Add live config reload for font family and style

Fixes #2737.

5 files changed, 101 insertions, 90 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 34c80e89..b29c6c1d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,11 +24,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Terminal escape bindings with combined modifiers
 - Bindings for ScrollToTop and ScrollToBottom actions
 - `ReceiveChar` key binding action to insert the key's text character
-- Live reload font size from config
 - New CLI flag `--hold` for keeping Alacritty opened after its child process exits
 - Escape sequence to save and restore window title from stack
 - Alternate scroll escape sequence (`CSI ? 1007 h` / `CSI ? 1007 l`)
 - Print name of launch command if Alacritty failed to execute it
+- Live reload font settings from config
 
 ### Changed
 
diff --git a/alacritty.yml b/alacritty.yml
index 5e9ca2af..fa40e0b1 100644
--- a/alacritty.yml
+++ b/alacritty.yml
@@ -99,7 +99,7 @@
 # change the `it` value in terminfo when altering this setting.
 #tabspaces: 8
 
-# Font configuration (changes require restart)
+# Font configuration
 #font:
   # Normal (roman) font face
   #normal:
diff --git a/alacritty/src/display.rs b/alacritty/src/display.rs
index ff91852f..07810ecd 100644
--- a/alacritty/src/display.rs
+++ b/alacritty/src/display.rs
@@ -14,7 +14,6 @@
 
 //! The display subsystem including window management, font rasterization, and
 //! GPU drawing.
-use std::cmp::max;
 use std::f64;
 use std::fmt;
 use std::time::Instant;
@@ -24,9 +23,9 @@ use glutin::event_loop::EventLoop;
 use log::{debug, info};
 use parking_lot::MutexGuard;
 
-use font::{self, Rasterize, Size};
+use font::{self, Rasterize};
 
-use alacritty_terminal::config::StartupMode;
+use alacritty_terminal::config::{Font, StartupMode};
 use alacritty_terminal::event::{Event, OnResize};
 use alacritty_terminal::index::Line;
 use alacritty_terminal::message_bar::MessageBuffer;
@@ -37,12 +36,9 @@ use alacritty_terminal::term::color::Rgb;
 use alacritty_terminal::term::{RenderableCell, SizeInfo, Term};
 
 use crate::config::Config;
-use crate::event::{FontResize, Resize};
+use crate::event::DisplayUpdate;
 use crate::window::{self, Window};
 
-/// Font size change interval
-pub const FONT_SIZE_STEP: f32 = 0.5;
-
 #[derive(Debug)]
 pub enum Error {
     /// Error with window management
@@ -116,7 +112,6 @@ impl From<glutin::ContextError> for Error {
 /// The display wraps a window, font rasterizer, and GPU renderer
 pub struct Display {
     pub size_info: SizeInfo,
-    pub font_size: Size,
     pub window: Window,
 
     renderer: QuadRenderer,
@@ -228,14 +223,7 @@ impl Display {
             _ => (),
         }
 
-        Ok(Display {
-            window,
-            renderer,
-            glyph_cache,
-            meter: Meter::new(),
-            size_info,
-            font_size: config.font.size,
-        })
+        Ok(Display { window, renderer, glyph_cache, meter: Meter::new(), size_info })
     }
 
     fn new_glyph_cache(
@@ -270,12 +258,10 @@ impl Display {
     }
 
     /// Update font size and cell dimensions
-    fn update_glyph_cache(&mut self, config: &Config, size: Size) {
+    fn update_glyph_cache(&mut self, config: &Config, font: Font) {
         let size_info = &mut self.size_info;
         let cache = &mut self.glyph_cache;
 
-        let font = config.font.clone().with_size(size);
-
         self.renderer.with_loader(|mut api| {
             let _ = cache.update_font_size(font, size_info.dpr, &mut api);
         });
@@ -286,27 +272,22 @@ impl Display {
         size_info.cell_height = cell_height;
     }
 
