fix(theming): dark contrast used incorrectly when only contrastStrongLightColors defined

- if `contrastStrongLightColors` is defined and `contrastLightColors` is not,
  `getContrastType()` was incorrectly picking `dark` instead of `strongLight`
- remove all of the duplicate `contrastLightColors` entries that had to remain before,
  due to this bug
- improve JSDoc
- checkbox's checkmark should always match the background color
  and never depend on the contrast of the accent color
- remove duplicate theme style generation for checkbox and button

Author: Splaktar

src/components/button/button-theme.scss

@@ -52,21 +52,6 @@
       }
     }
   }
-  &.md-fab {
-    background-color: '{{accent-color}}';
-    color: '{{accent-contrast}}';
-    &:not([disabled]) {
-      .md-icon {
-        color: '{{accent-contrast}}';
-      }
-      &:hover {
-        background-color: '{{accent-A700}}';
-      }
-      &.md-focused {
-        background-color: '{{accent-A700}}';
-      }
-    }
-  }
 
   &.md-raised {
     color: '{{background-900}}';

src/components/button/demoBasicUsage/style.css

@@ -13,5 +13,4 @@ section .md-button {
   bottom: 5px;
   left: 7px;
   font-size: 14px;
-  color: rgba(0, 0, 0, 0.54);
 }

src/components/checkbox/checkbox-theme.scss

@@ -28,7 +28,7 @@ md-checkbox.md-THEME_NAME-theme {
   }
 
   &.md-checked .md-icon:after {
-    border-color: '{{accent-contrast-0.87}}';
+    border-color: '{{background-default}}';
   }
 
   &:not([disabled]) {
@@ -60,10 +60,6 @@ md-checkbox.md-THEME_NAME-theme {
       &.md-checked.md-focused:not([disabled]) .md-container:before {
         background-color: '{{warn-color-0.26}}';
       }
-
-      &.md-checked .md-icon:after {
-        border-color: '{{background-200}}';
-      }
     }
   }
 
@@ -76,17 +72,8 @@ md-checkbox.md-THEME_NAME-theme {
       background-color: '{{foreground-3}}';
     }
 
-    &.md-checked .md-icon:after {
-      border-color: '{{background-200}}';
-    }
-
-    .md-icon:after {
-      border-color: '{{foreground-3}}';
-    }
-
     .md-label {
       color: '{{foreground-3}}';
     }
   }
-
 }

