Trait ViewModel 

pub trait ViewModel: Send + 'static {
    // Provided methods
    fn on_open(&mut self, cx: &mut Cx<'_, Self>)
       where Self: Sized { ... }
    fn on_close(&mut self, cx: &mut Cx<'_, Self>)
       where Self: Sized { ... }
    fn on_back(&mut self, cx: &mut Cx<'_, Self>) -> bool
       where Self: Sized { ... }
    fn customize(&self, root: &mut Widget) { ... }
}

A screen’s state and logic. Implement it (often with no methods) for the type named by the .yui file’s x:ViewModel.

All hooks run on the render thread with the screen locked; use Cx to close the screen, navigate, or get a ScreenHandle for updates from other threads.

Provided Methods

fn on_open(&mut self, cx: &mut Cx<'_, Self>)

where Self: Sized,

The screen was opened (every time).

fn on_close(&mut self, cx: &mut Cx<'_, Self>)

where Self: Sized,

The screen was closed (by any path).

fn on_back(&mut self, cx: &mut Cx<'_, Self>) -> bool

where Self: Sized,

Esc / back. Return true when handled; false (the default) goes back to the screen this one was navigated from, else closes it.

fn customize(&self, root: &mut Widget)

Escape hatch: imperative changes to the content tree after each binding update. Rarely needed.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors