feat(core): implement theme APIs for Linux (#4808)

Author: lucasfernog

.changes/linux-theme.md

@@ -0,0 +1,6 @@
+---
+"tauri-runtime-wry": patch
+"tauri": patch
+---
+
+Implement theme APIs for Linux.

core/tauri-runtime-wry/src/lib.rs

@@ -907,17 +907,14 @@ impl WindowBuilder for WindowBuilderWrapper {
 
   #[allow(unused_variables, unused_mut)]
   fn theme(mut self, theme: Option<Theme>) -> Self {
-    #[cfg(any(windows, target_os = "macos"))]
-    {
-      self.inner = self.inner.with_theme(if let Some(t) = theme {
-        match t {
-          Theme::Dark => Some(WryTheme::Dark),
-          _ => Some(WryTheme::Light),
-        }
-      } else {
-        None
-      });
-    }
+    self.inner = self.inner.with_theme(if let Some(t) = theme {
+      match t {
+        Theme::Dark => Some(WryTheme::Dark),
+        _ => Some(WryTheme::Light),
+      }
+    } else {
+      None
+    });
 
     self
   }
@@ -2304,10 +2301,7 @@ fn handle_user_message<T: UserEvent>(
               .send(RawWindowHandle(window.raw_window_handle()))
               .unwrap(),
             WindowMessage::Theme(tx) => {
-              #[cfg(any(windows, target_os = "macos"))]
               tx.send(map_theme(&window.theme())).unwrap();
-              #[cfg(not(any(windows, target_os = "macos")))]
-              tx.send(Theme::Light).unwrap();
             }
             // Setters
             WindowMessage::Center => {

core/tauri-runtime/src/window.rs

@@ -62,8 +62,6 @@ pub enum WindowEvent {
   /// The system window theme has changed.
   ///
   /// Applications might wish to react to this to change the theme of the content of the window when the system changes the window theme.
-  ///
-  /// At the moment this is only supported on Windows.
   ThemeChanged(Theme),
 }
 

core/tauri/src/app.rs

@@ -119,14 +119,13 @@ pub enum WindowEvent {
   },
   /// An event associated with the file drop action.
   FileDrop(FileDropEvent),
-  /// The system window theme has changed.
+  /// The system window theme has changed. Only delivered if the window [`theme`](`crate::window::WindowBuilder#method.theme`) is `None`.
   ///
   /// Applications might wish to react to this to change the theme of the content of the window when the system changes the window theme.
   ///
   /// ## Platform-specific
   ///
-  /// - **macOS / Linux**: Not supported.
-  /// - **Windows**: Only delivered if the window [`theme`](`crate::window::WindowBuilder#method.theme`) is `None`.
+  /// - **Linux**: Not supported.
   ThemeChanged(Theme),
 }
 

core/tauri/src/window.rs

@@ -352,7 +352,6 @@ impl<'a, R: Runtime> WindowBuilder<'a, R> {
   /// ## Platform-specific
   ///
   /// - **macOS**: Only supported on macOS 10.14+.
-  /// - **Linux**: Not implemented, the value is ignored.
   #[must_use]
   pub fn theme(mut self, theme: Option<Theme>) -> Self {
     self.window_builder = self.window_builder.theme(theme);
@@ -937,7 +936,6 @@ impl<R: Runtime> Window<R> {
   /// ## Platform-specific
   ///
   /// - **macOS**: Only supported on macOS 10.14+.
-  /// - **Linux**: Not implemented, always return [`Theme::Light`].
   pub fn theme(&self) -> crate::Result<Theme> {
     self.window.dispatcher.theme().map_err(Into::into)
   }