On 18 Jul 2001 09:11:21 -0400, Delbert Martin wrote:
> I am working on a new ICQ client. I am trying to pass some login and password values
>to a function.
> I am still having problems with this
>
> my code basically looks similar
> I have a window with two text boxes and two buttons. one button is a login button.
>the other is an exit button
> the exis button works fine. when i press the login button i want it to take the
>information typed into the two text
> entries and place it in a structure and send the structure over to a callback where
>i can write the code to actually
> log the person into the server. most everything is a callbcak function. the main
>program simply calls the login screen which
> is just a function.
>
> /* callbacks file */
>
> struct info {
> GtkWidget *UID;
> GtkWIdget *PASS;
> }
>
> gint do_login(GtkWidget *widget, struct info *myInfo) {
> gchar *user,*pass;
> user = gtk_entry_get_text(myInfo->UID);
> pass = gtk_entry_get_text(myInfo->PASS);
> /* print output to screen for now */
> .........
> }
First of all don't use gtk_entry_get_text, instead use
gtk_editable_get_chars. --> user =
gtk_editable_get_chars(GTK_EDITABLE(myInfo->UID),0,-1);
>
> void login_screen(void) {
> ......
> struct info lgInfo;
> lgInfo.UID = gtk_entry_new();
> lgInfo.PASS = gtk_entry_new();
>
> .........
>
>gtk_signal_connect(GTK_OBJECT(login_button),"clicked",GTK_SIGNAL_FUNC(do_login),
>&myInfo );
> ........
> }
>
The struct variabele won't exist anymore at the end of this function, so
you're passing a pointer to unallocated memory to the callback function,
which will screw up your entire program. Two sollutions: 1) use a global
variable or 2) allocate memory for the structure and pass that pointer
to the callback function, free the struct when you're ready (preffered).
So something like this:
struct info * lgInfo = g_malloc(sizeof(struct info));
gtk_signal_connect(...., lgInfo);
and when you don't need the struct anymore: g_free(lgInfo);
> /* main program */
>
> int main(......) {
> gtk_init(......);
> login();
> gtk_main();
> return 0;
> }
>
> any help possible would be greatly appreciated--Delbert Martin IV
>
>
>
> _______________________________________________
> gtk-list mailing list
> [EMAIL PROTECTED]
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Try to find some information about memory allocation and pointers in C.
This is really essential to know well when programming C, and a source
of many many bugs....
Greetz,
--
Jeroen Benckhuijsen
Software Engineer
Phoenix Software
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