Re: Is __modified__ graphics prop useful anymore?

[Rik]

On 10/24/2016 02:32 PM, Rik wrote:

On 10/24/2016 02:14 PM, John W. Eaton wrote:
> On 10/24/2016 05:10 PM, John W. Eaton wrote: >> On 10/24/2016 04:48 PM, Rik wrote: >>> 10/24/16 >>> >>> I made the graphics property __modified__ a hidden property >>> (http://hg.savannah.gnu.org/hgweb/octave/rev/4ea5b0c3b10f).  But, I can't >>> see that it is used anywhere usefully in the code.  Maybe it had a >>> purpose >>> a long time ago, but should it just be put on the road to deprecation >>> now? >> >> Isn't it used in base_properties::mark_modified method?  I think the >> purpose is to tag a set of properties as modified so that there is a >> quick way to know whether something has changed and the object needs to >> be drawn again. > > The base_properties::is_modified method checks the status.  It's used in Fdrawnow. >

But nothing seems to set the value to "off".

octave:12> hax = gca;
octave:13> get (hax, "__modified__")
ans = on
octave:14> drawnow
octave:15> get (hax, "__modified__")
ans = on

Actually, the only code that ever turns off a modified property is in Fdrawnow, and it only does it for figure objects

-- Code in Fdrawnow --
          Matrix hlist = gh_manager::figure_handle_list (true);

          for (int i = 0; i < hlist.numel (); i++)
            {
              graphics_handle h = gh_manager::lookup (hlist(i));

              if (h.ok () && h != 0)
                {
                  graphics_object go = gh_manager::get_object (h);
                  figure::properties& fprops
                    = dynamic_cast<figure::properties&> (go.get_properties ());

                  if (fprops.is_modified ())
                    {
                      if (fprops.is_visible ())
                        {
                          gh_manager::unlock ();

                          fprops.get_toolkit ().redraw_figure (go);

                          gh_manager::lock ();
                        }

                      fprops.set_modified (false);
                    }
                }
            }
-- End Code --

Even that doesn't seem to work completely as expected.  As soon as __modified__ property is "off" it seems that it is incapable of being set to "on".

octave:1> h = figure ();
octave:2> get (gcf, "__modified__")
ans = on
octave:3> drawnow
octave:4> get (gcf, "__modified__")
ans = off
octave:5> set (gcf, "__modified__", "on")
octave:6> get (gcf, "__modified__")
ans = off

There might be some performance savings from eliminating all the calls to mark_modified since the state variable is never used.

This issues should be addressed but I don't know where to keep track of it.  It is more than a bug report because the issue is architectural.

--Rik