Add system theme to RawInput

crates/egui/src/data/input.rs

@@ -2,7 +2,7 @@
 
 use epaint::ColorImage;
 
-use crate::{emath::*, Key, ViewportId, ViewportIdMap};
+use crate::{emath::*, Key, Theme, ViewportId, ViewportIdMap};
 
 /// What the integrations provides to egui at the start of each frame.
 ///
@@ -73,6 +73,11 @@ pub struct RawInput {
     ///
     /// False when the user alt-tab away from the application, for instance.
     pub focused: bool,
+
+    /// Does the OS use dark or light mode?
+    ///
+    /// `None` means "don't know".
+    pub system_theme: Option<Theme>,
 }
 
 impl Default for RawInput {
@@ -89,6 +94,7 @@ impl Default for RawInput {
             hovered_files: Default::default(),
             dropped_files: Default::default(),
             focused: true, // integrations opt into global focus tracking
+            system_theme: None,
         }
     }
 }
@@ -117,6 +123,7 @@ impl RawInput {
             hovered_files: self.hovered_files.clone(),
             dropped_files: std::mem::take(&mut self.dropped_files),
             focused: self.focused,
+            system_theme: self.system_theme.clone(),
         }
     }
 
@@ -134,6 +141,7 @@ impl RawInput {
             mut hovered_files,
             mut dropped_files,
             focused,
+            system_theme,
         } = newer;
 
         self.viewport_id = viewport_ids;
@@ -147,6 +155,7 @@ impl RawInput {
         self.hovered_files.append(&mut hovered_files);
         self.dropped_files.append(&mut dropped_files);
         self.focused = focused;
+        self.system_theme = system_theme;
     }
 }
 
@@ -1038,6 +1047,7 @@ impl RawInput {
             hovered_files,
             dropped_files,
             focused,
+            system_theme,
         } = self;
 
         ui.label(format!("Active viwport: {viewport_id:?}"));
@@ -1062,6 +1072,7 @@ impl RawInput {
         ui.label(format!("hovered_files: {}", hovered_files.len()));
         ui.label(format!("dropped_files: {}", dropped_files.len()));
         ui.label(format!("focused: {focused}"));
+        ui.label(format!("system_theme: {system_theme:?}"));
         ui.scope(|ui| {
             ui.set_min_height(150.0);
             ui.label(format!("events: {events:#?}"))