Re: gdk_settings()

[Owen Taylor <otaylor redhat com>]

Tim Janik <timj gtk org> writes:

> hey owen,
> 
> haven't looked at the gdk_settings code yet, but i don#t particularly like:
> 
> static void
> gtk_settings_get_property (GObject     *object,
>                            guint        property_id,
>                            GValue      *value,
>                            GParamSpec  *pspec)
> {
>   GtkSettings *settings = GTK_SETTINGS (object);
> 
>   if (!gdk_setting_get (pspec->name, value))
>     g_value_copy (settings->property_values + property_id - 1, value);
> }
> 
> 
> void
> _gtk_settings_handle_event (GdkEventSetting *event)
> {
>   GtkSettings *settings = gtk_settings_get_global ();
> 
>   if (g_object_class_find_property (G_OBJECT_GET_CLASS (settings), event->name))
>     g_object_notify (G_OBJECT (settings), event->name);
> }
> 
> 
> gtk_settings_get_property() should furtherly retrive values
> only from its local copy, and _gtk_settings_handle_event() should
> simply get the new value from gdk and set it on gtksettings, i.e.:
> 
> static void
> gtk_settings_get_property (GObject     *object,
>                            guint        property_id,
>                            GValue      *value,
>                            GParamSpec  *pspec)
> {
>   GtkSettings *settings = GTK_SETTINGS (object);
> 
>   g_value_copy (settings->property_values + property_id - 1, value);
> }
> 
> 
> void
> _gtk_settings_handle_event (GdkEventSetting *event)
> {
>   GtkSettings *settings = gtk_settings_get_global ();
>   GParamSpec *pspec = g_object_class_find_property (G_OBJECT_GET_CLASS (settings), event->name);
> 
>   if (pspec)
>     {
>       GValue tmp_value = { 0, };
>       
>       g_value_init (&tmp_value, G_PARAM_SPEC_VALUE_TYPE (pspec));
>       gdk_setting_get (pspec->name, &tmp_value);
>       g_object_set_property (G_OBJECT (settings), pspec->name, &tmp_value);
>       g_value_unset (&tmp_value);
>     }
> }
> 
> 
> is there any reason you didn't do things this way?

I originally did it essentially in this way, but backed that out and did
it the way that it is now for a number of reasons:

 - When a property is unset through the XSETTINGS mechanism, it should be
   restored to the RC file value, not to the default value

 - Even restoring to the default value required quite a bit of changes
   to GtkSettings because it became necessary to be able to unset
   a value.

 - By reading through to GDK, instead of trying to mirror, you get 
   consistency when multiple related settings change at once.
   (Otherwise, you would need to have more types of events, with a
   freeze-notify and thaw-notify, which is just ugly.)

 - It was a lot simpler the current way.

Regards,
                                        Owen