Enum Constraint 

pub enum Constraint {
    Length(u16),
    Percentage(u16),
    Ratio(u16, u16),
    Min(u16),
    Max(u16),
    Fill,
    Fit,
}

Sizing constraint for a layout child along the parent’s primary axis. Resolved by resolve_constraints against the parent’s total size, in declaration order:

1. Hard sizes first (Length, Percentage, Ratio, Max) and Fit (resolved against the leaf’s natural size via the active LeafSizer) consume their exact share of the available space.
2. Min(n) reserves at least n cells, then competes with Fill for the remainder.
3. Fill (and any unsatisfied Min) splits whatever remains evenly.

Fit reports the leaf’s natural size from LeafSizer; with the default NoopSizer it contributes 0 (i.e. behaves like Fill).

Variants

Length(u16)

Exactly n cells along the axis.

Percentage(u16)

p percent of the parent’s total size, clamped to remaining.

Ratio(u16, u16)

Proportional share num / denom of the parent. Multiple Ratio siblings split proportionally to one another.

Min(u16)

At least n cells; competes with Fill for the remainder once the minimum is satisfied.

Max(u16)

At most n cells. Acts like Length(n) when the parent has at least n available; smaller parents shrink it.

Fill

Fill the remaining space; siblings split evenly.

Fit

Size to the leaf’s natural content. Falls back to Fill until leaves expose a natural-size hook.

Trait Implementations

impl Clone for Constraint

fn clone(&self) -> Constraint

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Constraint

impl Debug for Constraint

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

Formats the value using the given formatter.

impl Eq for Constraint

impl PartialEq for Constraint

fn eq(&self, other: &Constraint) -> 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 Constraint