add 'styleOnSelect' method to Scatter* module

... that bypasses DOM style things selection doesn't affect.
    This speeds up on-selection perf and brings in back
    to a level comparably to before the persistent selection PR.

Author: etpinard

src/plots/cartesian/select.js

@@ -404,18 +404,20 @@ function updateSelectedState(gd, searchTraces, eventData) {
         var len = items.length;
         var item0 = items[0];
         var trace0 = item0.cd[0].trace;
+        var _module = item0._module;
+        var fn = _module.styleOnSelect || _module.style;
 
         if(Registry.traceIs(trace0, 'regl')) {
             // plot regl traces per module
             var cds = new Array(len);
             for(j = 0; j < len; j++) {
                 cds[j] = items[j].cd;
             }
-            item0._module.style(gd, cds);
+            fn(gd, cds);
         } else {
             // plot svg trace per trace
             for(j = 0; j < len; j++) {
-                item0._module.style(gd, items[j].cd);
+                fn(gd, items[j].cd);
             }
         }
     }

src/traces/scatter/index.js

@@ -27,6 +27,7 @@ Scatter.arraysToCalcdata = require('./arrays_to_calcdata');
 Scatter.plot = require('./plot');
 Scatter.colorbar = require('./colorbar');
 Scatter.style = require('./style').style;
+Scatter.styleOnSelect = require('./style').styleOnSelect;
 Scatter.hoverPoints = require('./hover');
 Scatter.selectPoints = require('./select');
 Scatter.animatable = true;

src/traces/scatter/style.js

@@ -45,7 +45,20 @@ function stylePoints(sel, trace, gd) {
     Drawing.selectedTextStyle(txs, trace);
 }
 
+function styleOnSelect(gd, cd) {
+    var s = cd[0].node3;
+    var trace = cd[0].trace;
+
+    if(trace.selectedpoints) {
+        Drawing.selectedPointStyle(s.selectAll('path.point'), trace, gd);
+        Drawing.selectedPointStyle(s.selectAll('text'), trace, gd);
+    } else {
+        stylePoints(s, trace, gd);
+    }
+}
+
 module.exports = {
     style: style,
-    stylePoints: stylePoints
+    stylePoints: stylePoints,
+    styleOnSelect: styleOnSelect
 };

src/traces/scattercarpet/index.js

@@ -16,6 +16,7 @@ ScatterCarpet.colorbar = require('../scatter/colorbar');
 ScatterCarpet.calc = require('./calc');
 ScatterCarpet.plot = require('./plot');
 ScatterCarpet.style = require('../scatter/style').style;
+ScatterCarpet.styleOnSelect = require('../scatter/style').styleOnSelect;
 ScatterCarpet.hoverPoints = require('./hover');
 ScatterCarpet.selectPoints = require('../scatter/select');
 ScatterCarpet.eventData = require('./event_data');

src/traces/scatterternary/index.js

@@ -16,6 +16,7 @@ ScatterTernary.colorbar = require('../scatter/colorbar');
 ScatterTernary.calc = require('./calc');
 ScatterTernary.plot = require('./plot');
 ScatterTernary.style = require('../scatter/style').style;
+ScatterTernary.styleOnSelect = require('../scatter/style').styleOnSelect;
 ScatterTernary.hoverPoints = require('./hover');
 ScatterTernary.selectPoints = require('../scatter/select');
 ScatterTernary.eventData = require('./event_data');