Struct iced::widget::canvas::Cache

pub struct Cache { /* fields omitted */ }

This is supported on feature="canvas" or feature="glow_canvas" only.

A simple cache that stores generated Geometry to avoid recomputation.

A Cache will not redraw its geometry unless the dimensions of its layer change or it is explicitly cleared.

Implementations

impl Cache

pub fn new() -> Cache

This is supported on feature="canvas" or feature="glow_canvas" only.

Creates a new empty Cache.

pub fn clear(&mut self)

This is supported on feature="canvas" or feature="glow_canvas" only.

Clears the Cache, forcing a redraw the next time it is used.

pub fn draw(&self, bounds: Size<f32>, draw_fn: impl Fn(&mut Frame)) -> Geometry

This is supported on feature="canvas" or feature="glow_canvas" only.

Draws Geometry using the provided closure and stores it in the Cache.

The closure will only be called when

• the bounds have changed since the previous draw call.
• the Cache is empty or has been explicitly cleared.

Otherwise, the previously stored Geometry will be returned. The Cache is not cleared in this case. In other words, it will keep returning the stored Geometry if needed.

Trait Implementations

impl Debug for Cache

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for Cache

fn default() -> Cache

Returns the "default value" for a type.