WindowsWindowStyleHelper.kt

// Define which Windows functions we need
internal interface User32 : Library {
    fun FindWindowA(className: String?, windowTitle: String?): Pointer?
    fun GetWindowLongA(hwnd: Pointer, index: Int): Int
    fun SetWindowLongA(hwnd: Pointer, index: Int, newStyle: Int): Int
}

class WindowsWindowStyleHelper : WindowStyleHelper {
    // JNA loads the actual Windows DLL at runtime
    val user32 = Native.load("user32", User32::class.java)

    override fun hideFromTaskbar(windowTitle: String) {
        val hwnd = user32.FindWindowA(null, windowTitle) ?: return
        val style = user32.GetWindowLongA(hwnd, GWL_EXSTYLE)
        user32.SetWindowLongA(hwnd, GWL_EXSTYLE,
            (style or WS_EX_TOOLWINDOW) and WS_EX_APPWINDOW.inv()
        )
    }
}