//! Write your own renderer. //! //! You will need to implement the `Renderer` trait first. It simply contains //! an `Output` associated type. //! //! There is no common trait to draw all the widgets. Instead, every [`Widget`] //! constrains its generic `Renderer` type as necessary. //! //! This approach is flexible and composable. For instance, the //! [`Text`] widget only needs a [`text::Renderer`] while a [`Checkbox`] widget //! needs both a [`text::Renderer`] and a [`checkbox::Renderer`], reusing logic. //! //! In the end, a __renderer__ satisfying all the constraints is //! needed to build a [`UserInterface`]. //! //! [`Widget`]: ../widget/trait.Widget.html //! [`UserInterface`]: ../struct.UserInterface.html //! [`Text`]: ../widget/text/struct.Text.html //! [`text::Renderer`]: ../widget/text/trait.Renderer.html //! [`Checkbox`]: ../widget/checkbox/struct.Checkbox.html //! [`checkbox::Renderer`]: ../widget/checkbox/trait.Renderer.html mod debugger; mod windowed; pub use debugger::Debugger; pub use windowed::{Target, Windowed}; use crate::{layout, Element}; pub trait Renderer: Sized { type Output; fn layout<'a, Message>( &mut self, element: &Element<'a, Message, Self>, ) -> layout::Node { element.layout(self, &layout::Limits::NONE) } }