XNextEvent Doesn't works for some reason - c++

Question

I'm trying to catch keypress events using XLib. But for some reasons XNextEvent not working.
I'm not receiving any errors, but it looks like my program stuck on the line of "XNextEvent" call.
Here is my code:
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
using namespace std;
int main()
{
XEvent event;
KeySym key;
char text[255];
Display *dis;
dis = XOpenDisplay(NULL);
while (1) {
XNextEvent(dis, &event);
if (event.type==KeyPress && XLookupString(&event.xkey,text,255,&key,0) == 1) {
if (text[0]=='q') {
XCloseDisplay(dis);
return 0;
}
printf("You pressed the %c key!\n", text[0]);
}
}
return 0;
}

Answer 1

This is not how X11 windowing system works.
Read this carefully. The key point is :
The source of the event is the viewable window that the pointer is in.
You do not create a window, therefore your program doesn't receive keyboard events. Even if you created window, it has to have focus :
The window used by the X server to report these events depends on the window's position in the window hierarchy and whether any intervening window prohibits the generation of these events.

Answer 2

Working example
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
using namespace std;
int main()
{
XEvent event;
Display *dis;
Window root;
Bool owner_events = False;
unsigned int modifiers = ControlMask | LockMask;
dis = XOpenDisplay(NULL);
root = XDefaultRootWindow(dis);
unsigned int keycode = XKeysymToKeycode(dis, XK_P);
XSelectInput(dis,root, KeyPressMask);
XGrabKey(dis, keycode, modifiers, root, owner_events, GrabModeAsync, GrabModeAsync);
while (1) {
Bool QuiteCycle = False;
XNextEvent(dis, &event);
if (event.type == KeyPress) {
cout << "Hot key pressed!" << endl;
XUngrabKey(dis, keycode, modifiers, root);
QuiteCycle = True;
}
if (QuiteCycle) {
break;
}
}
XCloseDisplay(dis);
return 0;
}