[gtk-server] Re: GTK Server ".cfg" File
- From: Sunburned Surveyor <sunburned.surveyor@xxxxxxxxx>
- To: gtk-server@xxxxxxxxxxxxx
- Date: Fri, 2 Dec 2005 13:06:13 -0800
That makes some sense. I was actually reading about the
"gtk_main_iteration()" function.
Just so I make sure that I understand correctly:
The GTK-Server calls gtk_main_interation(), which attempts, a single time,
to "catch" a callback signal from the GUI. This is why the
"gtk_server_callback(WAIT)" function must be embedded in the loop of the
client script. We are making repeateded calls to gtk_main_iteration() in the
loop of our client script, which, in essence, simulates the GTK main loop.
Is that correct?
Landon
P.S. - I'll check out that link that you forwarded. Thanks.
On 12/2/05, Peter van Eerten <administrator@xxxxxxxxxxxxxx> wrote:
>
> Hi Landon,
>
> The 'gtk_server_callback'-function actually calls "gtk_main_iteration()",
> which
> runs through a GTK event loop, and returns to the caller as soon a signal
> has
> occured. The occured callback signals and widgets are kept in a global
> struct,
> so as soon 'gtk_server_callback' returns to the client script, the value
> of the
> widget is returned (also as a string). The function "gtk_main()" however
> calls
> the GTK library but never returns, and the GTK-server never can pass
> information
> to the client script.
>
> FFI stands for "Foreign Function Interface". The original homepage can be
> found
> at http://sources.redhat.com/libffi/.
>
> Peter
>
> Citeren Sunburned Surveyor <sunburned.surveyor@xxxxxxxxx>:
>
> > Peter,
> >
> > Thank you for your quick responses!
> >
> > I will make sure that I forward information about my NewLISP wrapper for
> > GTK-Server as work progresses. I also hope to work on parsing glade-xml
> > files to generate GTK GUI's in NewLISP.
> >
> > I had a couple more questions for you:
> >
> > I was reading this morning that you use the gtk_main (void) function to
> > start GTK's main loop, and gtk_main_quit (void) function to terminate
> the
> > main loop when programming GTK GUI applications in the C programmig
> > language. However, I don't see either of these functions in the
> GTK-Server
> > dmeo for NewLISP. Are these 2 function calls handled automatically by
> > GTK-Server? How do indicate to GTK-Server when the main loop should
> start
> > and stop? Are these two functions somehow embodied in the
> > "gtk_server_callback WAIT" function that is called in the "main loop"
> > section of the GTK-Server demo for NewLISP?
> >
> > What is the full name for FFI? I did a Google search but came up
> dry...I'd
> > like to learn more about it.
> >
> >
> > On 12/1/05, Peter van Eerten <administrator@xxxxxxxxxxxxxx> wrote:
> > >
> > > Hi Landon,
> > >
> > > To answer your questions one by one:
> > >
> > > 1) Indeed this is an internal call of the GTK-server itself. The
> purpose
> > > of it
> > > is to 'wait' for a new event on the created widgets. If such an event
> > > occurs
> > > (e.g. a mouseclick on a button for example) the call will return the
> > > WidgetID to
> > > the script. Then the script can use this ID to take further action.
> > >
> > > The 'wait' argument will always wait for an event, meaning that the
> client
> > > script will not continue with execution. Instead of the 'wait'
> argument,
> > > you can
> > > also specify 'none' or 'update'. In these cases, the
> gtk_server_callback
> > > function will check for an event only once, and return immediately. If
> and
> > > only
> > > if an event has happened, the WidgetID is returned, otherwise a '0' is
> > > returned.
> > > The difference between 'none' and 'update' is, that the 'update' also
> will
> > > update all changes and visible mutations to the widgets. (So if you
> use
> > > 'none'
> > > then this has to be done within your client script.)
