Merge pull request #1647 from iced-rs/feature/widget-request-redraw

Widget-driven animations

core/Cargo.toml

@@ -15,4 +15,4 @@ version = "0.6"
 optional = true
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
-wasm-timer = { version = "0.2" }
+instant = "0.1"

core/src/time.rs

@@ -1,9 +1,13 @@
 //! Keep track of time, both in native and web platforms!
 
 #[cfg(target_arch = "wasm32")]
-pub use wasm_timer::Instant;
+pub use instant::Instant;
+
+#[cfg(target_arch = "wasm32")]
+pub use instant::Duration;
 
 #[cfg(not(target_arch = "wasm32"))]
 pub use std::time::Instant;
 
+#[cfg(not(target_arch = "wasm32"))]
 pub use std::time::Duration;

examples/events/Cargo.toml

@@ -6,5 +6,5 @@ edition = "2021"
 publish = false
 
 [dependencies]
-iced = { path = "../.." }
+iced = { path = "../..", features = ["debug"] }
 iced_native = { path = "../../native" }

examples/events/src/main.rs

@@ -1,11 +1,12 @@
 use iced::alignment;
 use iced::executor;
 use iced::widget::{button, checkbox, container, text, Column};
+use iced::window;
 use iced::{
     Alignment, Application, Command, Element, Length, Settings, Subscription,
     Theme,
 };
-use iced_native::{window, Event};
+use iced_native::Event;
 
 pub fn main() -> iced::Result {
     Events::run(Settings {
@@ -18,7 +19,6 @@ pub fn main() -> iced::Result {
 struct Events {
     last: Vec<iced_native::Event>,
     enabled: bool,
-    should_exit: bool,
 }
 
 #[derive(Debug, Clone)]
@@ -50,31 +50,29 @@ impl Application for Events {
                 if self.last.len() > 5 {
                     let _ = self.last.remove(0);
                 }
+
+                Command::none()
             }
             Message::EventOccurred(event) => {
                 if let Event::Window(window::Event::CloseRequested) = event {
-                    self.should_exit = true;
+                    window::close()
+                } else {
+                    Command::none()
                 }
             }
             Message::Toggled(enabled) => {
                 self.enabled = enabled;
-            }
-            Message::Exit => {
-                self.should_exit = true;
-            }
-        };
 
-        Command::none()
+                Command::none()
+            }
+            Message::Exit => window::close(),
+        }
     }
 
     fn subscription(&self) -> Subscription<Message> {
         iced_native::subscription::events().map(Message::EventOccurred)
     }
 
-    fn should_exit(&self) -> bool {
-        self.should_exit
-    }
-
     fn view(&self) -> Element<Message> {
         let events = Column::with_children(
             self.last

examples/exit/src/main.rs

@@ -1,5 +1,7 @@
+use iced::executor;
 use iced::widget::{button, column, container};
-use iced::{Alignment, Element, Length, Sandbox, Settings};
+use iced::window;
+use iced::{Alignment, Application, Command, Element, Length, Settings, Theme};
 
 pub fn main() -> iced::Result {
     Exit::run(Settings::default())
@@ -8,7 +10,6 @@ pub fn main() -> iced::Result {
 #[derive(Default)]
 struct Exit {
     show_confirm: bool,
-    exit: bool,
 }
 
 #[derive(Debug, Clone, Copy)]
@@ -17,28 +18,27 @@ enum Message {
     Exit,
 }
 
-impl Sandbox for Exit {
+impl Application for Exit {
+    type Executor = executor::Default;
     type Message = Message;
+    type Theme = Theme;
+    type Flags = ();
 
-    fn new() -> Self {
-        Self::default()
+    fn new(_flags: ()) -> (Self, Command<Message>) {
+        (Self::default(), Command::none())
     }
 
     fn title(&self) -> String {
         String::from("Exit - Iced")
     }
 
-    fn should_exit(&self) -> bool {
-        self.exit
-    }
-
-    fn update(&mut self, message: Message) {
+    fn update(&mut self, message: Message) -> Command<Message> {
         match message {
-            Message::Confirm => {
-                self.exit = true;
-            }
+            Message::Confirm => window::close(),
             Message::Exit => {
                 self.show_confirm = true;
+
+                Command::none()
             }
         }
     }

examples/solar_system/src/main.rs

@@ -9,7 +9,6 @@
 use iced::application;
 use iced::executor;
 use iced::theme::{self, Theme};
-use iced::time;
 use iced::widget::canvas;
 use iced::widget::canvas::gradient::{self, Gradient};
 use iced::widget::canvas::stroke::{self, Stroke};
@@ -90,7 +89,7 @@ impl Application for SolarSystem {
     }
 
     fn subscription(&self) -> Subscription<Message> {
-        time::every(time::Duration::from_millis(10)).map(Message::Tick)
+        window::frames().map(Message::Tick)
     }
 }
 

glutin/Cargo.toml

@@ -15,8 +15,8 @@ trace = ["iced_winit/trace"]
 debug = ["iced_winit/debug"]
 system = ["iced_winit/system"]
 
-[dependencies.log]
-version = "0.4"
+[dependencies]
+log = "0.4"
 
 [dependencies.glutin]
 version = "0.29"
@@ -39,4 +39,4 @@ features = ["opengl"]
 
 [dependencies.tracing]
 version = "0.1.6"
-optional = true
+optional = true

glutin/src/application.rs

@@ -11,8 +11,9 @@ use iced_winit::conversion;
 use iced_winit::futures;
 use iced_winit::futures::channel::mpsc;
 use iced_winit::renderer;
+use iced_winit::time::Instant;
 use iced_winit::user_interface;
-use iced_winit::{Clipboard, Command, Debug, Proxy, Settings};
+use iced_winit::{Clipboard, Command, Debug, Event, Proxy, Settings};
 
 use glutin::window::Window;
 use std::mem::ManuallyDrop;
@@ -131,7 +132,8 @@ where
         })?
     };
 
