frontend/src/helpers/colorIsDark.js
konrad cac8b09263 Add limits for kanban boards (#234)
Prevent dropping a task onto a bucket which has its limit reached

Fix closing the dropdown

Add notice to show the limit

Add input to change kanban bucket limit

Add menu item to save bucket limit

Fix parsing dates from the api

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: vikunja/frontend#234
2020-09-04 20:01:02 +00:00

18 lines
564 B
JavaScript

export const colorIsDark = color => {
if (color === '#' || color === '') {
return true // Defaults to dark
}
if (color.substring(0, 1) !== '#') {
color = '#' + color
}
let rgb = parseInt(color.substring(1, 7), 16) // convert rrggbb to decimal
let r = (rgb >> 16) & 0xff // extract red
let g = (rgb >> 8) & 0xff // extract green
let b = (rgb >> 0) & 0xff // extract blue
// luma will be a value 0..255 where 0 indicates the darkest, and 255 the brightest
let luma = 0.2126 * r + 0.7152 * g + 0.0722 * b // per ITU-R BT.709
return luma > 128
}