> > >
> > > 2) Your observation is correct. A client script always has to send a
> > > string in
> > > S-expression format to the GTK-server. First the GTK library needs to
> be
> > > opened
> > > with 'dlopen'. On a Linux system, just check 'man dlopen' for details.
> On
> > > Win32
> > > platforms I use a similar function for this called 'LoadLibrary' - see
> > > msdn.microsoft.com. Then the GTK-server parses the incoming string and
> > > creates a
> > > void pointer out of the function call.
> > >
> > > The problem of course is that GTK functions have arguments of a
> certain
> > > type
> > > (int, char, float etc). But we do not know in advance how many
> arguments a
> > > GTK
> > > function has, and which type. Therefore this has to be configured in a
> > > configfile. With the FFI library I can actually realize the GTK
> function.
> > > FFI
> > > was written especially for situations in which interpreted programs
> needed
> > > to
> > > execute compiled functions. FFI is part of GCC 3.x and newer (also
> part of
> > > MinGW
> > > nowadays).
> > >
> > > 3) I did not create a particular developer document. But as you will
> see,
> > > the
> > > sourcecode is commented very heavily. Also you can ask additional
> > > questions to
> > > this mailinglist.
> > >
> > > BTW I am very curious to see your newLisp wrapper!
> > >
> > > Br,
> > > Peter
> > >
> > >
> > > Citeren Sunburned Surveyor <sunburned.surveyor@xxxxxxxxx>:
> > >
> > > > Peter,
> > > >
> > > > It's been a few months since I've had a chance to work with
> GTK-Server.
> > > But
> > > > I had the Flu this last weekend, so I was laid up in the house for a
> > > couple
> > > > of days and I had some time to play around with it and NewLISP.
> > > >
> > > > Once again, I would like to thank you for your work on this great
> tool.
> > > >
> > > > I've learned quite a bit of C-Programming since I spoke to you last,
> and
> > > > I've set up a Linux box at home, and at work. (I'm using Debian
> though,
> > > not
> > > > Slackware.) The C Programming language has proved more of a
> challenge
> > > than I
> > > > thought it would be. I'm am picking it up, but a slower pace than I
> > > would
> > > > like. I really got thrown with the whole subject of pointers, but
> I'm
> > > > getting a handle on it now.
> > > >
> > > > At any rate, I've got a couple more questions for you.
> > > >
> > > > [1] What is the purpose of the "gtk server-callback WAIT" function
> that
> > > is
> > > > included in the main loop portion of the GTK-Server/NewLISP demo? (I
> > > > couldn't find any info on this function in the GTK API docs, and I'm
> > > > guessing by the name that it is a function internal to GTK-Server.)
> > > >
> > > > [2] It seems like the GTK-Server simply accepts GTK function calls
> and
> > > > arguments as a single string from NewLISP. Is this a correct
> > > observation? I
> > > > am really curious how the GTK-Server works. Do you parse those
> strings
> > > and
> > > > translate them into actual C calls? If so, how does this work? Are
> the
> > > > function calls in C compiled and executed as they are recieved, or
> are
> > > you
> > > > using some other mechanism?
> > > >
> > > > [3] I'm interested in taking a look at the code for GTK-Server. I'd
> > > still
> > > > like to contribute improvements and assist with maintenance as my
> > > knowledge
> > > > of C programming improves. Is there any documentation on how the
> program
> > > > works, or should I just take a look at the source code and ask my
> > > questions
> > > > on this mailing list?
> > > >
> > > > Thanks Peter,
> > > >
> > > > Landon
> > > >
> > > > P.S. - I hope to wrap many of the GTK-Server functions in NewLISP
> > > functions.
> > > > This will allow NewLISP users to use GTK GUI's without having to
> aquire
> > > an
> > > > extensive knowledge of GTK-Server. I'll keep you posted on how
> things
> > > work
> > > > out.
> > > >
> > >
> > > --
> > > http://www.gtk-server.org
> > >
> > >
> >
>
>
> --
> http://www.gtk-server.org
>
>
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