tawasuyu/taffy

1//! Final and cached data structures that represent the high-level UI layout
2
3use crate::geometry::{Point, Size};
4
5/// The final result of a layout algorithm for a single [`Node`](crate::node::Node).
6#[derive(Copy, Debug, Clone)]
7pub struct Layout {
8    /// The relative ordering of the node
9    ///
10    /// Nodes with a higher order should be rendered on top of those with a lower order.
11    /// This is effectively a topological sort of each tree.
12    pub order: u32,
13    /// The width and height of the node
14    pub size: Size<f32>,
15    /// The bottom-left corner of the node
16    pub location: Point<f32>,
17}
18
19impl Layout {
20    /// Creates a new zero-[`Layout`].
21    ///
22    /// The Zero-layout has size and location set to ZERO.
23    /// The `order` value of this layout is set to the minimum value of 0.
24    /// This means it should be rendered below all other [`Layout`]s.
25    #[must_use]
26    pub const fn new() -> Self {
27        Self { order: 0, size: Size::ZERO, location: Point::ZERO }
28    }
29
30    /// Creates a new zero-[`Layout`] with the supplied `order` value.
31    ///
32    /// Nodes with a higher order should be rendered on top of those with a lower order.
33    /// The Zero-layout has size and location set to ZERO.
34    #[must_use]
35    pub const fn with_order(order: u32) -> Self {
36        Self { order, size: Size::ZERO, location: Point::ZERO }
37    }
38}
39
40/// Cached intermediate layout results
41#[derive(Debug, Clone)]
42pub(crate) struct Cache {
43    /// The initial cached size of the node itself
44    pub(crate) node_size: Size<Option<f32>>,
45    /// The initial cached size of the parent's node
46    pub(crate) parent_size: Size<Option<f32>>,
47    /// Whether or not layout should be recomputed
48    pub(crate) perform_layout: bool,
49
50    /// The cached size of the item
51    pub(crate) size: Size<f32>,
52}