xcb-examples(3) XCB examples xcb-examples(3)

NAME
       xcb-examples - manpage examples

DESCRIPTION
       Many of the XCB manpages contain example code. These examples intend to
       explain how to use one particular part of XCB. They almost never repre‐
       sent a standalone (or even useful) program - X11 programs are rela‐
       tively involved and thus beyond the scope of a manpage example.


ENVIRONMENT
       Every example assumes you have an xcbconnection and possibly other
       variables at hand. For illustrating how xcbgetproperty works, you
       need the window of which you want to get the property, for example. To
       make it clear that these variables are your responsibility, these exam‐
       ples consist of a single function which takes the necessary variables
       as parameters.


FLUSHING
       Flushing means calling xcbflush to clear the XCB-internal write buffer
       and send all pending requests to the X11 server. You don't explicitly
       need to flush before using a reply function (like
       xcbquerypointerreply), but you do need to flush before entering the
       event loop of your program.

       There are only two cases when XCB flushes by itself. The first case is
       when its write buffer becomes full, the second case is when you are
       asking for the reply of a request which wasn't flushed out yet (like
       xcbquerypointerreply). This last point also includes
       xcbrequestcheck(). Please note that waiting for an event does NOT
       flush.

       Examples generally include the xcbflush call where appropriate (for
       example after setting a property). Therefore, including these functions
       and calling them in your application should just work. However, you
       might get better results when flushing outside of the function, depend‐
       ing on the architecture of your program.


COMPILATION
       If an example does not compile (without warnings) when using -std=c99,
       that is considered a documentation bug. Similarly, not handling errors
       or leaking memory is also considered a documentation bug. Please inform
       us about it on xcb@lists.freedesktop.org.


CODING STYLE
       Every example uses 4 spaces for indentation.

       Comments are in asterisks, like /* this */.

       No line is longer than 80 characters (including indentation).


SEE ALSO
       xcbconnect(3), xcbgetproperty(3), xcbflush(3)

AUTHOR
       Michael Stapelberg 



X Version 11                      libxcb 1.13                  xcb-examples(3)