Struct Scheme

pub struct Scheme {

    pub white: [Color; 4],
    pub black: [Color; 4],
    pub gray: [Color; 4],
    pub red: [Color; 4],
    pub orange: [Color; 4],
    pub yellow: [Color; 4],
    pub limegreen: [Color; 4],
    pub green: [Color; 4],
    pub bluegreen: [Color; 4],
    pub cyan: [Color; 4],
    pub blue: [Color; 4],
    pub deepblue: [Color; 4],
    pub purple: [Color; 4],
    pub magenta: [Color; 4],
    pub redpink: [Color; 4],
    pub primary: [Color; 4],
    pub secondary: [Color; 4],
}

Color scheme.

This provides the palette used for a theme.

The ideas packed in here are

• provide two colors for highlighting and accents.
• I always want some white, black and gray.
• I don’t want to miss out anything, so go once round the hue in HSV. Take steps of 30° then we hit pretty much anything interesting.
• Just one variant of each color is not enough, make it 4.

Fields

white: [Color; 4]

black: [Color; 4]

gray: [Color; 4]

red: [Color; 4]

orange: [Color; 4]

yellow: [Color; 4]

limegreen: [Color; 4]

green: [Color; 4]

bluegreen: [Color; 4]

cyan: [Color; 4]

blue: [Color; 4]

deepblue: [Color; 4]

purple: [Color; 4]

magenta: [Color; 4]

redpink: [Color; 4]

primary: [Color; 4]

secondary: [Color; 4]

Implementations

impl Scheme

pub fn style(&self, color: Color) -> Style

Create a style with the given background color. Foreground is calculated with text_color.

pub const fn linear4(c0: u32, c1: u32) -> [Color; 4]

Linear interpolation between the two colors.

pub fn text_color(&self, color: Color) -> Color

This gives back white[3] or black[0] for text foreground providing good contrast to the given background.

This converts RGB to grayscale and takes the grayscale value of VGA cyan as threshold, which is about 105 out of 255. This point is a bit arbitrary, just based on what I perceive as acceptable. But it produces a good reading contrast in my experience.

For the named colors it takes the VGA equivalent as a base. For indexed colors it splits the range in half as an estimate.

Trait Implementations

impl Clone for Scheme

fn clone(&self) -> Scheme

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Scheme

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

Formats the value using the given formatter.

impl Default for Scheme

fn default() -> Scheme

Returns the “default value” for a type.