From ee25e634f55765bc3e628de1a3e454b9ad637f4d Mon Sep 17 00:00:00 2001
From: Matthias Schmidt <gravatronics@live.com>
Date: Wed, 30 Jun 2021 13:51:02 +0200
Subject: [PATCH] Add `ColorUtil.rgbaToHex()`

---
 ts/WoltLabSuite/Core/ColorUtil.ts             | 38 +++++++++++++++++++
 .../files/js/WoltLabSuite/Core/ColorUtil.js   | 23 ++++++++++-
 2 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/ts/WoltLabSuite/Core/ColorUtil.ts b/ts/WoltLabSuite/Core/ColorUtil.ts
index cd6dea7f5f..a4c20ee3e3 100644
--- a/ts/WoltLabSuite/Core/ColorUtil.ts
+++ b/ts/WoltLabSuite/Core/ColorUtil.ts
@@ -189,12 +189,49 @@ export function rgbToHex(r: string | number, g?: number, b?: number): string {
   return rgbComponentToHex(r as number) + rgbComponentToHex(g) + rgbComponentToHex(b!);
 }
 
+/**
+ * @since 5.5
+ */
+function alphaToHex(alpha: number): string {
+  if (alpha < 0 || alpha > 1) {
+    throw new Error(`Invalid alpha value '${alpha}' given.`);
+  }
+
+  return Math.round(alpha * 255)
+    .toString(16)
+    .padStart(2, "0")
+    .toUpperCase();
+}
+
+/**
+ * Converts a RGBA value into a HEX value.
+ *
+ * @since 5.5
+ */
+export function rgbaToHex(rgba: RGBA): string;
+export function rgbaToHex(r: number, g: number, b: number, a: number);
+export function rgbaToHex(r: RGBA | number, g?: number, b?: number, a?: number): string {
+  if (g === undefined) {
+    const rgba = r as RGBA;
+    return rgbToHex(rgba.r, rgba.g, rgba.b) + alphaToHex(rgba.a);
+  }
+
+  return rgbToHex(r as number, g, b!) + alphaToHex(a!);
+}
+
 export interface RGB {
   r: number;
   g: number;
   b: number;
 }
 
+export interface RGBA {
+  r: number;
+  g: number;
+  b: number;
+  a: number;
+}
+
 export interface HSV {
   h: number;
   s: number;
@@ -205,6 +242,7 @@ export interface HSV {
 window.__wcf_bc_colorUtil = {
   hexToRgb,
   hsvToRgb,
+  rgbaToHex,
   rgbToHex,
   rgbToHsv,
 };
diff --git a/wcfsetup/install/files/js/WoltLabSuite/Core/ColorUtil.js b/wcfsetup/install/files/js/WoltLabSuite/Core/ColorUtil.js
index f52c402049..52d1b0c397 100644
--- a/wcfsetup/install/files/js/WoltLabSuite/Core/ColorUtil.js
+++ b/wcfsetup/install/files/js/WoltLabSuite/Core/ColorUtil.js
@@ -10,7 +10,7 @@
 define(["require", "exports"], function (require, exports) {
     "use strict";
     Object.defineProperty(exports, "__esModule", { value: true });
-    exports.rgbToHex = exports.hexToRgb = exports.rgbToHsv = exports.hsvToRgb = void 0;
+    exports.rgbaToHex = exports.rgbToHex = exports.hexToRgb = exports.rgbToHsv = exports.hsvToRgb = void 0;
     /**
      * Converts a HSV color into RGB.
      *
@@ -167,10 +167,31 @@ define(["require", "exports"], function (require, exports) {
         return rgbComponentToHex(r) + rgbComponentToHex(g) + rgbComponentToHex(b);
     }
     exports.rgbToHex = rgbToHex;
+    /**
+     * @since 5.5
+     */
+    function alphaToHex(alpha) {
+        if (alpha < 0 || alpha > 1) {
+            throw new Error(`Invalid alpha value '${alpha}' given.`);
+        }
+        return Math.round(alpha * 255)
+            .toString(16)
+            .padStart(2, "0")
+            .toUpperCase();
+    }
+    function rgbaToHex(r, g, b, a) {
+        if (g === undefined) {
+            const rgba = r;
+            return rgbToHex(rgba.r, rgba.g, rgba.b) + alphaToHex(rgba.a);
+        }
+        return rgbToHex(r, g, b) + alphaToHex(a);
+    }
+    exports.rgbaToHex = rgbaToHex;
     // WCF.ColorPicker compatibility (color format conversion)
     window.__wcf_bc_colorUtil = {
         hexToRgb,
         hsvToRgb,
+        rgbaToHex,
         rgbToHex,
         rgbToHsv,
     };
-- 
2.20.1