Struct Sender

pub struct Sender<T>(/* private fields */);

A Relm4 sender sends messages to a component or worker.

Implementations

impl<T> Sender<T>

pub fn emit(&self, message: T)

Sends a message through the channel.

This method ignores errors. Only a log message will appear when sending fails.

pub fn send(&self, message: T) -> Result<(), T>

Sends a message through the channel.

If all receivers where dropped, Err is returned with the content of the message.

Examples found in repository

examples/drawing.rs (line 134)

    fn init(
        _: Self::Init,
        root: Self::Root,
        sender: ComponentSender<Self>,
    ) -> ComponentParts<Self> {
        let model = App {
            width: 100.0,
            height: 100.0,
            points: Vec::new(),
            handler: DrawHandler::new(),
        };

        let area = model.handler.drawing_area();
        let widgets = view_output!();

        sender.command(|out, shutdown| {
            shutdown
                .register(async move {
                    loop {
                        tokio::time::sleep(Duration::from_millis(20)).await;
                        out.send(UpdatePointsMsg).unwrap();
                    }
                })
                .drop_on_shutdown()
        });

        ComponentParts { model, widgets }
    }

examples/progress.rs (line 131)

    fn update(&mut self, message: Self::Input, sender: ComponentSender<Self>, _root: &Self::Root) {
        match message {
            Input::Compute => {
                self.computing = true;
                sender.command(|out, shutdown| {
                    shutdown
                        // Performs this operation until a shutdown is triggered
                        .register(async move {
                            let mut progress = 0.0;

                            while progress < 1.0 {
                                out.send(CmdOut::Progress(progress)).unwrap();
                                progress += 0.1;
                                tokio::time::sleep(std::time::Duration::from_millis(333)).await;
                            }

                            out.send(CmdOut::Finished(Ok("42".into()))).unwrap();
                        })
                        // Perform task until a shutdown interrupts it
                        .drop_on_shutdown()
                        // Wrap into a `Pin<Box<Future>>` for return
                        .boxed()
                });
            }
        }
    }

examples/tab_game.rs (line 262)

    fn update(&mut self, msg: Self::Input, sender: ComponentSender<Self>, _root: &Self::Root) {
        match msg {
            AppMsg::StartGame(index) => {
                self.start_index = Some(index);
                sender.command(|sender, _| async move {
                    for i in (1..4).rev() {
                        *GAME_STATE.write() = GameState::Countdown(i);
                        relm4::tokio::time::sleep(Duration::from_millis(1000)).await;
                    }
                    *GAME_STATE.write() = GameState::Running;
                    for _ in 0..20 {
                        relm4::tokio::time::sleep(Duration::from_millis(500)).await;
                        sender.send(false).unwrap();
                    }
                    relm4::tokio::time::sleep(Duration::from_millis(1000)).await;
                    sender.send(true).unwrap();
                });
            }
            AppMsg::StopGame => {
                *GAME_STATE.write() = GameState::Guessing;
            }
            AppMsg::SelectedGuess(index) => {
                *GAME_STATE.write() = GameState::End(index == self.start_index.take().unwrap());
            }
        }
    }

examples/settings_list.rs (line 37)

fn main() {
    gtk::Application::builder()
        .application_id("org.relm4.SettingsListExample")
        .launch(|_app, window| {
            // Initialize a component's root widget
            let mut component = App::builder()
                // Attach the root widget to the given window.
                .attach_to(&window)
                // Start the component service with an initial parameter
                .launch("Settings List Demo".into())
                // Attach the returned receiver's messages to this closure.
                .connect_receiver(move |sender, message| match message {
                    Output::Clicked(id) => {
                        eprintln!("ID {id} Clicked");

                        match id {
                            0 => xdg_open("https://github.com/Relm4/Relm4".into()),
                            1 => xdg_open("https://docs.rs/relm4/".into()),
                            2 => {
                                sender.send(Input::Clear).unwrap();
                            }
                            _ => (),
                        }
                    }

                    Output::Reload => {
                        sender
                            .send(Input::AddSetting {
                                description: "Browse GitHub Repository".into(),
                                button: "GitHub".into(),
                                id: 0,
                            })
                            .unwrap();

                        sender
                            .send(Input::AddSetting {
                                description: "Browse Documentation".into(),
                                button: "Docs".into(),
                                id: 1,
                            })
                            .unwrap();

                        sender
                            .send(Input::AddSetting {
                                description: "Clear List".into(),
                                button: "Clear".into(),
                                id: 2,
                            })
                            .unwrap();
                    }
                });

            // Keep runtime alive after the component is dropped
            component.detach_runtime();

            println!("parent is {:?}", component.widget().toplevel_window());
        });
}

Trait Implementations

impl<T> Clone for Sender<T>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for Sender<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> From<Sender<T>> for Sender<T>

fn from(sender: Sender<T>) -> Self

Converts to this type from the input type.