feat(theming): add hue-specific contrast support

Author: rschmukler

src/components/calendar/calendar-theme.scss

@@ -32,6 +32,6 @@
 .md-calendar-date:focus.md-calendar-selected-date {
   .md-calendar-date-selection-indicator {
     background-color: '{{primary-500}}'; // blue-500
-    color: '{{primary-contrast}}'; // SHOULD BE WHITE (ish)
+    color: '{{primary-500-contrast}}'; // SHOULD BE WHITE (ish)
   }
 }

src/core/services/theming/theming.js

@@ -32,6 +32,7 @@ angular.module('material.core.theming', ['material.core.theming.palette'])
  *
  * {{primary-100}} - grab shade 100 from the primary palette
  * {{primary-100-0.7}} - grab shade 100, apply opacity of 0.7
+ * {{primary-100-contrast}} - grab shade 100's contrast color
  * {{primary-hue-1}} - grab the shade assigned to hue-1 from the primary palette
  * {{primary-hue-1-0.7}} - apply 0.7 opacity to primary-hue-1
  * {{primary-color}} - Generates .md-hue-1, .md-hue-2, .md-hue-3 with configured shades set for each hue
@@ -404,13 +405,13 @@ function parseRules(theme, colorType, rules) {
   var themeNameRegex = new RegExp('.md-' + theme.name + '-theme', 'g');
   // Matches '{{ primary-color }}', etc
   var hueRegex = new RegExp('(\'|")?{{\\s*(' + colorType + ')-(color|contrast)-?(\\d\\.?\\d*)?\\s*}}(\"|\')?','g');
-  var simpleVariableRegex = /'?"?\{\{\s*([a-zA-Z]+)-(A?\d+|hue\-[0-3]|shadow)-?(\d\.?\d*)?\s*\}\}'?"?/g;
+  var simpleVariableRegex = /'?"?\{\{\s*([a-zA-Z]+)-(A?\d+|hue\-[0-3]|shadow)-?(\d\.?\d*)?(contrast)?\s*\}\}'?"?/g;
   var palette = PALETTES[color.name];
 
   // find and replace simple variables where we use a specific hue, not an entire palette
   // eg. "{{primary-100}}"
   //\(' + THEME_COLOR_TYPES.join('\|') + '\)'
-  rules = rules.replace(simpleVariableRegex, function(match, colorType, hue, opacity) {
+  rules = rules.replace(simpleVariableRegex, function(match, colorType, hue, opacity, contrast) {
     if (colorType === 'foreground') {
       if (hue == 'shadow') {
         return theme.foregroundShadow;
@@ -421,7 +422,7 @@ function parseRules(theme, colorType, rules) {
     if (hue.indexOf('hue') === 0) {
       hue = theme.colors[colorType].hues[hue];
     }
-    return rgba( (PALETTES[ theme.colors[colorType].name ][hue] || '').value, opacity );
+    return rgba( (PALETTES[ theme.colors[colorType].name ][hue] || '')[contrast ? 'contrast' : 'value'], opacity );
   });
 
   // For each type, generate rules for each hue (ie. default, md-hue-1, md-hue-2, md-hue-3)