Go lang check if active window the window yo are looking for

check-window-type.go

package main

import (
	"fmt"
	"syscall"
	"unsafe"
	"golang.org/x/sys/windows"
)

var (
	mod 					= windows.NewLazyDLL("user32.dll")
	procGetClassNameW 		= mod.NewProc("GetClassNameW")
)

type (
	HANDLE uintptr
	HWND HANDLE
)

func GetClassName(hwnd HWND) (name string, err error) {
	n := make([]uint16, 256)
	p := &n[0]
	r0, _, e1 := syscall.Syscall(procGetClassNameW.Addr(), 3, uintptr(hwnd), uintptr(unsafe.Pointer(p)), uintptr(len(n)))
	if r0 == 0 {
		if e1 != 0 {
			err = error(e1)
		} else {
			err = syscall.EINVAL
		}
		return
	}
	name = syscall.UTF16ToString(n)
	return
}

func getWindow(funcName string) uintptr {
	proc := mod.NewProc(funcName)
	hwnd, _, _ := proc.Call()
	return hwnd
}

func chkinArray(a string, list []string) bool {
    for _, b := range list {
        if b == a {
            return true
        }
    }
    return false
}

func main() {
	classtolook := []string{
		"CabinetWClass",
	}
	
	for {

		if hwnd := getWindow("GetForegroundWindow") ; hwnd != 0 {
			cn , _ := GetClassName(HWND(hwnd))
			if chkinArray(cn ,classtolook) {
				fmt.Println("class :", cn, "# hwnd:", hwnd)
			}
		}
	}
}