merge next

src/lib/strformat.js

@@ -39,7 +39,7 @@ export function bytesToHumanSize(bytes) {
 
 // Get 32 bit integer hash value for a string. Ideally it should produce the same value
 // as Java's String#hash().
-export function stringHash(value) {
+function stringToColorHash(value) {
   let hash = 0;
   value = '' + value;
   for (let i = 0; i < value.length; i++) {
@@ -48,3 +48,12 @@ export function stringHash(value) {
   }
   return hash;
 }
+
+// Converts user or topic ID to a CSS color class. Ideally it should produce the same color value as Java version.
+// params:
+// - {string} id: user or topic ID
+// - {boolean} light: light or dark version of the color.
+// - {boolean} fg: foreground or background color.
+export function idToColorClass(id, light, fg) {
+  return (light ? 'lt-' : 'dk-') + (fg ? 'fg-' : 'bg-') + (Math.abs(stringToColorHash(id)) % 16);
+}