fix stacked bars on logarithmic axes

diff --git a/src/controllers/controller.bar.js b/src/controllers/controller.bar.js
index bf1fb69379338827e9423c16476d69977e1de27c..fc2f1c0c662ff62f5ee822b80e688e591651b557 100644 (file)
--- a/src/controllers/controller.bar.js
+++ b/src/controllers/controller.bar.js
@@ -99,7 +99,8 @@ module.exports = function(Chart) {
                        var me = this;
                        var meta = me.getMeta();
                        var yScale = me.getScaleForId(meta.yAxisID);
-                       var base = 0;
+                       var base = yScale.getBaseValue();
+                       var original = base;
 
                        if (yScale.options.stacked) {
                                var chart = me.chart;
@@ -111,7 +112,7 @@ module.exports = function(Chart) {
                                        var currentDsMeta = chart.getDatasetMeta(i);
                                        if (currentDsMeta.bar && currentDsMeta.yAxisID === yScale.id && chart.isDatasetVisible(i)) {
                                                var currentVal = Number(currentDs.data[index]);
-                                               base += value < 0 ? Math.min(currentVal, 0) : Math.max(currentVal, 0);
+                                               base += value < 0 ? Math.min(currentVal, original) : Math.max(currentVal, original);
                                        }
                                }
 
@@ -197,8 +198,9 @@ module.exports = function(Chart) {
 
                        if (yScale.options.stacked) {
 
-                               var sumPos = 0,
-                                       sumNeg = 0;
+                               var base = yScale.getBaseValue();
+                               var sumPos = base,
+                                       sumNeg = base;
 
                                for (var i = 0; i < datasetIndex; i++) {
                                        var ds = me.chart.data.datasets[i];
@@ -417,7 +419,8 @@ module.exports = function(Chart) {
                        var me = this;
                        var meta = me.getMeta();
                        var xScale = me.getScaleForId(meta.xAxisID);
-                       var base = 0;
+                       var base = xScale.getBaseValue();
+                       var originalBase = base;
 
                        if (xScale.options.stacked) {
                                var chart = me.chart;
@@ -429,7 +432,7 @@ module.exports = function(Chart) {
                                        var currentDsMeta = chart.getDatasetMeta(i);
                                        if (currentDsMeta.bar && currentDsMeta.xAxisID === xScale.id && chart.isDatasetVisible(i)) {
                                                var currentVal = Number(currentDs.data[index]);
-                                               base += value < 0 ? Math.min(currentVal, 0) : Math.max(currentVal, 0);
+                                               base += value < 0 ? Math.min(currentVal, originalBase) : Math.max(currentVal, originalBase);
                                        }
                                }
 
@@ -481,8 +484,9 @@ module.exports = function(Chart) {
 
                        if (xScale.options.stacked) {
 
-                               var sumPos = 0,
-                                       sumNeg = 0;
+                               var base = xScale.getBaseValue();
+                               var sumPos = base,
+                                       sumNeg = base;
 
                                for (var i = 0; i < datasetIndex; i++) {
                                        var ds = me.chart.data.datasets[i];

diff --git a/src/core/core.scale.js b/src/core/core.scale.js
index 0ea82451c6004b3aeef6508c766d17c639bbc380..06047e4e39ad49fea1519c49ee5946dfdcf0842e 100644 (file)
--- a/src/core/core.scale.js
+++ b/src/core/core.scale.js
@@ -454,15 +454,18 @@ module.exports = function(Chart) {
                },
 
                getBasePixel: function() {
+                       return this.getPixelForValue(this.getBaseValue());
+               },
+
+               getBaseValue: function() {
                        var me = this;
                        var min = me.min;
                        var max = me.max;
 
-                       return me.getPixelForValue(
-                               me.beginAtZero? 0:
+                       return me.beginAtZero ? 0:
                                min < 0 && max < 0? max :
                                min > 0 && max > 0? min :
-                               0);
+                               0;
                },
 
                // Actually draw the scale on the canvas

diff --git a/test/controller.bar.tests.js b/test/controller.bar.tests.js
index 4df23047e01493908f4afef07d26dc3e571036a9..fea88633ce9d218c0cc7590f9aea86885432d14e 100644 (file)
--- a/test/controller.bar.tests.js
+++ b/test/controller.bar.tests.js
@@ -337,6 +337,63 @@ describe('Bar controller tests', function() {
                });
        });
 
+       it('should update elements when the scales are stacked and the y axis is logarithmic', function() {
+               var chart = window.acquireChart({
+                       type: 'bar',
+                       data: {
+                               datasets: [{
+                                       data: [10, 100, 10, 100],
+                                       label: 'dataset1'
+                               }, {
+                                       data: [100, 10, 0, 100],
+                                       label: 'dataset2'
+                               }],
+                               labels: ['label1', 'label2', 'label3', 'label4']
+                       },
+                       options: {
+                               scales: {
+                                       xAxes: [{
+                                               type: 'category',
+                                               stacked: true,
+                                               barPercentage: 1
+                                       }],
+                                       yAxes: [{
+                                               type: 'logarithmic',
+                                               stacked: true
+                                       }]
+                               }
+                       }
+               });
+
+               var meta0 = chart.getDatasetMeta(0);
+
+               [
+                       {b: 484, w: 92, x: 94, y: 379},
+                       {b: 484, w: 92, x: 208, y: 122},
+                       {b: 484, w: 92, x: 322, y: 379},
+                       {b: 484, w: 92, x: 436, y: 122}
+               ].forEach(function(values, i) {
+                       expect(meta0.data[i]._model.base).toBeCloseToPixel(values.b);
+                       expect(meta0.data[i]._model.width).toBeCloseToPixel(values.w);
+                       expect(meta0.data[i]._model.x).toBeCloseToPixel(values.x);
+                       expect(meta0.data[i]._model.y).toBeCloseToPixel(values.y);
+               });
+
+               var meta1 = chart.getDatasetMeta(1);
+
+               [
+                       {b: 379, w: 92, x: 94, y: 109},
+                       {b: 122, w: 92, x: 208, y: 109},
+                       {b: 379, w: 92, x: 322, y: 379},
+                       {b: 122, w: 92, x: 436, y: 25}
+               ].forEach(function(values, i) {
+                       expect(meta1.data[i]._model.base).toBeCloseToPixel(values.b);
+                       expect(meta1.data[i]._model.width).toBeCloseToPixel(values.w);
+                       expect(meta1.data[i]._model.x).toBeCloseToPixel(values.x);
+                       expect(meta1.data[i]._model.y).toBeCloseToPixel(values.y);
+               });
+       });
+
        it('should draw all bars', function() {
                var chart = window.acquireChart({
                        type: 'bar',