From 414058379b1033a36d2f1ba0d1154e3e92ed0ff5 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@zed.dev>
Date: Tue, 9 Apr 2024 06:44:57 -0700
Subject: [PATCH] Switch to the system UI font on macOS (#10317)

To reference the system font, use the special ".SystemUIFont" family
name.

/cc @PixelJanitor

Release Notes:

- Switched to the system UI  font for user interface elements on macOS.

Co-authored-by: Antonio Scandurra <antonio@zed.dev>
---
 assets/settings/default.json                    |  2 +-
 crates/gpui/src/platform/linux/text_system.rs   |  9 ++++++++-
 crates/gpui/src/platform/mac/text_system.rs     | 16 +++++++++-------
 crates/gpui/src/platform/windows/text_system.rs |  9 ++++++++-
 crates/gpui/src/text_system.rs                  |  2 ++
 5 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/assets/settings/default.json b/assets/settings/default.json
index 19c1357f227c6210429474660ad3903872fdb08a..879fdce6d06f345942691a6e7250fdf8d46abe31 100644
--- a/assets/settings/default.json
+++ b/assets/settings/default.json
@@ -36,7 +36,7 @@
   //         },
   "buffer_line_height": "comfortable",
   // The name of a font to use for rendering text in the UI
-  "ui_font_family": "Zed Sans",
+  "ui_font_family": ".SystemUIFont",
   // The OpenType features to enable for text in the UI
   "ui_font_features": {
     // Disable ligatures:
diff --git a/crates/gpui/src/platform/linux/text_system.rs b/crates/gpui/src/platform/linux/text_system.rs
index e1d5648c134ed301ebff2c03c965db88a5254000..5164ebd93034b37a6ab0b1c48adac5cd709e61ee 100644
--- a/crates/gpui/src/platform/linux/text_system.rs
+++ b/crates/gpui/src/platform/linux/text_system.rs
@@ -210,9 +210,16 @@ impl LinuxTextSystemState {
     #[profiling::function]
     fn load_family(
         &mut self,
-        name: &SharedString,
+        name: &str,
         _features: FontFeatures,
     ) -> Result<SmallVec<[FontId; 4]>> {
+        // TODO: Determine the proper system UI font.
+        let name = if name == ".SystemUIFont" {
+            "Zed Sans"
+        } else {
+            name
+        };
+
         let mut font_ids = SmallVec::new();
         let families = self
             .font_system
diff --git a/crates/gpui/src/platform/mac/text_system.rs b/crates/gpui/src/platform/mac/text_system.rs
index d5bb7230127927c0cd16e489af07d3bce5f2901f..2892b517da58c2360b3a0e28bc4c8ef89a7be4b5 100644
--- a/crates/gpui/src/platform/mac/text_system.rs
+++ b/crates/gpui/src/platform/mac/text_system.rs
@@ -219,16 +219,18 @@ impl MacTextSystemState {
         Ok(())
     }
 
-    fn load_family(
-        &mut self,
-        name: &SharedString,
-        features: FontFeatures,
-    ) -> Result<SmallVec<[FontId; 4]>> {
+    fn load_family(&mut self, name: &str, features: FontFeatures) -> Result<SmallVec<[FontId; 4]>> {
+        let name = if name == ".SystemUIFont" {
+            ".AppleSystemUIFont"
+        } else {
+            name
+        };
+
         let mut font_ids = SmallVec::new();
         let family = self
             .memory_source
-            .select_family_by_name(name.as_ref())
-            .or_else(|_| self.system_source.select_family_by_name(name.as_ref()))?;
+            .select_family_by_name(name)
+            .or_else(|_| self.system_source.select_family_by_name(name))?;
         for font in family.fonts() {
             let mut font = font.load()?;
 
diff --git a/crates/gpui/src/platform/windows/text_system.rs b/crates/gpui/src/platform/windows/text_system.rs
index 5db1a0eea49785dfdfcbbbd628da15402fb7ed7f..6ad8c4be540de6c78532ee20f87bd1a47b1f4d63 100644
--- a/crates/gpui/src/platform/windows/text_system.rs
+++ b/crates/gpui/src/platform/windows/text_system.rs
@@ -209,9 +209,16 @@ impl WindowsTextSystemState {
     #[profiling::function]
     fn load_family(
         &mut self,
-        name: &SharedString,
+        name: &str,
         _features: FontFeatures,
     ) -> Result<SmallVec<[FontId; 4]>> {
+        // TODO: Determine the proper system UI font.
+        let name = if name == ".SystemUIFont" {
+            "Zed Sans"
+        } else {
+            name
+        };
+
         let mut font_ids = SmallVec::new();
         let families = self
             .font_system
diff --git a/crates/gpui/src/text_system.rs b/crates/gpui/src/text_system.rs
index f0c8cfafe3422a43f61f590e3c54c8252611a87b..4d044a2837ce32f243c2efc409d380c9b524703b 100644
--- a/crates/gpui/src/text_system.rs
+++ b/crates/gpui/src/text_system.rs
@@ -675,6 +675,8 @@ impl Hash for RenderEmojiParams {
 #[derive(Clone, Debug, Eq, PartialEq, Hash)]
 pub struct Font {
     /// The font family name.
+    ///
+    /// The special name ".SystemUIFont" is used to identify the system UI font, which varies based on platform.
     pub family: SharedString,
 
     /// The font features to use.