Struct CssDependencyChain 

pub struct CssDependencyChain {
    pub property_type: CssPropertyType,
    pub steps: Vec<CssDependencyChainStep>,
    pub cached_pixels: Option<f32>,
}

A dependency chain for a CSS property value. Example: [10% of node 10, then 1.2em of that, then 1.5em of that]

During layout, this chain is resolved by:

1. Starting with the root dependency (e.g., node 10’s resolved font-size)
2. Applying each transformation in sequence
3. Producing the final pixel value

Fields

property_type: CssPropertyType

The property type this chain is for

steps: Vec<CssDependencyChainStep>

The ordered list of dependencies, from root to leaf Empty if the value is absolute (no dependencies)

cached_pixels: Option<f32>

Cached resolved value (in pixels) from the last resolution None if the chain hasn’t been resolved yet

Implementations

impl CssDependencyChain

pub fn absolute(property_type: CssPropertyType, pixels: f32) -> Self

Create a new dependency chain for an absolute pixel value

pub fn percent( property_type: CssPropertyType, source_node: NodeId, factor: f32, ) -> Self

Create a new dependency chain for a percentage-based value

pub fn em( property_type: CssPropertyType, source_node: NodeId, factor: f32, ) -> Self

Create a new dependency chain for an em-based value

pub fn rem(property_type: CssPropertyType, factor: f32) -> Self

Create a new dependency chain for a rem-based value

pub fn depends_on(&self, node_id: NodeId) -> bool

Check if this chain depends on a specific node

pub fn resolve<F>( &mut self, resolve_node_value: F, root_font_size: f32, ) -> Option<f32>

where F: FnMut(NodeId, CssPropertyType) -> Option<f32>,

Resolve the dependency chain to a pixel value.

Arguments

• resolve_node_value - Closure to resolve a node’s property value to pixels
• root_font_size - Root element’s font-size for rem calculations

Returns

The resolved pixel value, or None if any dependency couldn’t be resolved

Trait Implementations

impl Clone for CssDependencyChain

fn clone(&self) -> CssDependencyChain

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CssDependencyChain

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for CssDependencyChain

fn eq(&self, other: &CssDependencyChain) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for CssDependencyChain