(js) Compute contrast color for background color

UI/WebServerResources/js/Common/sgFolderStylesheet.directive.js

@@ -1,6 +1,7 @@
 /* -*- Mode: javascript; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 
 (function() {
+  /* jshint validthis: true */
   'use strict';
 
   /*
@@ -22,23 +23,88 @@
       scope: {
         ngModel: '='
       },
+      bindToController: true,
+      controller: sgFolderStylesheetController,
+      controllerAs: 'cssCtrl',
       template: [
         '<style type="text/css">',
-        '  .bg-folder{{ ngModel.id }} {',
-        '    background-color: {{ ngModel.color }} !important;',
+        /* Background color */
+        '  .bg-folder{{ cssCtrl.ngModel.id }},',
+        '  .bg-folder{{ cssCtrl.ngModel.id }} label,',
+        '  .bg-folder{{ cssCtrl.ngModel.id }} .md-input,',
+        '  .sg-event.bg-folder{{ cssCtrl.ngModel.id }} md-icon {',
+        '    background-color: {{ cssCtrl.ngModel.color }} !important;',
+        '    color: {{ cssCtrl.contrast(cssCtrl.ngModel.color) }} !important;',
         '  }',
-        '  .fg-folder{{ ngModel.id }} {',
-        '    color: {{ ngModel.color }} !important;',
+        // Set the contrast color of toolbar icons except the one of the background
+        '  md-toolbar.bg-folder{{ cssCtrl.ngModel.id }} md-icon:not(.sg-icon-toolbar-bg) {',
+        '    color: {{ cssCtrl.contrast(cssCtrl.ngModel.color) }} !important;',
         '  }',
-        '  .bdr-folder{{ ngModel.id }} {',
-        '    border-color: {{ ngModel.color }} !important;',
+        // Set the contrast color of input labels
+        '  .bg-folder{{ cssCtrl.ngModel.id }} label {',
+        '    color: {{ cssCtrl.contrast(cssCtrl.ngModel.color) }} !important;',
+        '    opacity: 0.8;',
         '  }',
-        '  .checkbox-folder{{ ngModel.id }} .md-icon {',
-        '    background-color: {{ ngModel.color }} !important;',
+        /* Foreground color */
+        '  .fg-folder{{ cssCtrl.ngModel.id }} {',
+        '    color: {{ cssCtrl.ngModel.color }} !important;',
+        '  }',
+        /* Border color */
+        '  .bdr-folder{{ cssCtrl.ngModel.id }} {',
+        '    border-color: {{ cssCtrl.ngModel.color }} !important;',
+        '  }',
+        /* Checkbox color */
+        '  .checkbox-folder{{ cssCtrl.ngModel.id }} .md-icon {',
+        '    background-color: {{ cssCtrl.ngModel.color }} !important;',
+        '  }',
+        '  .checkbox-folder{{ cssCtrl.ngModel.id }}.md-checked .md-icon:after {',
+        '    border-color: {{ cssCtrl.contrast(cssCtrl.ngModel.color) }} !important;',
         '  }',
         '</style>'
       ].join('')
     };
+
+    function sgFolderStylesheetController() {
+      var vm = this;
+
+      vm.contrast = contrast;
+
+      function hexToRgb(hex) {
+        var result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
+        return result ? {
+          r: parseInt(result[1], 16),
+          g: parseInt(result[2], 16),
+          b: parseInt(result[3], 16)
+        } : null;
+      }
+
+      // Respect contrast ratio recommendation from W3C:
+      // http://www.w3.org/TR/WCAG20/#contrast-ratiodef
+      function contrast(hex) {
+        var color, c, l;
+
+        color = hexToRgb(hex);
+	c = [color.r / 255, color.g / 255, color.b / 255];
+
+	for (var i = 0; i < c.length; ++i) {
+	  if (c[i] <= 0.03928) {
+	    c[i] = c[i] / 12.92;
+	  }
+          else {
+	    c[i] = Math.pow((c[i] + 0.055) / 1.055, 2.4);
+	  }
+	}
+
+	l = 0.2126 * c[0] + 0.7152 * c[1] + 0.0722 * c[2];
+
+	if (l > 0.179) {
+          return 'black';
+        }
+        else {
+          return 'white';
+	}
+      }
+    }
   }
 
   angular

UI/WebServerResources/scss/views/SchedulerUI.scss

@@ -163,7 +163,7 @@ $scrollbar_width: 16px;
   .sg-event {
     font-size: $sg-font-size-2;
     &, md-icon {
-      color: #fff !important; // Overwrite dynamic CSS theme
+      //color: #fff !important; // Overwrite dynamic CSS theme
     }
     .material-icons {
       font-size: $sg-font-size-2;