isValidBackgroundImageValue static method
Implementation
static bool isValidBackgroundImageValue(String value) {
// According to CSS Backgrounds spec, 'none' is a valid <bg-image> keyword.
if (value == 'none') return true;
return (value.lastIndexOf(')') == value.length - 1) &&
(value.startsWith('url(') ||
value.startsWith('linear-gradient(') ||
value.startsWith('repeating-linear-gradient(') ||
value.startsWith('radial-gradient(') ||
value.startsWith('repeating-radial-gradient(') ||
value.startsWith('conic-gradient('));
}