Re: Graphics properties as objects

[Shai Ayal]

On Jan 3, 2008 5:41 PM, Michael Goffioul <address@hidden> wrote:
> On 1/2/08, John W. Eaton <address@hidden> wrote:
> > |   string_property& as_string_property (void) const
> > |     { return *(reinterpret_cast<string_property*> (rep)); }
> >
> > Since this is  casting within the inheritence hierarchy, shouldn't
> > this use dynamic_cast?
>
> Probably yes.
>
> > Also, should it really return a non-const reference?  Since rep is
> > shared, wouldn't that allow someone to modify multiple copies?  Is
> > that really what you want here?
>
> A const reference might be OK. I didn't think about this deeply.
> For the moment, I cannot figure out a use-case where a non-const
> reference might be needed.
>
> > | >>>>> property set in base_properties <<<<<
> > |
> > | class OCTINTERP_API base_properties
> > | {
> > | //...
> > | public:
> > |   void add (base_property *bp)
> > |     { all_props[bp->get_name ()] = property (bp); }
> >
> > Where is this function used?
>
> Nowhere, it's more to make the API complete. And in my first attempt,
> I thought about registering properties to the map in the base_property
> ctor (kind of automatic registering): but in that case, the base_property
> ctor would somehow need an access to the containing "properties"
> object, which it does not have (it has access to the graphics_object
> handle, but that's not a *direct* access; moreover a graphic object
> is still not bound to its handle at ctor time).
>
> > | >>>>> then the easiest is probably to rewrite properties ctor <<<<<
> > |
> > | text::properties::properties (const graphics_handle& mh,
> > |                             const graphics_handle& p)
> > |   : base_properties (go_name, mh, p),
> > |     string (new string_property ("string", mh, "")),
> > |     //...
> > | {
> > |   //...
> > |   add (string);
> > | }
> >
> > OK, I think this is a reasonable solution.
>
> OK, what do you want me to do now? Should I write a complete proposal
> including all specialized property classes, the property generation code
> and so on? (this will take some time, of course...)

Michael, I can share the work. I am not confident enough I understand
you skeleton, but if you post a giude like I did once: "HOWTO add a
new property", I will try and make an awk script to automatically
generate as much of it as possible.

Shai