feat(Utils): add parse color and is transparent util

Author: marcocesarato

src/Utils.js

@@ -29,6 +29,62 @@ export const isEmpty = (x) => {
 	return false;
 };
 
+/**
+ * Parse color.
+ * @param color
+ * @returns {number[]}
+ */
+export const parseColor = (color) => {
+	let cache;
+	let p = parseInt;
+	color = color.replace(/\s/g, "");
+	if (
+		(cache = /#([\da-fA-F]{2})([\da-fA-F]{2})([\da-fA-F]{2})([\da-fA-F]{2})/.exec(
+			color,
+		))
+	) {
+		// #000000FF
+		cache = [
+			p(cache[1], 16),
+			p(cache[2], 16),
+			p(cache[3], 16),
+			p(cache[4], 16),
+		];
+	} else if (
+		(cache = /#([\da-fA-F]{2})([\da-fA-F]{2})([\da-fA-F]{2})/.exec(color))
+	) {
+		// #000000
+		cache = [p(cache[1], 16), p(cache[2], 16), p(cache[3], 16)];
+	} else if ((cache = /#([\da-fA-F])([\da-fA-F])([\da-fA-F])/.exec(color))) {
+		cache = [p(cache[1], 16) * 17, p(cache[2], 16) * 17, p(cache[3], 16) * 17];
+	} else if (
+		// #000
+		(cache = /rgba\(([\d]+),([\d]+),([\d]+),([\d]+|[\d]*.[\d]+)\)/.exec(color))
+	) {
+		// rgba(255,255,255,255)
+		cache = [+cache[1], +cache[2], +cache[3], +cache[4]];
+	} else if ((cache = /rgb\(([\d]+),([\d]+),([\d]+)\)/.exec(color))) {
+		// rgb(255,255,255)
+		cache = [+cache[1], +cache[2], +cache[3]];
+	} else {
+		cache = [0, 0, 0, 0];
+	}
+	isNaN(cache[3]) && (cache[3] = 1);
+	return cache.slice(0, 4);
+};
+
+/**
+ * Is transparent color
+ * @private
+ * @param color
+ * @returns {boolean}
+ */
+export const isTransparentColor = (color) => {
+	color = String(color).toLowerCase().trim();
+	const parse = parseColor(color);
+	return String(color).toLowerCase().trim() === "transparent" || parse[4] === 0;
+};
+
 /**
  * Is variable callable
  * @private
@@ -96,17 +152,20 @@ export const mergeViewStyle = (style, defaultStyle) => {
  * @returns {string}
  */
 export const getColorContrast = (hexcolor) => {
-	if (hexcolor.slice(0, 1) === '#') {
+	if (hexcolor.slice(0, 1) === "#") {
 		hexcolor = hexcolor.slice(1);
 	}
 	if (hexcolor.length === 3) {
-		hexcolor = hexcolor.split('').map(function (hex) {
-			return hex + hex;
-		}).join('');
+		hexcolor = hexcolor
+			.split("")
+			.map(function (hex) {
+				return hex + hex;
+			})
+			.join("");
 	}
-	var r = parseInt(hexcolor.substr(0,2),16);
-	var g = parseInt(hexcolor.substr(2,2),16);
-	var b = parseInt(hexcolor.substr(4,2),16);
-	var yiq = ((r * 299) + (g * 587) + (b * 114)) / 1000;
-	return (yiq >= 128) ? '#000000' : '#FFFFFF';
+	var r = parseInt(hexcolor.substr(0, 2), 16);
+	var g = parseInt(hexcolor.substr(2, 2), 16);
+	var b = parseInt(hexcolor.substr(4, 2), 16);
+	var yiq = (r * 299 + g * 587 + b * 114) / 1000;
+	return yiq >= 170 ? "#000000" : "#FFFFFF";
 };