Addressing 2nd round of review feedback:

- adding colour and removing borders from image tests for legend blocks.
- corrected/adjusted all images in image tests
- changed default align for vertical positioned legends to 'center'
- refactored alignment offset function
- removed superfluous 'line' variable
- made consistent the check for moving to a new line/column between vertical/horizontal fit algorithm

docs/configuration/legend.md

@@ -26,8 +26,8 @@ Position of the legend. Options are:
 
 ## Align
 Alignment of the legend. Options are:
-* `'start'` (default for left/right positioned legends)
-* `'center'` (default for top/bottom positioned legends)
+* `'start'`
+* `'center'`
 * `'end'`
 
 Defaults to `'center'` for unrecognized values.

src/plugins/plugin.legend.js

@@ -12,6 +12,7 @@ defaults._set('global', {
 	legend: {
 		display: true,
 		position: 'top',
+		align: 'center',
 		fullWidth: true,
 		reverse: false,
 		weight: 1000,
@@ -105,10 +106,6 @@ var Legend = Element.extend({
 		var me = this;
 		helpers.extend(me, config);
 
-		if (me.options && !me.align) {
-			// to maintain backward compatibility with existing default
-			me.options.align = me.isHorizontal() ? 'center' : 'start';
-		}
 		// Contains hit boxes for each dataset (in dataset order)
 		me.legendHitBoxes = [];
 
@@ -258,7 +255,7 @@ var Legend = Element.extend({
 					var boxWidth = getBoxWidth(labelOpts, fontSize);
 					var width = boxWidth + (fontSize / 2) + ctx.measureText(legendItem.text).width;
 
-					if (i === 0 || lineWidths[lineWidths.length - 1] + width + labelOpts.padding > minSize.width) {
+					if (i === 0 || lineWidths[lineWidths.length - 1] + width + labelOpts.padding > minSize.width - labelOpts.padding) {
 						totalHeight += fontSize + labelOpts.padding;
 						lineWidths[lineWidths.length - (i > 0 ? 0 : 1)] = 0;
 					}
@@ -418,29 +415,29 @@ var Legend = Element.extend({
 			};
 
 			var alignmentOffset = function(dimension, blockSize) {
-				if (opts.align === 'start') {
+				switch (opts.align) {
+				case 'start':
 					return labelOpts.padding;
-				} else if (opts.align === 'end') {
+				case 'end':
 					return dimension - blockSize;
+				default: // center
+					return (dimension - blockSize + labelOpts.padding) / 2;
 				}
-				// default to center
-				return (dimension - blockSize + labelOpts.padding) / 2;
 			};
 
 			// Horizontal
 			var isHorizontal = me.isHorizontal();
-			var line = 0;
 			if (isHorizontal) {
 				cursor = {
-					x: me.left + alignmentOffset(legendWidth, lineWidths[line]),
+					x: me.left + alignmentOffset(legendWidth, lineWidths[0]),
 					y: me.top + labelOpts.padding,
-					line: line
+					line: 0
 				};
 			} else {
 				cursor = {
 					x: me.left + labelOpts.padding,
-					y: me.top + alignmentOffset(legendHeight, columnHeights[line]),
-					line: line
+					y: me.top + alignmentOffset(legendHeight, columnHeights[0]),
+					line: 0
 				};
 			}
 

test/fixtures/plugin.legend/legend-doughnut-left-center-mulitiline.json

@@ -4,7 +4,9 @@
 		"data": {
 			"labels": ["", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", ""],
 			"datasets": [{
-				"data": [10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 40, 50, 60, 70, 10, 20, 30]
+				"data": [10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 40, 50, 60, 70, 10, 20, 30],
+				"backgroundColor": "#00ff00",
+				"borderWidth": 0
 			}]
 		},
 		"options": {

test/fixtures/plugin.legend/legend-doughnut-left-center-single.json

@@ -4,7 +4,9 @@
 		"data": {
 			"labels": [""],
 			"datasets": [{
-				"data": [10]
+				"data": [10],
+				"backgroundColor": "#00ff00",
+				"borderWidth": 0
 			}]
 		},
 		"options": {

test/fixtures/plugin.legend/legend-doughnut-left-default-start.json → test/fixtures/plugin.legend/legend-doughnut-left-default-center.json

@@ -4,7 +4,9 @@
 		"data": {
 			"labels": ["", "", "", "", "", ""],
 			"datasets": [{
-				"data": [10, 20, 30, 40, 50]
+				"data": [10, 20, 30, 40, 50],
+				"backgroundColor": "#00ff00",
+				"borderWidth": 0
 			}]
 		},
 		"options": {

test/fixtures/plugin.legend/legend-doughnut-left-end-mulitiline.json

@@ -4,7 +4,9 @@
 		"data": {
 			"labels": ["", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", ""],
 			"datasets": [{
-				"data": [10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 40, 50, 60, 70, 10, 20, 30]
+				"data": [10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 40, 50, 60, 70, 10, 20, 30],
+				"backgroundColor": "#00ff00",
+				"borderWidth": 0
 			}]
 		},
 		"options": {

test/fixtures/plugin.legend/legend-doughnut-left-start-mulitiline.json

@@ -4,7 +4,9 @@
 		"data": {
 			"labels": ["", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", ""],
 			"datasets": [{
-				"data": [10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 40, 50, 60, 70, 10, 20, 30]
+				"data": [10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 40, 50, 60, 70, 10, 20, 30],
+				"backgroundColor": "#00ff00",
+				"borderWidth": 0
 			}]
 		},
 		"options": {

test/fixtures/plugin.legend/legend-doughnut-top-center-mulitiline.json

@@ -4,7 +4,9 @@
 		"data": {
 			"labels": ["", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", ""],
 			"datasets": [{
-				"data": [10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 20, 10]
+				"data": [10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 20, 10],
+				"backgroundColor": "#00ff00",
+				"borderWidth": 0
 			}]
 		},
 		"options": {

test/fixtures/plugin.legend/legend-doughnut-top-center-single.json

@@ -4,7 +4,9 @@
 		"data": {
 			"labels": [""],
 			"datasets": [{
-				"data": [10]
+				"data": [10],
+				"backgroundColor": "#00ff00",
+				"borderWidth": 0
 			}]
 		},
 		"options": {

test/fixtures/plugin.legend/legend-doughnut-top-end-mulitiline.json

@@ -4,7 +4,9 @@
 		"data": {
 			"labels": ["", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", ""],
 			"datasets": [{
-				"data": [10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 40, 50, 60, 70, 10]
+				"data": [10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 40, 50, 60, 70, 10],
+				"backgroundColor": "#00ff00",
+				"borderWidth": 0
 			}]
 		},
 		"options": {

test/fixtures/plugin.legend/legend-doughnut-top-start-mulitiline.json

@@ -4,7 +4,9 @@
 		"data": {
 			"labels": ["", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", ""],
 			"datasets": [{
-				"data": [10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 40, 50, 60, 70, 10]
+				"data": [10, 20, 30, 40, 50, 60, 70, 10, 20, 30, 40, 50, 60, 70, 10],
+				"backgroundColor": "#00ff00",
+				"borderWidth": 0
 			}]
 		},
 		"options": {

test/specs/plugin.legend.tests.js

@@ -6,6 +6,7 @@ describe('Legend block tests', function() {
 		expect(Chart.defaults.global.legend).toEqual({
 			display: true,
 			position: 'top',
+			align: 'center',
 			fullWidth: true, // marks that this box should take the full width of the canvas (pushing down other boxes)
 			reverse: false,
 			weight: 1000,