Alter 5 files

Update main.go
Update i3bar.go
Add backlight.go
Update cpu.go
Update providers.go

cmd/bar/main.go

@@ -53,9 +53,10 @@ func run() error {
 		// providers.NewDisk("/", 30, 10),
 		providers.NewBattery("BAT0", 80, 30, 20),
 		providers.NewWiFi("wlp0s20f3", 75),
-		providers.NewIPType("wlp0s20f3"),
+		// providers.NewIPType("wlp0s20f3"),
 		// providers.NewIPAddress("wlp0s20f3"),
 		providers.NewAudioPlayer(32),
+		providers.NewBacklight(),
 	)
 
 	if err := b.Emit([]*i3bar.Block{

internal/i3bar/i3bar.go

@@ -132,12 +132,6 @@ func (b *I3bar) tick(override bool) error {
 					TextColor: defaultColorSet.Bad,
 				}
 			}
-			if block == nil {
-				block = &Block{
-					FullText:  "MISSING",
-					TextColor: defaultColorSet.Warning,
-				}
-			}
 
 			if block != gen.Last {
 				gen.Last = block

internal/providers/backlight.go

@@ -0,0 +1,92 @@
+package providers
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/codemicro/bar/internal/i3bar"
+)
+
+type Backlight struct {
+	name string
+
+	showUntil time.Time
+	lastValue int
+
+	maxValue int
+}
+
+func NewBacklight() i3bar.BlockGenerator {
+	return &Backlight{
+		name: "backlight",
+	}
+}
+
+func (g *Backlight) Frequency() uint8 {
+	return 1
+}
+
+func (g *Backlight) parseIntFromFile(fname string) (int, error) {
+	fcont, err := os.ReadFile(fname)
+	if err != nil {
+		return 0, err
+	}
+
+	i, err := strconv.Atoi(strings.TrimSpace(string(fcont)))
+	if err != nil {
+		return 0, err
+	}
+
+	return i, nil
+}
+
+func (g *Backlight) getMaxVal() (int, error) {
+	if g.maxValue != 0 {
+		return g.maxValue, nil
+	}
+
+	i, err := g.parseIntFromFile("/sys/class/backlight/intel_backlight/max_brightness")
+	if err != nil {
+		return 0, nil
+	}
+
+	g.maxValue = i
+	return g.maxValue, nil
+}
+
+func (g *Backlight) getCurrentVal() (int, error) {
+	return g.parseIntFromFile("/sys/class/backlight/intel_backlight/brightness")
+}
+
+func (g *Backlight) Block(cs *i3bar.ColorSet) (*i3bar.Block, error) {
+	// this is a sun emoji: ☀
+
+	if g.maxValue == 0 {
+		if _, err := g.getMaxVal(); err != nil {
+			return nil, err
+		}
+	}
+
+	if cv, err := g.getCurrentVal(); err != nil {
+		return nil, err
+	} else if cv != g.lastValue {
+		g.lastValue = cv
+		g.showUntil = time.Now().Add(time.Second * 5)
+	}
+
+	if g.showUntil.After(time.Now()) {
+		return &i3bar.Block{
+			Name:     g.name,
+			FullText: fmt.Sprintf("☀ %s%%", leftPad(fmt.Sprint((g.lastValue*100)/g.maxValue), ' ', 3)),
+		}, nil
+	}
+
+	return nil, nil
+}
+
+func (g *Backlight) GetNameAndInstance() (string, string) {
+	return g.name, ""
+}

internal/providers/cpu.go

@@ -82,7 +82,7 @@ func (g *CPU) Block(colors *i3bar.ColorSet) (*i3bar.Block, error) {
 
 	block := &i3bar.Block{
 		Name:      g.name,
-		FullText:  fmt.Sprintf("CPU: %.1f%%", p),
+		FullText:  fmt.Sprintf("CPU: %s%%", leftPad(fmt.Sprintf("%.1f", p), ' ', 4)),
 		ShortText: fmt.Sprintf("C: %.1f%%", p),
 	}
 

internal/providers/providers.go

@@ -19,3 +19,10 @@ func runCommand(program string, args ...string) ([]byte, error) {
 	}
 	return bytes.TrimSpace(out), err
 }
+
+func leftPad(x string, c rune, n int) string {
+	for len(x) < n {
+		x = string(c) + x
+	}
+	return x
+}