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

[Christian Linhart]

Hi Patrick,

I suggest you use websites like
	stackoverflow.com
	ubuntuforums.org
	linuxquestions.org
	...


They usually pop up first when searching for questions like these.
So I guess they are the useful places to ask such questions, too.

You can also search for "x11 programming forum" in Google and this
gives you several useful websites.

Hope this helps,

Chris

P.S.: I am posting this answer to the list such that searchengine searches
will hopefully show this posting from our archives
and redirect people to the right places...

On 10/20/14 16:59, Patrick wrote:
> Thanks Chris
> 
> I haven't found anywhere else to post about xcb, could you point me somewhere?
> 
> There are not a lot of xcb examples floating around, I do have xlib books but it's quite the learning curve for both xlib and xcb. I have a lot of amateur questions, i don't want to bog down the development list.
> 
> Thanks again
> 
> 
> 
> On 14-10-20 10:53 AM, Christian Linhart wrote:
>> 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
>>>
>> _______________________________________________
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>>
> 
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