iris-aiandClaude Opus 5
d98969158f
A widget's region is now held in the coordinates of the slot it draws in rather than the window's, and `Painter::place` is how a container asks for a slot: it draws a child it decides the box of and may decide again. Everything under that slot is a fraction of its box, so placing the child a second time is one entry to write whether it moved or changed length. A child drawn any other way has no slot and shares its nearest ancestor's. That is what keeps the chain short. `chain_cost` measured depth as the cost -- free to 8, +42.6% at 16 -- and a slot per widget put a transcript's glyphs past that for nothing, since almost every slot was zero. `Span`, `Aligned` and `Scroll` are the containers that re-place a child after drawing it, and `tests/layout.rs` pins that four widgets between a span and a leaf leave the leaf's chain one deep. `UiRegion::stretch`, `UiRegion::stretchable` and `UiScalar::stretch` are gone. Nothing is inverted any more: a box that changed length is written to its slot, and the descendants recompose against it in the shader. That also retires the case the guard existed for, where a fixed length has no fraction to recover -- `tests/layout.rs` now stretches a 40-tall row on its other axis, which `stretchable` refused outright. What still walks the CPU is deciding who must draw again, which no chain can answer: `mark_resized` descends from the widget whose box changed and marks anything whose own box changed length and whose drawing reads it. A part of a box with no relative extent on an axis is a fixed length, and composing into it leaves none either, so the walk stops where a length did not change -- an 80-wide child in a widened row is not redrawn though it says `Redraw`. `Span`, `Pad`, `Stack`, `Offset`, `Aligned`, `SetSize` and `LayerOffset` say `Scale`: each places in fractions and offsets of its own box and none reads the box's pixel length. `Scroll` and `MaxSize` do read pixels and stay `Redraw`. 45 tests pass, five of them new. Render verification comes after the CPU side, per the owner. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
29 lines
995 B
Rust
29 lines
995 B
Rust
use crate::prelude::*;
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pub struct Aligned {
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pub inner: StrongWidget,
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pub align: Align,
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}
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impl Widget for Aligned {
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fn draw(&mut self, painter: &mut Painter) -> Size {
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// Drawn where it may be too big, then given its aligned box once its
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// size is known.
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let size = painter.place(&self.inner, UiRegion::FULL).size();
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let region = match self.align.tuple() {
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(Some(x), Some(y)) => size.to_uivec2().align(RegionAlign { x, y }),
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(Some(x), None) => UiRegion::new(size.x.apply_rest().align(x), UiSpan::FULL),
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(None, Some(y)) => UiRegion::new(UiSpan::FULL, size.y.apply_rest().align(y)),
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(None, None) => UiRegion::FULL,
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};
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painter.place(&self.inner, region);
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size
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}
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/// The aligned box is a fraction of its own, so the child keeps its
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/// length and stays against the edge it was aligned to.
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fn on_resize(&self, _: Axis) -> OnResize {
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OnResize::Scale
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}
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}
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