diff --git a/crates/bevy_ui/src/layout/debug.rs b/crates/bevy_ui/src/layout/debug.rs new file mode 100644 index 0000000000000..cc04b6d31033c --- /dev/null +++ b/crates/bevy_ui/src/layout/debug.rs @@ -0,0 +1,87 @@ +use crate::UiSurface; +use bevy_ecs::prelude::Entity; +use bevy_utils::HashMap; +use std::fmt::Write; +use taffy::prelude::Node; +use taffy::tree::LayoutTree; + +/// Prints a debug representation of the computed layout of the UI layout tree for each window. +pub fn print_ui_layout_tree(ui_surface: &UiSurface) { + let taffy_to_entity: HashMap = ui_surface + .entity_to_taffy + .iter() + .map(|(entity, node)| (*node, *entity)) + .collect(); + for (&entity, &node) in ui_surface.window_nodes.iter() { + let mut out = String::new(); + print_node( + ui_surface, + &taffy_to_entity, + entity, + node, + false, + String::new(), + &mut out, + ); + bevy_log::info!("Layout tree for window entity: {entity:?}\n{out}"); + } +} + +/// Recursively navigates the layout tree printing each node's information. +fn print_node( + ui_surface: &UiSurface, + taffy_to_entity: &HashMap, + entity: Entity, + node: Node, + has_sibling: bool, + lines_string: String, + acc: &mut String, +) { + let tree = &ui_surface.taffy; + let layout = tree.layout(node).unwrap(); + let style = tree.style(node).unwrap(); + + let num_children = tree.child_count(node).unwrap(); + + let display_variant = match (num_children, style.display) { + (_, taffy::style::Display::None) => "NONE", + (0, _) => "LEAF", + (_, taffy::style::Display::Flex) => "FLEX", + (_, taffy::style::Display::Grid) => "GRID", + }; + + let fork_string = if has_sibling { + "├── " + } else { + "└── " + }; + writeln!( + acc, + "{lines}{fork} {display} [x: {x:<4} y: {y:<4} width: {width:<4} height: {height:<4}] ({entity:?}) {measured}", + lines = lines_string, + fork = fork_string, + display = display_variant, + x = layout.location.x, + y = layout.location.y, + width = layout.size.width, + height = layout.size.height, + measured = if tree.needs_measure(node) { "measured" } else { "" } + ).ok(); + let bar = if has_sibling { "│ " } else { " " }; + let new_string = lines_string + bar; + + // Recurse into children + for (index, child_node) in tree.children(node).unwrap().iter().enumerate() { + let has_sibling = index < num_children - 1; + let child_entity = taffy_to_entity.get(child_node).unwrap(); + print_node( + ui_surface, + taffy_to_entity, + *child_entity, + *child_node, + has_sibling, + new_string.clone(), + acc, + ); + } +} diff --git a/crates/bevy_ui/src/layout/mod.rs b/crates/bevy_ui/src/layout/mod.rs index 75dc688f8b811..b1556515eb05c 100644 --- a/crates/bevy_ui/src/layout/mod.rs +++ b/crates/bevy_ui/src/layout/mod.rs @@ -1,4 +1,5 @@ mod convert; +pub mod debug; use crate::{ContentSize, Node, Style, UiScale}; use bevy_ecs::{