How do I bring a processes window to the foreground on X Windows? (C++)

Question

I have the PID for the process (and the name), I want to bring it to the front on linux (ubuntu). On mac I would simply do SetFrontProcess(pid), on windows I\'d

Answer 1

There is a command line tool that can do this: wmctrl. The source code of the tool is here (C++): wmctrl sources

Relevant part of the code (you will need to get some of the functions used here from the project under the link above):

static int activate_window (Display *disp, Window win, /* {{{ */
    gboolean switch_desktop) {
unsigned long *desktop;

/* desktop ID */
if ((desktop = (unsigned long *)get_property(disp, win,
        XA_CARDINAL, "_NET_WM_DESKTOP", NULL)) == NULL) {
    if ((desktop = (unsigned long *)get_property(disp, win,
            XA_CARDINAL, "_WIN_WORKSPACE", NULL)) == NULL) {
        p_verbose("Cannot find desktop ID of the window.\n");
    }
}

if (switch_desktop && desktop) {
    if (client_msg(disp, DefaultRootWindow(disp), 
                "_NET_CURRENT_DESKTOP", 
                *desktop, 0, 0, 0, 0) != EXIT_SUCCESS) {
        p_verbose("Cannot switch desktop.\n");
    }
    g_free(desktop);
}

client_msg(disp, win, "_NET_ACTIVE_WINDOW", 
        0, 0, 0, 0, 0);
XMapRaised(disp, win);

return EXIT_SUCCESS;
}

Hint: remember to call

XCloseDisplay(display);

Somewhere after the call to this function or you will see no effect.