Trait Theme 

pub trait Theme<DS: DrawSharedImpl> {
    type Window: Window;
    type Draw<'a>: ThemeDraw
       where DS: 'a,
             Self: 'a;

    // Required methods
    fn init(&mut self, config: &RefCell<Config>);
    fn new_window(&mut self, config: &WindowConfig) -> Self::Window;
    fn update_window(
        &mut self,
        window: &mut Self::Window,
        config: &WindowConfig,
    );
    fn draw<'a>(
        &'a self,
        draw: DrawIface<'a, DS>,
        ev: &'a mut EventState,
        window: &'a mut Self::Window,
    ) -> Self::Draw<'a>;
    fn draw_upcast<'a>(
        draw: DrawIface<'a, DS>,
        ev: &'a mut EventState,
        w: &'a mut Self::Window,
        cols: &'a ColorsLinear,
    ) -> Self::Draw<'a>;
    fn clear_color(&self) -> Rgba;
}

A theme provides widget sizing and drawing implementations.

The theme is generic over some DrawIface.

Objects of this type are copied within each window’s data structure. For large resources (e.g. fonts and icons) consider using external storage.

Required Associated Types

type Window: Window

The associated Window implementation.

type Draw<'a>: ThemeDraw where DS: 'a, Self: 'a

The associated [ThemeDraw] implementation.

Required Methods

fn init(&mut self, config: &RefCell<Config>)

Theme initialisation

The toolkit must call this method before Theme::new_window to allow initialisation specific to the DrawIface.

fn new_window(&mut self, config: &WindowConfig) -> Self::Window

Construct per-window storage

Updates theme from configuration and constructs a scaled per-window size cache.

On “standard” monitors, the dpi_factor is 1. High-DPI screens may have a factor of 2 or higher. The factor may not be an integer; e.g. 9/8 = 1.125 works well with many 1440p screens. It is recommended to round dimensions to the nearest integer, and cache the result:

self.margin = i32::conv_nearest(MARGIN * factor);

A reference to the draw backend is provided allowing configuration.

fn update_window(&mut self, window: &mut Self::Window, config: &WindowConfig)

Update a window created by Theme::new_window

This is called when the DPI factor changes or theme config or dimensions change.

fn draw<'a>( &'a self, draw: DrawIface<'a, DS>, ev: &'a mut EventState, window: &'a mut Self::Window, ) -> Self::Draw<'a>

Prepare to draw and construct a [ThemeDraw] object

This is called once per window per frame and should do any necessary preparation such as loading fonts and textures which are loaded on demand.

Drawing via this [ThemeDraw] object is restricted to the specified rect.

The window is guaranteed to be one created by a call to Theme::new_window on self.

fn draw_upcast<'a>( draw: DrawIface<'a, DS>, ev: &'a mut EventState, w: &'a mut Self::Window, cols: &'a ColorsLinear, ) -> Self::Draw<'a>

Construct a draw object from parts

This method allows a “derived” theme to construct a draw object for the inherited theme.

fn clear_color(&self) -> Rgba

The window/scene clear color

This is not used when the window is transparent.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<T: Theme<DS> + ?Sized, DS: DrawSharedImpl> Theme<DS> for Box<T>

type Window = <T as Theme<DS>>::Window

type Draw<'a> = <T as Theme<DS>>::Draw<'a> where DS: 'a, Self: 'a

fn init(&mut self, config: &RefCell<Config>)

fn new_window(&mut self, config: &WindowConfig) -> Self::Window

fn update_window(&mut self, window: &mut Self::Window, config: &WindowConfig)

fn draw<'a>( &'a self, draw: DrawIface<'a, DS>, ev: &'a mut EventState, window: &'a mut Self::Window, ) -> Self::Draw<'a>

fn draw_upcast<'a>( draw: DrawIface<'a, DS>, ev: &'a mut EventState, w: &'a mut Self::Window, cols: &'a ColorsLinear, ) -> Self::Draw<'a>

fn clear_color(&self) -> Rgba

Implementors

impl<DS: DrawSharedImpl> Theme<DS> for FlatTheme

where DS::Draw: DrawRoundedImpl,

type Window = Window<<DS as DrawSharedImpl>::Draw>

type Draw<'a> = DrawHandle<'a, DS>

impl<DS: DrawSharedImpl> Theme<DS> for MultiTheme<DS>

type Window = Box<dyn Window>

type Draw<'a> = Box<dyn ThemeDraw + 'a>

impl<DS: DrawSharedImpl> Theme<DS> for SimpleTheme

where DS::Draw: DrawRoundedImpl,

type Window = Window<<DS as DrawSharedImpl>::Draw>

type Draw<'a> = DrawHandle<'a, DS>