fix(legacy-preset-chart-nvd3): tooltip's disappearance and stickiness (…

…#1)

fix: tooltip disappearance and stickiness

superset-frontend/temporary_superset_ui/superset-ui/plugins/superset-ui-plugins/packages/superset-ui-legacy-preset-chart-nvd3/src/NVD3Vis.js

@@ -737,8 +737,9 @@ function nvd3Vis(element, props) {
         .attr('height', height)
         .call(chart);
 
-      // on scroll, hide tooltips. throttle to only 4x/second.
-      window.addEventListener('scroll', throttle(() => hideTooltips(element), 250));
+      // On scroll, hide (not remove) tooltips so they can reappear on hover.
+      // Throttle to only 4x/second.
+      window.addEventListener('scroll', throttle(() => hideTooltips(false), 250));
 
       // The below code should be run AFTER rendering because chart is updated in call()
       if (isTimeSeries && activeAnnotationLayers.length > 0) {
@@ -1001,10 +1002,10 @@ function nvd3Vis(element, props) {
     return chart;
   };
 
-  // hide tooltips before rendering chart, if the chart is being re-rendered sometimes
+  // Remove tooltips before rendering chart, if the chart is being re-rendered sometimes
   // there are left over tooltips in the dom,
   // this will clear them before rendering the chart again.
-  hideTooltips(element);
+  hideTooltips(true);
 
   nv.addGraph(drawGraph);
 }

superset-frontend/temporary_superset_ui/superset-ui/plugins/superset-ui-plugins/packages/superset-ui-legacy-preset-chart-nvd3/src/utils.js

@@ -190,12 +190,20 @@ export function generateBubbleTooltipContent({
   return s;
 }
 
-export function hideTooltips(element) {
-  if (element) {
-    const targets = element.querySelectorAll('.nvtooltip');
-    if (targets.length > 0) {
-      targets.forEach(t => t.remove());
-    }
+// shouldRemove indicates whether the nvtooltips should be removed from the DOM
+export function hideTooltips(shouldRemove) {
+  const targets = document.querySelectorAll('.nvtooltip');
+  if (targets.length > 0) {
+    // Only set opacity to 0 when hiding tooltips so they would reappear
+    // on hover, which sets the opacity to 1
+    targets.forEach(t => {
+      if (shouldRemove) {
+        t.remove();
+      } else {
+        // eslint-disable-next-line no-param-reassign
+        t.style.opacity = 0;
+      }
+    });
   }
 }