Add font loading & configuration

Cargo.lock

@@ -707,6 +707,15 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "cmake"
+version = "0.1.50"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a31c789563b815f77f4250caee12365734369f942439b7defd71e18a48197130"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "cocoa"
 version = "0.24.1"
@@ -801,6 +810,12 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "const-cstr"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed3d0b5ff30645a68f35ece8cea4556ca14ef8a1651455f789a099a0513532a6"
+
 [[package]]
 name = "const_format"
 version = "0.2.32"
@@ -861,6 +876,18 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "core-text"
+version = "19.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "99d74ada66e07c1cefa18f8abfba765b486f250de2e4a999e5727fc0dd4b4a25"
+dependencies = [
+ "core-foundation",
+ "core-graphics",
+ "foreign-types 0.3.2",
+ "libc",
+]
+
 [[package]]
 name = "cpufeatures"
 version = "0.2.11"
@@ -977,6 +1004,16 @@ dependencies = [
  "dirs-sys",
 ]
 
+[[package]]
+name = "dirs-next"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b98cf8ebf19c3d1b223e151f99a4f9f0690dca41414773390fc824184ac833e1"
+dependencies = [
+ "cfg-if",
+ "dirs-sys-next",
+]
+
 [[package]]
 name = "dirs-sys"
 version = "0.4.1"
@@ -1021,6 +1058,18 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9ea835d29036a4087793836fa931b08837ad5e957da9e23886b29586fb9b6650"
 
+[[package]]
+name = "dwrote"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "439a1c2ba5611ad3ed731280541d36d2e9c4ac5e7fb818a27b604bdc5a6aa65b"
+dependencies = [
+ "lazy_static",
+ "libc",
+ "winapi",
+ "wio",
+]
+
 [[package]]
 name = "ecolor"
 version = "0.23.0"
@@ -1374,12 +1423,49 @@ dependencies = [
  "miniz_oxide",
 ]
 
+[[package]]
+name = "float-ord"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7bad48618fdb549078c333a7a8528acb57af271d0433bdecd523eb620628364e"
+
+[[package]]
+name = "float-ord"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ce81f49ae8a0482e4c55ea62ebbd7e5a686af544c00b9d090bba3ff9be97b3d"
+
 [[package]]
 name = "fnv"
 version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
 
+[[package]]
+name = "font-kit"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "21fe28504d371085fae9ac7a3450f0b289ab71e07c8e57baa3fb68b9e57d6ce5"
+dependencies = [
+ "bitflags 1.3.2",
+ "byteorder",
+ "core-foundation",
+ "core-graphics",
+ "core-text",
+ "dirs-next",
+ "dwrote",
+ "float-ord 0.2.0",
+ "freetype",
+ "lazy_static",
+ "libc",
+ "log",
+ "pathfinder_geometry",
+ "pathfinder_simd",
+ "walkdir",
+ "winapi",
+ "yeslogic-fontconfig-sys",
+]
+
 [[package]]
 name = "foreign-types"
 version = "0.3.2"
@@ -1431,6 +1517,27 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "freetype"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bee38378a9e3db1cc693b4f88d166ae375338a0ff75cb8263e1c601d51f35dc6"
+dependencies = [
+ "freetype-sys",
+ "libc",
+]
+
+[[package]]
+name = "freetype-sys"
+version = "0.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a37d4011c0cc628dfa766fcc195454f4b068d7afdc2adfd28861191d866e731a"
+dependencies = [
+ "cmake",
+ "libc",
+ "pkg-config",
+]
+
 [[package]]
 name = "fsevent-sys"
 version = "4.1.0"
@@ -2674,6 +2781,8 @@ dependencies = [
  "exec",
  "filetime",
  "flagset",
+ "float-ord 0.3.2",
+ "font-kit",
  "globset",
  "log",
  "memmap2 0.9.0",
@@ -2857,6 +2966,25 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1e91099d4268b0e11973f036e885d652fb0b21fedcf69738c627f94db6a44f42"
 
+[[package]]
+name = "pathfinder_geometry"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b7b7e7b4ea703700ce73ebf128e1450eb69c3a8329199ffbfb9b2a0418e5ad3"
+dependencies = [
+ "log",
+ "pathfinder_simd",
+]
+
+[[package]]
+name = "pathfinder_simd"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0444332826c70dc47be74a7c6a5fc44e23a7905ad6858d4162b658320455ef93"
+dependencies = [
+ "rustc_version",
+]
+
 [[package]]
 name = "percent-encoding"
 version = "2.3.0"
@@ -3232,6 +3360,15 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
 
