Disable scrolling on a GtkScale in GTK4.

gistfile1.txt

/* No-op to prevent @w from propagating "scroll" events it receives.
 */
void disable_scroll_cb( GtkWidget *w ) {}

/* Disable scroll on a widget by adding a capture phase event handler and
 * connecting a no-op callback to the "scroll" event.
 */
static GtkWidget *
disable_scroll( GtkWidget *w )
{
        GtkEventController *ec;

        ec = gtk_event_controller_scroll_new(
                        GTK_EVENT_CONTROLLER_SCROLL_VERTICAL );

        gtk_event_controller_set_propagation_phase( ec, GTK_PHASE_CAPTURE );
        g_signal_connect( ec, "scroll", G_CALLBACK( disable_scroll_cb ), w );
        gtk_widget_add_controller( w, ec );

        return w;
}

/* Create a spin button with range, default value, and optionally enabled
 * scrolling.
 */
GtkWidget *
create_scale( double min, double max, double step,
                double value, bool scroll )
{
        GtkWidget *s;

        s = gtk_scale_new_with_range( GTK_ORIENTATION_HORIZONTAL, min, max, step );
        gtk_range_set_value( GTK_RANGE( s ), value );

        return scroll ? s : disable_scroll( s );
}