make hover AND select use same event data pipeline

Author: etpinard

src/components/fx/helpers.js

@@ -85,6 +85,52 @@ exports.quadrature = function quadrature(dx, dy) {
     };
 };
 
+/** Fill event data point object for hover and selection.
+ *  Invokes _module.eventData if present.
+ *
+ * N.B. note that point 'index' corresponds to input data array index
+ *  whereas 'number' is its post-transform version.
+ *
+ * If the hovered/selected pt corresponds to an multiple input points
+ * (e.g. for histogram and transformed traces), 'pointNumbers` and 'pointIndices'
+ * are include in the event data.
+ *
+ * @param {object} pt
+ * @param {object} trace
+ * @param {object} cd
+ * @return {object}
+ */
+exports.makeEventData = function makeEventData(pt, trace, cd) {
+    // hover uses 'index', select uses 'pointNumber'
+    var pointNumber = 'index' in pt ? pt.index : pt.pointNumber;
+
+    var out = {
+        data: trace._input,
+        fullData: trace,
+        curveNumber: trace.index,
+        pointNumber: pointNumber
+    };
+
+
+    if(trace._module.eventData) {
+        out = trace._module.eventData(out, pt, trace, cd, pointNumber);
+    } else {
+        if('xVal' in pt) out.x = pt.xVal;
+        else if('x' in pt) out.x = pt.x;
+
+        if('yVal' in pt) out.y = pt.yVal;
+        else if('y' in pt) out.y = pt.y;
+
+        if(pt.xa) out.xaxis = pt.xa;
+        if(pt.ya) out.yaxis = pt.ya;
+        if(pt.zLabelVal !== undefined) out.z = pt.zLabelVal;
+    }
+
+    exports.appendArrayPointValue(out, trace, pointNumber);
+
+    return out;
+};
+
 /** Appends values inside array attributes corresponding to given point number
  *
  * @param {object} pointData : point data object (gets mutated here)

src/components/fx/hover.js

@@ -417,26 +417,7 @@ function _hover(gd, evt, subplot, noHoverEvent) {
     // other people and send it to the event
     for(itemnum = 0; itemnum < hoverData.length; itemnum++) {
         var pt = hoverData[itemnum];
-
-        var out = {
-            data: pt.trace._input,
-            fullData: pt.trace,
-            curveNumber: pt.trace.index,
-            pointNumber: pt.index
-        };
-
-        if(pt.trace._module.eventData) out = pt.trace._module.eventData(out, pt);
-        else {
-            out.x = pt.xVal;
-            out.y = pt.yVal;
-            out.xaxis = pt.xa;
-            out.yaxis = pt.ya;
-
-            if(pt.zLabelVal !== undefined) out.z = pt.zLabelVal;
-        }
-
-        helpers.appendArrayPointValue(out, pt.trace, pt.index);
-        newhoverdata.push(out);
+        newhoverdata.push(helpers.makeEventData(pt, pt.trace, pt.cd));
     }
 
     gd._hoverdata = newhoverdata;

src/plots/cartesian/select.js

@@ -13,7 +13,7 @@ var polybool = require('polybooljs');
 var polygon = require('../../lib/polygon');
 var throttle = require('../../lib/throttle');
 var color = require('../../components/color');
-var appendArrayPointValue = require('../../components/fx/helpers').appendArrayPointValue;
+var makeEventData = require('../../components/fx/helpers').makeEventData;
 
 var axes = require('./axes');
 var constants = require('./constants');
@@ -355,15 +355,11 @@ function mergePolygons(list, poly, subtract) {
 
 function fillSelectionItem(selection, searchInfo) {
     if(Array.isArray(selection)) {
+        var cd = searchInfo.cd;
         var trace = searchInfo.cd[0].trace;
 
         for(var i = 0; i < selection.length; i++) {
-            var sel = selection[i];
-
-            sel.curveNumber = trace.index;
-            sel.data = trace._input;
-            sel.fullData = trace;
-            appendArrayPointValue(sel, trace, sel.pointNumber);
+            selection[i] = makeEventData(selection[i], trace, cd);
         }
     }