From 6a54fdbf5831b482bc2d9fc2bb13d61a5bad7faa Mon Sep 17 00:00:00 2001
From: GermainBergeron <gbergeron@coveo.com>
Date: Mon, 21 Mar 2016 09:27:43 -0400
Subject: [PATCH] Add option to configure pie label ratio

Keep default behaviour when no option is set
Works with a number or a function
Fixes  #1628
---
 src/arc.js    | 9 ++++++---
 src/config.js | 1 +
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/arc.js b/src/arc.js
index 748291e..fa31784 100644
--- a/src/arc.js
+++ b/src/arc.js
@@ -87,15 +87,18 @@ c3_chart_internal_fn.getArc = function (d, withoutUpdate, force) {
 
 
 c3_chart_internal_fn.transformForArcLabel = function (d) {
-    var $$ = this,
+    var $$ = this, config = $$.config,
         updated = $$.updateAngle(d), c, x, y, h, ratio, translate = "";
     if (updated && !$$.hasType('gauge')) {
         c = this.svgArc.centroid(updated);
         x = isNaN(c[0]) ? 0 : c[0];
         y = isNaN(c[1]) ? 0 : c[1];
         h = Math.sqrt(x * x + y * y);
-        // TODO: ratio should be an option?
-        ratio = $$.radius && h ? (36 / $$.radius > 0.375 ? 1.175 - 36 / $$.radius : 0.8) * $$.radius / h : 0;
+        if (config.pie_label_ratio) {
+            ratio = isFunction(config.pie_label_ratio) ? config.pie_label_ratio(d, $$.radius, h) : config.pie_label_ratio;
+        } else {
+            ratio = $$.radius && h ? (36 / $$.radius > 0.375 ? 1.175 - 36 / $$.radius : 0.8) * $$.radius / h : 0;
+        }
         translate = "translate(" + (x * ratio) +  ',' + (y * ratio) +  ")";
     }
     return translate;
diff --git a/src/config.js b/src/config.js
index 6b65e1f..1e3f19b 100644
--- a/src/config.js
+++ b/src/config.js
@@ -172,6 +172,7 @@ c3_chart_internal_fn.getDefaultConfig = function () {
         pie_label_show: true,
         pie_label_format: undefined,
         pie_label_threshold: 0.05,
+        pie_label_ratio: undefined,
         pie_expand: {},
         pie_expand_duration: 50,
         // gauge