Trait kas_theme::Theme [−][src]
pub trait Theme<DS: DrawSharedImpl>: ThemeApi {
type Config: ThemeConfig;
type Window: Window;
type DrawHandle: DrawHandle;
fn config(&self) -> Cow<'_, Self::Config>;
fn apply_config(&mut self, config: &Self::Config) -> TkAction;
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);
unsafe fn draw_handle(
&self,
draw: DrawIface<'_, DS>,
window: &mut Self::Window
) -> Self::DrawHandle;
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.
Associated Types
type Config: ThemeConfig
type Config: ThemeConfig
The associated config type
type DrawHandle: DrawHandle
type DrawHandle: DrawHandle
The associated DrawHandle
implementation.
Required methods
fn apply_config(&mut self, config: &Self::Config) -> TkAction
fn apply_config(&mut self, config: &Self::Config) -> TkAction
Apply/set the passed config
fn 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 [kas::text::fonts
].
The first font loaded (by any theme) becomes the default font.
fn 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.
fn 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.
unsafe fn draw_handle(
&self,
draw: DrawIface<'_, DS>,
window: &mut Self::Window
) -> Self::DrawHandle
unsafe fn draw_handle(
&self,
draw: DrawIface<'_, DS>,
window: &mut Self::Window
) -> Self::DrawHandle
Prepare to draw and construct a DrawHandle
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 DrawHandle
is restricted to the specified rect
.
The window
is guaranteed to be one created by a call to
Theme::new_window
on self
, and the draw
reference is guaranteed
to be identical to the one passed to Theme::new_window
.
Safety
(This section only applies when not using the gat
feature.)
All references passed into the method must outlive the returned object.
fn clear_color(&self) -> Rgba
fn clear_color(&self) -> Rgba
Background colour