-    /// Process resize events
-    pub fn handle_resize<T>(
+    /// Process update events
+    pub fn handle_update<T>(
         &mut self,
         terminal: &mut Term<T>,
         pty_resize_handle: &mut dyn OnResize,
         message_buffer: &MessageBuffer,
         config: &Config,
-        resize_pending: Resize,
+        update_pending: DisplayUpdate,
     ) {
         // Update font size and cell dimensions
-        if let Some(resize) = resize_pending.font_size {
-            self.font_size = match resize {
-                FontResize::Delta(delta) => max(self.font_size + delta, FONT_SIZE_STEP.into()),
-                FontResize::Reset => config.font.size,
-            };
-
-            self.update_glyph_cache(config, self.font_size);
+        if let Some(font) = update_pending.font {
+            self.update_glyph_cache(config, font);
         }
 
         // Update the window dimensions
-        if let Some(size) = resize_pending.dimensions {
+        if let Some(size) = update_pending.dimensions {
             self.size_info.width = size.width as f32;
             self.size_info.height = size.height as f32;
         }
diff --git a/alacritty/src/event.rs b/alacritty/src/event.rs
index 225dc2b5..75e06f30 100644
--- a/alacritty/src/event.rs
+++ b/alacritty/src/event.rs
@@ -1,5 +1,6 @@
 //! Process window events
 use std::borrow::Cow;
+use std::cmp::max;
 use std::env;
 #[cfg(unix)]
 use std::fs;
@@ -20,6 +21,7 @@ use serde_json as json;
 use font::Size;
 
 use alacritty_terminal::clipboard::ClipboardType;
+use alacritty_terminal::config::Font;
 use alacritty_terminal::config::LOG_TARGET_CONFIG;
 use alacritty_terminal::event::OnResize;
 use alacritty_terminal::event::{Event, EventListener, Notify};
@@ -36,25 +38,19 @@ use alacritty_terminal::util::{limit, start_daemon};
 use crate::config;
 use crate::config::Config;
 use crate::display::Display;
-use crate::input::{self, ActionContext as _, Modifiers};
+use crate::input::{self, ActionContext as _, Modifiers, FONT_SIZE_STEP};
 use crate::window::Window;
 
-#[derive(Copy, Clone, Debug, PartialEq)]
-pub enum FontResize {
-    Delta(f32),
-    Reset,
-}
-
-#[derive(Default, Copy, Clone, Debug, PartialEq)]
-pub struct Resize {
+#[derive(Default, Clone, Debug, PartialEq)]
+pub struct DisplayUpdate {
     pub dimensions: Option<PhysicalSize>,
     pub message_buffer: Option<()>,
-    pub font_size: Option<FontResize>,
+    pub font: Option<Font>,
 }
 
-impl Resize {
+impl DisplayUpdate {
     fn is_empty(&self) -> bool {
-        self.dimensions.is_none() && self.font_size.is_none() && self.message_buffer.is_none()
+        self.dimensions.is_none() && self.font.is_none() && self.message_buffer.is_none()
     }
 }
 
@@ -68,8 +64,9 @@ pub struct ActionContext<'a, N, T> {
     pub modifiers: &'a mut Modifiers,
     pub window: &'a mut Window,
     pub message_buffer: &'a mut MessageBuffer,
-    pub resize_pending: &'a mut Resize,
-    pub font_size: &'a Size,
+    pub display_update_pending: &'a mut DisplayUpdate,
+    pub config: &'a mut Config,
+    font_size: &'a mut Size,
 }
 
 impl<'a, N: Notify + 'a, T: EventListener> input::ActionContext<T> for ActionContext<'a, N, T> {
@@ -227,23 +224,30 @@ impl<'a, N: Notify + 'a, T: EventListener> input::ActionContext<T> for ActionCon
     }
 
     fn change_font_size(&mut self, delta: f32) {
-        self.resize_pending.font_size = Some(FontResize::Delta(delta));
+        *self.font_size = max(*self.font_size + delta, Size::new(FONT_SIZE_STEP));
+        let font = self.config.font.clone().with_size(*self.font_size);
+        self.display_update_pending.font = Some(font);
         self.terminal.dirty = true;
     }
 
