Signal on transparent problem colors

Author: vmcj

webapp/src/Service/CheckConfigService.php

@@ -474,6 +474,9 @@ public function checkContestsValidate(): ConfigCheckItem
                 if (empty($cp->getColor())) {
                     $result = ($result === 'E' ? 'E' : 'W');
                     $cperrors[$cid] .= "  - No color for problem `" . $cp->getShortname() . "` in contest c" . $cid . "\n";
+                } elseif (count(Utils::parseHexColor($cp->getColor())) === 4 && Utils::parseHexColor($cp->getColor())[3] !== 255) {
+                    $result = ($result === 'E' ? 'E' : 'W');
+                    $cperrors[$cid] .= "  - Semi-transparent color for problem `" . $cp->getShortname() . "` in contest c" . $cid . "\n";
                 }
             }
         }

webapp/src/Utils/Utils.php

@@ -343,9 +343,9 @@ public static function convertToColor(string $hex): ?string
     }
 
     /**
-     * Parse a hex color into it's three RGB values.
+     * Parse a hex color into it's four RGBA values.
      *
-     * @return array{int, int, int}
+     * @return array{int, int, int, int}
      */
     public static function parseHexColor(string $hex): array
     {