Re: Questions regarding PGTK, high-dpi font-rendering, new X11-Warning

[Po Lu]

xenodasein@tutanota.de writes:

> Xlib uses XCB underneath anyway, what is this shortsightedness about?

Because you cannot give ownership of the event queue to Xlib if the
connection to the display was obtained through XCB.  As a result, Qt has
had to move from only using XCB to using both Xlib and XCB for the two
libraries that are much better than their XCB counterparts: the direct
rendering GLX library and the XInput client library.

You have to understand that Xlib uses XCB only as an underlying
transport.  It encodes all requests and reads events solely by itself,
with occasional hooks into XCB to synchronize i.e. the request serial
used (see the calls to xcb_take_socket.)  No matter whether or or not
_XSend, _XReadEvents, _XRead, _XReadPad or _XEatDataWords is implemented
on top of XCB, Xlib is still the only library reading events.