Learn event handling and proper rendering

I'm tired of building crappy and ugly interactive interfaces by hand, I
learned Cobra to build CLI tools so I might as well learn tcell to
create TUI tools.

tcell-practice/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"log"
+	"os"
 	"time"
 
 	"github.com/gdamore/tcell/v2"
@@ -10,22 +11,38 @@ import (
 
 func main() {
 	fmt.Println()
-	s, err := tcell.NewScreen()
+	screen, err := tcell.NewScreen()
 	if err != nil {
 		log.Fatalf("%v", err)
 	}
-	if err := s.Init(); err != nil {
+	if err := screen.Init(); err != nil {
 		log.Fatalf("%v", err)
 	}
 
 	//defStyle := tcell.StyleDefault.Background
 	defStyle := tcell.StyleDefault.Background(tcell.ColorReset).Foreground(tcell.ColorReset)
-	s.SetStyle(defStyle)
+	screen.SetStyle(defStyle)
+	go Run(screen, defStyle)
+
 	for {
+		switch event := screen.PollEvent().(type) {
+		case *tcell.EventResize:
+			screen.Sync()
+		case *tcell.EventKey:
+			switch event.Key() == tcell.KeyEscape || event.Key() == tcell.KeyCtrlC {
+			case true:
+				screen.Fini()
+				os.Exit(0)
+			}
+		}
+	}
 
-		s.Clear()
-		s.SetContent(20, 20, 'A', nil, defStyle)
+}
 
+func Run(screen tcell.Screen, defStyle tcell.Style) {
+	for {
+		screen.SetContent(20, 20, 'A', nil, defStyle)
+		screen.Show()
 		time.Sleep(time.Second)
 	}
 }