handle theme changed event

v2/src/renderer.rs

@@ -180,6 +180,7 @@ pub trait Renderer {
     fn set_title(&self, title: &str);
     fn window_state(&self) -> Option<WindowState>;
     fn theme(&self) -> Theme;
+    fn set_theme(&self, theme: Theme) -> Result<()>;
     fn show(&self);
     fn set_background_color(&self, rbga: (u8, u8, u8, u8)) -> Result<()>;
     fn print(&self) -> Result<()>;
@@ -209,5 +210,6 @@ pub trait Rendering: Sized {
 pub trait EventHandler {
     fn handle_user_event(&mut self, event: UserEvent) -> Result<RenderingFlow>;
     fn handle_menu_event(&mut self, item: MenuItem) -> Result<RenderingFlow>;
+    fn handle_theme_changed(&mut self, theme: Theme) -> Result<RenderingFlow>;
     fn handle_exit(&self) -> Result<()>;
 }

v2/src/shiba.rs

@@ -5,7 +5,7 @@ use crate::markdown::{DisplayText, MarkdownContent, MarkdownParser};
 use crate::opener::Opener;
 use crate::renderer::{
     EventHandler, MenuItem, MessageFromRenderer, MessageToRenderer, Renderer, Rendering,
-    RenderingFlow, UserEvent,
+    RenderingFlow, Theme, UserEvent,
 };
 use crate::watcher::{PathFilter, Watcher};
 use anyhow::{Context as _, Result};
@@ -494,6 +494,11 @@ where
         Ok(RenderingFlow::Continue)
     }
 
+    fn handle_theme_changed(&mut self, theme: Theme) -> Result<RenderingFlow> {
+        self.renderer.set_theme(theme)?;
+        Ok(RenderingFlow::Continue)
+    }
+
     fn handle_exit(&self) -> Result<()> {
         log::debug!("Handling application exit");
         let data_dir = self.config.data_dir();

v2/src/wry/event_loop.rs

@@ -1,10 +1,13 @@
 use crate::config::Config;
-use crate::renderer::{EventHandler, Rendering, RenderingFlow, UserEvent, UserEventSender};
+use crate::renderer::{
+    EventHandler, Rendering, RenderingFlow, Theme as RendererTheme, UserEvent, UserEventSender,
+};
 use crate::wry::menu::{Menu, MenuEvents};
 use crate::wry::webview::{EventLoop, WebViewRenderer};
 use anyhow::{Error, Result};
 use wry::application::event::{Event, StartCause, WindowEvent};
 use wry::application::event_loop::{ControlFlow, EventLoopBuilder, EventLoopProxy};
+use wry::application::window::Theme;
 
 pub struct Wry {
     event_loop: EventLoop,
@@ -88,6 +91,22 @@ impl Rendering for Wry {
                     log::debug!("Closing window was requested");
                     RenderingFlow::Exit
                 }
+                Event::WindowEvent {
+                    event: WindowEvent::ThemeChanged(theme @ (Theme::Light | Theme::Dark)),
+                    ..
+                } => {
+                    log::debug!("Window theme was changed: {:?}", theme);
+                    let theme = match theme {
+                        Theme::Light => RendererTheme::Light,
+                        Theme::Dark => RendererTheme::Dark,
+                        _ => unreachable!(),
+                    };
+                    handler.handle_theme_changed(theme).unwrap_or_else(|err| {
+                        log::error!("Could not handle theme change: {:?}", theme);
+                        log_causes(err);
+                        RenderingFlow::Continue
+                    })
+                }
                 Event::UserEvent(event) => handler.handle_user_event(event).unwrap_or_else(|err| {
                     log::error!("Could not handle user event");
                     log_causes(err);

v2/src/wry/webview.rs

@@ -286,6 +286,22 @@ impl Renderer for WebViewRenderer {
         window_theme(self.webview.window())
     }
 
+    #[cfg(target_os = "windows")]
+    fn set_theme(&self, theme: RendererTheme) -> Result<()> {
+        use wry::webview::{Theme as WebViewTheme, WebviewExtWindows as _};
+        let theme = match theme {
+            RendererTheme::Dark => WebViewTheme::Dark,
+            RendererTheme::Light => WebViewTheme::Light,
+        };
+        self.webview.set_theme(theme);
+        Ok(())
+    }
+    #[cfg(not(target_os = "windows"))]
+    fn set_theme(&self, _theme: RendererTheme) -> Result<()> {
+        // Note: winit has Window::set_theme but tao doesn't
+        Ok(())
+    }
+
     fn show(&self) {
         self.webview.window().set_visible(true);
     }