pub trait Theme<DS: DrawSharedImpl>: ThemeControl {
type Config: ThemeConfig;
type Window: Window;
type Draw<'a>: ThemeDraw
where DS: 'a,
Self: 'a;
// Required methods
fn config(&self) -> Cow<'_, Self::Config>;
fn apply_config(&mut self, config: &Self::Config) -> Action;
fn init(&mut self, shared: &mut SharedState<DS>);
fn new_window(&self, dpi_factor: f32) -> Self::Window;
fn update_window(&self, window: &mut Self::Window, dpi_factor: f32);
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;
}Expand description
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§
sourcetype Config: ThemeConfig
type Config: ThemeConfig
The associated config type
Required Methods§
sourcefn apply_config(&mut self, config: &Self::Config) -> Action
fn apply_config(&mut self, config: &Self::Config) -> Action
Apply/set the passed config
sourcefn init(&mut self, shared: &mut SharedState<DS>)
fn init(&mut self, shared: &mut SharedState<DS>)
Theme initialisation
The toolkit must call this method before Theme::new_window
to allow initialisation specific to the DrawIface.
At a minimum, a theme must load a font to crate::text::fonts.
The first font loaded (by any theme) becomes the default font.
sourcefn new_window(&self, dpi_factor: f32) -> Self::Window
fn new_window(&self, dpi_factor: f32) -> Self::Window
Construct per-window storage
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.
sourcefn update_window(&self, window: &mut Self::Window, dpi_factor: f32)
fn update_window(&self, window: &mut Self::Window, dpi_factor: f32)
Update a window created by Theme::new_window
This is called when the DPI factor changes or theme dimensions change.
sourcefn draw<'a>(
&'a self,
draw: DrawIface<'a, DS>,
ev: &'a mut EventState,
window: &'a mut Self::Window
) -> Self::Draw<'a>
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.
sourcefn draw_upcast<'a>(
draw: DrawIface<'a, DS>,
ev: &'a mut EventState,
w: &'a mut Self::Window,
cols: &'a ColorsLinear
) -> 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>
Construct a draw object from parts
This method allows a “derived” theme to construct a draw object for the inherited theme.
sourcefn clear_color(&self) -> Rgba
fn clear_color(&self) -> Rgba
The window/scene clear color
This is not used when the window is transparent.