+[[package]]
+name = "rustc_version"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bfa0f585226d2e68097d4f95d113b15b83a82e819ab25717ec0590d9584ef366"
+dependencies = [
+ "semver",
+]
+
 [[package]]
 name = "rustix"
 version = "0.37.27"
@@ -4768,6 +4905,15 @@ dependencies = [
  "toml 0.5.11",
 ]
 
+[[package]]
+name = "wio"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d129932f4644ac2396cb456385cbf9e63b5b30c6e8dc4820bdca4eb082037a5"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "x11-dl"
 version = "2.21.0"
@@ -4826,6 +4972,18 @@ version = "0.8.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0fcb9cbac069e033553e8bb871be2fbdffcab578eb25bd0f7c508cedc6dcd75a"
 
+[[package]]
+name = "yeslogic-fontconfig-sys"
+version = "3.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2bbd69036d397ebbff671b1b8e4d918610c181c5a16073b96f984a38d08c386"
+dependencies = [
+ "const-cstr",
+ "dlib",
+ "once_cell",
+ "pkg-config",
+]
+
 [[package]]
 name = "zbus"
 version = "3.14.1"

Cargo.toml

@@ -36,6 +36,8 @@ egui = "0.23.0"
 egui_extras = "0.23.0"
 filetime = "0.2.22"
 flagset = "0.4.4"
+float-ord = "0.3.2"
+font-kit = "0.11.0"
 globset = { version = "0.4.13", features = ["serde1"] }
 log = "0.4.20"
 memmap2 = "0.9.0"

src/app.rs

@@ -223,9 +223,6 @@ impl App {
         utc_offset: UtcOffset,
         relaunch_path: Rc<Mutex<Option<PathBuf>>>,
     ) -> Self {
-        // This is also where you can customized the look at feel of egui using
-        // `cc.egui_ctx.set_visuals` and `cc.egui_ctx.set_fonts`.
-
         // Load previous app state (if any).
         // Note that you must enable the `persistence` feature for this to work.
         let mut app = Self::default();
@@ -245,12 +242,15 @@ impl App {
                 app.config = Arc::new(RwLock::new(config));
             }
         }
+        app.appearance.init_fonts(&cc.egui_ctx);
         app.appearance.utc_offset = utc_offset;
         app.relaunch_path = relaunch_path;
         app
     }
 
-    fn pre_update(&mut self) {
+    fn pre_update(&mut self, ctx: &egui::Context) {
+        self.appearance.pre_update(ctx);
+
         let ViewState { jobs, diff_state, config_state, .. } = &mut self.view_state;
 
         let mut results = vec![];
@@ -306,6 +306,8 @@ impl App {
     }
 
     fn post_update(&mut self, ctx: &egui::Context) {
+        self.appearance.post_update(ctx);
+
         let ViewState { jobs, diff_state, config_state, .. } = &mut self.view_state;
         config_state.post_update(ctx, jobs, &self.config);
         diff_state.post_update(&self.config);
@@ -400,11 +402,9 @@ impl eframe::App for App {
             return;
         }
 
-        self.pre_update();
+        self.pre_update(ctx);
 
         let Self { config, appearance, view_state, .. } = self;
-        ctx.set_style(appearance.apply(ctx.style().as_ref()));
-
         let ViewState {
             jobs,
             config_state,

