Implement alignmentgroup and offsetgroup

src/plots/cartesian/axis_ids.js

@@ -114,3 +114,13 @@ exports.idSort = function(id1, id2) {
     if(letter1 !== letter2) return letter1 > letter2 ? 1 : -1;
     return +(id1.substr(1) || 1) - +(id2.substr(1) || 1);
 };
+
+exports.getAxisGroup = function getAxisGroup(fullLayout, axId) {
+    var matchGroups = fullLayout._axisMatchGroups;
+
+    for(var i = 0; i < matchGroups.length; i++) {
+        var group = matchGroups[i];
+        if(group[axId]) return 'g' + i;
+    }
+    return axId;
+};

src/plots/plots.js

@@ -394,6 +394,8 @@ plots.supplyDefaults = function(gd, opts) {
     newFullLayout._scatterStackOpts = {};
     // for the first scatter trace on each subplot (so it knows tonext->tozero)
     newFullLayout._firstScatter = {};
+    // for grouped bar/box/violin trace to share config across traces
+    newFullLayout._alignmentOpts = {};
 
     // for traces to request a default rangeslider on their x axes
     // eg set `_requestRangeslider.x2 = true` for xaxis2

src/traces/bar/attributes.js

@@ -174,6 +174,30 @@ module.exports = {
 
     marker: marker,
 
+    offsetgroup: {
+        valType: 'string',
+        role: 'info',
+        dflt: '',
+        editType: 'calc',
+        description: [
+            'Set several traces linked to the same position axis',
+            'or matching axes to the same',
+            'offsetgroup where bars of the same position coordinate will line up.'
+        ].join(' ')
+    },
+    alignmentgroup: {
+        valType: 'string',
+        role: 'info',
+        dflt: '',
+        editType: 'calc',
+        description: [
+            'Set several traces linked to the same position axis',
+            'or matching axes to the same',
+            'alignmentgroup. This controls whether bars compute their positional',
+            'range dependently or independently.'
+        ].join(' ')
+    },
+
     selected: {
         marker: {
             opacity: scatterAttrs.selected.marker.opacity,

src/traces/bar/cross_trace_calc.js

@@ -14,6 +14,7 @@ var BADNUM = require('../../constants/numerical').BADNUM;
 
 var Registry = require('../../registry');
 var Axes = require('../../plots/cartesian/axes');
+var getAxisGroup = require('../../plots/cartesian/axis_ids').getAxisGroup;
 var Sieve = require('./sieve.js');
 
 /*
@@ -279,26 +280,42 @@ function setOffsetAndWidthInGroupMode(gd, pa, sieve) {
     var distinctPositions = sieve.distinctPositions;
     var minDiff = sieve.minDiff;
     var calcTraces = sieve.traces;
+    var nTraces = calcTraces.length;
 
     // if there aren't any overlapping positions,
     // let them have full width even if mode is group
     var overlap = (positions.length !== distinctPositions.length);
-
-    var nTraces = calcTraces.length;
     var barGroupWidth = minDiff * (1 - bargap);
-    var barWidthPlusGap = (overlap) ? barGroupWidth / nTraces : barGroupWidth;
-    var barWidth = barWidthPlusGap * (1 - bargroupgap);
+
+    var groupId = getAxisGroup(fullLayout, pa._id) + calcTraces[0][0].trace.orientation;
+    var alignmentGroups = fullLayout._alignmentOpts[groupId] || {};
 
     for(var i = 0; i < nTraces; i++) {
         var calcTrace = calcTraces[i];
-        var t = calcTrace[0].t;
+        var trace = calcTrace[0].trace;
 
-        // computer bar group center and bar offset
-        var offsetFromCenter = overlap ?
-            ((2 * i + 1 - nTraces) * barWidthPlusGap - barWidth) / 2 :
-            -barWidth / 2;
+        var alignmentGroupOpts = alignmentGroups[trace.alignmentgroup] || {};
+        var nOffsetGroups = Object.keys(alignmentGroupOpts.offsetGroups || {}).length;
 
