add alignmentgroup and offsetgroup to bar and violin traces

Author: etpinard

src/traces/box/attributes.js

@@ -9,6 +9,7 @@
 'use strict';
 
 var scatterAttrs = require('../scatter/attributes');
+var barAttrs = require('../bar/attributes');
 var colorAttrs = require('../../components/color/attributes');
 var extendFlat = require('../../lib/extend').extendFlat;
 
@@ -250,6 +251,9 @@ module.exports = {
     },
     fillcolor: scatterAttrs.fillcolor,
 
+    offsetgroup: barAttrs.offsetgroup,
+    alignmentgroup: barAttrs.alignmentgroup,
+
     selected: {
         marker: scatterAttrs.selected.marker,
         editType: 'style'

src/traces/box/cross_trace_calc.js

@@ -51,9 +51,6 @@ function setPositionOffset(traceType, gd, boxList, posAxis) {
     var axId = posAxis._id;
     var axLetter = axId.charAt(0);
 
-    // N.B. reused in violin
-    var numKey = traceType === 'violin' ? '_numViolins' : '_numBoxes';
-
     var i, j, calcTrace;
     var pointList = [];
     var shownPts = 0;
@@ -76,8 +73,9 @@ function setPositionOffset(traceType, gd, boxList, posAxis) {
     // check for forced minimum dtick
     Axes.minDtick(posAxis, boxdv.minDiff, boxdv.vals[0], true);
 
-    var num = fullLayout[numKey];
-    var group = (fullLayout[traceType + 'mode'] === 'group' && num > 1);
+    var numKey = traceType === 'violin' ? '_numViolins' : '_numBoxes';
+    var numTotal = fullLayout[numKey];
+    var group = fullLayout[traceType + 'mode'] === 'group' && numTotal > 1;
     var groupFraction = 1 - fullLayout[traceType + 'gap'];
     var groupGapFraction = 1 - fullLayout[traceType + 'groupgap'];
 
@@ -104,9 +102,23 @@ function setPositionOffset(traceType, gd, boxList, posAxis) {
             bPos = 0;
         } else {
             dPos = dPos0;
-            bdPos = dPos * groupFraction * groupGapFraction / (group ? num : 1);
-            bPos = group ? 2 * dPos * (-0.5 + (t.num + 0.5) / num) * groupFraction : 0;
-            wHover = dPos * (group ? groupFraction / num : 1);
+
+            if(group) {
+                var groupId = posAxis._id + trace.orientation;
+                var alignmentGroups = fullLayout._alignmentOpts[groupId] || {};
+                var alignmentGroupOpts = alignmentGroups[trace.alignmentgroup] || {};
+                var nOffsetGroups = Object.keys(alignmentGroupOpts.offsetGroups || {}).length;
+                var num = nOffsetGroups || numTotal;
+                var shift = nOffsetGroups ? trace._offsetIndex : t.num;
+
+                bdPos = dPos * groupFraction * groupGapFraction / num;
+                bPos = 2 * dPos * (-0.5 + (shift + 0.5) / num) * groupFraction;
+                wHover = dPos * groupFraction / num;
+            } else {
+                bdPos = dPos * groupFraction * groupGapFraction;
+                bPos = 0;
+                wHover = dPos;
+            }
         }
         t.dPos = dPos;
         t.bPos = bPos;

src/traces/box/defaults.js

@@ -11,7 +11,7 @@
 var Lib = require('../../lib');
 var Registry = require('../../registry');
 var Color = require('../../components/color');
-
+var handleGroupingDefaults = require('../bar/defaults').handleGroupingDefaults;
 var attributes = require('./attributes');
 
 function supplyDefaults(traceIn, traceOut, defaultColor, layout) {
@@ -34,6 +34,7 @@ function supplyDefaults(traceIn, traceOut, defaultColor, layout) {
     if(notched) coerce('notchwidth');
 
     handlePointsDefaults(traceIn, traceOut, coerce, {prefix: 'box'});
+    handleGroupingDefaults(traceIn, traceOut, layout, coerce);
 }
 
 function handleSampleDefaults(traceIn, traceOut, coerce, layout) {

src/traces/violin/attributes.js

@@ -238,6 +238,9 @@ module.exports = {
         ].join(' ')
     },
 
+    offsetgroup: boxAttrs.offsetgroup,
+    alignmentgroup: boxAttrs.alignmentgroup,
+
     selected: boxAttrs.selected,
     unselected: boxAttrs.unselected,
 

src/traces/violin/defaults.js

@@ -12,6 +12,7 @@ var Lib = require('../../lib');
 var Color = require('../../components/color');
 
 var boxDefaults = require('../box/defaults');
+var handleGroupingDefaults = require('../bar/defaults').handleGroupingDefaults;
 var attributes = require('./attributes');
 
 module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout) {
@@ -56,4 +57,6 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
     var meanLineWidth = coerce2('meanline.width', lineWidth);
     var meanLineVisible = coerce('meanline.visible', Boolean(meanLineColor || meanLineWidth));
     if(!meanLineVisible) traceOut.meanline = {visible: false};
+
+    handleGroupingDefaults(traceIn, traceOut, layout, coerce);
 };