1 files changed, 26 insertions, 15 deletions

diff --git a/winit/src/application.rs b/winit/src/application.rs
index 90b03d56..c7905c60 100644
--- a/winit/src/application.rs
+++ b/winit/src/application.rs
@@ -7,8 +7,8 @@ use crate::clipboard::{self, Clipboard};
 use crate::conversion;
 use crate::mouse;
 use crate::{
-    Color, Command, Debug, Error, Executor, Mode, Proxy, Runtime, Settings,
-    Size, Subscription,
+    Command, Debug, Error, Executor, Mode, Proxy, Runtime, Settings, Size,
+    Subscription,
 };
 
 use iced_futures::futures;
@@ -18,6 +18,8 @@ use iced_graphics::window;
 use iced_native::program::Program;
 use iced_native::user_interface::{self, UserInterface};
 
+pub use iced_native::application::StyleSheet;
+
 use std::mem::ManuallyDrop;
 
 /// An interactive, native cross-platform application.
@@ -51,6 +53,9 @@ pub trait Application: Program {
     /// title of your application when necessary.
     fn title(&self) -> String;
 
+    /// Returns the current [`Theme`] of the [`Application`].
+    fn theme(&self) -> <Self::Renderer as iced_native::Renderer>::Theme;
+
     /// Returns the event `Subscription` for the current state of the
     /// application.
     ///
@@ -74,13 +79,6 @@ pub trait Application: Program {
         Mode::Windowed
     }
 
-    /// Returns the background [`Color`] of the [`Application`].
-    ///
-    /// By default, it returns [`Color::WHITE`].
-    fn background_color(&self) -> Color {
-        Color::WHITE
-    }
-
     /// Returns the scale factor of the [`Application`].
     ///
     /// It can be used to dynamically control the size of the UI at runtime
@@ -112,6 +110,7 @@ where
     A: Application + 'static,
     E: Executor + 'static,
     C: window::Compositor<Renderer = A::Renderer> + 'static,
+    <A::Renderer as iced_native::Renderer>::Theme: StyleSheet,
 {
     use futures::task;
     use futures::Future;
@@ -247,6 +246,7 @@ async fn run_instance<A, E, C>(
     A: Application + 'static,
     E: Executor + 'static,
     C: window::Compositor<Renderer = A::Renderer> + 'static,
+    <A::Renderer as iced_native::Renderer>::Theme: StyleSheet,
 {
     use iced_futures::futures::stream::StreamExt;
     use winit::event;
@@ -255,6 +255,7 @@ async fn run_instance<A, E, C>(
 
     let mut state = State::new(&application, &window);
     let mut viewport_version = state.viewport_version();
+    let mut theme = application.theme();
 
     let physical_size = state.physical_size();
 
@@ -327,6 +328,7 @@ async fn run_instance<A, E, C>(
 
                     let should_exit = application.should_exit();
 
+                    theme = application.theme();
                     user_interface = ManuallyDrop::new(build_user_interface(
                         &mut application,
                         cache,
@@ -341,8 +343,11 @@ async fn run_instance<A, E, C>(
                 }
 
                 debug.draw_started();
-                let new_mouse_interaction =
-                    user_interface.draw(&mut renderer, state.cursor_position());
+                let new_mouse_interaction = user_interface.draw(
+                    &mut renderer,
+                    &theme,
+                    state.cursor_position(),
+                );
                 debug.draw_finished();
 
                 if new_mouse_interaction != mouse_interaction {
@@ -389,8 +394,11 @@ async fn run_instance<A, E, C>(
                     debug.layout_finished();
 
                     debug.draw_started();
-                    let new_mouse_interaction = user_interface
-                        .draw(&mut renderer, state.cursor_position());
+                    let new_mouse_interaction = user_interface.draw(
+                        &mut renderer,
+                        &theme,
+                        state.cursor_position(),
+                    );
 
                     if new_mouse_interaction != mouse_interaction {
                         window.set_cursor_icon(conversion::mouse_interaction(
@@ -414,7 +422,7 @@ async fn run_instance<A, E, C>(
                     &mut renderer,
                     &mut surface,
                     state.viewport(),
-                    state.background_color(),
+                    theme.background_color(),
                     &debug.overlay(),
                 ) {
                     Ok(()) => {
@@ -497,7 +505,10 @@ pub fn build_user_interface<'a, A: Application>(
     renderer: &mut A::Renderer,
     size: Size,
     debug: &mut Debug,
-) -> UserInterface<'a, A::Message, A::Renderer> {
+) -> UserInterface<'a, A::Message, A::Renderer>
+where
+    <A::Renderer as crate::Renderer>::Theme: StyleSheet,
+{
     debug.view_started();
     let view = application.view();
     debug.view_finished();