Xlib, свойства окна

#include <cstdio>
#include <string>

#include <X11/Xutil.h>

class WindowFolder {
  protected:
    Display *display;
    Window root_window;
  public:
    WindowFolder() {
        display = XOpenDisplay(NULL);
        root_window = XDefaultRootWindow(display);
    }
    ~WindowFolder() { XCloseDisplay(display); }
    virtual void action(Window) = 0;
    void sub_fold(Window);
    void fold() { sub_fold(root_window); }
};

void WindowFolder::sub_fold(Window window)
{
    action(window);

    unsigned n;
    Window root, parent, *childs;
    XQueryTree(display, window, &root, &parent, &childs, &n);

    for (unsigned i = 0; i < n; ++i)
        sub_fold(childs[i]);

    XFree(childs);
}

class WindowClassFinderPrinter : public WindowFolder {
    std::string res_class;
  public:
    WindowClassFinderPrinter(std::string res_class_) : res_class(res_class_) {}
    virtual void action(Window);
};

void WindowClassFinderPrinter::action(Window window)
{
    XClassHint *hint = XAllocClassHint();
    XGetClassHint(display, window, hint);

    if (hint->res_class && !res_class.compare(hint->res_class))
        printf("WINDOW = %lu, NAME = %s, CLASS = %s\n",
               window, hint->res_name, hint->res_class);

    XFree(hint);
}

int main()
{
    WindowClassFinderPrinter browserFinder("Google-chrome");
    browserFinder.fold();
}