fix(android): semantic colors with alpha value

refs TIMOB-27519

common/Resources/ti.internal/extensions/ti/ti.ui.js

@@ -7,6 +7,8 @@
 
 let colorset;
 let osVersion;
+const shorthandRegex = /^#?([a-f\d])([a-f\d])([a-f\d])$/i;
+const fallbackColor = 'black'; // To match iphone/Classes/TiUIiOSProxy.m#fetchSemanticColor
 
 // As Android passes a new instance of Ti.UI to every JS file we can't just
 // Ti.UI within this file, we must call kroll.binding to get the Titanium
@@ -32,6 +34,20 @@ Object.defineProperty(uiModule, 'semanticColorType', {
 	}
 });
 
+function hexToRgb(hex) {
+	let alpha = 1;
+	let color = hex;
+	if (hex.color) {
+		alpha = hex.alpha / 100; // convert from 0-100 range to 0-1 range
+		color = hex.color;
+	}
+	// Expand shorthand form (e.g. "03F") to full form (e.g. "0033FF")
+	color = color.replace(shorthandRegex, (m, r, g, b) => r + r + g + g + b + b);
+
+	const r = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(color);
+	return r ? `rgba(${parseInt(r[1], 16)}, ${parseInt(r[2], 16)}, ${parseInt(r[3], 16)}, ${alpha.toFixed(3)})` : null;
+};
+
 uiModule.fetchSemanticColor = function fetchSemanticColor (colorName) {
 	if (!osVersion) {
 		osVersion = parseInt(Ti.Platform.version.split('.')[0]);
@@ -51,10 +67,22 @@ uiModule.fetchSemanticColor = function fetchSemanticColor (colorName) {
 				return;
 			}
 		}
-		try {
-			return colorset[colorName][uiModule.semanticColorType].color || colorset[colorName][uiModule.semanticColorType];
-		} catch (error) {
-			console.error(`Failed to lookup color for ${colorName}`);
+		if (!colorset[colorName]) {
+			return fallbackColor;
+		}
+		const color = colorset[colorName][Ti.UI.semanticColorType];
+		if (typeof color === 'string') {
+			return color;
+		}
+		if (!color || typeof color !== 'object') {
+			return fallbackColor;
+		}
+		if (color['color'] && color['alpha']) {
+			const result = hexToRgb(color);
+			if (result) {
+				return result;
+			}
 		}
+		return fallbackColor;
 	}
 };