4 files changed, 32 insertions, 5 deletions
diff --git a/alacritty/src/config/window.rs b/alacritty/src/config/window.rs
index e4236b99..d546f686 100644
--- a/alacritty/src/config/window.rs
+++ b/alacritty/src/config/window.rs
@@ -7,7 +7,7 @@ use serde::{Deserialize, Deserializer, Serialize};
 use winit::window::{Fullscreen, Theme};
 
 #[cfg(target_os = "macos")]
-use winit::platform::macos::OptionAsAlt;
+use winit::platform::macos::OptionAsAlt as WinitOptionAsAlt;
 
 use alacritty_config_derive::{ConfigDeserialize, SerdeReplace};
 use alacritty_terminal::config::{Percentage, LOG_TARGET_CONFIG};
@@ -51,7 +51,7 @@ pub struct WindowConfig {
 
     /// Controls which `Option` key should be treated as `Alt`.
     #[cfg(target_os = "macos")]
-    pub option_as_alt: OptionAsAlt,
+    option_as_alt: OptionAsAlt,
 
     /// Resize increments.
     pub resize_increments: bool,
@@ -137,6 +137,16 @@ impl WindowConfig {
     pub fn maximized(&self) -> bool {
         self.startup_mode == StartupMode::Maximized
     }
+
+    #[cfg(target_os = "macos")]
+    pub fn option_as_alt(&self) -> WinitOptionAsAlt {
+        match self.option_as_alt {
+            OptionAsAlt::OnlyLeft => WinitOptionAsAlt::OnlyLeft,
+            OptionAsAlt::OnlyRight => WinitOptionAsAlt::OnlyRight,
+            OptionAsAlt::Both => WinitOptionAsAlt::Both,
+            OptionAsAlt::None => WinitOptionAsAlt::None,
+        }
+    }
 }
 
 #[derive(ConfigDeserialize, Debug, Clone, PartialEq, Eq)]
@@ -263,3 +273,20 @@ impl<'de> Deserialize<'de> for Class {
         deserializer.deserialize_any(ClassVisitor)
     }
 }
+
+#[cfg(target_os = "macos")]
+#[derive(ConfigDeserialize, Default, Debug, Clone, Copy, PartialEq, Eq)]
+pub enum OptionAsAlt {
+    /// The left `Option` key is treated as `Alt`.
+    OnlyLeft,
+
+    /// The right `Option` key is treated as `Alt`.
+    OnlyRight,
+
+    /// Both `Option` keys are treated as `Alt`.
+    Both,
+
+    /// No special handling is applied for `Option` key.
+    #[default]
+    None,
+}
diff --git a/alacritty/src/display/window.rs b/alacritty/src/display/window.rs
index 185e7305..0cf95f7f 100644
--- a/alacritty/src/display/window.rs
+++ b/alacritty/src/display/window.rs
@@ -314,7 +314,7 @@ impl Window {
 
     #[cfg(target_os = "macos")]
     pub fn get_platform_window(_: &Identity, window_config: &WindowConfig) -> WindowBuilder {
-        let window = WindowBuilder::new().with_option_as_alt(window_config.option_as_alt);
+        let window = WindowBuilder::new().with_option_as_alt(window_config.option_as_alt());
 
         match window_config.decorations {
             Decorations::Full => window,
diff --git a/alacritty/src/input.rs b/alacritty/src/input.rs
index dc46a316..5075729b 100644
--- a/alacritty/src/input.rs
+++ b/alacritty/src/input.rs
@@ -1027,7 +1027,7 @@ impl<T: EventListener, A: ActionContext<T>> Processor<T, A> {
 
     #[cfg(target_os = "macos")]
     fn alt_send_esc(&mut self) -> bool {
-        let option_as_alt = self.ctx.config().window.option_as_alt;
+        let option_as_alt = self.ctx.config().window.option_as_alt();
         self.ctx.modifiers().state().alt_key()
             && (option_as_alt == OptionAsAlt::Both
                 || (option_as_alt == OptionAsAlt::OnlyLeft
diff --git a/alacritty/src/window_context.rs b/alacritty/src/window_context.rs
index 568f8c22..8935a9cc 100644
--- a/alacritty/src/window_context.rs
+++ b/alacritty/src/window_context.rs
@@ -337,7 +337,7 @@ impl WindowContext {
         self.display.window.set_has_shadow(opaque);
 
         #[cfg(target_os = "macos")]
-        self.display.window.set_option_as_alt(self.config.window.option_as_alt);
+        self.display.window.set_option_as_alt(self.config.window.option_as_alt());
 
         // Change opacity state.
         self.display.window.set_transparent(!opaque);