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Handling User Input

User Events in Widgets​

All widgets possess member variables for the user events they provide, following the naming conventions of the DOM in JavaScript. For instance, on_click handles clicks on a button.

These events are easily handled by setting these variables with a callback function. These events are of type Box<Fn() -> Box<Message>>. When the event occurs, the callback function is invoked, and the returned message is propagated to the application.

The example below demonstrates a back button that changes the route to Home.

IconButton::new("back_icon").on_click(Box::new(|| msg!(Message::ChangePage {
  page: crate::gui::Pages::Home
})));

User Events in Components​

User input events are handled differently in Components compared to Widgets. The Component trait contains functions for user input, sharing the same names as widget events. These functions are called when the corresponding events are received.

impl Component for BackButton {

  ... 

  fn on_click(&mut self, event: &mut event::Event<event::Click>) {
      event.emit(msg!(Message::ChangePage {
        page: crate::gui::Pages::Home
      }));
  }
}