Fix the flickering issue

filter.go

@@ -18,6 +18,7 @@ package main
 import (
 	"fmt"
 	"log"
+	"strings"
 
 	"github.com/gdamore/tcell/v2"
 )
@@ -42,7 +43,7 @@ var helpStyle tcell.Style
 func drawText(s tcell.Screen, x1, y1, x2, y2 int, style tcell.Style, text string) {
 	row := y1
 	col := x1
-	for _, r := range []rune(text) {
+	for _, r := range text {
 		s.SetContent(col, row, r, nil, style)
 		col++
 		if col >= x2 {
@@ -65,10 +66,10 @@ func Render(s tcell.Screen, inputs Items, lowerBound int, upperBound int, curren
 		var txt string
 
 		if item.Selected {
-			txt = fmt.Sprintf(" X %s", item.Text)
+			txt = fmt.Sprintf("  X %s", item.Text)
 			style = selectedStyle
 		} else {
-			txt = fmt.Sprintf("   %s", item.Text)
+			txt = fmt.Sprintf("    %s", item.Text)
 		}
 
 		if current == lowerBound+i {
@@ -76,8 +77,16 @@ func Render(s tcell.Screen, inputs Items, lowerBound int, upperBound int, curren
 		}
 
 		drawText(s, 0, y, xmax-1, y+1, style, txt)
+		// Clean up the rest of the line that might've been filled with a previous render.
+		// This is a hack to NOT use `Clear` on each loop
+		drawText(s, len(txt), y, xmax-1, y+1, style, strings.Repeat(" ", xmax-1-len(txt)))
+		if current == lowerBound+i {
+			drawText(s, 0, y, 1, y+1, tcell.StyleDefault.Foreground(tcell.ColorGreen).Bold(true), ">")
+		}
+
 		y += 1
 	}
+
 }
 
 func main() {
@@ -88,7 +97,7 @@ func main() {
 
 	// TODO: Make the default style configurable
 	defStyle := tcell.StyleDefault.Background(tcell.ColorDefault).Foreground(tcell.ColorDefault)
-	highlight = tcell.StyleDefault.Background(tcell.ColorDarkGray).Foreground(tcell.ColorWhite)
+	highlight = tcell.StyleDefault.Background(tcell.ColorDefault).Foreground(tcell.ColorWhite).Bold(true)
 	selectedStyle = tcell.StyleDefault.Foreground(tcell.ColorYellow)
 	helpStyle = tcell.StyleDefault.Foreground(tcell.ColorDefault)
 
@@ -129,8 +138,6 @@ func main() {
 
 	// Event loop
 	for !done {
-		//s.Clear()
-
 		Render(s, input, lowerBound, upperBound, currentLine)
 
 		// Update screen