     fn reset_font_size(&mut self) {
-        self.resize_pending.font_size = Some(FontResize::Reset);
+        *self.font_size = self.config.font.size;
+        self.display_update_pending.font = Some(self.config.font.clone());
         self.terminal.dirty = true;
     }
 
     fn pop_message(&mut self) {
-        self.resize_pending.message_buffer = Some(());
+        self.display_update_pending.message_buffer = Some(());
         self.message_buffer.pop();
     }
 
     fn message(&self) -> Option<&Message> {
         self.message_buffer.message()
     }
+
+    fn config(&self) -> &Config {
+        self.config
+    }
 }
 
 pub enum ClickState {
@@ -306,6 +310,7 @@ pub struct Processor<N> {
     pty_resize_handle: Box<dyn OnResize>,
     message_buffer: MessageBuffer,
     display: Display,
+    font_size: Size,
 }
 
 impl<N: Notify> Processor<N> {
@@ -326,6 +331,7 @@ impl<N: Notify> Processor<N> {
             received_count: 0,
             suppress_chars: false,
             modifiers: Default::default(),
+            font_size: config.font.size,
             config,
             pty_resize_handle,
             message_buffer,
@@ -374,7 +380,7 @@ impl<N: Notify> Processor<N> {
 
             let mut terminal = terminal.lock();
 
-            let mut resize_pending = Resize::default();
+            let mut display_update_pending = DisplayUpdate::default();
 
             let context = ActionContext {
                 terminal: &mut terminal,
@@ -385,11 +391,12 @@ impl<N: Notify> Processor<N> {
                 suppress_chars: &mut self.suppress_chars,
                 modifiers: &mut self.modifiers,
                 message_buffer: &mut self.message_buffer,
-                resize_pending: &mut resize_pending,
+                display_update_pending: &mut display_update_pending,
                 window: &mut self.display.window,
-                font_size: &self.display.font_size,
+                font_size: &mut self.font_size,
+                config: &mut self.config,
             };
-            let mut processor = input::Processor::new(context, &mut self.config);
+            let mut processor = input::Processor::new(context);
 
             for event in event_queue.drain(..) {
                 Processor::handle_event(event, &mut processor);
@@ -407,21 +414,21 @@ impl<N: Notify> Processor<N> {
 
                     let size = self.display.window.inner_size().to_physical(dpr);
 
-                    resize_pending.font_size = Some(FontResize::Delta(0.));
-                    resize_pending.dimensions = Some(size);
+                    display_update_pending.font = Some(self.config.font.clone());
+                    display_update_pending.dimensions = Some(size);
 
                     terminal.dirty = true;
                 }
             }
 
-            // Process resize events
-            if !resize_pending.is_empty() {
-                self.display.handle_resize(
+            // Process DisplayUpdate events
+            if !display_update_pending.is_empty() {
+                self.display.handle_update(
                     &mut terminal,
                     self.pty_resize_handle.as_mut(),
                     &self.message_buffer,
                     &self.config,
-                    resize_pending,
+                    display_update_pending,
                 );
             }
 
@@ -460,23 +467,29 @@ impl<N: Notify> Processor<N> {
                 },
                 Event::ConfigReload(path) => {
                     processor.ctx.message_buffer.remove_target(LOG_TARGET_CONFIG);
-                    processor.ctx.resize_pending.message_buffer = Some(());
+                    processor.ctx.display_update_pending.message_buffer = Some(());
 
                     if let Ok(config) = config::reload_from(&path) {
                         processor.ctx.terminal.update_config(&config);
 
-                        if *processor.ctx.font_size == processor.config.font.size {
-                            processor.ctx.resize_pending.font_size = Some(FontResize::Reset);
+                        if processor.ctx.config.font != config.font {
+                            // Do not update font size if it has been changed at runtime
+                            if *processor.ctx.font_size == processor.ctx.config.font.size {
+                                *processor.ctx.font_size = config.font.size;
+                            }
+
+                            let font = config.font.clone().with_size(*processor.ctx.font_size);
+                            processor.ctx.display_update_pending.font = Some(font);
                         }
 
