[Xcb] a tutorial and some examples

[Vincent Torri]

Hello,

here are some stuff that are on my hd since a long time:

a tutorial:

http://www.iecn.u-nancy.fr/~torri/files/xcb/doc/index.html

it needs improvements  (in particular the font and cursor section, and
some stuff about the interaction with the window manager). I'm stuck with
them, i can't draw a text and change the cursor. If someone has succeeded
in doing that, please tell me.

there are some "TODO" in the page, which are also sometimes questions.

Here are some very simple examples:

http://www.iecn.u-nancy.fr/~torri/files/xcb/examples/

xcbpoints draws 4 points around the cursor when one cliks (top bottom left
and right of the cursor)

xcblines draws a point at first click and the segment between this point
and the cursor at second click

xcblines_shift does the same thing than xcblines, but the shift key must
be pressed

xcbrubber draws a point a first click, and draws the segment between this
point and the cursor when this one is moving. At second click, the segment
is "fixed"

feel free to add this stuff on the xcb page if you find it usefull.

I've already done some stuff about the equivalent of XImage, for XCB. It's
not finished yet.

regards

Vincent TORRI