Merge pull request #7067 from Lexachoc/fix_legend_scroll

fix wrong scrollBoxY value for legend scroll

Author: alexshoe

draftlogs/7067_fix.md

@@ -0,0 +1 @@
+- Fix wrong scrolling behavior for legend [[#7067](https://github.com/plotly/plotly.js/pull/7067)]

src/components/legend/draw.js

@@ -337,7 +337,7 @@ function drawOne(gd, opts) {
                 legend.on('wheel', function() {
                     scrollBoxY = Lib.constrain(
                         legendObj._scrollY +
-                            ((d3.event.deltaY / scrollBarYMax) * scrollBoxYMax),
+                            ((d3.event.deltaY / scrollBoxYMax) * scrollBarYMax),
                         0, scrollBoxYMax);
                     scrollHandler(scrollBoxY, scrollBarHeight, scrollRatio);
                     if(scrollBoxY !== 0 && scrollBoxY !== scrollBoxYMax) {

test/jasmine/tests/legend_scroll_test.js

@@ -101,14 +101,15 @@ describe('The legend', function() {
             var initialDataScroll = getScroll(gd);
             var wheelDeltaY = 100;
             var finalDataScroll = Lib.constrain(initialDataScroll +
-                wheelDeltaY / scrollBarYMax * scrollBoxYMax,
+                ((wheelDeltaY / scrollBoxYMax) * scrollBarYMax),
                 0, scrollBoxYMax);
 
             legend.dispatchEvent(scrollTo(wheelDeltaY));
-
-            expect(getScroll(gd)).toBe(finalDataScroll);
+                
+            var dataScroll = getScroll(gd);
+            expect(dataScroll).toBeCloseTo(finalDataScroll, 3);
             expect(scrollBox.getAttribute('transform')).toBe(
-                'translate(0,' + -finalDataScroll + ')');
+                'translate(0,' + -dataScroll + ')');
         });
 
         function dragScroll(element, rightClick, mainClick) {