centos man page for xcb_query_tree

xcb_query_tree(3)						   XCB Requests 						 xcb_query_tree(3)

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 *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
", reply->root);
	       printf("parent = 0x%08x
", 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
", 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.

XCB
								    2014-06-10							 xcb_query_tree(3)