Merge pull request #193 from hecrj/feature/canvas

Canvas widget for 2D graphics

2 files changed, 208 insertions, 0 deletions

diff --git a/examples/clock/Cargo.toml b/examples/clock/Cargo.toml
new file mode 100644
index 00000000..308cbfbb
--- /dev/null
+++ b/examples/clock/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "clock"
+version = "0.1.0"
+authors = ["Héctor Ramón Jiménez <hector0193@gmail.com>"]
+edition = "2018"
+publish = false
+
+[features]
+canvas = []
+
+[dependencies]
+iced = { path = "../..", features = ["canvas", "async-std", "debug"] }
+iced_native = { path = "../../native" }
+chrono = "0.4"
+async-std = { version = "1.0", features = ["unstable"] }
diff --git a/examples/clock/src/main.rs b/examples/clock/src/main.rs
new file mode 100644
index 00000000..d8266f06
--- /dev/null
+++ b/examples/clock/src/main.rs
@@ -0,0 +1,193 @@
+use iced::{
+    canvas, executor, Application, Canvas, Color, Command, Container, Element,
+    Length, Point, Settings, Subscription, Vector,
+};
+
+pub fn main() {
+    Clock::run(Settings {
+        antialiasing: true,
+        ..Settings::default()
+    })
+}
+
+struct Clock {
+    now: LocalTime,
+    clock: canvas::layer::Cache<LocalTime>,
+}
+
+#[derive(Debug, Clone, Copy)]
+enum Message {
+    Tick(chrono::DateTime<chrono::Local>),
+}
+
+impl Application for Clock {
+    type Executor = executor::Default;
+    type Message = Message;
+
+    fn new() -> (Self, Command<Message>) {
+        (
+            Clock {
+                now: chrono::Local::now().into(),
+                clock: canvas::layer::Cache::new(),
+            },
+            Command::none(),
+        )
+    }
+
+    fn title(&self) -> String {
+        String::from("Clock - Iced")
+    }
+
+    fn update(&mut self, message: Message) -> Command<Message> {
+        match message {
+            Message::Tick(local_time) => {
+                let now = local_time.into();
+
+                if now != self.now {
+                    self.now = now;
+                    self.clock.clear();
+                }
+            }
+        }
+
+        Command::none()
+    }
+
+    fn subscription(&self) -> Subscription<Message> {
+        time::every(std::time::Duration::from_millis(500)).map(Message::Tick)
+    }
+
+    fn view(&mut self) -> Element<Message> {
+        let canvas = Canvas::new()
+            .width(Length::Units(400))
+            .height(Length::Units(400))
+            .push(self.clock.with(&self.now));
+
+        Container::new(canvas)
+            .width(Length::Fill)
+            .height(Length::Fill)
+            .center_x()
+            .center_y()
+            .into()
+    }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+struct LocalTime {
+    hour: u32,
+    minute: u32,
+    second: u32,
+}
+
+impl From<chrono::DateTime<chrono::Local>> for LocalTime {
+    fn from(date_time: chrono::DateTime<chrono::Local>) -> LocalTime {
+        use chrono::Timelike;
+
+        LocalTime {
+            hour: date_time.hour(),
+            minute: date_time.minute(),
+            second: date_time.second(),
+        }
+    }
+}
+
+impl canvas::Drawable for LocalTime {
+    fn draw(&self, frame: &mut canvas::Frame) {
+        let center = frame.center();
+        let radius = frame.width().min(frame.height()) / 2.0;
+        let offset = Vector::new(center.x, center.y);
+
+        let clock = canvas::Path::new(|path| path.circle(center, radius));
+
+        frame.fill(
+            &clock,
+            canvas::Fill::Color(Color::from_rgb8(0x12, 0x93, 0xD8)),
+        );
+
+        fn draw_hand(
+            n: u32,
+            total: u32,
+            length: f32,
+            offset: Vector,
+            path: &mut canvas::path::Builder,
+        ) {
+            let turns = n as f32 / total as f32;
+            let t = 2.0 * std::f32::consts::PI * (turns - 0.25);
+
+            let x = length * t.cos();
+            let y = length * t.sin();
+
+            path.line_to(Point::new(x, y) + offset);
+        }
+
+        let hour_and_minute_hands = canvas::Path::new(|path| {
+            path.move_to(center);
+            draw_hand(self.hour, 12, 0.5 * radius, offset, path);
+
+            path.move_to(center);
+            draw_hand(self.minute, 60, 0.8 * radius, offset, path)
+        });
+
+        frame.stroke(
+            &hour_and_minute_hands,
+            canvas::Stroke {
+                width: 6.0,
+                color: Color::WHITE,
+                line_cap: canvas::LineCap::Round,
+                ..canvas::Stroke::default()
+            },
+        );
+
+        let second_hand = canvas::Path::new(|path| {
+            path.move_to(center);
+            draw_hand(self.second, 60, 0.8 * radius, offset, path)
+        });
+
+        frame.stroke(
+            &second_hand,
+            canvas::Stroke {
+                width: 3.0,
+                color: Color::WHITE,
+                line_cap: canvas::LineCap::Round,
+                ..canvas::Stroke::default()
+            },
+        );
+    }
+}
+
+mod time {
+    use iced::futures;
+
+    pub fn every(
+        duration: std::time::Duration,
+    ) -> iced::Subscription<chrono::DateTime<chrono::Local>> {
+        iced::Subscription::from_recipe(Every(duration))
+    }
+
+    struct Every(std::time::Duration);
+
+    impl<H, I> iced_native::subscription::Recipe<H, I> for Every
+    where
+        H: std::hash::Hasher,
+    {
+        type Output = chrono::DateTime<chrono::Local>;
+
+        fn hash(&self, state: &mut H) {
+            use std::hash::Hash;
+
+            std::any::TypeId::of::<Self>().hash(state);
+            self.0.hash(state);
+        }
+
+        fn stream(
+            self: Box<Self>,
+            _input: futures::stream::BoxStream<'static, I>,
+        ) -> futures::stream::BoxStream<'static, Self::Output> {
+            use futures::stream::StreamExt;
+
+            async_std::stream::interval(self.0)
+                .map(|_| chrono::Local::now())
+                .boxed()
+        }
+    }
+}