Enum ButtonStyleSpec 

pub enum ButtonStyleSpec {
    Automatic,
    Bordered,
    Prominent,
    Tinted(Color),
    Compact,
    Plain,
}

A button’s native styling tier. Automatic is the toolkit’s stock look; Bordered asks for a visually contained button where the stock look is borderless (iOS’s plain system button reads as a link); Prominent asks for the platform’s accent-filled / default-action affordance. Toolkits whose stock buttons are already contained treat Bordered as Automatic.

Variants

Automatic

Bordered

Prominent

Tinted(Color)

A filled button in an app-chosen color, still drawn by the native control: the platform keeps its own pressed, hover, focus and disabled rendering, its button role, and its keyboard activation. The label color is not carried; each backend picks the readable one for the fill (see ButtonStyleSpec::on_tint), the same call the platform’s own tinted buttons make.

A backend with no way to recolor its button ignores this and draws its ordinary button. That is the trade: a plain button everywhere beats a colored rectangle that is no longer a button on the platforms that cannot.

Compact

A button no wider than its title asks for (a one-glyph “−” or “+” in a stepper, a “×” on a chip) on toolkits whose stock button carries a minimum width and wide insets (Material’s 88 dp button turns a two-button stepper into 240 dp). The native control stays: only its minimum width and horizontal padding are reduced. A toolkit whose buttons already hug their title (AppKit, UIKit’s plain button, Qt) draws its ordinary button.

Plain

Borderless native action button; compact horizontal insets on Material.

Implementations

impl ButtonStyleSpec

pub fn on_tint(fill: Color) -> Color

The label color to draw on a ButtonStyleSpec::Tinted fill: whichever of black or white contrasts better against it, by WCAG’s contrast ratio.

Comparing the two ratios rather than thresholding the luminance is the difference between right and nearly right. A mid amber (#F0A64C) has a relative luminance of 0.44; under a “brighter than half” test it reads as dark and takes white text, at a hopeless 2.2:1. Its contrast against black is 9.7:1. The two ratios cross at a luminance of 0.179, not 0.5, and everything between those two numbers is a button nobody can read.

Trait Implementations

impl Clone for ButtonStyleSpec

fn clone(&self) -> ButtonStyleSpec

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ButtonStyleSpec

impl Debug for ButtonStyleSpec

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

Formats the value using the given formatter.

impl Default for ButtonStyleSpec

fn default() -> ButtonStyleSpec

Returns the “default value” for a type.

impl PartialEq for ButtonStyleSpec

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ButtonStyleSpec