src/fonts/matching.rs

@@ -0,0 +1,146 @@
+// font-kit/src/matching.rs
+//
+// Copyright © 2018 The Pathfinder Project Developers.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Determines the closest font matching a description per the CSS Fonts Level 3 specification.
+
+use float_ord::FloatOrd;
+use font_kit::{
+    error::SelectionError,
+    properties::{Properties, Stretch, Style, Weight},
+};
+
+/// This follows CSS Fonts Level 3 § 5.2 [1].
+///
+/// https://drafts.csswg.org/css-fonts-3/#font-style-matching
+pub fn find_best_match(
+    candidates: &[Properties],
+    query: &Properties,
+) -> Result<usize, SelectionError> {
+    // Step 4.
+    let mut matching_set: Vec<usize> = (0..candidates.len()).collect();
+    if matching_set.is_empty() {
+        return Err(SelectionError::NotFound);
+    }
+
+    // Step 4a (`font-stretch`).
+    let matching_stretch = if matching_set
+        .iter()
+        .any(|&index| candidates[index].stretch == query.stretch)
+    {
+        // Exact match.
+        query.stretch
+    } else if query.stretch <= Stretch::NORMAL {
+        // Closest width, first checking narrower values and then wider values.
+        match matching_set
+            .iter()
+            .filter(|&&index| candidates[index].stretch < query.stretch)
+            .min_by_key(|&&index| FloatOrd(query.stretch.0 - candidates[index].stretch.0))
+        {
+            Some(&matching_index) => candidates[matching_index].stretch,
+            None => {
+                let matching_index = *matching_set
+                    .iter()
+                    .min_by_key(|&&index| FloatOrd(candidates[index].stretch.0 - query.stretch.0))
+                    .unwrap();
+                candidates[matching_index].stretch
+            }
+        }
+    } else {
+        // Closest width, first checking wider values and then narrower values.
+        match matching_set
+            .iter()
+            .filter(|&&index| candidates[index].stretch > query.stretch)
+            .min_by_key(|&&index| FloatOrd(candidates[index].stretch.0 - query.stretch.0))
+        {
+            Some(&matching_index) => candidates[matching_index].stretch,
+            None => {
+                let matching_index = *matching_set
+                    .iter()
+                    .min_by_key(|&&index| FloatOrd(query.stretch.0 - candidates[index].stretch.0))
+                    .unwrap();
+                candidates[matching_index].stretch
+            }
+        }
+    };
+    matching_set.retain(|&index| candidates[index].stretch == matching_stretch);
+
+    // Step 4b (`font-style`).
+    let style_preference = match query.style {
+        Style::Italic => [Style::Italic, Style::Oblique, Style::Normal],
+        Style::Oblique => [Style::Oblique, Style::Italic, Style::Normal],
+        Style::Normal => [Style::Normal, Style::Oblique, Style::Italic],
+    };
+    let matching_style = *style_preference
+        .iter()
+        .find(|&query_style| {
+            matching_set.iter().any(|&index| candidates[index].style == *query_style)
+        })
+        .unwrap();
+    matching_set.retain(|&index| candidates[index].style == matching_style);
+
+    // Step 4c (`font-weight`).
+    //
+    // The spec doesn't say what to do if the weight is between 400 and 500 exclusive, so we
+    // just use 450 as the cutoff.
+    let matching_weight =
+        if matching_set.iter().any(|&index| candidates[index].weight == query.weight) {
+            query.weight
+        } else if query.weight >= Weight(400.0)
+            && query.weight < Weight(450.0)
+            && matching_set.iter().any(|&index| candidates[index].weight == Weight(500.0))
+        {
+            // Check 500 first.
+            Weight(500.0)
+        } else if query.weight >= Weight(450.0)
+            && query.weight <= Weight(500.0)
+            && matching_set.iter().any(|&index| candidates[index].weight == Weight(400.0))
+        {
+            // Check 400 first.
+            Weight(400.0)
+        } else if query.weight <= Weight(500.0) {
+            // Closest weight, first checking thinner values and then fatter ones.
+            match matching_set
+                .iter()
+                .filter(|&&index| candidates[index].weight <= query.weight)
+                .min_by_key(|&&index| FloatOrd(query.weight.0 - candidates[index].weight.0))
+            {
+                Some(&matching_index) => candidates[matching_index].weight,
+                None => {
+                    let matching_index = *matching_set
+                        .iter()
+                        .min_by_key(|&&index| FloatOrd(candidates[index].weight.0 - query.weight.0))
+                        .unwrap();
+                    candidates[matching_index].weight
+                }
+            }
+        } else {
+            // Closest weight, first checking fatter values and then thinner ones.
+            match matching_set
+                .iter()
+                .filter(|&&index| candidates[index].weight >= query.weight)
+                .min_by_key(|&&index| FloatOrd(candidates[index].weight.0 - query.weight.0))
+            {
+                Some(&matching_index) => candidates[matching_index].weight,
+                None => {
+                    let matching_index = *matching_set
+                        .iter()
+                        .min_by_key(|&&index| FloatOrd(query.weight.0 - candidates[index].weight.0))
+                        .unwrap();
+                    candidates[matching_index].weight
+                }
+            }
+        };
+    matching_set.retain(|&index| candidates[index].weight == matching_weight);
+
+    // Step 4d concerns `font-size`, but fonts in `font-kit` are unsized, so we ignore that.
+
+    // Return the result.
+    matching_set.into_iter().next().ok_or(SelectionError::NotFound)
+}

