Rehighlight TextEditor when Theme changes

core/src/theme.rs

@@ -168,31 +168,7 @@ impl Theme {
 
 impl fmt::Display for Theme {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::Light => write!(f, "Light"),
-            Self::Dark => write!(f, "Dark"),
-            Self::Dracula => write!(f, "Dracula"),
-            Self::Nord => write!(f, "Nord"),
-            Self::SolarizedLight => write!(f, "Solarized Light"),
-            Self::SolarizedDark => write!(f, "Solarized Dark"),
-            Self::GruvboxLight => write!(f, "Gruvbox Light"),
-            Self::GruvboxDark => write!(f, "Gruvbox Dark"),
-            Self::CatppuccinLatte => write!(f, "Catppuccin Latte"),
-            Self::CatppuccinFrappe => write!(f, "Catppuccin Frappé"),
-            Self::CatppuccinMacchiato => write!(f, "Catppuccin Macchiato"),
-            Self::CatppuccinMocha => write!(f, "Catppuccin Mocha"),
-            Self::TokyoNight => write!(f, "Tokyo Night"),
-            Self::TokyoNightStorm => write!(f, "Tokyo Night Storm"),
-            Self::TokyoNightLight => write!(f, "Tokyo Night Light"),
-            Self::KanagawaWave => write!(f, "Kanagawa Wave"),
-            Self::KanagawaDragon => write!(f, "Kanagawa Dragon"),
-            Self::KanagawaLotus => write!(f, "Kanagawa Lotus"),
-            Self::Moonfly => write!(f, "Moonfly"),
-            Self::Nightfly => write!(f, "Nightfly"),
-            Self::Oxocarbon => write!(f, "Oxocarbon"),
-            Self::Ferra => write!(f, "Ferra"),
-            Self::Custom(custom) => custom.fmt(f),
-        }
+        f.write_str(self.name())
     }
 }
 
@@ -270,6 +246,12 @@ pub trait Base {
     /// debugging purposes; like displaying performance
     /// metrics or devtools.
     fn palette(&self) -> Option<Palette>;
+
+    /// Returns the unique name of the theme.
+    ///
+    /// This name may be used to efficiently detect theme
+    /// changes in some widgets.
+    fn name(&self) -> &str;
 }
 
 impl Base for Theme {
@@ -313,6 +295,34 @@ impl Base for Theme {
     fn palette(&self) -> Option<Palette> {
         Some(self.palette())
     }
+
+    fn name(&self) -> &str {
+        match self {
+            Self::Light => "Light",
+            Self::Dark => "Dark",
+            Self::Dracula => "Dracula",
+            Self::Nord => "Nord",
+            Self::SolarizedLight => "Solarized Light",
+            Self::SolarizedDark => "Solarized Dark",
+            Self::GruvboxLight => "Gruvbox Light",
+            Self::GruvboxDark => "Gruvbox Dark",
+            Self::CatppuccinLatte => "Catppuccin Latte",
+            Self::CatppuccinFrappe => "Catppuccin Frappé",
+            Self::CatppuccinMacchiato => "Catppuccin Macchiato",
+            Self::CatppuccinMocha => "Catppuccin Mocha",
+            Self::TokyoNight => "Tokyo Night",
+            Self::TokyoNightStorm => "Tokyo Night Storm",
+            Self::TokyoNightLight => "Tokyo Night Light",
+            Self::KanagawaWave => "Kanagawa Wave",
+            Self::KanagawaDragon => "Kanagawa Dragon",
+            Self::KanagawaLotus => "Kanagawa Lotus",
+            Self::Moonfly => "Moonfly",
+            Self::Nightfly => "Nightfly",
+            Self::Oxocarbon => "Oxocarbon",
+            Self::Ferra => "Ferra",
+            Self::Custom(custom) => &custom.name,
+        }
+    }
 }
 
 /// The default [`Style`] of a built-in [`Theme`].

widget/src/text_editor.rs

@@ -42,6 +42,7 @@ use crate::core::renderer;
 use crate::core::text::editor::{Cursor, Editor as _};
 use crate::core::text::highlighter::{self, Highlighter};
 use crate::core::text::{self, LineHeight, Text, Wrapping};
+use crate::core::theme;
 use crate::core::time::{Duration, Instant};
 use crate::core::widget::operation;
 use crate::core::widget::{self, Widget};
@@ -148,7 +149,7 @@ where
             max_height: f32::INFINITY,
             padding: Padding::new(5.0),
             wrapping: Wrapping::default(),
-            class: Theme::default(),
+            class: <Theme as Catalog>::default(),
             key_binding: None,
             on_edit: None,
             highlighter_settings: (),
@@ -514,6 +515,7 @@ pub struct State<Highlighter: text::Highlighter> {
     last_click: Option<mouse::Click>,
     drag_click: Option<mouse::click::Kind>,
     partial_scroll: f32,
+    last_theme: RefCell<Option<String>>,
     highlighter: RefCell<Highlighter>,
     highlighter_settings: Highlighter::Settings,
     highlighter_format_address: usize,
@@ -588,6 +590,7 @@ where
             last_click: None,
             drag_click: None,
             partial_scroll: 0.0,
+            last_theme: RefCell::default(),
             highlighter: RefCell::new(Highlighter::new(
                 &self.highlighter_settings,
             )),
@@ -938,6 +941,19 @@ where
 
         let font = self.font.unwrap_or_else(|| renderer.default_font());
 
+        let theme_name = theme.name();
+
+        if state
+            .last_theme
+            .borrow()
+            .as_ref()
+            .is_none_or(|last_theme| last_theme != theme_name)
+        {
+            state.highlighter.borrow_mut().change_line(0);
+            let _ =
+                state.last_theme.borrow_mut().replace(theme_name.to_owned());
+        }
+
         internal.editor.highlight(
             font,
             state.highlighter.borrow_mut().deref_mut(),
@@ -1391,7 +1407,7 @@ pub struct Style {
 }
 
 /// The theme catalog of a [`TextEditor`].
-pub trait Catalog {
+pub trait Catalog: theme::Base {
     /// The item class of the [`Catalog`].
     type Class<'a>;