Re: using multiple widgets in a callback

[TP Muller <tpm01 aber ac uk>]

On Friday 26 July 2002 21:21, Jeffrey Goddard wrote:

> I've seen, somewhere, a method for passing more than two widgets to a
> callback routine, but I can't seem to find it anywhere in my office. Could
> someone please give me a clue?

Pass a pointer to a structure or to an array containing the widgets, e.g.

typedef struct
{
        GtkWidget       *widget1, *widget2, *widget3;
} threeWidgetsStructure;


and then in your code ...

threeWidgetStucture     *tws = g_new0 (threeWidgetStructure, 1);
if (tws)
{
  tws->widget1 = somewidget;
  tws->widget2 = anotherwidget;
  tws->widget3 = yetanotherwidget;
  gtk_signal_connect (GTK_OBJECT (some_object), "some-signal",
                            GTK_SIGNAL_FUNC(some_signal_function), (gpointer)tws);
} else g_printerr ("mem alloc failed in %s!\n", __FUNCTION__);

alternatively:

GtkWidget **threeWidgets = g_new( (GtkWidget*), 3);
threeWidgets[0]=somewidget;
threeWidgets[1]=anotherwidget;
threeWidgets[2]=yetanotherwidget;
gtk_signal_connect (GTK_OBJECT(some_object), "some-signal",
                        GTK_SIGNAL_FUNC(some_signal_function), (gpointer) threeWidgets);


then in some_signal_function(), (for example);

GtkWidget **threeWidgets = (GtkWidget**)user_data;
.... 
gtk_widget_hide (threeWidgets[0]);
gtk_widget_hide (threeWidgets[1]);
gtk_widget_hide (threeWidgets[2]);


Dunno if those are good methods or not.

Cheers
-Tim