add timer subcommand

2 files changed, 119 insertions, 0 deletions

diff --git a/cmd/root.go b/cmd/root.go
index d0f9713..34a12f3 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -11,6 +11,7 @@ var rootCmd = &cobra.Command{
 
 func init() {
 	rootCmd.AddCommand(clockCmd)
+	rootCmd.AddCommand(timerCmd)
 }
 
 func Execute() error {
diff --git a/cmd/timer.go b/cmd/timer.go
new file mode 100644
index 0000000..0a47f8d
--- /dev/null
+++ b/cmd/timer.go
@@ -0,0 +1,118 @@
+package cmd
+
+import (
+	"log"
+	"time"
+
+	"github.com/gdamore/tcell/v2"
+	"github.com/spf13/cobra"
+)
+
+func drawTimer(scr tcell.Screen, time time.Duration, elapsed time.Duration, bgStyle, clockStyle tcell.Style) {
+	left := time-elapsed
+	if left<0{
+		left=0
+		bgStyle, clockStyle = clockStyle, bgStyle
+	}
+
+	// Clear the entire screen.
+	scr.SetStyle(bgStyle)
+	scr.Clear()
+
+	// Calculate square width/height and offset.
+	scrW, scrH := scr.Size()
+	//         17
+	// <--------------->
+	// ### ###   ### ### ^
+	// # # # # # # # # # |
+	// # # # #   # # # # | 5
+	// # # # # # # # # # |
+	// ### ###   ### ### v
+	squareW := scrW / (17 + 2)
+	squareH := scrH / (5 + 2)
+	if squareH > squareW {
+		squareH = squareW
+	}
+	if squareW > squareH*3/2 {
+		squareW = squareH * 3 / 2
+	}
+	xOffset := (scrW - squareW*17) / 2
+	yOffset := (scrH - squareH*5) / 2
+
+	// Minute
+	minute := left.Minutes()
+	drawNumber(scr, int(minute)/10, xOffset+squareW*0, yOffset, squareW, squareH, clockStyle)
+	drawNumber(scr, int(minute)%10, xOffset+squareW*4, yOffset, squareW, squareH, clockStyle)
+
+	// Colon
+	drawSquare(scr, xOffset+squareW*8, yOffset+squareH*1, squareW, squareH, clockStyle)
+	drawSquare(scr, xOffset+squareW*8, yOffset+squareH*3, squareW, squareH, clockStyle)
+
+	// Second
+	second := left.Seconds()
+	drawNumber(scr, int(second)/10, xOffset+squareW*10, yOffset, squareW, squareH, clockStyle)
+	drawNumber(scr, int(second)%10, xOffset+squareW*14, yOffset, squareW, squareH, clockStyle)
+}
+
+func cmdTimer(cmd *cobra.Command, args []string) {
+	timerTime, err := time.ParseDuration(args[0])
+	if err != nil {
+	log.Fatalf("%+v", err)
+	}
+
+	bgStyle := tcell.StyleDefault.Background(tcell.ColorReset).Foreground(tcell.ColorReset)
+	clockStyle := tcell.StyleDefault.Foreground(tcell.ColorWhite).Background(tcell.ColorOlive)
+
+	scr, err := tcell.NewScreen()
+	if err != nil {
+		log.Fatalf("%+v", err)
+	}
+	if err := scr.Init(); err != nil {
+		log.Fatalf("%+v", err)
+	}
+	defer scr.Fini()
+
+	startTime := time.Now()
+
+	drawTimer(scr, timerTime, time.Now().Sub(startTime), bgStyle, clockStyle)
+
+	quitC := make(chan struct{})
+
+	go func() {
+		for {
+			scr.Show()
+
+			ev := scr.PollEvent()
+			switch ev := ev.(type) {
+			case *tcell.EventResize:
+				drawTimer(scr, timerTime, time.Now().Sub(startTime), bgStyle, clockStyle)
+				scr.Sync()
+			case *tcell.EventKey:
+				if ev.Key() == tcell.KeyEscape || ev.Key() == tcell.KeyCtrlC || ev.Rune() == 'q' {
+					close(quitC)
+					return
+				}
+			}
+		}
+	}()
+
+	t := time.NewTicker(1 * time.Second)
+	defer t.Stop()
+
+	for {
+		select {
+		case <-quitC:
+			return
+		case now := <-t.C:
+			drawTimer(scr, timerTime, now.Sub(startTime), bgStyle, clockStyle)
+			scr.Show()
+		}
+	}
+}
+
+var timerCmd =&cobra.Command{
+	Use: "timer",
+	Short: "Timer mode",
+	Run: cmdTimer,
+	Args: cobra.ExactArgs(1),
+}