fix #4985 - reimplement get_appearance for wayland

- was dropped with wayland reimplementation (#4777, 3eaba4e3d6)
- get appearance from xdg desktop portal
- advise all windows of appearance changes to reload config

window/src/os/wayland/connection.rs

@@ -13,7 +13,7 @@ use wayland_client::{Connection as WConnection, EventQueue};
 
 use crate::screen::{ScreenInfo, Screens};
 use crate::spawn::SPAWN_QUEUE;
-use crate::{Connection, ConnectionOps, ScreenRect};
+use crate::{Appearance, Connection, ConnectionOps, ScreenRect};
 
 use super::state::WaylandState;
 use super::WaylandWindowInner;
@@ -46,7 +46,11 @@ impl WaylandConnection {
         Ok(wayland_connection)
     }
 
-    pub(crate) fn advise_of_appearance_change(&self, _appearance: crate::Appearance) {}
+    pub(crate) fn advise_of_appearance_change(&self, appearance: crate::Appearance) {
+        for win in self.wayland_state.borrow().windows.borrow().values() {
+            win.borrow_mut().appearance_changed(appearance);
+        }
+    }
 
     fn run_message_loop_impl(&self) -> anyhow::Result<()> {
         const TOK_WL: usize = 0xffff_fffc;
@@ -172,6 +176,18 @@ impl ConnectionOps for WaylandConnection {
         res
     }
 
+    fn get_appearance(&self) -> Appearance {
+        match promise::spawn::block_on(crate::os::xdg_desktop_portal::get_appearance()) {
+            Ok(Some(appearance)) => return appearance,
+            Ok(None) => {}
+            Err(err) => {
+                log::warn!("Unable to resolve appearance using xdg-desktop-portal: {err:#}");
+            }
+        }
+        // fallback
+        Appearance::Light
+    }
+
     fn screens(&self) -> anyhow::Result<crate::screen::Screens> {
         log::trace!("Getting screens for wayland connection");
 

window/src/os/wayland/window.rs

@@ -48,6 +48,7 @@ use wezterm_input_types::{
 use crate::wayland::WaylandConnection;
 use crate::x11::KeyboardWithFallback;
 use crate::{
+    Appearance,
     Clipboard, Connection, ConnectionOps, Dimensions, MouseCursor, Point, Rect,
     RequestedWindowGeometry, ResizeIncrement, ResolvedGeometry, Window, WindowEvent,
     WindowEventSender, WindowKeyEvent, WindowOps, WindowState,
@@ -268,6 +269,8 @@ impl WaylandWindow {
             surface_to_pending.insert(surface.id(), Arc::clone(&pending_mouse));
         }
 
+        let appearance = conn.get_appearance();
+
         let inner = Rc::new(RefCell::new(WaylandWindowInner {
             events: WindowEventSender::new(event_handler),
             surface_factor: 1.0,
@@ -294,6 +297,7 @@ impl WaylandWindow {
             frame_callback: None,
 
             text_cursor: None,
+            appearance,
 
             config,
 
@@ -525,7 +529,7 @@ pub struct WaylandWindowInner {
     invalidated: bool,
     // font_config: Rc<FontConfiguration>,
     text_cursor: Option<Rect>,
-    // appearance: Appearance,
+    appearance: Appearance,
     config: ConfigHandle,
     // cache the title for comparison to avoid spamming
     // the compositor with updates that don't actually change it
@@ -1083,6 +1087,14 @@ impl WaylandWindowInner {
         self.text_cursor.take();
     }
 
+    pub(crate) fn appearance_changed(&mut self, appearance: Appearance) {
+        if appearance != self.appearance {
+            self.appearance = appearance;
+            self.events
+                .dispatch(WindowEvent::AppearanceChanged(appearance));
+        }
+    }
+
     pub(super) fn keyboard_event(
         &mut self,
         mapper: &mut KeyboardWithFallback,