logo

Trait embedded_graphics::Drawable

source · [−]
pub trait Drawable {
    type Color: PixelColor;
    type Output;
    fn draw<D>(
        &self, 
        target: &mut D
    ) -> Result<Self::Output, <D as DrawTarget>::Error>
    where
        D: DrawTarget<Color = Self::Color>;
}
Expand description

Marks an object as “drawable”. Must be implemented for all graphics objects

The Drawable trait describes how a particular graphical object is drawn. A Drawable object can define its draw method as a collection of graphical primitives or as an iterator over pixels being rendered with DrawTarget’s draw_iter method.

use embedded_graphics::{
    mono_font::{ascii::FONT_6X9, MonoTextStyle},
    pixelcolor::{BinaryColor, PixelColor, Rgb888},
    prelude::*,
    primitives::{Rectangle, PrimitiveStyle},
    text::Text,
};

struct Button<'a, C: PixelColor> {
    top_left: Point,
    size: Size,
    bg_color: C,
    fg_color: C,
    text: &'a str,
}

impl<C> Drawable for Button<'_, C>
where
    C: PixelColor + From<BinaryColor>,
{
    type Color = C;
    type Output = ();

    fn draw<D>(&self, target: &mut D) -> Result<Self::Output, D::Error>
    where
        D: DrawTarget<Color = C>,
    {
        Rectangle::new(self.top_left, self.size)
            .into_styled(PrimitiveStyle::with_fill(self.bg_color))
            .draw(target)?;

        let style = MonoTextStyle::new(&FONT_6X9, self.fg_color);

        Text::new(self.text, Point::new(6, 13), style).draw(target)?;

        Ok(())
    }
}

let mut button = Button {
    top_left: Point::zero(),
    size: Size::new(60, 20),
    bg_color: Rgb888::RED,
    fg_color: Rgb888::BLUE,
    text: "Click me!",
};

button.draw(&mut display)?;

Associated Types

The pixel color type.

The return type of the draw method.

The Output type can be used to return results and values produced from the drawing of the current item. For example, rendering two differently styled text items next to each other can make use of a returned value, allowing the next text to be positioned after the first:

use embedded_graphics::{
    mono_font::{
        ascii::{FONT_10X20, FONT_6X10},
        MonoTextStyle,
    },
    pixelcolor::BinaryColor,
    prelude::*,
    text::Text,
};

let label_style = MonoTextStyle::new(&FONT_6X10, BinaryColor::On);
let value_style = MonoTextStyle::new(&FONT_10X20, BinaryColor::On);

let next_point = Text::new("Label ", Point::new(10, 20), label_style)
    .draw(&mut display)?;

Text::new("1234", next_point, value_style).draw(&mut display)?;

Use () if no value should be returned.

Required methods

Draw the graphics object using the supplied DrawTarget.

Implementors