src/fonts/mod.rs

@@ -0,0 +1,104 @@
+pub mod matching;
+
+use std::{borrow::Cow, fs, sync::Arc};
+
+use anyhow::{Context, Result};
+
+use crate::fonts::matching::find_best_match;
+
+pub struct LoadedFontFamily {
+    pub family_name: String,
+    pub fonts: Vec<font_kit::font::Font>,
+    pub handles: Vec<font_kit::handle::Handle>,
+    pub properties: Vec<font_kit::properties::Properties>,
+    pub default_index: usize,
+}
+
+pub struct LoadedFont {
+    pub font_name: String,
+    pub font_data: egui::FontData,
+}
+
+pub fn load_font_family(
+    source: &font_kit::source::SystemSource,
+    name: &str,
+) -> Option<LoadedFontFamily> {
+    let family_handle = source.select_family_by_name(name).ok()?;
+    if family_handle.fonts().is_empty() {
+        log::warn!("No fonts found for family '{}'", name);
+        return None;
+    }
+    let handles = family_handle.fonts().to_vec();
+    let mut loaded = Vec::with_capacity(handles.len());
+    for handle in handles.iter() {
+        match font_kit::loaders::default::Font::from_handle(handle) {
+            Ok(font) => loaded.push(font),
+            Err(err) => {
+                log::warn!("Failed to load font '{}': {}", name, err);
+                return None;
+            }
+        }
+    }
+    let properties = loaded.iter().map(|f| f.properties()).collect::<Vec<_>>();
+    let default_index =
+        find_best_match(&properties, &font_kit::properties::Properties::new()).unwrap_or(0);
+    let font_family_name =
+        loaded.first().map(|f| f.family_name()).unwrap_or_else(|| name.to_string());
+    Some(LoadedFontFamily {
+        family_name: font_family_name,
+        fonts: loaded,
+        handles,
+        properties,
+        default_index,
+    })
+}
+
+pub fn load_font(handle: &font_kit::handle::Handle) -> Result<LoadedFont> {
+    let loaded = font_kit::loaders::default::Font::from_handle(handle)?;
+    let data = match handle {
+        font_kit::handle::Handle::Memory { bytes, font_index } => egui::FontData {
+            font: Cow::Owned(bytes.to_vec()),
+            index: *font_index,
+            tweak: Default::default(),
+        },
+        font_kit::handle::Handle::Path { path, font_index } => {
+            let vec = fs::read(path).with_context(|| {
+                format!("Failed to load font '{}' (index {})", path.display(), font_index)
+            })?;
+            egui::FontData { font: Cow::Owned(vec), index: *font_index, tweak: Default::default() }
+        }
+    };
+    Ok(LoadedFont { font_name: loaded.full_name(), font_data: data })
+}
+
+pub fn load_font_if_needed(
+    ctx: &egui::Context,
+    source: &font_kit::source::SystemSource,
+    font_id: &egui::FontId,
+    base_family: egui::FontFamily,
+    fonts: &mut egui::FontDefinitions,
+) -> Result<()> {
+    if fonts.families.contains_key(&font_id.family) {
+        return Ok(());
+    }
+    let family_name = match &font_id.family {
+        egui::FontFamily::Proportional | egui::FontFamily::Monospace => return Ok(()),
+        egui::FontFamily::Name(v) => v,
+    };
+    let family = load_font_family(source, family_name)
+        .with_context(|| format!("Failed to load font family '{}'", family_name))?;
+    let default_fonts = fonts.families.get(&base_family).cloned().unwrap_or_default();
+    // FIXME clean up
+    let default_font_ref = family.fonts.get(family.default_index).unwrap();
+    let default_font = family.handles.get(family.default_index).unwrap();
+    let default_font_data = load_font(default_font).unwrap();
+    log::info!("Loaded font family '{}'", family.family_name);
+    fonts.font_data.insert(default_font_ref.full_name(), default_font_data.font_data);
+    fonts
+        .families
+        .entry(egui::FontFamily::Name(Arc::from(family.family_name)))
+        .or_insert_with(|| default_fonts)
+        .insert(0, default_font_ref.full_name());
+    ctx.set_fonts(fonts.clone());
+    Ok(())
+}

src/lib.rs

@@ -6,6 +6,7 @@ mod app;
 mod app_config;
 mod config;
 mod diff;
+mod fonts;
 mod jobs;
 mod obj;
 mod update;

src/views/appearance.rs

@@ -1,6 +1,10 @@
-use egui::{Color32, FontFamily, FontId, TextStyle};
+use std::sync::Arc;
+
+use egui::{text::LayoutJob, Color32, FontFamily, FontId, TextStyle, Widget};
 use time::UtcOffset;
 
