no_std support

src/font/system/no_std.rs

@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: MIT OR Apache-2.0
+
+use alloc::{
+    string::{String, ToString},
+    sync::Arc,
+    vec::Vec,
+};
+
+use crate::{Attrs, Font, FontMatches};
+
+/// Access system fonts
+pub struct FontSystem{
+    locale: String,
+    db: fontdb::Database,
+}
+
+impl FontSystem {
+    pub fn new() -> Self {
+        //TODO: get locale from argument?
+        let locale = "en-US".to_string();
+
+        //TODO: allow loading fonts from memory
+        let mut db = fontdb::Database::new();
+        {
+            //TODO: configurable default fonts
+            db.set_monospace_family("Fira Mono");
+            db.set_sans_serif_family("Fira Sans");
+            db.set_serif_family("DejaVu Serif");
+        }
+
+        Self {
+            locale,
+            db,
+        }
+    }
+
+    pub fn locale(&self) -> &str {
+        &self.locale
+    }
+
+    pub fn db(&self) -> &fontdb::Database {
+        &self.db
+    }
+
+    pub fn get_font<'a>(&'a self, id: fontdb::ID) -> Option<Arc<Font<'a>>> {
+        let face = self.db.face(id)?;
+        match Font::new(face) {
+            Some(font) => Some(Arc::new(font)),
+            None => {
+                log::warn!("failed to load font '{}'", face.post_script_name);
+                None
+            }
+        }
+    }
+
+    pub fn get_font_matches<'a>(&'a self, attrs: Attrs) -> Arc<FontMatches<'a>> {
+        let mut fonts = Vec::new();
+        for face in self.db.faces() {
+            if !attrs.matches(face) {
+                continue;
+            }
+
+            match self.get_font(face.id) {
+                Some(font) => fonts.push(font),
+                None => (),
+            }
+        }
+
+        Arc::new(FontMatches {
+            locale: &self.locale,
+            default_family: self.db.family_name(&attrs.family).to_string(),
+            fonts
+        })
+    }
+}