From 02abc46d5e1ece800bfb20501950aebb0d79825e Mon Sep 17 00:00:00 2001
From: Evert Timberg <evert.timberg@gmail.com>
Date: Sat, 22 Aug 2015 16:56:02 -0400
Subject: [PATCH] Count the number of bars when determining the bar width

---
 src/controllers/controller.bar.js | 30 +++++++++++++++++++++++++-----
 src/scales/scale.category.js      | 10 +++++-----
 2 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/src/controllers/controller.bar.js b/src/controllers/controller.bar.js
index c68d478c5..94decab04 100644
--- a/src/controllers/controller.bar.js
+++ b/src/controllers/controller.bar.js
@@ -61,6 +61,21 @@
 			return this.chart.scales[scaleID];
 		},
 
+		// Get the number of datasets that display bars. We use this to correctly calculate the bar width
+		getBarCount: function getBarCount() {
+			var barCount = 0;
+
+			helpers.each(this.chart.data.datasets, function(dataset) {
+				if (dataset.type === 'bar') {
+					++barCount;
+				} else if (dataset.type === undefined && this.chart.config.type === 'bar') {
+					++barCount;
+				}
+			}, this);
+
+			return barCount;
+		},
+
 		addElements: function() {
 			this.getDataset().metaData = this.getDataset().metaData || [];
 			helpers.each(this.getDataset().data, function(value, index) {
@@ -78,7 +93,10 @@
 				_datasetIndex: this.index,
 				_index: index,
 			});
-			this.updateElement(rectangle, index, true);
+
+			var numBars = this.getBarCount();
+
+			this.updateElement(rectangle, index, true, numBars);
 			this.getDataset().metaData.splice(index, 0, rectangle);
 		},
 		removeElement: function(index) {
@@ -90,12 +108,14 @@
 		},
 
 		update: function(reset) {
+			var numBars = this.getBarCount();
+
 			helpers.each(this.getDataset().metaData, function(rectangle, index) {
-				this.updateElement(rectangle, index, reset);
+				this.updateElement(rectangle, index, reset, numBars);
 			}, this);
 		},
 
-		updateElement: function updateElement(rectangle, index, reset) {
+		updateElement: function updateElement(rectangle, index, reset, numBars) {
 			var xScale = this.getScaleForId(this.getDataset().xAxisID);
 			var yScale = this.getScaleForId(this.getDataset().yAxisID);
 			var yScalePoint;
@@ -120,7 +140,7 @@
 
 				// Desired view properties
 				_model: {
-					x: xScale.calculateBarX(this.chart.data.datasets.length, this.index, index),
+					x: xScale.calculateBarX(numBars, this.index, index),
 					y: reset ? yScalePoint : yScale.calculateBarY(this.index, index),
 
 					// Tooltip
@@ -129,7 +149,7 @@
 
 					// Appearance
 					base: yScale.calculateBarBase(this.index, index),
-					width: xScale.calculateBarWidth(this.chart.data.datasets.length),
+					width: xScale.calculateBarWidth(numBars),
 					backgroundColor: rectangle.custom && rectangle.custom.backgroundColor ? rectangle.custom.backgroundColor : helpers.getValueAtIndexOrDefault(this.getDataset().backgroundColor, index, this.chart.options.elements.rectangle.backgroundColor),
 					borderColor: rectangle.custom && rectangle.custom.borderColor ? rectangle.custom.borderColor : helpers.getValueAtIndexOrDefault(this.getDataset().borderColor, index, this.chart.options.elements.rectangle.borderColor),
 					borderWidth: rectangle.custom && rectangle.custom.borderWidth ? rectangle.custom.borderWidth : helpers.getValueAtIndexOrDefault(this.getDataset().borderWidth, index, this.chart.options.elements.rectangle.borderWidth),
diff --git a/src/scales/scale.category.js b/src/scales/scale.category.js
index ec355c77c..d97699c1f 100644
--- a/src/scales/scale.category.js
+++ b/src/scales/scale.category.js
@@ -75,19 +75,19 @@
         calculateBaseWidth: function() {
             return (this.getPixelForValue(null, 1, 0, true) - this.getPixelForValue(null, 0, 0, true)) - (2 * this.options.categorySpacing);
         },
-        calculateBarWidth: function(datasetCount) {
+        calculateBarWidth: function(barDatasetCount) {
             //The padding between datasets is to the right of each bar, providing that there are more than 1 dataset
-            var baseWidth = this.calculateBaseWidth() - ((datasetCount - 1) * this.options.spacing);
+            var baseWidth = this.calculateBaseWidth() - ((barDatasetCount - 1) * this.options.spacing);
 
             if (this.options.stacked) {
                 return baseWidth;
             }
-            return (baseWidth / datasetCount);
+            return (baseWidth / barDatasetCount);
         },
-        calculateBarX: function(datasetCount, datasetIndex, elementIndex) {
+        calculateBarX: function(barDatasetCount, datasetIndex, elementIndex) {
             var xWidth = this.calculateBaseWidth(),
                 xAbsolute = this.getPixelForValue(null, elementIndex, datasetIndex, true) - (xWidth / 2),
-                barWidth = this.calculateBarWidth(datasetCount);
+                barWidth = this.calculateBarWidth(barDatasetCount);
 
             if (this.options.stacked) {
                 return xAbsolute + barWidth / 2;
-- 
2.47.2