Trait Widget 

pub trait Widget {
    // Required methods
    fn measure(&self, constraints: &Constraints) -> Size;
    fn layout(&mut self, size: Size);
    fn paint(&self, canvas: &mut dyn Canvas);
}

Widget trait - measure/layout/paint cycle

Required Methods

fn measure(&self, constraints: &Constraints) -> Size

Measure desired size given constraints

fn layout(&mut self, size: Size)

Layout with allocated size

fn paint(&self, canvas: &mut dyn Canvas)

Paint to canvas

Dyn Compatibility

This trait is dyn compatible.

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

Implementors