-    let (mut sender, receiver) = mpsc::unbounded();
+    let (mut event_sender, event_receiver) = mpsc::unbounded();
+    let (control_sender, mut control_receiver) = mpsc::unbounded();
 
     let mut instance = Box::pin({
         let run_instance = run_instance::<A, E, C>(
@@ -141,7 +143,8 @@ where
             runtime,
             proxy,
             debug,
-            receiver,
+            event_receiver,
+            control_sender,
             context,
             init_command,
             settings.exit_on_close_request,
@@ -179,14 +182,20 @@ where
         };
 
         if let Some(event) = event {
-            sender.start_send(event).expect("Send event");
+            event_sender.start_send(event).expect("Send event");
 
             let poll = instance.as_mut().poll(&mut context);
 
-            *control_flow = match poll {
-                task::Poll::Pending => ControlFlow::Wait,
-                task::Poll::Ready(_) => ControlFlow::Exit,
-            };
+            match poll {
+                task::Poll::Pending => {
+                    if let Ok(Some(flow)) = control_receiver.try_next() {
+                        *control_flow = flow;
+                    }
+                }
+                task::Poll::Ready(_) => {
+                    *control_flow = ControlFlow::Exit;
+                }
+            }
         }
     });
 
@@ -200,7 +209,10 @@ async fn run_instance<A, E, C>(
     mut runtime: Runtime<E, Proxy<A::Message>, A::Message>,
     mut proxy: glutin::event_loop::EventLoopProxy<A::Message>,
     mut debug: Debug,
-    mut receiver: mpsc::UnboundedReceiver<glutin::event::Event<'_, A::Message>>,
+    mut event_receiver: mpsc::UnboundedReceiver<
+        glutin::event::Event<'_, A::Message>,
+    >,
+    mut control_sender: mpsc::UnboundedSender<glutin::event_loop::ControlFlow>,
     mut context: glutin::ContextWrapper<glutin::PossiblyCurrent, Window>,
     init_command: Command<A::Message>,
     exit_on_close_request: bool,
@@ -211,6 +223,7 @@ async fn run_instance<A, E, C>(
     <A::Renderer as iced_native::Renderer>::Theme: StyleSheet,
 {
     use glutin::event;
+    use glutin::event_loop::ControlFlow;
     use iced_winit::futures::stream::StreamExt;
 
     let mut clipboard = Clipboard::connect(context.window());
@@ -247,13 +260,22 @@ async fn run_instance<A, E, C>(
     let mut mouse_interaction = mouse::Interaction::default();
     let mut events = Vec::new();
     let mut messages = Vec::new();
+    let mut redraw_pending = false;
 
     debug.startup_finished();
 
-    while let Some(event) = receiver.next().await {
+    while let Some(event) = event_receiver.next().await {
         match event {
+            event::Event::NewEvents(start_cause) => {
+                redraw_pending = matches!(
+                    start_cause,
+                    event::StartCause::Init
+                        | event::StartCause::Poll
+                        | event::StartCause::ResumeTimeReached { .. }
+                );
+            }
             event::Event::MainEventsCleared => {
-                if events.is_empty() && messages.is_empty() {
+                if !redraw_pending && events.is_empty() && messages.is_empty() {
                     continue;
                 }
 
@@ -315,6 +337,23 @@ async fn run_instance<A, E, C>(
                     }
                 }
 
+                // TODO: Avoid redrawing all the time by forcing widgets to
+                // request redraws on state changes
+                //
+                // Then, we can use the `interface_state` here to decide if a redraw
+                // is needed right away, or simply wait until a specific time.
+                let redraw_event = Event::Window(
+                    crate::window::Event::RedrawRequested(Instant::now()),
+                );
+
+                let (interface_state, _) = user_interface.update(
+                    &[redraw_event.clone()],
+                    state.cursor_position(),
+                    &mut renderer,
+                    &mut clipboard,
+                    &mut messages,
+                );
+
                 debug.draw_started();
                 let new_mouse_interaction = user_interface.draw(
                     &mut renderer,
@@ -335,6 +374,24 @@ async fn run_instance<A, E, C>(
                 }
 
                 context.window().request_redraw();
+                runtime
+                    .broadcast((redraw_event, crate::event::Status::Ignored));
+
+                let _ = control_sender.start_send(match interface_state {
+                    user_interface::State::Updated {
+                        redraw_request: Some(redraw_request),
+                    } => match redraw_request {
+                        crate::window::RedrawRequest::NextFrame => {
+                            ControlFlow::Poll
+                        }
+                        crate::window::RedrawRequest::At(at) => {
+                            ControlFlow::WaitUntil(at)
+                        }
+                    },
+                    _ => ControlFlow::Wait,
+                });
+
+                redraw_pending = false;
             }
             event::Event::PlatformSpecific(event::PlatformSpecific::MacOS(
                 event::MacOS::ReceivedUrl(url),

native/src/renderer.rs

@@ -36,11 +36,11 @@ pub trait Renderer: Sized {
         f: impl FnOnce(&mut Self),
     );
 
-    /// Clears all of the recorded primitives in the [`Renderer`].
-    fn clear(&mut self);
-
     /// Fills a [`Quad`] with the provided [`Background`].
     fn fill_quad(&mut self, quad: Quad, background: impl Into<Background>);
+
+    /// Clears all of the recorded primitives in the [`Renderer`].
+    fn clear(&mut self);
 }
 
 /// A polygon with four sides.