diff options
Diffstat (limited to 'graphics/src/widget/canvas/cache.rs')
-rw-r--r-- | graphics/src/widget/canvas/cache.rs | 100 |
1 files changed, 0 insertions, 100 deletions
diff --git a/graphics/src/widget/canvas/cache.rs b/graphics/src/widget/canvas/cache.rs deleted file mode 100644 index 52217bbb..00000000 --- a/graphics/src/widget/canvas/cache.rs +++ /dev/null @@ -1,100 +0,0 @@ -use crate::widget::canvas::{Frame, Geometry}; -use crate::Primitive; - -use iced_native::Size; -use std::{cell::RefCell, sync::Arc}; - -enum State { - Empty, - Filled { - bounds: Size, - primitive: Arc<Primitive>, - }, -} - -impl Default for State { - fn default() -> Self { - State::Empty - } -} -/// 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. -#[derive(Debug, Default)] -pub struct Cache { - state: RefCell<State>, -} - -impl Cache { - /// Creates a new empty [`Cache`]. - pub fn new() -> Self { - Cache { - state: Default::default(), - } - } - - /// Clears the [`Cache`], forcing a redraw the next time it is used. - pub fn clear(&self) { - *self.state.borrow_mut() = State::Empty; - } - - /// 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. - pub fn draw( - &self, - bounds: Size, - draw_fn: impl FnOnce(&mut Frame), - ) -> Geometry { - use std::ops::Deref; - - if let State::Filled { - bounds: cached_bounds, - primitive, - } = self.state.borrow().deref() - { - if *cached_bounds == bounds { - return Geometry::from_primitive(Primitive::Cached { - cache: primitive.clone(), - }); - } - } - - let mut frame = Frame::new(bounds); - draw_fn(&mut frame); - - let primitive = { - let geometry = frame.into_geometry(); - - Arc::new(geometry.into_primitive()) - }; - - *self.state.borrow_mut() = State::Filled { - bounds, - primitive: primitive.clone(), - }; - - Geometry::from_primitive(Primitive::Cached { cache: primitive }) - } -} - -impl std::fmt::Debug for State { - fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { - match self { - State::Empty => write!(f, "Empty"), - State::Filled { primitive, bounds } => f - .debug_struct("Filled") - .field("primitive", primitive) - .field("bounds", bounds) - .finish(), - } - } -} |