Display centered welcome message

fn/fn.go

@@ -0,0 +1,23 @@
+package fn
+
+import "strings"
+
+func TruncateString(s string, length int) string {
+	if length < 1 {
+		return ""
+	}
+
+	var buf strings.Builder
+	count := 0
+
+	for _, char := range s {
+		if count == length {
+			break
+		}
+
+		buf.WriteRune(char)
+		count++
+	}
+
+	return buf.String()
+}

internal/editor/editor.go

@@ -3,11 +3,14 @@ package editor
 import (
 	"fmt"
 	"strings"
+	"timshome.page/gilo/fn"
 	"timshome.page/gilo/internal/ansi"
 	"timshome.page/gilo/internal/char"
 	"timshome.page/gilo/internal/terminal"
 )
 
+const KiloVersion = "0.0.1"
+
 // ----------------------------------------------------------------------------
 // !Editor
 // ----------------------------------------------------------------------------
@@ -52,7 +55,28 @@ func (e *editor) ProcessKeypress() bool {
 
 func (e *editor) drawRows(ab *buffer) {
 	for y :=0; y < e.rows; y += 1 {
-		ab.appendRune('~')
+		if y == e.rows / 3 {
+			welcome := fmt.Sprintf("Gilo editor -- version %s", KiloVersion)
+			if len(welcome) > e.cols {
+				welcome = fn.TruncateString(welcome, e.cols)
+			}
+
+			padding := (e.cols - len(welcome)) / 2
+			if padding > 0 {
+				ab.appendRune('~')
+				padding--
+			}
+
+			for padding > 0 {
+				padding--
+				ab.appendRune(' ')
+			}
+
+			ab.append(welcome)
+		} else {
+			ab.appendRune('~')
+		}
+
 		ab.append(ansi.ClearLine)
 
 		if y < (e.rows - 1) {
@@ -99,4 +123,4 @@ func (b *buffer) appendLn(s string) int {
 
 func (b *buffer) toString() string {
 	return b.buf.String()
-}
+}