Add `spin` mode to `ferris` example :crab:

4 files changed, 87 insertions, 16 deletions

diff --git a/core/src/angle.rs b/core/src/angle.rs
index 8322273c..9c8a9b24 100644
--- a/core/src/angle.rs
+++ b/core/src/angle.rs
@@ -1,7 +1,7 @@
 use crate::{Point, Rectangle, Vector};
 
 use std::f32::consts::{FRAC_PI_2, PI};
-use std::ops::{Add, AddAssign, Div, Mul, RangeInclusive, Sub, SubAssign};
+use std::ops::{Add, AddAssign, Div, Mul, RangeInclusive, Rem, Sub, SubAssign};
 
 /// Degrees
 #[derive(Debug, Copy, Clone, PartialEq, PartialOrd)]
@@ -48,6 +48,14 @@ impl From<Degrees> for f64 {
     }
 }
 
+impl Mul<f32> for Degrees {
+    type Output = Degrees;
+
+    fn mul(self, rhs: f32) -> Self::Output {
+        Self(self.0 * rhs)
+    }
+}
+
 impl num_traits::FromPrimitive for Degrees {
     fn from_i64(n: i64) -> Option<Self> {
         Some(Self(n as f32))
@@ -156,6 +164,14 @@ impl Add for Radians {
     }
 }
 
+impl Add<Degrees> for Radians {
+    type Output = Self;
+
+    fn add(self, rhs: Degrees) -> Self::Output {
+        Self(self.0 + rhs.0.to_radians())
+    }
+}
+
 impl AddAssign for Radians {
     fn add_assign(&mut self, rhs: Radians) {
         self.0 = self.0 + rhs.0;
@@ -202,6 +218,14 @@ impl Div for Radians {
     }
 }
 
+impl Rem for Radians {
+    type Output = Self;
+
+    fn rem(self, rhs: Self) -> Self::Output {
+        Self(self.0 % rhs.0)
+    }
+}
+
 impl PartialEq<f32> for Radians {
     fn eq(&self, other: &f32) -> bool {
         self.0.eq(other)
diff --git a/core/src/rotation.rs b/core/src/rotation.rs
index 00a8c302..afa8d79e 100644
--- a/core/src/rotation.rs
+++ b/core/src/rotation.rs
@@ -31,6 +31,13 @@ impl Rotation {
         }
     }
 
+    /// Returns a mutable reference to the angle of the [`Rotation`] in [`Radians`].
+    pub fn radians_mut(&mut self) -> &mut Radians {
+        match self {
+            Rotation::Floating(radians) | Rotation::Solid(radians) => radians,
+        }
+    }
+
     /// Returns the angle of the [`Rotation`] in [`Degrees`].
     pub fn degrees(self) -> Degrees {
         Degrees(self.radians().0.to_degrees())
diff --git a/examples/ferris/Cargo.toml b/examples/ferris/Cargo.toml
index 0d91749b..e98341d2 100644
--- a/examples/ferris/Cargo.toml
+++ b/examples/ferris/Cargo.toml
@@ -7,4 +7,4 @@ publish = false
 
 [dependencies]
 iced.workspace = true
-iced.features = ["image", "debug"]
+iced.features = ["image", "tokio", "debug"]
diff --git a/examples/ferris/src/main.rs b/examples/ferris/src/main.rs
index d846f560..b7536740 100644
--- a/examples/ferris/src/main.rs
+++ b/examples/ferris/src/main.rs
@@ -1,10 +1,16 @@
-use iced::widget::{column, container, image, pick_list, row, slider, text};
+use iced::time::Instant;
+use iced::widget::{
+    checkbox, column, container, image, pick_list, row, slider, text,
+};
+use iced::window;
 use iced::{
-    Alignment, Color, ContentFit, Degrees, Element, Length, Rotation, Theme,
+    Alignment, Color, ContentFit, Degrees, Element, Length, Radians, Rotation,
+    Subscription, Theme,
 };
 
 pub fn main() -> iced::Result {
     iced::program("Ferris - Iced", Image::update, Image::view)
+        .subscription(Image::subscription)
         .theme(|_| Theme::TokyoNight)
         .run()
 }
@@ -13,6 +19,8 @@ struct Image {
     width: f32,
     rotation: Rotation,
     content_fit: ContentFit,
+    spin: bool,
+    last_tick: Instant,
 }
 
 #[derive(Debug, Clone, Copy)]
@@ -21,6 +29,8 @@ enum Message {
     RotationStrategyChanged(RotationStrategy),
     RotationChanged(Degrees),
     ContentFitChanged(ContentFit),
+    SpinToggled(bool),
+    RedrawRequested(Instant),
 }
 
 impl Image {
@@ -50,6 +60,29 @@ impl Image {
             Message::ContentFitChanged(content_fit) => {
                 self.content_fit = content_fit;
             }
+            Message::SpinToggled(spin) => {
+                self.spin = spin;
+                self.last_tick = Instant::now();
+            }
+            Message::RedrawRequested(now) => {
+                const ROTATION_SPEED: Degrees = Degrees(360.0);
+
+                let delta = (now - self.last_tick).as_millis() as f32 / 1_000.0;
+
+                *self.rotation.radians_mut() = (self.rotation.radians()
+                    + ROTATION_SPEED * delta)
+                    % (2.0 * Radians::PI);
+
+                self.last_tick = now;
+            }
+        }
+    }
+
+    fn subscription(&self) -> Subscription<Message> {
+        if self.spin {
+            window::frames().map(Message::RedrawRequested)
+        } else {
+            Subscription::none()
         }
     }
 
@@ -111,18 +144,23 @@ impl Image {
                 Message::RotationStrategyChanged,
             )
             .width(Length::Fill),
-            column![
-                slider(
-                    Degrees::RANGE,
-                    self.rotation.degrees(),
-                    Message::RotationChanged
-                ),
-                text(format!(
-                    "Rotation: {:.0}°",
-                    f32::from(self.rotation.degrees())
-                ))
-                .size(14)
-                .line_height(1.0)
+            row![
+                column![
+                    slider(
+                        Degrees::RANGE,
+                        self.rotation.degrees(),
+                        Message::RotationChanged
+                    ),
+                    text(format!(
+                        "Rotation: {:.0}°",
+                        f32::from(self.rotation.degrees())
+                    ))
+                    .size(14)
+                    .line_height(1.0)
+                ]
+                .spacing(5)
+                .align_items(Alignment::Center),
+                checkbox("Spin!", self.spin).on_toggle(Message::SpinToggled)
             ]
             .spacing(5)
             .align_items(Alignment::Center)
@@ -141,6 +179,8 @@ impl Default for Image {
             width: 300.0,
             rotation: Rotation::default(),
             content_fit: ContentFit::default(),
+            spin: false,
+            last_tick: Instant::now(),
         }
     }
 }