Add settings for custom UI fonts

contrib/Settings-sample.toml

@@ -26,6 +26,9 @@ time-format = "%H:%M"
 date-format = "%A, %B %-d, %Y"
 # Appends the tapped external URLs to this file.
 external-urls-queue = "bin/article_fetcher/urls.txt"
+# UI fonts
+font-family-sans = "Inter"
+font-family-serif = "Libre Baskerville"
 
 # You can create libraries by adding further [[libraries]] entries.
 [[libraries]]

crates/core/src/font/mod.rs

@@ -24,6 +24,7 @@ use crate::geom::{Point, Vec2};
 use crate::helpers::IsHidden;
 use crate::framebuffer::Framebuffer;
 use crate::device::CURRENT_DEVICE;
+use crate::settings::{Settings, DEFAULT_UI_FONT_FAMILY_SANS, DEFAULT_UI_FONT_FAMILY_SERIF};
 
 // Font sizes in 1/64th of a point
 pub const FONT_SIZES: [u32; 3] = [349, 524, 629];
@@ -477,7 +478,7 @@ impl FontFamily {
             styles.get("Regular")
                   .or_else(|| styles.get("Roman"))
                   .or_else(|| styles.get("Book"))
-                  .ok_or_else(|| format_err!("can't find regular style"))?
+                  .ok_or_else(|| format_err!("can't find regular style for {family_name}"))?
         };
         let italic_path = styles.get("Italic")
                                 .or_else(|| styles.get("Book Italic"))
@@ -510,21 +511,34 @@ pub struct Fonts {
 }
 
 impl Fonts {
-    pub fn load() -> Result<Fonts, Error> {
+    pub fn load(settings: &Settings) -> Result<Fonts, Error> {
         let opener = FontOpener::new()?;
+
+        // Default to builtin fonts
+        let mut sans_path = "fonts";
+        let mut serif_path = "fonts";
+        let mut font_family_sans = DEFAULT_UI_FONT_FAMILY_SANS;
+        let mut font_family_serif = DEFAULT_UI_FONT_FAMILY_SERIF;
+
+        // Look for fonts in settings path if a custom font is given
+        if let Some(custom_sans) = &settings.font_family_sans {
+            sans_path = &settings.reader.font_path;
+            font_family_sans = custom_sans.as_str()
+        }
+        if let Some(custom_serif) = &settings.font_family_serif {
+            serif_path = &settings.reader.font_path;
+            font_family_serif = custom_serif.as_str()
+        }
+
         let mut fonts = Fonts {
-            sans_serif: FontFamily {
-                regular: opener.open("fonts/NotoSans-Regular.ttf")?,
-                italic: opener.open("fonts/NotoSans-Italic.ttf")?,
-                bold: opener.open("fonts/NotoSans-Bold.ttf")?,
-                bold_italic: opener.open("fonts/NotoSans-BoldItalic.ttf")?,
-            },
-            serif: FontFamily {
-                regular: opener.open("fonts/NotoSerif-Regular.ttf")?,
-                italic: opener.open("fonts/NotoSerif-Italic.ttf")?,
-                bold: opener.open("fonts/NotoSerif-Bold.ttf")?,
-                bold_italic: opener.open("fonts/NotoSerif-BoldItalic.ttf")?,
-            },
+            sans_serif: FontFamily::from_name(
+                font_family_sans,
+                sans_path,
+            )?,
+            serif: FontFamily::from_name(
+                font_family_serif,
+                serif_path,
+            )?,
             monospace: FontFamily {
                 regular: opener.open("fonts/SourceCodeVariable-Roman.otf")?,
                 italic: opener.open("fonts/SourceCodeVariable-Italic.otf")?,

crates/core/src/settings/mod.rs

@@ -29,6 +29,8 @@ pub const DEFAULT_MARGIN_WIDTH: i32 = 8;
 pub const DEFAULT_LINE_HEIGHT: f32 = 1.2;
 // Default font family name.
 pub const DEFAULT_FONT_FAMILY: &str = "Libertinus Serif";
+pub const DEFAULT_UI_FONT_FAMILY_SANS: &str = "Noto Sans";
+pub const DEFAULT_UI_FONT_FAMILY_SERIF: &str = "Noto Serif";
 // Default text alignment.
 pub const DEFAULT_TEXT_ALIGN: TextAlign = TextAlign::Left;
 pub const HYPHEN_PENALTY: i32 = 50;
@@ -112,6 +114,8 @@ pub struct Settings {
     pub date_format: String,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub external_urls_queue: Option<PathBuf>,
+    pub font_family_sans: Option<String>,
+    pub font_family_serif: Option<String>,
     #[serde(skip_serializing_if = "Vec::is_empty")]
     pub libraries: Vec<LibrarySettings>,
     pub intermissions: Intermissions,
@@ -531,6 +535,8 @@ impl Default for Settings {
             inverted: false,
             sleep_cover: true,
             auto_share: false,
+            font_family_sans: None,
+            font_family_serif: None,
             rotation_lock: None,
             button_scheme: ButtonScheme::Natural,
             auto_suspend: 30.0,

crates/emulator/src/main.rs

@@ -61,7 +61,7 @@ pub fn build_context(fb: Box<dyn Framebuffer>) -> Result<Context, Error> {
     let battery = Box::new(FakeBattery::new()) as Box<dyn Battery>;
     let frontlight = Box::new(LightLevels::default()) as Box<dyn Frontlight>;
     let lightsensor = Box::new(0u16) as Box<dyn LightSensor>;
-    let fonts = Fonts::load()?;
+    let fonts = Fonts::load(&settings)?;
 
     Ok(Context::new(fb, None, library, settings,
                     fonts, battery, frontlight, lightsensor))

crates/plato/src/app.rs

@@ -106,7 +106,7 @@ fn build_context(fb: Box<dyn Framebuffer>) -> Result<Context, Error> {
     let library_settings = &settings.libraries[settings.selected_library];
     let library = Library::new(&library_settings.path, library_settings.mode)?;
 
-    let fonts = Fonts::load().context("can't load fonts")?;
+    let fonts = Fonts::load(&settings).context("can't load fonts")?;
 
     let battery = Box::new(KoboBattery::new().context("can't create battery")?) as Box<dyn Battery>;