Pulse Audio Control Widget (mute/unmute only atm)

README.md

@@ -284,6 +284,23 @@ corresponding icons with correct names need to be placed in
 `~/.local/share/deckmaster/themes/[theme]`. The default icons with their
 respective names can be found [here](https://github.com/muesli/deckmaster/tree/master/assets/weather).
 
+#### Pulseaudio Control
+
+A widget that can controls a specific pulseaudio input sink (like Rhythmbox, Firefox etc.). 
+
+```toml
+[keys.widget]
+  id = "pulseAudioControl"
+  [keys.widget.config]
+    appName = "Application name" # Like "Rhythmbox"
+    mode = "mute" # Only mute is supported at the moment.
+    showTitle = true # optional
+```
+
+This widget is using "pactl" and "pacmd".
+
+You can use `pacmd list-sink-inputs` to see the current sinks. Use the value of "application.name" for appName.
+
 ### Actions
 
 You can hook up any key with several actions. A regular keypress will trigger

decks/pulseaudio_control.deck

@@ -0,0 +1,20 @@
+[[keys]]
+  index = 0
+  [keys.widget]
+    id = "pulseAudioControl"
+    interval = 1000
+    [keys.widget.config]
+      appName = "Firefox"
+      mode = "mute"
+      showTitle = false
+
+[[keys]]
+  index = 1
+  [keys.widget]
+    id = "pulseAudioControl"
+    interval = 1000
+    [keys.widget.config]
+      appName = "Rhythmbox"
+      mode = "mute"
+      showTitle = true
+

widget.go

@@ -124,6 +124,9 @@ func NewWidget(dev *streamdeck.Device, base string, kc KeyConfig, bg image.Image
 
 	case "weather":
 		return NewWeatherWidget(bw, kc.Widget)
+
+	case "pulseAudioControl":
+		return NewPulseAudioControlWidget(bw, kc.Widget)
 	}
 
 	// unknown widget ID

widget_pulseaudio_control.go

@@ -0,0 +1,169 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"regexp"
+)
+
+const (
+	regexExpression     = `index: ([0-9]+)[\s\S]*?muted: (no|yes)[\s\S]*?media.name = \"(.*?)\"[\s\S]*?application.name = \"(.*?)\"`
+	regexGroupClientId  = 1
+	regexGroupMuted     = 2
+	regexGroupMediaName = 3
+	regexGroupAppName   = 4
+
+	listInputSinksCommand = "pacmd list-sink-inputs"
+)
+
+// PulseAudioControlWidget is a widget displaying a recently activated window.
+type PulseAudioControlWidget struct {
+	*ButtonWidget
+
+	appName   string
+	mode      string
+	showTitle bool
+}
+
+type sinkInputData struct {
+	muted bool
+	title string
+	index string
+}
+
+// NewPulseAudioControlWidget returns a new PulseAudioControlWidget.
+func NewPulseAudioControlWidget(bw *BaseWidget, opts WidgetConfig) (*PulseAudioControlWidget, error) {
+	var appName string
+	if err := ConfigValue(opts.Config["appName"], &appName); err != nil {
+		return nil, err
+	}
+
+	var mode string
+	if err := ConfigValue(opts.Config["mode"], &mode); err != nil {
+		return nil, err
+	}
+
+	var showTitle bool
+	_ = ConfigValue(opts.Config["showTitle"], &showTitle)
+	widget, err := NewButtonWidget(bw, opts)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &PulseAudioControlWidget{
+		ButtonWidget: widget,
+		appName:      appName,
+		mode:         mode,
+		showTitle:    showTitle,
+	}, nil
+}
+
+// RequiresUpdate returns true when the widget wants to be repainted.
+func (w *PulseAudioControlWidget) RequiresUpdate() bool {
+	//TODO
+
+	return w.BaseWidget.RequiresUpdate()
+}
+
+// Update renders the widget.
+func (w *PulseAudioControlWidget) Update() error {
+	sinkInputData, err := getSinkInputDataForApp(w.appName)
+	if err != nil {
+		return err
+	}
+
+	var icon string
+	var label string
+	if sinkInputData != nil {
+		if sinkInputData.muted {
+			icon = "assets/muted.png"
+		} else {
+			icon = "assets/not_muted.png"
+		}
+		if w.showTitle && sinkInputData.title != "" {
+			label = sinkInputData.title
+		} else {
+			label = w.appName
+		}
+	} else {
+		icon = "assets/not_playing.png"
+		label = w.appName
+	}
+
+	if err := w.LoadImage(icon); err != nil {
+		return err
+	}
+
+	w.label = stripTextTo(10, label)
+	return w.ButtonWidget.Update()
+}
+
+// TriggerAction gets called when a button is pressed.
+func (w *PulseAudioControlWidget) TriggerAction(hold bool) {
+	if w.mode != "mute" {
+		fmt.Fprintln(os.Stderr, "unknown mode:", w.mode)
+		return
+	}
+
+	sinkInputData, err := getSinkInputDataForApp(w.appName)
+
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "can't toggle mute for pulseaudio app "+w.appName, err)
+	}
+
+	if sinkInputData == nil {
+		fmt.Fprintln(os.Stderr, "No running sink found for pulseaudio app "+w.appName, err)
+	}
+
+	toggleMute(sinkInputData.index)
+}
+
+func toggleMute(sinkIndex string) {
+	err := exec.Command("sh", "-c", "pactl set-sink-input-mute "+sinkIndex+" toggle").Run()
+
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "can't toggle mute for pulseaudio sink index: "+sinkIndex, err)
+	}
+}
+
+func stripTextTo(maxLength int, text string) string {
+	runes := []rune(text)
+	if len(runes) > maxLength {
+		return string(runes[:maxLength])
+	}
+	return text
+}
+
+func getSinkInputDataForApp(appName string) (*sinkInputData, error) {
+	output, err := exec.Command("sh", "-c", listInputSinksCommand).Output()
+	if err != nil {
+		return nil, fmt.Errorf("can't get pulseaudio sinks. 'pacmd' missing? %s", err)
+	}
+
+	var regex = regexp.MustCompile(regexExpression)
+	matches := regex.FindAllStringSubmatch(string(output), -1)
+	var sinkData *sinkInputData
+	for match := range matches {
+		if appName == matches[match][regexGroupAppName] {
+			sinkData = &sinkInputData{}
+			sinkData.index = matches[match][regexGroupClientId]
+			sinkData.muted = yesOrNoToBool(matches[match][regexGroupMuted])
+			sinkData.title = matches[match][regexGroupMediaName]
+		}
+	}
+
+	return sinkData, nil
+}
+
+func yesOrNoToBool(yesOrNo string) bool {
+	switch yesOrNo {
+	case "yes":
+		return true
+	case "no":
+		return false
+	}
+	fmt.Fprintln(os.Stderr, "can't convert yes|no to bool: "+yesOrNo)
+	return false
+}