Re: some quetsions about features and plugins

["Sameer Sahasrabuddhe" <sameerds gmail com>]

On Wed, Jun 11, 2008 at 2:38 AM, Hans Breuer <hans breuer org> wrote:

> > \me delurks.
> Welcome back ;)

One certainly hopes so. But my current academic situation keeps me
from putting non-trivial amounts of time into things other than work,
so keeping a low profile. But this feature, or at least what I
understand of it, comes close to my personal Dia wishlist.

> I don't buy this "not just a plugin", so I'd rather like to improve on the
> things possible from a plug-in instead of being forced to develop every
> prototype in the core.

I am not advocating that at all. By "not just a plug-in", I meant a
set of functions that can be called in any part of Dia. If it is
possible to invoke plugins in this manner, then that's great! I have
not done my homework in this area.

> > 1) The first that comes to mind is changing the properties of some
> > objects. Imagine being able to select "all red lines" and then making
> > them dotted, for example!
> Already possible with a plug-in, namely selec_by.py - but apparently not
> well advertized.

Maybe this plugin can be the starting point for Marleine.

> > 2) This would also be useful for improving the properties dialog ...
> > in its current state, the dialog becomes mostly useless if you try to
> > change the properties of a large number of different objects. The box
> > could have buttons that show objects grouped by different criteria,
> > and allow the user to change properties for these selected subsets.
> As already mentioned I'm not sure I have understood the "filtering ..."
> idea. Didn't it mean selecting objects based on certain criteria, rather
> than selecting attributes of a group of objects?

Yes, I am also talking about selected objects, not attributes. Say for
example I select a few standard objects and a few UML objects and
invoke the properties dialog. It would be nice to be able to say
"apply this change to only the standard objects" even if the attribute
in question is present on both types of objects.

Another use would be to really filter objects from a selection. If I
am only interested in the arrows in some region of the diagram, I
could just select all objects in that region, and then filter out all
objects that are not arrows.

The internal code to do this kind of filtering might already be in
place. One could think of just iterating through all objects for
matches in the worst case. But the interface to the user for
specifying these criteria would need a lot of thinking.

I think I might be getting a bit of the track here. The original post
mentions "exploring" the diagram. I guess he is interested in the
ability to display objects based on some selected criteria ... more of
a visual tool to mask and umask arbitrary parts of the diagram without
resorting to layers. If every object and every distinct visible
component of that object had an independent "visible" attribute, the
tool could accomplish this by turning that attribute on and off when
the user says so.

Sameer.
-- 
Research Scholar, Department of CSE, IIT Bombay
http://www.it.iitb.ac.in/~sameerds/