Fix for removing erratic jittering during scrolling/zooming

draftlogs/7704_fix.md

@@ -0,0 +1 @@
+- Fix visual jumps when zooming/scrolling through plots [[#7704](https://github.com/plotly/plotly.js/pull/7704)]

src/plots/cartesian/dragbox.js

@@ -467,6 +467,16 @@ function makeDragBox(gd, plotinfo, x, y, w, h, ns, ew) {
             return;
         }
 
+        // Store (sub)plot that initiated a scroll
+        if (gd._currentScrollingSubplot == null) {
+            gd._currentScrollingSubplot = plotinfo.id;
+        }
+        // Early exit to prevent jitters if this subplot didn't initiate the scroll
+        if (gd._currentScrollingSubplot !== plotinfo.id) {
+            e.preventDefault();
+            return;
+        }
+
         clearAndResetSelect();
 
         // If a transition is in progress, then disable any behavior:
@@ -528,6 +538,7 @@ function makeDragBox(gd, plotinfo, x, y, w, h, ns, ew) {
         }
 
         // viewbox redraw at first
+        gd._fullLayout._replotting = true;
         updateSubplots(scrollViewBox);
         ticksAndAnnotations();
 
@@ -537,6 +548,7 @@ function makeDragBox(gd, plotinfo, x, y, w, h, ns, ew) {
         // no more scrolling is coming
         redrawTimer = setTimeout(function() {
             if(!gd._fullLayout) return;
+            gd._currentScrollingSubplot = null;
             scrollViewBox = [0, 0, pw, ph];
             dragTail();
         }, REDRAWDELAY);

src/plots/plots.js

@@ -1663,6 +1663,7 @@ plots.purge = function(gd) {
     delete gd._editing;
     delete gd._mouseDownTime;
     delete gd._legendMouseDownTime;
+    delete gd._currentScrollingSubplot;
 
     // remove all event listeners
     if(gd.removeAllListeners) gd.removeAllListeners();