R.Wieser wrote:

> Mel,
>
>> Windows was designed to support a GUI, so the DLLs provided with
>> Windows have those functions.  Linux wasn't, so you need to install extra
>> DLLs to get the GUI functions
>
> Same answer to you (as to Eli): If Linux does not have/expose them (by
> default),

Linux (the kernel) does not have and, therefore, cannot "expose" a GUI API.

The kernel, if compiled with the appropriate options, does, however, expose
an API to an optional in-kernel "direct rendering infrastructure" that gives
appropriately-permissioned user-space processes the ability to draw pixels
on a display device.

> how the heck can its own programs display themselves ?

User-space libraries (DLLs, to the Microsoft crowd) provide a number of
abstraction levels that builds on the kernel DRI "draw a single pixel"
facility to provide line-drawing, polygon drawing, colour-fill-polygon
drawing, fonts, boxes, inputboxes, messageboxes, windows, icons, and the
rest of the "GUI" that you are looking for.

There are a variety of these libraries; The X Window system includes a
number of (line draw/polygon draw) primitives ("Xlib"), as do the other
windowing platforms. On top of these primitives, other user space libraries
have built boxes and windows (a couple of names include "QT" and the GIMP
ToolKit ("GTK" and "GTK+") .

> No,
> something definitily does not compute there ... :-|
>
> The only thing I can conclude is that either those controls are available
> without a framework being present,

Nope. They need a framework.

> *or* that such a (minimal?) framework has already been installed (by the
> OS).

If, by "minimal", you mean "draw a pixel", then yes. If you mean something
more complex than that, then no.

> In that last case, how do I figure out which one it is ?
> And in the first case, where are they ?

Mu. Your questions assume facts not in evidence.

To answer you, pick a framework. You probably already have QT and GTK
installed, but if they aren't sufficient, try the Enlightenment Foundation
Libraries ("EFL"), or (the old-school) Xlib.


--
Lew Pitcher
"In Skills, We Trust"
PGP public key available upon request

--- SoupGate-Win32 v1.05