musicgrid: title hover, set font color dependent on background

1 files changed, 29 insertions, 0 deletions

diff --git a/www/js/utils.js b/www/js/utils.js
index 8331ea1..470b3b5 100644
--- a/www/js/utils.js
+++ b/www/js/utils.js
@@ -101,3 +101,32 @@ function locationHrefValue() {
   var value = window.location.href.match(/import.helsinki.at\/([a-z]+)\/?.*/);
   return value ? value[1] : '';
 }
+
+/*
+ see: https://gist.github.com/kozo002/6806421
+ */
+jQuery.fn.isBackgroundDark = function() {
+  return this.brightness() === 'dark';
+};
+
+jQuery.fn.brightness = function() {
+  var bg_color, rgba, y;
+  bg_color = this.css('background-color');
+  if ((bg_color != null) && bg_color.length) {
+    rgba = bg_color.match(/^rgb(?:a)?\(([0-9]{1,3}),\s([0-9]{1,3}),\s([0-9]{1,3})(?:,\s)?([0-9]{1,3})?\)$/);
+    if (rgba != null) {
+      if (rgba[4] === '0') {
+        if (this.parent().length) return this.parent().brightness();
+      } else {
+        y = 2.99 * rgba[1] + 5.87 * rgba[2] + 1.14 * rgba[3];
+        if (y >= 1275) {
+          return 'light';
+        } else {
+          return 'dark';
+        }
+      }
+    }
+  } else {
+    if (this.parent().length) return this.parent().brightness();
+  }
+};