better fallback border color for axis common hover labels

Author: alexcjohnson

src/components/fx/hover.js

@@ -713,9 +713,12 @@ function createHoverText(hoverData, opts, gd) {
             s.attr('data-notex', 1);
         });
 
+        var commonBgColor = commonLabelOpts.bgcolor || Color.defaultLine;
+        var commonStroke = commonLabelOpts.bordercolor || Color.contrast(commonBgColor);
+
         lpath.style({
-            fill: commonLabelOpts.bgcolor || Color.defaultLine,
-            stroke: commonLabelOpts.bordercolor || Color.background,
+            fill: commonBgColor,
+            stroke: commonStroke
         });
 
         ltext.text(t0)

test/jasmine/tests/hover_label_test.js

@@ -1918,7 +1918,7 @@ describe('Test hover label custom styling:', function() {
                 text: [20, 'Arial', 'rgb(255, 0, 0)']
             });
             assertCommonLabel({
-                path: ['rgb(255, 255, 255)', 'rgb(255, 255, 255)'],
+                path: ['rgb(255, 255, 255)', 'rgb(68, 68, 68)'],
                 text: [13, 'Arial', 'rgb(255, 255, 255)']
             });
         })
@@ -1930,7 +1930,7 @@ describe('Test hover label custom styling:', function() {
                 text: [20, 'Arial', 'rgb(0, 128, 0)']
             });
             assertCommonLabel({
-                path: ['rgb(255, 255, 255)', 'rgb(255, 255, 255)'],
+                path: ['rgb(255, 255, 255)', 'rgb(68, 68, 68)'],
                 text: [13, 'Arial', 'rgb(255, 255, 255)']
             });
         })
@@ -1942,7 +1942,7 @@ describe('Test hover label custom styling:', function() {
                 text: [20, 'Arial', 'rgb(0, 0, 255)']
             });
             assertCommonLabel({
-                path: ['rgb(255, 255, 255)', 'rgb(255, 255, 255)'],
+                path: ['rgb(255, 255, 255)', 'rgb(68, 68, 68)'],
                 text: [13, 'Arial', 'rgb(255, 255, 255)']
             });
 
@@ -1969,7 +1969,7 @@ describe('Test hover label custom styling:', function() {
 
             assertPtLabel(null);
             assertCommonLabel({
-                path: ['rgb(255, 255, 255)', 'rgb(255, 255, 255)'],
+                path: ['rgb(255, 255, 255)', 'rgb(68, 68, 68)'],
                 text: [13, 'Arial', 'rgb(255, 255, 255)']
             });