[Xcb] is it possible to monitor events in other windows?

[Christian Linhart]

Hi Patrick,

The function xcb_wait_for_event does not have an implicit window passed. 
It waits for all events that have been selected using the appropriate X11-requests.

There are X11-requests for selecting which events your application subscribes to for which window.

Please read the man-pages for the Xlib-functions
	XSelectInput
and
	XSelectExtensionEvent
for details.

Selecting events via XCB is similar to the Xlib-functions. 
You just have to use the underlying X11-request.

Hope this helps,

Chris

P.S.: This mailinglist is primarily for the development for XCB itself.
For questions about X11-programming, with or without XCB, there may be better forums or websites.

On 10/20/14 16:00, Patrick wrote:
> Hi Everyone
> 
> So this is a bit of a long story and to keep it suitable for the mailing list, I am basically trying to monitor mouse clicks in a terminal under X as opposed to using gpm through ncurses.
> 
> I have chopped down an example from freedsktop.org and I have it pasted at the end of this email.
> 
> This is the part I am confused about:
> xcb_wait_for_event (c)
> 
> 
> This is responding to events in the window created but is the windows ID passed implicitly ? Is there a way to pass another windows ID ? I am basically planning on creating a small xcb program that will take the window ID of the terminal that the program is running in, I don't want to create another window.
> 
> Thanks for reading my post-Patrick
> 
> 
> 
> 
> code-->---------------------------->
> 
> #include <stdlib.h>
> #include <stdio.h>
> #include <xcb/xcb.h>
> 
> int main (int argc, int * argv[])
> {
>   xcb_connection_t    *c;
>   xcb_screen_t        *screen;
>   xcb_window_t         win;
>   xcb_generic_event_t *e;
>   uint32_t             mask = 0;
>   uint32_t             values[2];
> 
>   /* Open the connection to the X server */
>   c = xcb_connect (NULL, NULL);
> 
>   /* Get the first screen */
>   screen = xcb_setup_roots_iterator (xcb_get_setup (c)).data;
> 
>   /* Ask for our window's Id */
>   win = xcb_generate_id (c);
> //  win = 65574484 ;
> 
>   /* Create the window */
>   mask = XCB_CW_BACK_PIXEL | XCB_CW_EVENT_MASK;
>   values[0] = screen->white_pixel;
>   values[1] = XCB_EVENT_MASK_EXPOSURE  | XCB_EVENT_MASK_BUTTON_PRESS   | XCB_EVENT_MASK_BUTTON_RELEASE | XCB_EVENT_MASK_KEY_PRESS      | XCB_EVENT_MASK_KEY_RELEASE;
>   xcb_create_window (c,                             /* Connection          */
>                      0,                             /* depth               */
>                      win,                           /* window Id           */
>                      screen->root,                  /* parent window       */
>                      0, 0,                          /* x, y                */
>                      150, 150,                      /* width, height       */
>                      10,                            /* border_width        */
>                      XCB_WINDOW_CLASS_INPUT_OUTPUT, /* class               */
>                      screen->root_visual,           /* visual              */
>                      mask, values);                 /* masks */
> 
>   /* Map the window on the screen */
>   xcb_map_window (c, win);
>   xcb_flush (c);
> //CONFUSED HERE
>   while (    (e = xcb_wait_for_event (c) )      ) {
>     switch (e->response_type & ~0x80) {
> 
>                     case XCB_BUTTON_RELEASE: {
>                     xcb_button_release_event_t *ev = (xcb_button_release_event_t *)e;
>                     printf ("Button %d released in window %ld, at coordinates (%d,%d)\n",  ev->detail, ev->event, ev->event_x, ev->event_y);
>                     break;
>                     }
> 
>                case XCB_KEY_PRESS: {
>                xcb_key_press_event_t *ev = (xcb_key_press_event_t *)e;
>                printf ("Key pressed in window %ld\n", ev->event);
>                break;
>                }
>     case XCB_KEY_RELEASE: {
>     xcb_key_release_event_t *ev = (xcb_key_release_event_t *)e;
>     printf ("Key released in window %ld\n",  ev->event);
>     break;
>     }
>     default:
>     ;
>     break;
>     }
> /* Free the Generic Event */
> free (e);
> }
> 
>   return 0;
> }
> _______________________________________________
> Xcb mailing list
> Xcb at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/xcb
>