+use crate::fonts::load_font_if_needed;
+
 #[derive(serde::Deserialize, serde::Serialize)]
 #[serde(default)]
 pub struct Appearance {
@@ -28,13 +32,29 @@ pub struct Appearance {
     // Global
     #[serde(skip)]
     pub utc_offset: UtcOffset,
+    #[serde(skip)]
+    pub fonts: FontState,
+    #[serde(skip)]
+    pub next_ui_font: Option<FontId>,
+    #[serde(skip)]
+    pub next_code_font: Option<FontId>,
 }
 
+pub struct FontState {
+    definitions: egui::FontDefinitions,
+    source: font_kit::source::SystemSource,
+    family_names: Vec<String>,
+    // loaded_families: HashMap<String, LoadedFontFamily>,
+}
+
+const DEFAULT_UI_FONT: FontId = FontId { size: 12.0, family: FontFamily::Proportional };
+const DEFAULT_CODE_FONT: FontId = FontId { size: 14.0, family: FontFamily::Monospace };
+
 impl Default for Appearance {
     fn default() -> Self {
         Self {
-            ui_font: FontId { size: 12.0, family: FontFamily::Proportional },
+            ui_font: DEFAULT_UI_FONT,
-            code_font: FontId { size: 14.0, family: FontFamily::Monospace },
+            code_font: DEFAULT_CODE_FONT,
             diff_colors: DEFAULT_COLOR_ROTATION.to_vec(),
             theme: eframe::Theme::Dark,
             text_color: Color32::GRAY,
@@ -45,13 +65,27 @@ impl Default for Appearance {
             insert_color: Color32::GREEN,
             delete_color: Color32::from_rgb(200, 40, 41),
             utc_offset: UtcOffset::UTC,
+            fonts: FontState::default(),
+            next_ui_font: None,
+            next_code_font: None,
+        }
+    }
+}
+
+impl Default for FontState {
+    fn default() -> Self {
+        Self {
+            definitions: Default::default(),
+            source: font_kit::source::SystemSource::new(),
+            family_names: Default::default(),
+            // loaded_families: Default::default(),
         }
     }
 }
 
 impl Appearance {
-    pub fn apply(&mut self, style: &egui::Style) -> egui::Style {
+    pub fn pre_update(&mut self, ctx: &egui::Context) {
-        let mut style = style.clone();
+        let mut style = ctx.style().as_ref().clone();
         style.text_styles.insert(TextStyle::Body, FontId {
             size: (self.ui_font.size * 0.75).floor(),
             family: self.ui_font.family.clone(),
@@ -85,7 +119,71 @@ impl Appearance {
                 self.delete_color = Color32::from_rgb(200, 40, 41);
             }
         }
-        style
+        ctx.set_style(style);
+    }
+
+    pub fn post_update(&mut self, ctx: &egui::Context) {
+        // Load fonts for next frame
+        if let Some(next_ui_font) = self.next_ui_font.take() {
+            match load_font_if_needed(
+                ctx,
+                &self.fonts.source,
+                &next_ui_font,
+                DEFAULT_UI_FONT.family,
+                &mut self.fonts.definitions,
+            ) {
+                Ok(()) => self.ui_font = next_ui_font,
+                Err(e) => {
+                    log::error!("Failed to load font: {}", e)
+                }
+            }
+        }
+        if let Some(next_code_font) = self.next_code_font.take() {
+            match load_font_if_needed(
+                ctx,
+                &self.fonts.source,
+                &next_code_font,
+                DEFAULT_CODE_FONT.family,
+                &mut self.fonts.definitions,
+            ) {
+                Ok(()) => self.code_font = next_code_font,
+                Err(e) => {
+                    log::error!("Failed to load font: {}", e)
+                }
+            }
+        }
+    }
+
+    pub fn init_fonts(&mut self, ctx: &egui::Context) {
+        self.fonts.family_names = self.fonts.source.all_families().unwrap_or_default();
+        match load_font_if_needed(
+            ctx,
+            &self.fonts.source,
+            &self.ui_font,
+            DEFAULT_UI_FONT.family,
+            &mut self.fonts.definitions,
+        ) {
+            Ok(_) => {}
+            Err(e) => {
+                log::error!("Failed to load font: {}", e);
+                // Revert to default
+                self.ui_font = DEFAULT_UI_FONT;
+            }
+        }
+        match load_font_if_needed(
+            ctx,
+            &self.fonts.source,
+            &self.code_font,
+            DEFAULT_CODE_FONT.family,
+            &mut self.fonts.definitions,
+        ) {
+            Ok(_) => {}
+            Err(e) => {
+                log::error!("Failed to load font: {}", e);
+                // Revert to default
+                self.code_font = DEFAULT_CODE_FONT;
+            }
+        }
     }
 }
 
