Listens to the global hotkey MEDIA_PLAY_PAUSE and toggles mumble's self mute.

mumble-muter.go

package main

import (
	"fmt"
	"os"
	"os/exec"
	"syscall"
	"time"
	"unsafe"
)

type (
	HANDLE uintptr
	HWND   HANDLE
)

var (
	user32dll          = syscall.NewLazyDLL("user32.dll")
	procGetMessage     = user32dll.NewProc("GetMessageW")
	procRegisterHotKey = user32dll.NewProc("RegisterHotKey")
)

type MSG struct {
	Hwnd    HWND
	Message uint32
	WParam  uintptr
	LParam  uintptr
	Time    uint32
	Pt      struct{ X, Y int64 }
}

func registerHotKey(hWnd HWND, id int, fsModifiers uint, vk uint) bool {
	// modifiers: https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-registerhotkey#parameters
	// kecodes: https://docs.microsoft.com/en-us/windows/win32/inputdev/virtual-key-codes
	ret, _, _ := procRegisterHotKey.Call(
		uintptr(hWnd),
		uintptr(id),
		uintptr(fsModifiers),
		uintptr(vk),
	)
	return ret != 0
}

func getMessage(msg *MSG, hwnd HWND, msgFilterMin, msgFilterMax uint32) int {
	ret, _, _ := procGetMessage.Call(
		uintptr(unsafe.Pointer(msg)),
		uintptr(hwnd),
		uintptr(msgFilterMin),
		uintptr(msgFilterMax))

	return int(ret)
}

func main() {

	// default Mumble binary
	mumblePath := "c:\\Program Files\\Mumble\\mumble.exe"

	// can be overwritten by first command line argument
	if len(os.Args) > 1 {
		mumblePath = os.Args[1]
	}

	if _, err := os.Stat(mumblePath); os.IsNotExist(err) {
		fmt.Printf("Path to mumble doesn't exists: %s", mumblePath)
		return
	}

	var msg MSG

	regOk := registerHotKey(0, 42030, 0x0, 0xB3)
	if !regOk {
		fmt.Println("Cant register hotkey!")
		return
	}

	fmt.Printf("Okay, using Mumble at: %s\n", mumblePath)

	for {
		ok := getMessage(&msg, 0, 0, 0)
		if ok != 1 {
			time.Sleep(time.Millisecond * 50)
			continue
		}

		switch msg.WParam {
		case 42030:
			fmt.Println("Toggle.")
			cmdInstance := exec.Command("cmd", "/c", mumblePath, "rpc", "togglemute")
			cmdInstance.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
			err := cmdInstance.Run()
			if err != nil {
				fmt.Printf("ERROR: %s\n", err.Error())
			}
		}
	}
}