Gradients refactor

* Add start and end support to the horizontal gradient as well
* Change all variables from camelCase to use-dashes
* Better comments in the gradients mixins area
* Update current uses of gradients in dropdowns and carousel to specify only two values by direct assignment of variables

3 files changed, 60 insertions, 45 deletions

diff --git a/less/carousel.less b/less/carousel.less
index c1b0e9b9a..31f9b8aff 100644
--- a/less/carousel.less
+++ b/less/carousel.less
@@ -90,13 +90,13 @@
 
   // Set gradients for backgrounds
   &.left {
-    #gradient > .horizontal(rgba(0,0,0,.5), rgba(0,0,0,.0001));
+    #gradient > .horizontal(@start-color: rgba(0,0,0,.5); @end-color: rgba(0,0,0,.0001));
     background-color: transparent;
   }
   &.right {
     left: auto;
     right: 0;
-    #gradient > .horizontal(rgba(0,0,0,.0001), rgba(0,0,0,.5));
+    #gradient > .horizontal(@start-color: rgba(0,0,0,.0001); @end-color: rgba(0,0,0,.5));
     background-color: transparent;
   }
 
diff --git a/less/dropdowns.less b/less/dropdowns.less
index e2c9805ae..3e0152788 100644
--- a/less/dropdowns.less
+++ b/less/dropdowns.less
@@ -68,7 +68,7 @@
 .dropdown-submenu:focus > a {
   text-decoration: none;
   color: @dropdown-link-hover-color;
-  #gradient > .vertical(@dropdown-link-hover-bg, darken(@dropdown-link-hover-bg, 5%));
+  #gradient > .vertical(@start-color: @dropdown-link-hover-bg; @end-color: darken(@dropdown-link-hover-bg, 5%));
 }
 
 // Active state
@@ -79,7 +79,7 @@
   color: @dropdown-link-active-color;
   text-decoration: none;
   outline: 0;
-  #gradient > .vertical(@dropdown-link-active-bg, darken(@dropdown-link-active-bg, 5%));
+  #gradient > .vertical(@start-color: @dropdown-link-active-bg; @end-color: darken(@dropdown-link-active-bg, 5%));
 }
 
 // Disabled state
diff --git a/less/mixins.less b/less/mixins.less
index bdd787166..e900351be 100644
--- a/less/mixins.less
+++ b/less/mixins.less
@@ -241,61 +241,71 @@
 
 
 