-        // store bar width and offset for this trace
+        var barWidthPlusGap;
+        if(nOffsetGroups) {
+            barWidthPlusGap = barGroupWidth / nOffsetGroups;
+        } else {
+            barWidthPlusGap = overlap ? barGroupWidth / nTraces : barGroupWidth;
+        }
+
+        var barWidth = barWidthPlusGap * (1 - bargroupgap);
+
+        var offsetFromCenter;
+        if(nOffsetGroups) {
+            offsetFromCenter = ((2 * trace._offsetIndex + 1 - nOffsetGroups) * barWidthPlusGap - barWidth) / 2;
+        } else {
+            offsetFromCenter = overlap ?
+                ((2 * i + 1 - nTraces) * barWidthPlusGap - barWidth) / 2 :
+                -barWidth / 2;
+        }
+
+        var t = calcTrace[0].t;
         t.barwidth = barWidth;
         t.poffset = offsetFromCenter;
         t.bargroupwidth = barGroupWidth;

src/traces/bar/defaults.js

@@ -6,7 +6,6 @@
 * LICENSE file in the root directory of this source tree.
 */
 
-
 'use strict';
 
 var Lib = require('../../lib');
@@ -15,9 +14,10 @@ var Registry = require('../../registry');
 
 var handleXYDefaults = require('../scatter/xy_defaults');
 var handleStyleDefaults = require('../bar/style_defaults');
+var getAxisGroup = require('../../plots/cartesian/axis_ids').getAxisGroup;
 var attributes = require('./attributes');
 
-module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout) {
+function supplyDefaults(traceIn, traceOut, defaultColor, layout) {
     function coerce(attr, dflt) {
         return Lib.coerce(traceIn, traceOut, attributes, attr, dflt);
     }
@@ -78,4 +78,68 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
     errorBarsSupplyDefaults(traceIn, traceOut, lineColor || Color.defaultLine, {axis: 'x', inherit: 'y'});
 
     Lib.coerceSelectionMarkerOpacity(traceOut, coerce);
+}
+
+function handleGroupingDefaults(traceIn, traceOut, fullLayout, coerce) {
+    var orientation = traceOut.orientation;
+    // N.B. grouping is done across all trace trace types that support it
+    var posAxId = traceOut[{v: 'x', h: 'y'}[orientation] + 'axis'];
+    var groupId = getAxisGroup(fullLayout, posAxId) + orientation;
+
+    var alignmentOpts = fullLayout._alignmentOpts || {};
+    var alignmentgroup = coerce('alignmentgroup');
+
+    var alignmentGroups = alignmentOpts[groupId];
+    if(!alignmentGroups) alignmentGroups = alignmentOpts[groupId] = {};
+
+    var alignmentGroupOpts = alignmentGroups[alignmentgroup];
+
+    if(alignmentGroupOpts) {
+        alignmentGroupOpts.traces.push(traceOut);
+    } else {
+        alignmentGroupOpts = alignmentGroups[alignmentgroup] = {
+            traces: [traceOut],
+            alignmentIndex: Object.keys(alignmentGroups).length,
+            offsetGroups: {}
+        };
+    }
+
+    var offsetgroup = coerce('offsetgroup');
+    var offsetGroups = alignmentGroupOpts.offsetGroups;
+    var offsetGroupOpts = offsetGroups[offsetgroup];
+
+    if(offsetgroup) {
+        if(!offsetGroupOpts) {
+            offsetGroupOpts = offsetGroups[offsetgroup] = {
+                offsetIndex: Object.keys(offsetGroups).length
+            };
+        }
+
+        traceOut._offsetIndex = offsetGroupOpts.offsetIndex;
+    }
+}
+
+function crossTraceDefaults(fullData, fullLayout) {
+    var traceIn, traceOut;
+
+    function coerce(attr) {
+        return Lib.coerce(traceOut._input, traceOut, attributes, attr);
+    }
+
+    for(var i = 0; i < fullData.length; i++) {
+        traceOut = fullData[i];
+
+        if(traceOut.type === 'bar') {
+            traceIn = traceOut._input;
+            if(fullLayout.barmode === 'group') {
+                handleGroupingDefaults(traceIn, traceOut, fullLayout, coerce);
+            }
+        }
+    }
+}
+
+module.exports = {
+    supplyDefaults: supplyDefaults,
+    crossTraceDefaults: crossTraceDefaults,
+    handleGroupingDefaults: handleGroupingDefaults
 };

src/traces/bar/index.js

@@ -6,14 +6,14 @@
 * LICENSE file in the root directory of this source tree.
 */
 
-
 'use strict';
 
 var Bar = {};
 