src/core/services/theming/theme.palette.js

@@ -136,7 +136,6 @@ angular.module('material.core.theming.palette', [])
     'contrastDefaultColor': 'dark',
     // Dark on 700 does not meet the minimum 4.5 contrast ratio (at 4.07),
     // but it's worse with a white foreground (3.85).
-    'contrastLightColors': '800 900 A700',
     'contrastStrongLightColors': '800 900 A700'
   },
   'cyan': {
@@ -157,7 +156,6 @@ angular.module('material.core.theming.palette', [])
     'contrastDefaultColor': 'dark',
     // Dark on 700 does not meet the minimum 4.5 contrast ratio (at 4.47),
     // but it's worse with a white foreground (3.5).
-    'contrastLightColors': '800 900',
     'contrastStrongLightColors': '800 900'
   },
   'teal': {
@@ -180,7 +178,6 @@ angular.module('material.core.theming.palette', [])
     // but it's worse with a white foreground (3.67).
     // White on 600 does not meet the minimum 4.5 contrast ratio (at 4.31),
     // but it's worse with a dark foreground (3.64).
-    'contrastLightColors': '600 700 800 900',
     'contrastStrongLightColors': '600 700 800 900'
   },
   'green': {
@@ -201,7 +198,6 @@ angular.module('material.core.theming.palette', [])
     'contrastDefaultColor': 'dark',
     // White on 700 does not meet the minimum 4.5 contrast ratio (at 4.11),
     // but it's worse with a dark foreground (3.81).
-    'contrastLightColors': '700 800 900',
     'contrastStrongLightColors': '700 800 900'
   },
   'light-green': {
@@ -220,7 +216,6 @@ angular.module('material.core.theming.palette', [])
     'A400': '#76ff03',
     'A700': '#64dd17',
     'contrastDefaultColor': 'dark',
-    'contrastLightColors': '800 900',
     'contrastStrongLightColors': '800 900'
   },
   'lime': {
@@ -239,7 +234,6 @@ angular.module('material.core.theming.palette', [])
     'A400': '#c6ff00',
     'A700': '#aeea00',
     'contrastDefaultColor': 'dark',
-    'contrastLightColors': '900',
     'contrastStrongLightColors': '900'
   },
   'yellow': {
@@ -292,7 +286,6 @@ angular.module('material.core.theming.palette', [])
     'A400': '#ff9100',
     'A700': '#ff6d00',
     'contrastDefaultColor': 'dark',
-    'contrastLightColors': '900',
     'contrastStrongLightColors': '900'
   },
   'deep-orange': {
@@ -315,7 +308,7 @@ angular.module('material.core.theming.palette', [])
     // but it's worse with a white foreground (3.91).
     // White on 800 does not meet the minimum 4.5 contrast ratio (at 4.43),
     // but it's worse with a dark foreground (3.54).
-    'contrastLightColors': '800 900 A400 A700',
+    'contrastStrongLightColors': '800 900 A400 A700',
   },
   'brown': {
     '50': '#efebe9',
@@ -352,7 +345,7 @@ angular.module('material.core.theming.palette', [])
     'A400': '#303030',
     'A700': '#616161',
     'contrastDefaultColor': 'dark',
-    'contrastLightColors': '600 700 800 900 A200 A400 A700',
+    'contrastLightColors': '700 800 900 A200 A400 A700',
     'contrastStrongLightColors': '600'
   },
   'blue-grey': {

src/core/services/theming/theming.js

@@ -1217,15 +1217,25 @@ function generateAllThemes($injector, $mdTheming) {
     delete palette.contrastStrongLightColors;
     delete palette.contrastDarkColors;
 
+    /**
+     * @param {string} hueName
+     * @return {'dark'|'light'|'strongLight'}
+     */
     function getContrastType(hueName) {
-      if (defaultContrast === 'light' ? darkColors.indexOf(hueName) !== -1  : lightColors.indexOf(hueName) === -1) {
+      if (defaultContrast === 'light' ? darkColors.indexOf(hueName) !== -1  :
+        (lightColors.indexOf(hueName) === -1 && strongLightColors.indexOf(hueName) === -1)) {
         return 'dark';
       }
       if (strongLightColors.indexOf(hueName) !== -1) {
         return 'strongLight';
       }
       return 'light';
     }
+
+    /**
+     * @param {'dark'|'light'|'strongLight'} contrastType
+     * @return {[number, number, number]} [red, green, blue] array
+     */
     function getContrastColor(contrastType) {
       switch (contrastType) {
         default:
@@ -1237,6 +1247,11 @@ function generateAllThemes($injector, $mdTheming) {
           return DARK_CONTRAST_COLOR;
       }
     }
+
+    /**
+     * @param {'dark'|'light'|'strongLight'} contrastType
+     * @return {{secondary: number, divider: number, hint: number, icon: number, disabled: number}}
+     */
     function getOpacityValues(contrastType) {
       switch (contrastType) {
         default:
@@ -1313,6 +1328,10 @@ function checkValidPalette(theme, colorType) {
   }
 }
 
+/**
+ * @param {string} clr rbg or rgba color
+ * @return {number[]|undefined} [red, green, blue] array if it can be computed
+ */
 function colorToRgbaArray(clr) {
   if (angular.isArray(clr) && clr.length === 3) return clr;
   if (/^rgb/.test(clr)) {