From 87ac933c106450b77dd00b8d08e083baef41b88e Mon Sep 17 00:00:00 2001
From: Evert Timberg <evert.timberg@gmail.com>
Date: Sat, 8 Aug 2015 11:52:20 -0400
Subject: [PATCH] Linear scale has proper padding in both vertical and
 horizontal orientations. Should prevent labels from getting cut off even when
 axes are not displayed.

---
 src/scales/scale.linear.js | 40 +++++++++++++++++++++++++++++++++++---
 1 file changed, 37 insertions(+), 3 deletions(-)

diff --git a/src/scales/scale.linear.js b/src/scales/scale.linear.js
index 8ab840eb9..c9827e02e 100644
--- a/src/scales/scale.linear.js
+++ b/src/scales/scale.linear.js
@@ -166,10 +166,14 @@
 			var range = this.end - this.start;
 
 			if (this.isHorizontal()) {
-				pixel = this.left + (this.width / range * (value - this.start));
+				var innerWidth = this.width - (this.paddingLeft + this.paddingRight);
+				pixel = this.left + (innerWidth / range * (value - this.start));
+				pixel += this.paddingLeft;
 			} else {
 				// Bottom - top since pixels increase downard on a screen
-				pixel = this.bottom - (this.height / range * (value - this.start));
+				var innerHeight = this.height - (this.paddingTop + this.paddingBottom);
+				pixel = this.bottom - (innerHeight / range * (value - this.start));
+				pixel += this.paddingTop;
 			}
 
 			return pixel;
@@ -343,7 +347,7 @@
 		// @param {number} maxWidth : the max width the axis can be
 		// @param {number} maxHeight: the max height the axis can be
 		// @return {object} minSize : the minimum size needed to draw the axis
-		fit: function(maxWidth, maxHeight) {
+		fit: function(maxWidth, maxHeight, margins) {
 			this.calculateRange();
 			this.generateTicks(maxWidth, maxHeight);
 			this.buildLabels();
@@ -386,6 +390,10 @@
 				minSize.height = maxHeight; // fill all the height
 			}
 
+			this.paddingLeft = 0;
+			this.paddingRight = 0;
+			this.paddingTop = 0;
+			this.paddingBottom = 0;
 
 
 			if (this.options.labels.show && this.options.display) {
@@ -398,6 +406,16 @@
 					var maxLabelHeight = maxHeight - minSize.height;
 					var labelHeight = 1.5 * this.options.labels.fontSize;
 					minSize.height = Math.min(maxHeight, minSize.height + labelHeight);
+
+					var labelFont = helpers.fontString(this.options.labels.fontSize, this.options.labels.fontStyle, this.options.labels.fontFamily);
+					this.ctx.font = labelFont;
+
+					var firstLabelWidth = this.ctx.measureText(this.labels[0]).width;
+					var lastLabelWidth = this.ctx.measureText(this.labels[this.labels.length - 1]).width;
+
+					// Ensure that our labels are always inside the canvas
+					this.paddingLeft = firstLabelWidth / 2;
+					this.paddingRight = lastLabelWidth / 2;
 				} else {
 					// A vertical axis is more constrained by the width. Labels are the dominant factor 
 					// here, so get that length first
@@ -407,13 +425,29 @@
 					if (largestTextWidth < maxLabelWidth) {
 						// We don't need all the room
 						minSize.width += largestTextWidth;
+						minSize.width += 3; // extra padding
 					} else {
 						// Expand to max size
 						minSize.width = maxWidth;
 					}
+
+					this.paddingTop = this.options.labels.fontSize / 2;
+					this.paddingBottom = this.options.labels.fontSize / 2;
 				}
 			}
 
+			if (margins) {
+				this.paddingLeft -= margins.left;
+				this.paddingTop -= margins.top;
+				this.paddingRight -= margins.right;
+				this.paddingBottom -= margins.bottom;
+
+				this.paddingLeft = Math.max(this.paddingLeft, 0);
+				this.paddingTop = Math.max(this.paddingTop, 0);
+				this.paddingRight = Math.max(this.paddingRight, 0);
+				this.paddingBottom = Math.max(this.paddingBottom, 0);
+			}
+
 			this.width = minSize.width;
 			this.height = minSize.height;
 			return minSize;