Linux x11 keyboard hook

Robotechnic

Hello,
I want to create an application that can capture keyboard in the application until the user press a certain keystroke as VM do.
I did that on windows with windows.h but now, I am on linux and my program don't work (as expected because I have used windows.h).
My problem is that when I try to include X11 in my project I have a lots of errors (556):
https://pastebin.com/1d7G8r5f
Do you know how to do that?
I am on arch linux with kde and x11

Thanks in advance for your help.

Christian Ehrlicher

@Robotechnic said in Linux x11 keyboard hook:

Do you know how to do that?

The X11 headers do some weird defines. Include them after the Qt includes or undefine them before including Qt headers.

Robotechnic

Thanks @Christian-Ehrlicher , now the code work bu only in main:

int main(int argc, char *argv[])
{
    bool quit = false;
    Display *d = XOpenDisplay(NULL);

    XGrabKeyboard(d, DefaultRootWindow(d),
                     true, GrabModeAsync, GrabModeAsync, CurrentTime);

   while(!quit) {
      XEvent ev;

      XNextEvent(d, &ev);

      switch (ev.type) {
      case KeyPress:
        char *s;
        unsigned int kc;

        kc = ((XKeyPressedEvent*)&ev)->keycode;
        s = XKeysymToString(XKeycodeToKeysym(d, kc, 0));

        if(s) {
            qDebug()<<"Key :"<<s;
        }
        if(!strcmp(s, "q")) quit=~0;
      }
   }

   XUngrabKeyboard(d, CurrentTime);

   if (XCloseDisplay(d)) {
      return 1;
   }

    return 0;
}

When I try to put in in QMainWindows errors happen

Christian Ehrlicher

Will not work the way you do it - you block the Qt event loop.

Robotechnic

Ok, so how can I do it?

Robotechnic

Sorry my question is not for the Qt main loop, I can do that with thread or QTimer this is not my problem.
My problem was that when I have putted x11 headers in .h file, that generated errors but I fixed it and It work. Thanks @Christian-Ehrlicher , I have writing before thinking.