From a761595ce3bd3b06cc8fc7f8878a9d4172c39fe4 Mon Sep 17 00:00:00 2001
From: Liam Galvin <liam@liam-galvin.co.uk>
Date: Fri, 26 Oct 2018 09:46:43 +0100
Subject: [PATCH] Add tabbing support

---
 buffer/buffer.go | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/buffer/buffer.go b/buffer/buffer.go
index 079a770..1ee1d77 100644
--- a/buffer/buffer.go
+++ b/buffer/buffer.go
@@ -554,6 +554,9 @@ func (buffer *Buffer) Write(runes ...rune) {
 		} else if r == 0x0d {
 			buffer.CarriageReturn()
 			continue
+		} else if r == 0x9 {
+			buffer.Tab()
+			continue
 		}
 		line := buffer.getCurrentLine()
 
@@ -638,6 +641,18 @@ func (buffer *Buffer) CarriageReturn() {
 	buffer.cursorX = 0
 }
 
+func (buffer *Buffer) Tab() {
+	defer buffer.emitDisplayChange()
+	tabSize := 4
+	shift := int(buffer.cursorX) % tabSize
+	if shift == 0 {
+		shift = tabSize
+	}
+	for i := 0; i < shift; i++ {
+		buffer.Write(' ')
+	}
+}
+
 func (buffer *Buffer) NewLine() {
 	defer buffer.emitDisplayChange()