-// BACKGROUNDS
+// GRADIENTS
 // --------------------------------------------------
 
-// Gradients
 #gradient {
-  .horizontal(@startColor: #555, @endColor: #333) {
-    background-color: @endColor;
-    background-image: -webkit-gradient(linear, 0 0, 100% 0, from(@startColor), to(@endColor)); // Safari 4+, Chrome 2+
-    background-image: -webkit-linear-gradient(left, @startColor, @endColor); // Safari 5.1+, Chrome 10+
-    background-image: -moz-linear-gradient(left, @startColor, @endColor); // FF 3.6+
-    background-image: linear-gradient(to right, @startColor, @endColor); // Standard, IE10
+
+  // Horizontal gradient, from left to right
+  //
+  // Creates two color stops, start and end, by specifying a color and position for each color stop.
+  // Color stops are not available in IE9 and below.
+  .horizontal(@start-color: #555; @start-percent: 0%; @end-color: #333; @end-percent: 100%) {
+    background-color: @end-color;
+    background-image: -webkit-gradient(linear, @start-percent top, @end-percent top, from(@start-color), to(@end-color)); // Safari 4+, Chrome 2+
+    background-image: -webkit-linear-gradient(left, color-stop(@start-color @start-percent), color-stop(@end-color @end-percent)); // Safari 5.1+, Chrome 10+
+    background-image: -moz-linear-gradient(left, @start-color @start-percent, @end-color @end-percent); // FF 3.6+
+    background-image:  linear-gradient(to right, @start-color @start-percent, @end-color @end-percent); // Standard, IE10
     background-repeat: repeat-x;
-    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=1)",argb(@startColor),argb(@endColor))); // IE9 and down
+    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=1)",argb(@start-color),argb(@end-color))); // IE9 and down
   }
-  .vertical(@startColor: #555, @endColor: #333, @startPercent: 0%, @endPercent: 100%) {
-    background-color: @endColor;
-    background-image: -webkit-gradient(linear, 0 @startPercent, 0 @endPercent, from(@startColor), to(@endColor)); // Safari 4+, Chrome 2+
-    background-image: -webkit-linear-gradient(top, @startColor, @startPercent, @endColor, @endPercent); // Safari 5.1+, Chrome 10+
-    background-image: -moz-linear-gradient(top, @startColor @startPercent, @endColor @endPercent); // FF 3.6+
-    background-image: linear-gradient(to bottom, @startColor @startPercent, @endColor @endPercent); // Standard, IE10
+
+  // Vertical gradient, from top to bottom
+  //
+  // Creates two color stops, start and end, by specifying a color and position for each color stop.
+  // Color stops are not available in IE9 and below.
+  .vertical(@start-color: #555; @start-percent: 0%; @end-color: #333; @end-percent: 100%) {
+    background-color: @end-color;
+    background-image: -webkit-gradient(linear, left @start-percent, left @end-percent, from(@start-color), to(@end-color)); // Safari 4+, Chrome 2+
+    background-image: -webkit-linear-gradient(top, @start-color, @start-percent, @end-color, @end-percent); // Safari 5.1+, Chrome 10+
+    background-image:  -moz-linear-gradient(top, @start-color @start-percent, @end-color @end-percent); // FF 3.6+
+    background-image: linear-gradient(to bottom, @start-color @start-percent, @end-color @end-percent); // Standard, IE10
     background-repeat: repeat-x;
-    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=0)",argb(@startColor),argb(@endColor))); // IE9 and down
+    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=0)",argb(@start-color),argb(@end-color))); // IE9 and down
   }
-  .directional(@startColor: #555, @endColor: #333, @deg: 45deg) {
-    background-color: @endColor;
+
+  .directional(@start-color: #555, @end-color: #333, @deg: 45deg) {
+    background-color: @end-color;
     background-repeat: repeat-x;
-    background-image: -webkit-linear-gradient(@deg, @startColor, @endColor); // Safari 5.1+, Chrome 10+
-    background-image: -moz-linear-gradient(@deg, @startColor, @endColor); // FF 3.6+
-    background-image: linear-gradient(@deg, @startColor, @endColor); // Standard, IE10
+    background-image: -webkit-linear-gradient(@deg, @start-color, @end-color); // Safari 5.1+, Chrome 10+
+    background-image: -moz-linear-gradient(@deg, @start-color, @end-color); // FF 3.6+
+    background-image: linear-gradient(@deg, @start-color, @end-color); // Standard, IE10
   }
-  .horizontal-three-colors(@startColor: #00b3ee, @midColor: #7a43b6, @colorStop: 50%, @endColor: #c3325f) {
-    background-color: mix(@midColor, @endColor, 80%);
-    background-image: -webkit-gradient(left, linear, 0 0, 0 100%, from(@startColor), color-stop(@colorStop, @midColor), to(@endColor));
-    background-image: -webkit-linear-gradient(left, @startColor, @midColor @colorStop, @endColor);
-    background-image: -moz-linear-gradient(left, @startColor, @midColor @colorStop, @endColor);
-    background-image: linear-gradient(to right, @startColor, @midColor @colorStop, @endColor);
+  .horizontal-three-colors(@start-color: #00b3ee, @mid-color: #7a43b6, @color-stop: 50%, @end-color: #c3325f) {
+    background-color: mix(@mid-color, @end-color, 80%);
+    background-image: -webkit-gradient(left, linear, 0 0, 0 100%, from(@start-color), color-stop(@color-stop, @mid-color), to(@end-color));
+    background-image: -webkit-linear-gradient(left, @start-color, @mid-color @color-stop, @end-color);
+    background-image: -moz-linear-gradient(left, @start-color, @mid-color @color-stop, @end-color);
+    background-image: linear-gradient(to right, @start-color, @mid-color @color-stop, @end-color);
     background-repeat: no-repeat;
-    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=1)",argb(@startColor),argb(@endColor))); // IE9 and down, gets no color-stop at all for proper fallback
+    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=1)",argb(@start-color),argb(@end-color))); // IE9 and down, gets no color-stop at all for proper fallback
   }
 
