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use super::*;
/// A node that can fix its child's width and height.
#[derive(Debug, Clone, PartialEq)]
pub struct FixedNode {
/// The fixed width, if any.
pub width: Option<Linear>,
/// The fixed height, if any.
pub height: Option<Linear>,
/// The fixed aspect ratio between width and height, if any.
///
/// The resulting frame will satisfy `width = aspect * height`.
pub aspect: Option<f64>,
/// The child node whose size to fix.
pub child: AnyNode,
}
impl Layout for FixedNode {
fn layout(&self, ctx: &mut LayoutContext, areas: &Areas) -> Vec<Frame> {
let Areas { current, full, .. } = areas;
let full = Size::new(
self.width.map(|w| w.resolve(full.width)).unwrap_or(current.width),
self.height.map(|h| h.resolve(full.height)).unwrap_or(current.height),
);
let mut size = full;
if let Some(aspect) = self.aspect {
// Shrink the size to ensure that the aspect ratio can be satisfied.
let width = size.width.min(aspect * size.height);
size = Size::new(width, width / aspect);
}
let fill_if = |cond| if cond { Expand::Fill } else { Expand::Fit };
let expand = Spec::new(
fill_if(self.width.is_some()),
fill_if(self.height.is_some()),
);
let areas = Areas::once(size, full, expand).with_aspect(self.aspect);
self.child.layout(ctx, &areas)
}
}
impl From<FixedNode> for AnyNode {
fn from(fixed: FixedNode) -> Self {
Self::new(fixed)
}
}
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