Trait Context 

pub trait Context<B: Backend> {
    // Required methods
    fn pixel_format(&self) -> PixelFormat;
    fn path_builder(&self) -> Option<B::PathBuilder>;
    fn raster_builder(&self) -> Option<B::RasterBuilder>;
    fn new_image(&mut self, size: Size2D<u32>) -> B::Image;
    fn new_image_from_png<R: BufRead + Seek>(
        &mut self,
        reader: &mut Reader<R>,
    ) -> Result<B::Image, Error>;
    fn get_image(&mut self, image_index: u32) -> B::Image;
    fn get_current_image(&mut self, context: &ViewAssistantContext) -> B::Image;
    fn render_with_clip(
        &mut self,
        composition: &mut B::Composition,
        clip: Rect<u32>,
        image: B::Image,
        ext: &RenderExt<B>,
    );

    // Provided method
    fn render(
        &mut self,
        composition: &mut B::Composition,
        clip: Option<Rect<u32>>,
        image: B::Image,
        ext: &RenderExt<B>,
    ) { ... }
}

Rendering context and API start point.

Required Methods

fn pixel_format(&self) -> PixelFormat

Returns the context’s pixel format.

fn path_builder(&self) -> Option<B::PathBuilder>

Optionally returns a PathBuilder. May return None of old builder is still alive.

fn raster_builder(&self) -> Option<B::RasterBuilder>

Optionally returns a RasterBuilder. May return None of old builder is still alive.

fn new_image(&mut self, size: Size2D<u32>) -> B::Image

Creates a new image with size.

fn new_image_from_png<R: BufRead + Seek>( &mut self, reader: &mut Reader<R>, ) -> Result<B::Image, Error>

Creates a new image from PNG reader.

fn get_image(&mut self, image_index: u32) -> B::Image

Returns the image at image_index.

fn get_current_image(&mut self, context: &ViewAssistantContext) -> B::Image

Returns the context’s current image.

fn render_with_clip( &mut self, composition: &mut B::Composition, clip: Rect<u32>, image: B::Image, ext: &RenderExt<B>, )

Renders the composition with a clip to the image.

Provided Methods

fn render( &mut self, composition: &mut B::Composition, clip: Option<Rect<u32>>, image: B::Image, ext: &RenderExt<B>, )

Renders the composition with an optional clip to the image.

Dyn Compatibility

This trait is not dyn compatible.

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

Implementors

impl Context<Forma> for FormaContext