Function FindWindowById

src/window.cpp:1153–1160

* Find a window by its class and window number * @param cls Window class * @param number Number of the window within the window class * @return Pointer to the found window, or \c nullptr if not available */

 * @return Pointer to the found window, or \c nullptr if not available
 */
Window *FindWindowById(WindowClass cls, WindowNumber number)
{
	for (Window *w : Window::Iterate()) {
		if (w->window_class == cls && w->window_number == number) return w;
	}

	return nullptr;
}

/**
 * Find any window by its class. Useful when searching for a window that uses