-  .vertical-three-colors(@startColor: #00b3ee, @midColor: #7a43b6, @colorStop: 50%, @endColor: #c3325f) {
-    background-color: mix(@midColor, @endColor, 80%);
-    background-image: -webkit-gradient(linear, 0 0, 0 100%, from(@startColor), color-stop(@colorStop, @midColor), to(@endColor));
-    background-image: -webkit-linear-gradient(@startColor, @midColor @colorStop, @endColor);
-    background-image: -moz-linear-gradient(top, @startColor, @midColor @colorStop, @endColor);
-    background-image: linear-gradient(@startColor, @midColor @colorStop, @endColor);
+  .vertical-three-colors(@start-color: #00b3ee, @mid-color: #7a43b6, @color-stop: 50%, @end-color: #c3325f) {
+    background-color: mix(@mid-color, @end-color, 80%);
+    background-image: -webkit-gradient(linear, 0 0, 0 100%, from(@start-color), color-stop(@color-stop, @mid-color), to(@end-color));
+    background-image: -webkit-linear-gradient(@start-color, @mid-color @color-stop, @end-color);
+    background-image: -moz-linear-gradient(top, @start-color, @mid-color @color-stop, @end-color);
+    background-image: linear-gradient(@start-color, @mid-color @color-stop, @end-color);
     background-repeat: no-repeat;
-    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=0)",argb(@startColor),argb(@endColor))); // IE9 and down, gets no color-stop at all for proper fallback
+    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=0)",argb(@start-color),argb(@end-color))); // IE9 and down, gets no color-stop at all for proper fallback
   }
-  .radial(@innerColor: #555, @outerColor: #333) {
-    background-color: @outerColor;
-    background-image: -webkit-gradient(radial, center center, 0, center center, 460, from(@innerColor), to(@outerColor));
-    background-image: -webkit-radial-gradient(circle, @innerColor, @outerColor);
-    background-image: -moz-radial-gradient(circle, @innerColor, @outerColor);
-    background-image: radial-gradient(circle, @innerColor, @outerColor);
+  .radial(@inner-color: #555, @outer-color: #333) {
+    background-color: @outer-color;
+    background-image: -webkit-gradient(radial, center center, 0, center center, 460, from(@inner-color), to(@outer-color));
+    background-image: -webkit-radial-gradient(circle, @inner-color, @outer-color);
+    background-image: -moz-radial-gradient(circle, @inner-color, @outer-color);
+    background-image: radial-gradient(circle, @inner-color, @outer-color);
     background-repeat: no-repeat;
   }
   .striped(@color: #555, @angle: 45deg) {
@@ -306,12 +316,17 @@
     background-image: linear-gradient(@angle, rgba(255,255,255,.15) 25%, transparent 25%, transparent 50%, rgba(255,255,255,.15) 50%, rgba(255,255,255,.15) 75%, transparent 75%, transparent);
   }
 }
+
 // Reset filters for IE
+//
+// When you need to remove a gradient background, don't forget to use this to reset
+// the IE filter for IE9 and below.
 .reset-filter() {
   filter: e(%("progid:DXImageTransform.Microsoft.gradient(enabled = false)"));
 }
 
 
+
 // RETINA IMAGE SUPPORT
 // --------------------------------------------------