Remove `Sandbox` trait :tada:

3 files changed, 146 insertions, 212 deletions

diff --git a/src/lib.rs b/src/lib.rs
index ae6bb344..060cc6c5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -172,7 +172,6 @@ pub use iced_futures::futures;
 pub use iced_highlighter as highlighter;
 
 mod error;
-mod sandbox;
 
 pub mod application;
 pub mod program;
@@ -311,7 +310,6 @@ pub use executor::Executor;
 pub use font::Font;
 pub use program::Program;
 pub use renderer::Renderer;
-pub use sandbox::Sandbox;
 pub use settings::Settings;
 pub use subscription::Subscription;
 
diff --git a/src/program.rs b/src/program.rs
index c2841763..8aa1a4e7 100644
--- a/src/program.rs
+++ b/src/program.rs
@@ -194,12 +194,16 @@ impl<P: Definition> Program<P> {
                 self.program.view(&self.state)
             }
 
+            fn subscription(&self) -> Subscription<Self::Message> {
+                self.program.subscription(&self.state)
+            }
+
             fn theme(&self) -> Self::Theme {
                 self.program.theme(&self.state)
             }
 
-            fn subscription(&self) -> Subscription<Self::Message> {
-                self.program.subscription(&self.state)
+            fn style(&self, theme: &Self::Theme) -> application::Appearance {
+                self.program.style(&self.state, theme)
             }
         }
 
@@ -221,11 +225,11 @@ impl<P: Definition> Program<P> {
         Self { settings, ..self }
     }
 
-    /// Toggles the [`Settings::antialiasing`] to `true` for the [`Program`].
-    pub fn antialiased(self) -> Self {
+    /// Sets the [`Settings::antialiasing`] of the [`Program`].
+    pub fn antialiasing(self, antialiasing: bool) -> Self {
         Self {
             settings: Settings {
-                antialiasing: true,
+                antialiasing,
                 ..self.settings
             },
             ..self
@@ -263,12 +267,26 @@ impl<P: Definition> Program<P> {
         }
     }
 
-    /// Sets the [`window::Settings::exit_on_close_request`] to `false` in the [`Program`].
-    pub fn ignore_close_request(self) -> Self {
+    /// Sets the [`window::Settings::exit_on_close_request`] of the [`Program`].
+    pub fn exit_on_close_request(self, exit_on_close_request: bool) -> Self {
         Self {
             settings: Settings {
                 window: window::Settings {
-                    exit_on_close_request: false,
+                    exit_on_close_request,
+                    ..self.settings.window
+                },
+                ..self.settings
+            },
+            ..self
+        }
+    }
+
+    /// Sets the [`window::Settings::transparent`] of the [`Program`].
+    pub fn transparent(self, transparent: bool) -> Self {
+        Self {
+            settings: Settings {
+                window: window::Settings {
+                    transparent,
                     ..self.settings.window
                 },
                 ..self.settings
@@ -328,6 +346,19 @@ impl<P: Definition> Program<P> {
             settings: self.settings,
         }
     }
+
+    /// Sets the style logic of the [`Program`].
+    pub fn style(
+        self,
+        f: impl Fn(&P::State, &P::Theme) -> application::Appearance,
+    ) -> Program<
+        impl Definition<State = P::State, Message = P::Message, Theme = P::Theme>,
+    > {
+        Program {
+            raw: with_style(self.raw, f),
+            settings: self.settings,
+        }
+    }
 }
 
 /// The internal definition of a [`Program`].
@@ -377,6 +408,14 @@ pub trait Definition: Sized {
     fn theme(&self, _state: &Self::State) -> Self::Theme {
         Self::Theme::default()
     }
+
+    fn style(
+        &self,
+        _state: &Self::State,
+        theme: &Self::Theme,
+    ) -> application::Appearance {
+        application::DefaultStyle::default_style(theme)
+    }
 }
 
 fn with_title<P: Definition>(
@@ -431,6 +470,14 @@ fn with_title<P: Definition>(
         ) -> Subscription<Self::Message> {
             self.program.subscription(state)
         }
+
+        fn style(
+            &self,
+            state: &Self::State,
+            theme: &Self::Theme,
+        ) -> application::Appearance {
+            self.program.style(state, theme)
+        }
     }
 
     WithTitle { program, title }
@@ -479,15 +526,23 @@ fn with_load<P: Definition>(
             self.program.title(state)
         }
 
+        fn subscription(
+            &self,
+            state: &Self::State,
+        ) -> Subscription<Self::Message> {
+            self.program.subscription(state)
+        }
+
         fn theme(&self, state: &Self::State) -> Self::Theme {
             self.program.theme(state)
         }
 
-        fn subscription(
+        fn style(
             &self,
             state: &Self::State,
-        ) -> Subscription<Self::Message> {
-            self.program.subscription(state)
+            theme: &Self::Theme,
+        ) -> application::Appearance {
+            self.program.style(state, theme)
         }
     }
 
