initial implementation

2 files changed, 221 insertions, 0 deletions

diff --git a/cmd/clock.go b/cmd/clock.go
new file mode 100644
index 0000000..69c125d
--- /dev/null
+++ b/cmd/clock.go
@@ -0,0 +1,203 @@
+package cmd
+
+import (
+	"log"
+	"time"
+
+	"github.com/gdamore/tcell/v2"
+	"github.com/spf13/cobra"
+)
+
+func drawSquare(scr tcell.Screen, xOffset, yOffset, w, h int, style tcell.Style) {
+	for dx := 0; dx < w; dx++ {
+		x := xOffset + dx
+		for dy := 0; dy < h; dy++ {
+			y := yOffset + dy
+			scr.SetContent(x, y, ' ', nil, style)
+		}
+	}
+}
+
+func drawNumber(scr tcell.Screen, n, xOffset, yOffset, squareW, squareH int, style tcell.Style) {
+	defs := [...][15]bool{
+		{
+			true, true, true,
+			true, false, true,
+			true, false, true,
+			true, false, true,
+			true, true, true,
+		},
+		{
+			false, false, true,
+			false, false, true,
+			false, false, true,
+			false, false, true,
+			false, false, true,
+		},
+		{
+			true, true, true,
+			false, false, true,
+			true, true, true,
+			true, false, false,
+			true, true, true,
+		},
+		{
+			true, true, true,
+			false, false, true,
+			true, true, true,
+			false, false, true,
+			true, true, true,
+		},
+		{
+			true, false, true,
+			true, false, true,
+			true, true, true,
+			false, false, true,
+			false, false, true,
+		},
+		{
+			true, true, true,
+			true, false, false,
+			true, true, true,
+			false, false, true,
+			true, true, true,
+		},
+		{
+			true, true, true,
+			true, false, false,
+			true, true, true,
+			true, false, true,
+			true, true, true,
+		},
+		{
+			true, true, true,
+			false, false, true,
+			false, false, true,
+			false, false, true,
+			false, false, true,
+		},
+		{
+			true, true, true,
+			true, false, true,
+			true, true, true,
+			true, false, true,
+			true, true, true,
+		},
+		{
+			true, true, true,
+			true, false, true,
+			true, true, true,
+			false, false, true,
+			true, true, true,
+		},
+	}
+
+	squares := defs[n]
+	for i, draw := range squares {
+		if !draw {
+			continue
+		}
+		x := i % 3
+		y := i / 3
+		drawSquare(scr, xOffset+squareW*x, yOffset+squareH*y, squareW, squareH, style)
+	}
+}
+
+func drawClock(scr tcell.Screen, now time.Time, bgStyle, clockStyle tcell.Style) {
+	// 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
+
+	// Hour
+	hour := now.Hour()
+	drawNumber(scr, hour/10, xOffset+squareW*0, yOffset, squareW, squareH, clockStyle)
+	drawNumber(scr, hour%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)
+
+	// Minute
+	minute := now.Minute()
+	drawNumber(scr, minute/10, xOffset+squareW*10, yOffset, squareW, squareH, clockStyle)
+	drawNumber(scr, minute%10, xOffset+squareW*14, yOffset, squareW, squareH, clockStyle)
+}
+
+func cmdClock(cmd *cobra.Command, args []string) {
+	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()
+
+	drawClock(scr, time.Now(), bgStyle, clockStyle)
+
+	quitC := make(chan struct{})
+
+	go func() {
+		for {
+			scr.Show()
+
+			ev := scr.PollEvent()
+			switch ev := ev.(type) {
+			case *tcell.EventResize:
+				drawClock(scr, time.Now(), 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()
+
+	prev := time.Now()
+	for {
+		select {
+		case <-quitC:
+			return
+		case now := <-t.C:
+			if now.Minute() != prev.Minute() {
+				drawClock(scr, now, bgStyle, clockStyle)
+				scr.Show()
+				prev = now
+			}
+		}
+	}
+}
+
+var clockCmd =&cobra.Command{
+	Use: "clock",
+	Short: "Clock mode",
+	Run: cmdClock,
+}
diff --git a/cmd/root.go b/cmd/root.go
new file mode 100644
index 0000000..d0f9713
--- /dev/null
+++ b/cmd/root.go
@@ -0,0 +1,18 @@
+package cmd
+
+import (
+	"github.com/spf13/cobra"
+)
+
+var rootCmd = &cobra.Command{
+	Use:   "term-clock",
+	Short: "A clock on your terminal",
+}
+
+func init() {
+	rootCmd.AddCommand(clockCmd)
+}
+
+func Execute() error {
+	return rootCmd.Execute()
+}