Provided by: libxcb-doc_1.13.1-2_all bug

NAME

       xcb_query_tree - query the window tree

SYNOPSIS

       #include <xcb/xproto.h>

   Request function
       xcb_query_tree_cookie_t xcb_query_tree(xcb_connection_t *conn, xcb_window_t window);

   Reply datastructure
       typedef struct xcb_query_tree_reply_t {
           uint8_t      response_type;
           uint8_t      pad0;
           uint16_t     sequence;
           uint32_t     length;
           xcb_window_t root;
           xcb_window_t parent;
           uint16_t     children_len;
           uint8_t      pad1[14];
       } xcb_query_tree_reply_t;

   Reply function
       xcb_query_tree_reply_t *xcb_query_tree_reply(xcb_connection_t *conn,
              xcb_query_tree_cookie_t cookie, xcb_generic_error_t **e);

   Reply accessors
       xcb_window_t *xcb_query_tree_children(const xcb_query_tree_request_t *reply);

       int xcb_query_tree_children_length(const xcb_query_tree_reply_t *reply);

       xcb_generic_iterator_t xcb_query_tree_children_end(const xcb_query_tree_reply_t *reply);

REQUEST ARGUMENTS

       conn      The XCB connection to X11.

       window    The window to query.

REPLY FIELDS

       response_type
                 The type of this reply, in this case XCB_QUERY_TREE. This field is also present
                 in the xcb_generic_reply_t and can be used to tell replies apart from each
                 other.

       sequence  The sequence number of the last request processed by the X11 server.

       length    The length of the reply, in words (a word is 4 bytes).

       root      The root window of window.

       parent    The parent window of window.

       children_len
                 The number of child windows.

DESCRIPTION

       Gets the root window ID, parent window ID and list of children windows for the specified
       window. The children are listed in bottom-to-top stacking order.

RETURN VALUE

       Returns an xcb_query_tree_cookie_t. Errors have to be handled when calling the reply
       function xcb_query_tree_reply.

       If you want to handle errors in the event loop instead, use xcb_query_tree_unchecked. See
       xcb-requests(3) for details.

ERRORS

       This request does never generate any errors.

EXAMPLE

       /*
        * Displays the root, parent and children of the specified window.
        *
        */
       void my_example(xcb_connection_t *conn, xcb_window_t window) {
           xcb_query_tree_cookie_t cookie;
           xcb_query_tree_reply_t *reply;

           cookie = xcb_query_tree(conn, window);
           if ((reply = xcb_query_tree_reply(conn, cookie, NULL))) {
               printf("root = 0x%08x\n", reply->root);
               printf("parent = 0x%08x\n", reply->parent);

               xcb_window_t *children = xcb_query_tree_children(reply);
               for (int i = 0; i < xcb_query_tree_children_length(reply); i++)
                   printf("child window = 0x%08x\n", children[i]);

               free(reply);
           }
       }

SEE ALSO

       xcb-requests(3), xcb-examples(3), xwininfo(1)

AUTHOR

       Generated from xproto.xml. Contact xcb@lists.freedesktop.org for corrections and
       improvements.