From 99973c9c71b3b1b2b103ba5fa883239f3ea12b72 Mon Sep 17 00:00:00 2001
From: dhilipkumars <dhilip.kumar.s@huawei.com>
Date: Wed, 15 Apr 2015 16:50:49 -0400
Subject: [PATCH] Fix an OutofIndex Panic on empty bargraphs and introduce
 SetMax()

---
 bar.go | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/bar.go b/bar.go
index 807b02d..57bae0a 100644
--- a/bar.go
+++ b/bar.go
@@ -59,7 +59,11 @@ func (bc *BarChart) layout() {
 		bc.dataNum[i] = trimStr2Runes(s, bc.BarWidth)
 	}
 
-	bc.max = bc.Data[0] //  what if Data is nil?
+	//bc.max = bc.Data[0] //  what if Data is nil? Sometimes when bar graph is nill it produces panic with panic: runtime error: index out of range
+	// Asign a negative value to get maxvalue auto-populates
+	if bc.max == 0 {
+		bc.max = -1
+	}
 	for i := 0; i < len(bc.Data); i++ {
 		if bc.max < bc.Data[i] {
 			bc.max = bc.Data[i]
@@ -68,6 +72,13 @@ func (bc *BarChart) layout() {
 	bc.scale = float64(bc.max) / float64(bc.innerHeight-1)
 }
 
+func (bc *BarChart) SetMax(max int) {
+
+	if max > 0 {
+		bc.max = max
+	}
+}
+
 // Buffer implements Bufferer interface.
 func (bc *BarChart) Buffer() []Point {
 	ps := bc.Block.Buffer()