Legend: add helper.isVertical(legendLayout)

Author: n-riesco

src/components/legend/helpers.js

@@ -20,6 +20,10 @@ exports.isGrouped = function isGrouped(legendLayout) {
     return (legendLayout.traceorder || '').indexOf('grouped') !== -1;
 };
 
+exports.isVertical = function isVertical(legendLayout) {
+    return legendLayout.orientation !== 'h';
+};
+
 exports.isReversed = function isReversed(legendLayout) {
     return (legendLayout.traceorder || '').indexOf('reversed') !== -1;
 };