@@ -545,6 +600,14 @@ fn with_subscription<P: Definition>(
         fn theme(&self, state: &Self::State) -> Self::Theme {
             self.program.theme(state)
         }
+
+        fn style(
+            &self,
+            state: &Self::State,
+            theme: &Self::Theme,
+        ) -> application::Appearance {
+            self.program.style(state, theme)
+        }
     }
 
     WithSubscription {
@@ -604,11 +667,83 @@ fn with_theme<P: Definition>(
         ) -> Subscription<Self::Message> {
             self.program.subscription(state)
         }
+
+        fn style(
+            &self,
+            state: &Self::State,
+            theme: &Self::Theme,
+        ) -> application::Appearance {
+            self.program.style(state, theme)
+        }
     }
 
     WithTheme { program, theme: f }
 }
 
+fn with_style<P: Definition>(
+    program: P,
+    f: impl Fn(&P::State, &P::Theme) -> application::Appearance,
+) -> impl Definition<State = P::State, Message = P::Message, Theme = P::Theme> {
+    struct WithStyle<P, F> {
+        program: P,
+        style: F,
+    }
+
+    impl<P: Definition, F> Definition for WithStyle<P, F>
+    where
+        F: Fn(&P::State, &P::Theme) -> application::Appearance,
+    {
+        type State = P::State;
+        type Message = P::Message;
+        type Theme = P::Theme;
+        type Executor = P::Executor;
+
+        fn style(
+            &self,
+            state: &Self::State,
+            theme: &Self::Theme,
+        ) -> application::Appearance {
+            (self.style)(state, theme)
+        }
+
+        fn build(&self) -> (Self::State, Command<Self::Message>) {
+            self.program.build()
+        }
+
+        fn title(&self, state: &Self::State) -> String {
+            self.program.title(state)
+        }
+
+        fn update(
+            &self,
+            state: &mut Self::State,
+            message: Self::Message,
+        ) -> Command<Self::Message> {
+            self.program.update(state, message)
+        }
+
+        fn view<'a>(
+            &self,
+            state: &'a Self::State,
+        ) -> Element<'a, Self::Message, Self::Theme> {
+            self.program.view(state)
+        }
+
+        fn subscription(
+            &self,
+            state: &Self::State,
+        ) -> Subscription<Self::Message> {
+            self.program.subscription(state)
+        }
+
+        fn theme(&self, state: &Self::State) -> Self::Theme {
+            self.program.theme(state)
+        }
+    }
+
+    WithStyle { program, style: f }
+}
+
 /// The title logic of some [`Program`].
 ///
 /// This trait is implemented both for `&static str` and
diff --git a/src/sandbox.rs b/src/sandbox.rs
deleted file mode 100644
index 568b673e..00000000
--- a/src/sandbox.rs
+++ /dev/null
@@ -1,199 +0,0 @@
-use crate::application::{self, Application};
-use crate::{Command, Element, Error, Settings, Subscription, Theme};
-
-/// A sandboxed [`Application`].
-///
-/// If you are a just getting started with the library, this trait offers a
-/// simpler interface than [`Application`].
-///
-/// Unlike an [`Application`], a [`Sandbox`] cannot run any asynchronous
-/// actions or be initialized with some external flags. However, both traits
-/// are very similar and upgrading from a [`Sandbox`] is very straightforward.
-///
-/// Therefore, it is recommended to always start by implementing this trait and
-/// upgrade only once necessary.
-///
-/// # Examples
-/// [The repository has a bunch of examples] that use the [`Sandbox`] trait:
-///
-/// - [`bezier_tool`], a Paint-like tool for drawing Bézier curves using the
-/// [`Canvas widget`].
-/// - [`counter`], the classic counter example explained in [the overview].
-/// - [`custom_widget`], a demonstration of how to build a custom widget that
-/// draws a circle.
-/// - [`geometry`], a custom widget showcasing how to draw geometry with the
-/// `Mesh2D` primitive in [`iced_wgpu`].
-/// - [`pane_grid`], a grid of panes that can be split, resized, and
-/// reorganized.
-/// - [`progress_bar`], a simple progress bar that can be filled by using a
-/// slider.
-/// - [`styling`], an example showcasing custom styling with a light and dark
-/// theme.
-/// - [`svg`], an application that renders the [Ghostscript Tiger] by leveraging
-/// the [`Svg` widget].
-/// - [`tour`], a simple UI tour that can run both on native platforms and the
-/// web!
-///
-/// [The repository has a bunch of examples]: https://github.com/iced-rs/iced/tree/0.12/examples
-/// [`bezier_tool`]: https://github.com/iced-rs/iced/tree/0.12/examples/bezier_tool
-/// [`counter`]: https://github.com/iced-rs/iced/tree/0.12/examples/counter
-/// [`custom_widget`]: https://github.com/iced-rs/iced/tree/0.12/examples/custom_widget
