Function cosmic::iced_widget::canvas
source · pub fn canvas<P, Message, Theme, Renderer>(
program: P,
) -> Canvas<P, Message, Theme, Renderer>
Expand description
Creates a new Canvas
.
Canvases can be leveraged to draw interactive 2D graphics.
§Example: Drawing a Simple Circle
use iced::mouse;
use iced::widget::canvas;
use iced::{Color, Rectangle, Renderer, Theme};
// First, we define the data we need for drawing
#[derive(Debug)]
struct Circle {
radius: f32,
}
// Then, we implement the `Program` trait
impl<Message> canvas::Program<Message> for Circle {
// No internal state
type State = ();
fn draw(
&self,
_state: &(),
renderer: &Renderer,
_theme: &Theme,
bounds: Rectangle,
_cursor: mouse::Cursor
) -> Vec<canvas::Geometry> {
// We prepare a new `Frame`
let mut frame = canvas::Frame::new(renderer, bounds.size());
// We create a `Path` representing a simple circle
let circle = canvas::Path::circle(frame.center(), self.radius);
// And fill it with some color
frame.fill(&circle, Color::BLACK);
// Then, we produce the geometry
vec![frame.into_geometry()]
}
}
// Finally, we simply use our `Circle` to create the `Canvas`!
fn view<'a, Message: 'a>(_state: &'a State) -> Element<'a, Message> {
canvas(Circle { radius: 50.0 }).into()
}