Re: SQL parser ready to hook up to Dia

[Cyrille Chepelov <chepelov calixo net>]

Le mar, aoû 14, 2001, à 07:33:58 -0700, Andrew S . Halper a écrit:

> About that...  I've gotten as far as being ready to set the "name" property of
> the UML class (may not have the terminology correct here...still learning the
> StdProp interface), but now I'm kind of stuck and could use some help.
>
> The code leading up to it is:
>
>       /* these should be probably changed to more useful defaults
>        eventually */
>       startpoint.x = 0.0;
>       startpoint.y = 0.0;
>       umlclass_obj = otype->ops->create(&startpoint, otype->default_user_data,
>                                       &h1, &h2);
>       layer_add_object(layer, umlclass_obj);
>
>       props = prop_list_from_descs(sql_prop_descs, pdtpp_true);
>       g_assert(props->len == 11);
>
> which should look familiar, because I just nicked it from dxf-import.c and
> renamed some variables.  In the next line, I think I need to set up the "name"
> property of UML class I created in umlclass_obj.  In the DXF import plug-in, you
> have:

>     ((PointProperty *)(g_ptr_array_index(props,0)))->point_data.x = start.x;

In fact, that's the first snippet I wrote. I now prefer to write slightly
differently:

        PointProperty *ptprop; /* one for each of the types I'll need */
        /* ... */

        ptprop = g_ptr_array_index(props,0);
        ptrop->point_data = start; /* you can move a small struct in a
                                        single statement */

and then let gcc simplify the code down to the first form. Neither form
really satisfies me.

> and I assume I need to do something similar, but with different casts and
> structure references.  Where should I look to relate the 4th element of
> sql_prop_descs:
>
>   { "name", PROP_TYPE_STRING, PROP_FLAG_VISIBLE, N_("Name"), NULL, NULL },

(In those property descriptors, where you never use the properties to do
anything else than obj->ops->set_props(obj,props), no clipboard, no
load/save, no dialogs, you can abridge to just the first two fields).

> to the type of structure pointer cast I need to do?

"Almost" trivial:
        grep PROP_TYPE_WHATEVER lib/prop_*.c | grep register
and then you look for the type used in the whateverprop_ops methods.
 (WhateverProperty *) defined in lib/prop_*.h would be a safe bet, in this 
case.

Hmmm.... A few comments in lib/properties.h wouldn't hurt, would they ?
On my TODO.

> Also, of course I was wondering if there was some luxurious plug-in writer's
> documentation I could add this to once I figure it out?  If not, I can attempt
> to cook one up while I'm doing this.

ahem :-)

        -- Cyrille

-- 
Grumpf.