-                        *processor.config = config;
+                        *processor.ctx.config = config;
 
                         processor.ctx.terminal.dirty = true;
                     }
                 },
                 Event::Message(message) => {
                     processor.ctx.message_buffer.push(message);
-                    processor.ctx.resize_pending.message_buffer = Some(());
+                    processor.ctx.display_update_pending.message_buffer = Some(());
                     processor.ctx.terminal.dirty = true;
                 },
                 Event::MouseCursorDirty => processor.reset_mouse_cursor(),
@@ -488,14 +501,14 @@ impl<N: Notify> Processor<N> {
                     CloseRequested => processor.ctx.terminal.exit(),
                     Resized(lsize) => {
                         let psize = lsize.to_physical(processor.ctx.size_info.dpr);
-                        processor.ctx.resize_pending.dimensions = Some(psize);
+                        processor.ctx.display_update_pending.dimensions = Some(psize);
                         processor.ctx.terminal.dirty = true;
                     },
                     KeyboardInput { input, .. } => {
                         processor.process_key(input);
                         if input.state == ElementState::Pressed {
                             // Hide cursor while typing
-                            if processor.config.ui_config.mouse.hide_when_typing {
+                            if processor.ctx.config.ui_config.mouse.hide_when_typing {
                                 processor.ctx.window.set_mouse_visible(false);
                             }
                         }
@@ -540,17 +553,18 @@ impl<N: Notify> Processor<N> {
                     },
                     HiDpiFactorChanged(dpr) => {
                         let dpr_change = (dpr / processor.ctx.size_info.dpr) as f32;
-                        let resize_pending = &mut processor.ctx.resize_pending;
+                        let display_update_pending = &mut processor.ctx.display_update_pending;
 
                         // Push current font to update its DPR
-                        resize_pending.font_size = Some(FontResize::Delta(0.));
+                        display_update_pending.font = Some(processor.ctx.config.font.clone());
 
                         // Scale window dimensions with new DPR
                         let old_width = processor.ctx.size_info.width;
                         let old_height = processor.ctx.size_info.height;
-                        let dimensions = resize_pending.dimensions.get_or_insert_with(|| {
-                            PhysicalSize::new(f64::from(old_width), f64::from(old_height))
-                        });
+                        let dimensions =
+                            display_update_pending.dimensions.get_or_insert_with(|| {
+                                PhysicalSize::new(f64::from(old_width), f64::from(old_height))
+                            });
                         dimensions.width *= f64::from(dpr_change);
                         dimensions.height *= f64::from(dpr_change);
 
diff --git a/alacritty/src/input.rs b/alacritty/src/input.rs
index b9b99565..5404085e 100644
--- a/alacritty/src/input.rs
+++ b/alacritty/src/input.rs
@@ -42,17 +42,18 @@ use alacritty_terminal::url::Url;
 use alacritty_terminal::util::start_daemon;
 
 use crate::config::{Action, Binding, Config, Key, RelaxedEq};
-use crate::display::FONT_SIZE_STEP;
 use crate::event::{ClickState, Mouse};
 use crate::window::Window;
 
+/// Font size change interval
+pub const FONT_SIZE_STEP: f32 = 0.5;
+
 /// Processes input from glutin.
 ///
 /// An escape sequence may be emitted in case specific keys or key combinations
 /// are activated.
-pub struct Processor<'a, T: EventListener, A: ActionContext<T> + 'a> {
+pub struct Processor<T: EventListener, A: ActionContext<T>> {
     pub ctx: A,
-    pub config: &'a mut Config,
     _phantom: PhantomData<T>,
 }
 
@@ -83,6 +84,7 @@ pub trait ActionContext<T: EventListener> {
     fn reset_font_size(&mut self);
     fn pop_message(&mut self);
     fn message(&self) -> Option<&Message>;
+    fn config(&self) -> &Config;
 }
 
 #[derive(Debug, Default, Copy, Clone)]
@@ -226,9 +228,9 @@ impl From<MouseState> for CursorIcon {
     }
 }
 