 Bar.attributes = require('./attributes');
 Bar.layoutAttributes = require('./layout_attributes');
-Bar.supplyDefaults = require('./defaults');
+Bar.supplyDefaults = require('./defaults').supplyDefaults;
+Bar.crossTraceDefaults = require('./defaults').crossTraceDefaults;
 Bar.supplyLayoutDefaults = require('./layout_defaults');
 Bar.calc = require('./calc');
 Bar.crossTraceCalc = require('./cross_trace_calc').crossTraceCalc;

src/traces/bar/layout_defaults.js

@@ -6,7 +6,6 @@
 * LICENSE file in the root directory of this source tree.
 */
 
-
 'use strict';
 
 var Registry = require('../../registry');
@@ -15,7 +14,6 @@ var Lib = require('../../lib');
 
 var layoutAttributes = require('./layout_attributes');
 
-
 module.exports = function(layoutIn, layoutOut, fullData) {
     function coerce(attr, dflt) {
         return Lib.coerce(layoutIn, layoutOut, layoutAttributes, attr, dflt);

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

@@ -10,6 +10,7 @@
 
 var Axes = require('../../plots/cartesian/axes');
 var Lib = require('../../lib');
+var getAxisGroup = require('../../plots/cartesian/axis_ids').getAxisGroup;
 
 var orientations = ['v', 'h'];
 
@@ -51,9 +52,6 @@ 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 +74,9 @@ 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 +103,23 @@ 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 = getAxisGroup(fullLayout, 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) {
@@ -109,8 +109,30 @@ function handlePointsDefaults(traceIn, traceOut, coerce, opts) {
     Lib.coerceSelectionMarkerOpacity(traceOut, coerce);
 }
 
+function crossTraceDefaults(fullData, fullLayout) {
+    var traceIn, traceOut;
+
+    function coerce(attr) {
+        return Lib.coerce(traceOut._input, traceOut, attributes, attr);
+    }
+
+    for(var i = 0; i < fullData.length; i++) {
+        traceOut = fullData[i];
+        var traceType = traceOut.type;
+
+        if(traceType === 'box' || traceType === 'violin') {
+            traceIn = traceOut._input;
+            if(fullLayout[traceType + 'mode'] === 'group') {
+                handleGroupingDefaults(traceIn, traceOut, fullLayout, coerce);
+            }
+        }
+    }
+}
+
 module.exports = {
     supplyDefaults: supplyDefaults,
+    crossTraceDefaults: crossTraceDefaults,
+
     handleSampleDefaults: handleSampleDefaults,
     handlePointsDefaults: handlePointsDefaults
 };

src/traces/box/index.js

@@ -13,6 +13,7 @@ var Box = {};
 Box.attributes = require('./attributes');
 Box.layoutAttributes = require('./layout_attributes');
 Box.supplyDefaults = require('./defaults').supplyDefaults;
+Box.crossTraceDefaults = require('./defaults').crossTraceDefaults;
 Box.supplyLayoutDefaults = require('./layout_defaults').supplyLayoutDefaults;
 Box.calc = require('./calc');
 Box.crossTraceCalc = require('./cross_trace_calc').crossTraceCalc;

src/traces/box/layout_defaults.js

@@ -13,10 +13,13 @@ var Lib = require('../../lib');
 var layoutAttributes = require('./layout_attributes');
 
 function _supply(layoutIn, layoutOut, fullData, coerce, traceType) {
-    var hasTraceType;
     var category = traceType + 'Layout';
+    var hasTraceType = false;
+
     for(var i = 0; i < fullData.length; i++) {
-        if(Registry.traceIs(fullData[i], category)) {
+        var trace = fullData[i];
+
+        if(Registry.traceIs(trace, category)) {
             hasTraceType = true;
             break;
         }

src/traces/histogram/attributes.js

@@ -188,6 +188,9 @@ module.exports = {
 
     marker: barAttrs.marker,
 
+    offsetgroup: barAttrs.offsetgroup,
+    alignmentgroup: barAttrs.alignmentgroup,
+
     selected: barAttrs.selected,
     unselected: barAttrs.unselected,