Struct TextSpan 

pub struct TextSpan { /* private fields */ }

A rich-text tree: each node carries a fragment of text, partial style overrides — whatever is unspecified inherits from the parent, so a .bold() child keeps its parent’s size — and children of its own.

let span = TextSpan::new("Hello ")
    .child(TextSpan::new("bold").bold())
    .child(TextSpan::new(" world"));
let runs = span.flatten(TextStyle::new(20.0));
assert_eq!(runs.len(), 3);
assert_eq!(runs[1].1.size, 20.0); // the bold child inherits the size

Implementations

impl TextSpan

pub fn new(text: impl Into<String>) -> Self

A text fragment with no overrides — it inherits everything.

pub fn bold(self) -> Self

Makes this subtree bold.

pub fn weight(self, weight: FontWeight) -> Self

Sets this subtree’s weight.

pub fn italic(self) -> Self

Makes this subtree italic.

pub fn size(self, size: f32) -> Self

Sets this subtree’s size.

pub fn color(self, color: Color) -> Self

Sets this subtree’s colour.

pub fn underline(self) -> Self

Underlines this subtree. It combines with the decoration already set on this node, but not with the parent’s.

pub fn strikethrough(self) -> Self

Strikes through this subtree.

pub fn decoration(self, decoration: TextDecoration) -> Self

Sets this subtree’s decoration lines.

pub fn decoration_color(self, color: Color) -> Self

Sets this subtree’s decoration colour.

pub fn style(self, style: TextStyle) -> Self

Applies a whole TextStyle as this subtree’s override, replacing whatever this span had said before.

It used to force every typographic field to answered, because a TextStyle could not say otherwise. It no longer has to: a style naming only a size now overrides only the size, and the weight goes on being inherited from the parent span.

pub fn child(self, child: TextSpan) -> Self

Adds a child, rendered after this node’s own text.

pub fn flatten(&self, base: TextStyle) -> Vec<(String, ResolvedTextStyle)>

Flattens the tree into resolved runs (text, style), in reading order, cascading the overrides down from base, the paragraph’s default style. Nodes with no text of their own produce no empty run.

pub fn measure_hash<H: Hasher>(&self, hasher: &mut H)

Mixes into hasher everything that affects the tree’s measurement: text, sizes, weights and italics. Colours and decorations are excluded, having no effect on geometry. This serves as the measurement fingerprint (measure_key) without having to flatten the tree.

Trait Implementations

impl Clone for TextSpan

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TextSpan

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

Formats the value using the given formatter.

impl Default for TextSpan

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for TextSpan

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for TextSpan