-impl<'a, T: EventListener, A: ActionContext<T> + 'a> Processor<'a, T, A> {
-    pub fn new(ctx: A, config: &'a mut Config) -> Self {
-        Self { ctx, config, _phantom: Default::default() }
+impl<T: EventListener, A: ActionContext<T>> Processor<T, A> {
+    pub fn new(ctx: A) -> Self {
+        Self { ctx, _phantom: Default::default() }
     }
 
     fn mouse_state(&mut self, point: Point, mods: ModifiersState) -> MouseState {
@@ -245,9 +247,9 @@ impl<'a, T: EventListener, A: ActionContext<T> + 'a> Processor<'a, T, A> {
         }
 
         // Check for URL at point with required modifiers held
-        if self.config.ui_config.mouse.url.mods().relaxed_eq(mods)
+        if self.ctx.config().ui_config.mouse.url.mods().relaxed_eq(mods)
             && (!self.ctx.terminal().mode().intersects(mouse_mode) || mods.shift)
-            && self.config.ui_config.mouse.url.launcher.is_some()
+            && self.ctx.config().ui_config.mouse.url.launcher.is_some()
             && self.ctx.selection_is_empty()
             && self.ctx.mouse().left_button_state != ElementState::Pressed
         {
@@ -426,7 +428,7 @@ impl<'a, T: EventListener, A: ActionContext<T> + 'a> Processor<'a, T, A> {
         self.ctx.mouse_mut().click_state = match self.ctx.mouse().click_state {
             ClickState::Click
                 if !button_changed
-                    && elapsed < self.config.ui_config.mouse.double_click.threshold =>
+                    && elapsed < self.ctx.config().ui_config.mouse.double_click.threshold =>
             {
                 self.ctx.mouse_mut().block_url_launcher = true;
                 self.on_mouse_double_click(button, point);
@@ -434,7 +436,7 @@ impl<'a, T: EventListener, A: ActionContext<T> + 'a> Processor<'a, T, A> {
             }
             ClickState::DoubleClick
                 if !button_changed
-                    && elapsed < self.config.ui_config.mouse.triple_click.threshold =>
+                    && elapsed < self.ctx.config().ui_config.mouse.triple_click.threshold =>
             {
                 self.ctx.mouse_mut().block_url_launcher = true;
                 self.on_mouse_triple_click(button, point);
@@ -512,7 +514,7 @@ impl<'a, T: EventListener, A: ActionContext<T> + 'a> Processor<'a, T, A> {
             return;
         }
 
-        if let Some(ref launcher) = self.config.ui_config.mouse.url.launcher {
+        if let Some(ref launcher) = self.ctx.config().ui_config.mouse.url.launcher {
             let mut args = launcher.args().to_vec();
             args.push(self.ctx.terminal().url_to_string(url));
 
@@ -566,10 +568,11 @@ impl<'a, T: EventListener, A: ActionContext<T> + 'a> Processor<'a, T, A> {
             }
         } else if self.ctx.terminal().mode().contains(alt_scroll_modes) && !modifiers.shift {
             let multiplier = i32::from(
-                self.config
+                self.ctx
+                    .config()
                     .scrolling
                     .faux_multiplier()
-                    .unwrap_or_else(|| self.config.scrolling.multiplier()),
+                    .unwrap_or_else(|| self.ctx.config().scrolling.multiplier()),
             );
             self.ctx.mouse_mut().scroll_px += new_scroll_px * multiplier;
 
@@ -584,7 +587,7 @@ impl<'a, T: EventListener, A: ActionContext<T> + 'a> Processor<'a, T, A> {
             }
             self.ctx.write_to_pty(content);
         } else {
-            let multiplier = i32::from(self.config.scrolling.multiplier());
+            let multiplier = i32::from(self.ctx.config().scrolling.multiplier());
             self.ctx.mouse_mut().scroll_px += new_scroll_px * multiplier;
 
             let lines = self.ctx.mouse().scroll_px / height;
@@ -677,7 +680,7 @@ impl<'a, T: EventListener, A: ActionContext<T> + 'a> Processor<'a, T, A> {
             c.encode_utf8(&mut bytes[..]);
         }
 
