Fix caching of display:none nodes (backport of #454) (#456)

src/compute/mod.rs

@@ -371,6 +371,9 @@ fn perform_hidden_layout(tree: &mut impl LayoutTree, node: Node) {
  /// Recursive function to apply hidden layout to all descendents
  fn perform_hidden_layout_inner(tree: &mut impl LayoutTree, node: Node, order: u32) {
  *tree.layout_mut(node) = Layout::with_order(order);
+ for i in 0..7 {
+ *tree.cache_mut(node, i) = None;
+ }
  for order in 0..tree.child_count(node) {
  perform_hidden_layout_inner(tree, tree.child(node, order), order as _);
  }

tests/relayout.rs

@@ -101,6 +101,41 @@ fn toggle_root_display_none() {
  assert_eq!(layout.size.height, 0.0);
 }
 
+#[test]
+fn toggle_root_display_none_with_children() {
+ use taffy::prelude::*;
+
+ let mut taffy = taffy::Taffy::new();
+
+ let child = taffy
+ .new_leaf(Style { size: Size { width: points(800.0), height: points(100.0) }, ..Default::default() })
+ .unwrap();
+
+ let parent = taffy
+ .new_with_children(
+ Style { size: Size { width: points(800.0), height: points(100.0) }, ..Default::default() },
+ &[child],
+ )
+ .unwrap();
+
+ let root = taffy.new_with_children(Style::default(), &[parent]).unwrap();
+ taffy.compute_layout(root, Size::MAX_CONTENT).unwrap();
+ assert_eq!(taffy.layout(child).unwrap().size.width, 800.0);
+ assert_eq!(taffy.layout(child).unwrap().size.height, 100.0);
+
+ taffy.set_style(root, Style { display: Display::None, ..Default::default() }).unwrap();
+ taffy.compute_layout(root, Size::MAX_CONTENT).unwrap();
+ assert_eq!(taffy.layout(child).unwrap().size.width, 0.0);
+ assert_eq!(taffy.layout(child).unwrap().size.height, 0.0);
+
+ taffy.set_style(root, Style::default()).unwrap();
+ taffy.compute_layout(root, Size::MAX_CONTENT).unwrap();
+ assert_eq!(taffy.layout(parent).unwrap().size.width, 800.0);
+ assert_eq!(taffy.layout(parent).unwrap().size.height, 100.0);
+ assert_eq!(taffy.layout(child).unwrap().size.width, 800.0);
+ assert_eq!(taffy.layout(child).unwrap().size.height, 100.0);
+}
+
 #[test]
 fn toggle_flex_child_display_none() {
  let hidden_style = Style {