-/// [`geometry`]: https://github.com/iced-rs/iced/tree/0.12/examples/geometry
-/// [`pane_grid`]: https://github.com/iced-rs/iced/tree/0.12/examples/pane_grid
-/// [`progress_bar`]: https://github.com/iced-rs/iced/tree/0.12/examples/progress_bar
-/// [`styling`]: https://github.com/iced-rs/iced/tree/0.12/examples/styling
-/// [`svg`]: https://github.com/iced-rs/iced/tree/0.12/examples/svg
-/// [`tour`]: https://github.com/iced-rs/iced/tree/0.12/examples/tour
-/// [`Canvas widget`]: crate::widget::Canvas
-/// [the overview]: index.html#overview
-/// [`iced_wgpu`]: https://github.com/iced-rs/iced/tree/0.12/wgpu
-/// [`Svg` widget]: crate::widget::Svg
-/// [Ghostscript Tiger]: https://commons.wikimedia.org/wiki/File:Ghostscript_Tiger.svg
-///
-/// ## A simple "Hello, world!"
-///
-/// If you just want to get started, here is a simple [`Sandbox`] that
-/// says "Hello, world!":
-///
-/// ```no_run
-/// use iced::{Element, Sandbox, Settings};
-///
-/// pub fn main() -> iced::Result {
-///     Hello::run(Settings::default())
-/// }
-///
-/// struct Hello;
-///
-/// impl Sandbox for Hello {
-///     type Message = ();
-///
-///     fn new() -> Hello {
-///         Hello
-///     }
-///
-///     fn title(&self) -> String {
-///         String::from("A cool application")
-///     }
-///
-///     fn update(&mut self, _message: Self::Message) {
-///         // This application has no interactions
-///     }
-///
-///     fn view(&self) -> Element<Self::Message> {
-///         "Hello, world!".into()
-///     }
-/// }
-/// ```
-pub trait Sandbox {
-    /// The type of __messages__ your [`Sandbox`] will produce.
-    type Message: std::fmt::Debug + Send;
-
-    /// Initializes the [`Sandbox`].
-    ///
-    /// Here is where you should return the initial state of your app.
-    fn new() -> Self;
-
-    /// Returns the current title of the [`Sandbox`].
-    ///
-    /// This title can be dynamic! The runtime will automatically update the
-    /// title of your application when necessary.
-    fn title(&self) -> String;
-
-    /// Handles a __message__ and updates the state of the [`Sandbox`].
-    ///
-    /// This is where you define your __update logic__. All the __messages__,
-    /// produced by user interactions, will be handled by this method.
-    fn update(&mut self, message: Self::Message);
-
-    /// Returns the widgets to display in the [`Sandbox`].
-    ///
-    /// These widgets can produce __messages__ based on user interaction.
-    fn view(&self) -> Element<'_, Self::Message>;
-
-    /// Returns the current [`Theme`] of the [`Sandbox`].
-    ///
-    /// If you want to use your own custom theme type, you will have to use an
-    /// [`Application`].
-    ///
-    /// By default, it returns [`Theme::default`].
-    fn theme(&self) -> Theme {
-        Theme::default()
-    }
-
-    /// Returns the current [`application::Appearance`].
-    fn style(&self, theme: &Theme) -> application::Appearance {
-        use application::DefaultStyle;
-
-        theme.default_style()
-    }
-
-    /// Returns the scale factor of the [`Sandbox`].
-    ///
-    /// It can be used to dynamically control the size of the UI at runtime
-    /// (i.e. zooming).
-    ///
-    /// For instance, a scale factor of `2.0` will make widgets twice as big,
-    /// while a scale factor of `0.5` will shrink them to half their size.
-    ///
-    /// By default, it returns `1.0`.
-    fn scale_factor(&self) -> f64 {
-        1.0
-    }
-
-    /// Runs the [`Sandbox`].
-    ///
-    /// On native platforms, this method will take control of the current thread
-    /// and __will NOT return__.
-    ///
-    /// It should probably be that last thing you call in your `main` function.
-    fn run(settings: Settings<()>) -> Result<(), Error>
-    where
-        Self: 'static + Sized,
-    {
-        <Self as Application>::run(settings)
-    }
-}
-
-impl<T> Application for T
-where
-    T: Sandbox,
-{
-    type Executor = iced_futures::backend::null::Executor;
-    type Flags = ();
-    type Message = T::Message;
-    type Theme = Theme;
-
-    fn new(_flags: ()) -> (Self, Command<T::Message>) {
-        (T::new(), Command::none())
-    }
-
-    fn title(&self) -> String {
-        T::title(self)
-    }
-
-    fn update(&mut self, message: T::Message) -> Command<T::Message> {
-        T::update(self, message);
-
-        Command::none()
-    }
-
-    fn view(&self) -> Element<'_, T::Message> {
-        T::view(self)
-    }
-
-    fn theme(&self) -> Self::Theme {
-        T::theme(self)
-    }
-
-    fn style(&self, theme: &Theme) -> application::Appearance {
-        T::style(self, theme)
-    }
-
-    fn subscription(&self) -> Subscription<T::Message> {
-        Subscription::none()
-    }
-
-    fn scale_factor(&self) -> f64 {
-        T::scale_factor(self)
-    }
-}