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>How do I attach data to some GTK+ object/widget?
[GTK 2.x]</TITLE
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>How do I attach data to some GTK+ object/widget?
<I
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>[GTK 2.x]</I
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><P
>First of all, the attached data is stored in the
object_data field of a GtkObject. The type of this field is
GData, which is defined in glib.h. So you should read the
gdataset.c file in your glib source directory very
carefully.</P
><P
>There are two (easy) ways to attach some data to a gtk
object. Using <TT
CLASS="LITERAL"
>g_object_set_data()</TT
> and
<TT
CLASS="LITERAL"
>g_object_get_data()</TT
> seems to be the most
common way to do this, as it provides a powerful interface to
connect objects and data.</P
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><PRE
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>void g_object_set_data(GObject *object, const gchar *key, gpointer data);
gpointer g_object_get_data(GObject *object, const gchar *key);</PRE
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>Since a short example is better than any lengthy speech:</P
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>struct my_struct p1,p2,*result;
GtkWidget *w;
g_object_set_data(G_OBJECT(w),"p1 data",(gpointer)&p1);
g_object_set_data(G_OBJECT(w),"p2 data",(gpointer)&p2);
result = g_object_get_data(G_OBJECT(w),"p1 data");</PRE
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>The <TT
CLASS="LITERAL"
>gtk_object_set_user_data()</TT
> and
<TT
CLASS="LITERAL"
>gtk_object_get_user_data()</TT
> functions does
exactly the same thing as the functions above, but does not
let you specify the "key" parameter.Instead, it uses a
standard "user_data" key. Note that the use of these functions
is deprecated in 1.2. They only provide a compatibility mode
with some old gtk packages.</P
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