@@ -101,6 +199,65 @@ pub const DEFAULT_COLOR_ROTATION: [Color32; 9] = [
     Color32::from_rgb(213, 138, 138),
 ];
 
+fn font_id_ui(
+    ui: &mut egui::Ui,
+    label: &str,
+    mut font_id: FontId,
+    default: FontId,
+    appearance: &Appearance,
+) -> Option<FontId> {
+    ui.push_id(label, |ui| {
+        let font_size = font_id.size;
+        let label_job = LayoutJob::simple(
+            font_id.family.to_string(),
+            font_id.clone(),
+            appearance.text_color,
+            0.0,
+        );
+        let mut changed = ui
+            .horizontal(|ui| {
+                ui.label(label);
+                let mut changed = egui::Slider::new(&mut font_id.size, 4.0..=40.0)
+                    .max_decimals(1)
+                    .ui(ui)
+                    .changed();
+                if ui.button("Reset").clicked() {
+                    font_id = default;
+                    changed = true;
+                }
+                changed
+            })
+            .inner;
+        let family = &mut font_id.family;
+        changed |= egui::ComboBox::from_label("Font family")
+            .selected_text(label_job)
+            .width(font_size * 20.0)
+            .show_ui(ui, |ui| {
+                let mut result = false;
+                result |= ui
+                    .selectable_value(family, FontFamily::Proportional, "Proportional (built-in)")
+                    .changed();
+                result |= ui
+                    .selectable_value(family, FontFamily::Monospace, "Monospace (built-in)")
+                    .changed();
+                for family_name in &appearance.fonts.family_names {
+                    result |= ui
+                        .selectable_value(
+                            family,
+                            FontFamily::Name(Arc::from(family_name.as_str())),
+                            family_name,
+                        )
+                        .changed();
+                }
+                result
+            })
+            .inner
+            .unwrap_or(false);
+        changed.then_some(font_id)
+    })
+    .inner
+}
+
 pub fn appearance_window(ctx: &egui::Context, show: &mut bool, appearance: &mut Appearance) {
     egui::Window::new("Appearance").open(show).show(ctx, |ui| {
         egui::ComboBox::from_label("Theme")
@@ -109,11 +266,17 @@ pub fn appearance_window(ctx: &egui::Context, show: &mut bool, appearance: &mut
                 ui.selectable_value(&mut appearance.theme, eframe::Theme::Dark, "Dark");
                 ui.selectable_value(&mut appearance.theme, eframe::Theme::Light, "Light");
             });
-        ui.label("UI font:");
-        egui::introspection::font_id_ui(ui, &mut appearance.ui_font);
         ui.separator();
-        ui.label("Code font:");
+        appearance.next_ui_font =
-        egui::introspection::font_id_ui(ui, &mut appearance.code_font);
+            font_id_ui(ui, "UI font:", appearance.ui_font.clone(), DEFAULT_UI_FONT, appearance);
+        ui.separator();
+        appearance.next_code_font = font_id_ui(
+            ui,
+            "Code font:",
+            appearance.code_font.clone(),
+            DEFAULT_CODE_FONT,
+            appearance,
+        );
         ui.separator();
         ui.label("Diff colors:");
         if ui.button("Reset").clicked() {

src/views/function_diff.rs

@@ -4,8 +4,7 @@ use std::{
 };
 
 use cwdemangle::demangle;
-use eframe::emath::Align;
+use egui::{text::LayoutJob, Align, Color32, Label, Layout, RichText, Sense, TextFormat, Vec2};
-use egui::{text::LayoutJob, Color32, Label, Layout, RichText, Sense, TextFormat, Vec2};
 use egui_extras::{Column, TableBuilder, TableRow};
 use ppc750cl::Argument;
 use time::format_description;