Trait embedded_graphics::text::renderer::TextRenderer

pub trait TextRenderer {
    type Color: PixelColor;
    fn draw_string<D>(
        &self, 
        text: &str, 
        position: Point, 
        baseline: Baseline, 
        target: &mut D
    ) -> Result<Point, D::Error>
    where
        D: DrawTarget<Color = Self::Color>;
    fn draw_whitespace<D>(
        &self, 
        width: u32, 
        position: Point, 
        baseline: Baseline, 
        target: &mut D
    ) -> Result<Point, D::Error>
    where
        D: DrawTarget<Color = Self::Color>;
    fn measure_string(
        &self, 
        text: &str, 
        position: Point, 
        baseline: Baseline
    ) -> TextMetrics;
    fn line_height(&self) -> u32;
}

Text renderer.

The TextRenderer trait is used to integrate text renderers into embedded-graphics. Users should not call it directly and instead use the functions provided by the Text type.

Associated Types

type Color: PixelColor

Color type.

Required methods

fn draw_string<D>(
    &self,
    text: &str,
    position: Point,
    baseline: Baseline,
    target: &mut D
) -> Result<Point, D::Error> where
    D: DrawTarget<Color = Self::Color>, 

Draws a string.

The method returns the start position of the next character to allow chaining of multiple draw calls.

Implementation notes

This method must not interpret any control characters and only render a single line of text. Any control character in the text should be handled the same way as any other character that isn’t included in the font.

fn draw_whitespace<D>(
    &self,
    width: u32,
    position: Point,
    baseline: Baseline,
    target: &mut D
) -> Result<Point, D::Error> where
    D: DrawTarget<Color = Self::Color>, 

Draws whitespace of the given width.

The method returns the start position of the next character to allow chaining of multiple draw calls.

fn measure_string(
    &self,
    text: &str,
    position: Point,
    baseline: Baseline
) -> TextMetrics

Returns the text metrics for a string.

Implementation notes

The returned bounding box must be independent of the text color. This is different to the Dimensions trait, which should return a zero sized bounding box for completely transparent drawables. But this behavior would make it impossible to correctly layout text which contains a mixture of transparent and non transparent words.

This method must not interpret any control characters and only render a single line of text. Any control character in the text should be handled the same way as any other character that isn’t included in the font.

fn line_height(&self) -> u32

Returns the default line height.

The line height is defined as the vertical distance between the baseline of two adjacent lines in pixels.

Implementors

impl<C: PixelColor> TextRenderer for MonoTextStyle<'_, C>

type Color = C

fn draw_string<D>(
    &self,
    text: &str,
    position: Point,
    baseline: Baseline,
    target: &mut D
) -> Result<Point, D::Error> where
    D: DrawTarget<Color = Self::Color>, 

fn draw_whitespace<D>(
    &self,
    width: u32,
    position: Point,
    baseline: Baseline,
    target: &mut D
) -> Result<Point, D::Error> where
    D: DrawTarget<Color = Self::Color>, 

fn measure_string(
    &self,
    text: &str,
    position: Point,
    baseline: Baseline
) -> TextMetrics

fn line_height(&self) -> u32