I just had an epiphany. I tried so many ways to make saving function name and
args work, it never occured to me that you could just as easily save undo
information as a pair of mementos, even in the Command-based structure we
agreed on.
Since many (read: almost all) existing undo commands take this form:
begin_reversible_command (_("change fade in length"));
session->add_undo (arv->region.get_memento());
arv->region.set_fade_in_length (fade_length);
session->add_redo_no_execute (arv->region.get_memento());
commit_reversible_command ();
We are already doing the save a memento before and after work. All we need to
do is instantiate an appropriate instance of MementoCommand. So the above
becomes:
begin_reversible_command (_("change fade in length"));
MementoCommand<arv_region_t, arv_region_memento_t> before, after;
before = arv->region.get_memento();
arv->region.set_fade_in_length (fade_length);
after = arv->region.get_memento();
session->add_command(arv->region, before, after);
commit_reversible_command ();
(With apologies for being too lazy to go look up what arv_region_t and
arv_region_memento_t are)
Note that the true command approach is still possible, and encouraged (both by
dictate and design).
git-svn-id: svn://localhost/ardour2/branches/undo@680 d708f5d6-7413-0410-9779-e7cbd77b26cf
