X-Git-Url: https://vcs.fsf.org/?a=blobdiff_plain;f=CRM%2FUtils%2FColor.php;h=2cceca9ff33468d6027255e2f5361fa96bfc96fc;hb=850d8c7cf555cdb11176418b2d1ecd035eddcb14;hp=80bac7f8f898dfe7fccda91c2f401549b1b14a3a;hpb=6fe426fc1c924bbfcf29735d5f9e9763b1dbd389;p=civicrm-core.git

diff --git a/CRM/Utils/Color.php b/CRM/Utils/Color.php
index 80bac7f8f8..2cceca9ff3 100644
--- a/CRM/Utils/Color.php
+++ b/CRM/Utils/Color.php
@@ -42,15 +42,55 @@ class CRM_Utils_Color {
    * Based on YIQ value.
    *
    * @param string $hexcolor
+   * @param string $black
+   * @param string $white
    * @return string
    */
-  public static function getContrast($hexcolor) {
-    $hexcolor = trim($hexcolor, ' #');
-    $r = hexdec(substr($hexcolor, 0, 2));
-    $g = hexdec(substr($hexcolor, 2, 2));
-    $b = hexdec(substr($hexcolor, 4, 2));
+  public static function getContrast($hexcolor, $black = 'black', $white = 'white') {
+    list($r, $g, $b) = self::getRgb($hexcolor);
     $yiq = (($r * 299) + ($g * 587) + ($b * 114)) / 1000;
-    return ($yiq >= 128) ? 'black' : 'white';
+    return ($yiq >= 128) ? $black : $white;
+  }
+
+  /**
+   * Convert hex color to decimal
+   *
+   * @param string $hexcolor
+   * @return array
+   *   [red, green, blue]
+   */
+  public static function getRgb($hexcolor) {
+    $hexcolor = trim($hexcolor, ' #');
+    if (strlen($hexcolor) === 3) {
+      $hexcolor = $hexcolor[0] . $hexcolor[0] . $hexcolor[1] . $hexcolor[1] . $hexcolor[2] . $hexcolor[2];
+    }
+    return [
+      hexdec(substr($hexcolor, 0, 2)),
+      hexdec(substr($hexcolor, 2, 2)),
+      hexdec(substr($hexcolor, 4, 2)),
+    ];
+  }
+
+  /**
+   * Calculate a highlight color from a base color
+   *
+   * @param $hexcolor
+   * @return string
+   */
+  public static function getHighlight($hexcolor) {
+    $rgb = CRM_Utils_Color::getRgb($hexcolor);
+    $avg = array_sum($rgb) / 3;
+    foreach ($rgb as &$v) {
+      if ($avg > 242) {
+        // For very bright values, lower the brightness
+        $v -= 50;
+      }
+      else {
+        // Bump up brightness on a nonlinear curve - darker colors get more of a boost
+        $v = min(255, intval((-.0035 * ($v - 242) ** 2) + 260));
+      }
+    }
+    return '#' . implode(array_map('dechex', $rgb));
   }
 
 }