summaryrefslogtreecommitdiffstats
path: root/graphics/src/widget/canvas/cache.rs
diff options
context:
space:
mode:
Diffstat (limited to 'graphics/src/widget/canvas/cache.rs')
-rw-r--r--graphics/src/widget/canvas/cache.rs97
1 files changed, 0 insertions, 97 deletions
diff --git a/graphics/src/widget/canvas/cache.rs b/graphics/src/widget/canvas/cache.rs
deleted file mode 100644
index 678b0f92..00000000
--- a/graphics/src/widget/canvas/cache.rs
+++ /dev/null
@@ -1,97 +0,0 @@
-use crate::widget::canvas::{Frame, Geometry};
-use crate::Primitive;
-
-use iced_native::Size;
-use std::{cell::RefCell, sync::Arc};
-
-#[derive(Default)]
-enum State {
- #[default]
- Empty,
- Filled {
- bounds: Size,
- primitive: Arc<Primitive>,
- },
-}
-
-/// 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(),
- }
- }
-}