From afdb20d88ecfd0d3464adf2ca7a8f87d7935409b Mon Sep 17 00:00:00 2001
From: Klaus Weidner <klausw@google.com>
Date: Mon, 27 Feb 2012 10:31:16 -0800
Subject: [PATCH] Change option to highlightSeriesBackgroundAlpha

This is 1 - highlightSeriesBackgroundFade (using the old option), and hopefully more intuitive.
---
 auto_tests/tests/callback.js | 2 +-
 dygraph-options-reference.js | 4 ++--
 dygraph.js                   | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/auto_tests/tests/callback.js b/auto_tests/tests/callback.js
index aad0dad..fe7f7fd 100644
--- a/auto_tests/tests/callback.js
+++ b/auto_tests/tests/callback.js
@@ -167,7 +167,7 @@ var runClosestTest = function(isStacked, widthNormal, widthHighlighted) {
         strokeWidth: widthNormal,
         strokeBorderWidth: 2,
         highlightCircleSize: widthNormal * 2,
-        highlightSeriesBackgroundFade: 0.7,
+        highlightSeriesBackgroundAlpha: 0.3,
 
         highlightSeriesOpts: {
           strokeWidth: widthHighlighted,
diff --git a/dygraph-options-reference.js b/dygraph-options-reference.js
index bc5867e..cb8b767 100644
--- a/dygraph-options-reference.js
+++ b/dygraph-options-reference.js
@@ -145,11 +145,11 @@ Dygraph.OPTIONS_REFERENCE =  // <JSON>
     "type": "Object",
     "description": "When set, the options from this object are applied to the timeseries closest to the mouse pointer for interactive highlighting. See also 'highlightCallback'. Example: highlightSeriesOpts: { strokeWidth: 3 }."
   },
-  "highlightSeriesBackgroundFade": {
+  "highlightSeriesBackgroundAlpha": {
     "default": "0.5",
     "labels": ["Interactive Elements"],
     "type": "float",
-    "description": "When nonzero, dim the background while highlighting series. 0=fully visible background, 1=hiddden background (show highlighted series only)."
+    "description": "Fade the background while highlighting series. 1=fully visible background (disable fading), 0=hiddden background (show highlighted series only)."
   },
   "includeZero": {
     "default": "false",
diff --git a/dygraph.js b/dygraph.js
index 298f64b..9979587 100644
--- a/dygraph.js
+++ b/dygraph.js
@@ -187,7 +187,7 @@ Dygraph.dateAxisFormatter = function(date, granularity) {
 Dygraph.DEFAULT_ATTRS = {
   highlightCircleSize: 3,
   highlightSeriesOpts: null,
-  highlightSeriesBackgroundFade: 0.5,
+  highlightSeriesBackgroundAlpha: 0.5,
 
   labelsDivWidth: 250,
   labelsDivStyles: {
@@ -1885,7 +1885,7 @@ Dygraph.prototype.updateSelection_ = function(opt_animFraction) {
   var ctx = this.canvas_ctx_;
   if (this.attr_('highlightSeriesOpts')) {
     ctx.clearRect(0, 0, this.width_, this.height_);
-    var alpha = this.attr_('highlightSeriesBackgroundFade');
+    var alpha = 1.0 - this.attr_('highlightSeriesBackgroundAlpha');
     if (alpha) {
       // Activating background fade includes an animation effect for a gradual
       // fade. TODO(klausw): make this independently configurable if it causes
-- 
2.7.4