Is it possible to add private data to a GtkWidget?

Question

Is it possible to add private data to a GtkWidget?

Background:

I have many GtkCheckBottons, all these widgets are connected to the same callback. In the callback, I would like to handle the widgets private data (or at least distinguish between the widgets).

Example:

// checkbox signal callback
void on_checkbox_tcoggled(GtkWidget* widget, gpointer data) {
    MyClass* me = data;
    MyPrivateData* priv = widget->priv;  // ???

    MyClass_foo(me, priv);
}

See my comment to @el.pescado's answer. You have some errors. — unwind, Apr 06 '16 at 13:38
Why not gtkmm instead since you are mixing gtk (c) with C++? — Joel, Apr 06 '16 at 14:33
@Joel I can not use gtkmm, because I am using a c compiler. Where am I mixing C with C++? — sergej, Apr 06 '16 at 14:43
There's nothing wrong mixing C libraries with C++, but there's a reason that there are GTK ports. I only commented as an alternative and get the advantage of C++ with gtkmm. My $0.02. — Joel, Apr 06 '16 at 17:10

el.pescado - нет войне · Accepted Answer · 2016-04-06T13:35:38.457

7

Is it possible to add private data to a GtkWidget?

You can use functions g_object_set_data and g_object_get_data to add arbitrary data to any GObject.

MyPrivateData *priv = ...
g_object_set_data(G_OBJECT(widget), "my private data", priv);

// ...

void on_checkbox1_toggled(GtkWidget* widget, gpointer data) {
    MyClass* me = data;
    MyPrivateData* priv = (MyPrivateData*) g_object_get_data(G_OBJECT(widget), "my private data");

    MyClass_foo(me, priv);
}

edited Apr 06 '16 at 13:35

answered Apr 06 '16 at 13:16

el.pescado - нет войне

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The second argument to the callback is just `gpointer`, not `gpointer *`. And since that's just a `void *`, the cast is not necessary. – unwind Apr 06 '16 at 13:30
You're right. I didn't notice it when copying code from question. – el.pescado - нет войне Apr 06 '16 at 13:36
Many thanks, I like this solution, works like a charm. – sergej Apr 06 '16 at 16:06

Is it possible to add private data to a GtkWidget?

1 Answers1