>();
         let first_face = |need, ui| samples(need, ui).first().and_then(|(_, f)| f.first()).copied();
-        assert_eq!(order(KANA | HAN | HANGUL, 0), "あ漢한");
+        assert_eq!(order(KANA | HAN | HANGUL | BENGALI, 0), "あ漢한অ");
         assert_eq!(order(KANA | HAN | HANGUL, KANA | HAN), "あ漢한");
         assert_eq!(order(KANA | HAN | HANGUL, HANGUL), "한漢あ");
         assert_eq!(order(HANGUL, 0), "한");
@@ -150,6 +175,6 @@ mod tests {
         assert_eq!(order(KANA | HAN, language("zh-Hans")), "们あ");
         assert!(["Microsoft YaHei UI", "PingFang SC", "Noto Sans CJK SC"].iter().all(|f| samples(HAN, HAN)[0].1[..4].contains(f)));
         assert!(faces(0, "en", &|_| false).is_empty());
-        assert!(faces(KANA | HANGUL | HAN, "ja", &|_| true).is_empty(), "nothing is looked up for scripts the UI draws");
+        assert!(faces(KANA | HANGUL | HAN | BENGALI, "ja", &|_| true).is_empty(), "nothing is looked up for scripts the UI draws");
     }
 }