-        if self.config.alt_send_esc()
+        if self.ctx.config().alt_send_esc()
             && *self.ctx.received_count() == 0
             && self.ctx.modifiers().alt()
             && utf8_len == 1
@@ -698,7 +701,9 @@ impl<'a, T: EventListener, A: ActionContext<T> + 'a> Processor<'a, T, A> {
     fn process_key_bindings(&mut self, input: KeyboardInput) {
         let mut suppress_chars = None;
 
-        for binding in &self.config.ui_config.key_bindings {
+        for i in 0..self.ctx.config().ui_config.key_bindings.len() {
+            let binding = &self.ctx.config().ui_config.key_bindings[i];
+
             let key = match (binding.trigger, input.virtual_keycode) {
                 (Key::Scancode(_), _) => Key::Scancode(input.scancode),
                 (_, Some(key)) => Key::from_glutin_input(key),
@@ -707,6 +712,7 @@ impl<'a, T: EventListener, A: ActionContext<T> + 'a> Processor<'a, T, A> {
 
             if binding.is_triggered_by(*self.ctx.terminal().mode(), input.modifiers, &key, false) {
                 // Binding was triggered; run the action
+                let binding = binding.clone();
                 binding.execute(&mut self.ctx, false);
 
                 // Don't suppress when there has been a `ReceiveChar` action
@@ -723,7 +729,9 @@ impl<'a, T: EventListener, A: ActionContext<T> + 'a> Processor<'a, T, A> {
     /// The provided mode, mods, and key must match what is allowed by a binding
     /// for its action to be executed.
     fn process_mouse_bindings(&mut self, mods: ModifiersState, button: MouseButton) {
-        for binding in &self.config.ui_config.mouse_bindings {
+        for i in 0..self.ctx.config().ui_config.mouse_bindings.len() {
+            let binding = &self.ctx.config().ui_config.mouse_bindings[i];
+
             if binding.is_triggered_by(*self.ctx.terminal().mode(), mods, &button, true) {
                 // binding was triggered; run the action
                 let mouse_mode = !mods.shift
@@ -732,6 +740,8 @@ impl<'a, T: EventListener, A: ActionContext<T> + 'a> Processor<'a, T, A> {
                             | TermMode::MOUSE_DRAG
                             | TermMode::MOUSE_MOTION,
                     );
+
+                let binding = binding.clone();
                 binding.execute(&mut self.ctx, mouse_mode);
             }
         }
@@ -780,7 +790,7 @@ impl<'a, T: EventListener, A: ActionContext<T> + 'a> Processor<'a, T, A> {
 
     /// Copy text selection.
     fn copy_selection(&mut self) {
-        if self.config.selection.save_to_clipboard {
+        if self.ctx.config().selection.save_to_clipboard {
             self.ctx.copy_selection(ClipboardType::Clipboard);
         }
         self.ctx.copy_selection(ClipboardType::Selection);
@@ -849,6 +859,7 @@ mod tests {
         pub received_count: usize,
         pub suppress_chars: bool,
         pub modifiers: Modifiers,
+        config: &'a Config,
     }
 
     impl<'a, T: EventListener> super::ActionContext<T> for ActionContext<'a, T> {
@@ -947,6 +958,10 @@ mod tests {
         fn message(&self) -> Option<&Message> {
             self.message_buffer.message()
         }
+
+        fn config(&self) -> &Config {
+            self.config
+        }
     }
 
     macro_rules! test_clickstate {
@@ -1002,9 +1017,10 @@ mod tests {
                     suppress_chars: false,
                     modifiers: Modifiers::default(),
                     message_buffer: &mut message_buffer,
+                    config: &cfg,
                 };
 
-                let mut processor = Processor::new(context, &mut cfg);
+                let mut processor = Processor::new(context);
 
                 if let Event::WindowEvent { event: WindowEvent::MouseInput { state, button, modifiers, .. }, .. } = $input {
                     processor.mouse_input(state, button, modifiers);