From 5ff459b6ad12bddd1009505c1f1c43cec27c621c Mon Sep 17 00:00:00 2001
From: Timothy Warren <twarren@nabancard.com>
Date: Thu, 5 Oct 2023 15:29:37 -0400
Subject: [PATCH] Complete Chapter 7 Step 176

---
 editor/draw.go | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/editor/draw.go b/editor/draw.go
index 3b867be..c9e33d4 100644
--- a/editor/draw.go
+++ b/editor/draw.go
@@ -8,6 +8,7 @@ import (
 	"timshome.page/gilo/editor/highlight"
 	"timshome.page/gilo/internal/gilo"
 	"timshome.page/gilo/terminal"
+	"unicode"
 )
 
 // ----------------------------------------------------------------------------
@@ -57,6 +58,7 @@ func (e *Editor) scroll() {
 	}
 }
 
+// drawRows is the equivalent to editorDrawRows in kilo
 func (e *Editor) drawRows(ab *gilo.Buffer) {
 	for y := 0; y < e.screen.Rows; y++ {
 		fileRow := y + e.offset.Y
@@ -89,7 +91,19 @@ func (e *Editor) drawFileRow(fileRow int, ab *gilo.Buffer) {
 	// this by runes so that multibyte-characters (like emoji) can
 	// all be displayed
 	for i, ch := range row.RenderRune(e.offset) {
-		if row.Hl[i] == highlight.Normal {
+		if unicode.IsControl(ch) {
+			sym := '?'
+			if ch <= 26 {
+				sym = '@' + ch
+			}
+
+			ab.Append(terminal.InvertColor)
+			ab.AppendRune(sym)
+			ab.Append(terminal.ResetColor)
+			if currentColor != terminal.DefaultFGColor {
+				ab.Append(currentColor)
+			}
+		} else if row.Hl[i] == highlight.Normal {
 			if currentColor != terminal.DefaultFGColor {
 				ab.Append(terminal.DefaultFGColor)
 				currentColor = terminal.DefaultFGColor
@@ -189,6 +203,7 @@ func (e *Editor) drawStatusBar(ab *gilo.Buffer) {
 	ab.Append(terminal.ResetColor)
 }
 
+// drawMessageBar is the equivalent of editorDrawMessageBar in kilo
 func (e *Editor) drawMessageBar(ab *gilo.Buffer) {
 	ab.Append("\r\n")
 	ab.Append(terminal.ClearLine)