>In article <b3gf5i$60...@hyppo.gu.net>, RG RG wrote:
>> Hm, what do you usually do if you want to type-cast, say, tview pointer as
>> tdialog one?

>tdialog(tview)

>> I mean, tgroup.current returns pointer to active view (be it a window,
>> dialog, whatever), which is declared as pview.
>> How do I execute some method of tdialog, if active window is a dialog, and,
>> therefore, pointer returned by tgroup.current points to
>> an instance of tdialog object?

>pdialog(tmygroup.current)^.method(param1,param2);

>> I'm searching for a civilized way to do so:)) Would be very thankful for
>one
>> who points thist way out.

>There is some danger in this, because it doesn't check if it is a dialog. So
>if somehow
>you cast the wrong pointer, you probably get a nice RTE 216.

>But afaik there is no systematic way to check this in BP/TP. (Delphi has IS
>and AS)

> > I mean, tgroup.current returns pointer to active view (be it a
window,
> > dialog, whatever), which is declared as pview.
> > How do I execute some method of tdialog, if active window is a
dialog, and,
> > therefore, pointer returned by tgroup.current points to
> > an instance of tdialog object?

> pdialog(tmygroup.current)^.method(param1,param2);

> > I'm searching for a civilized way to do so:)) Would be very thankful
for one
> > who points thist way out.

> There is some danger in this, because it doesn't check if it is a

> But afaik there is no systematic way to check this in BP/TP. (Delphi
has IS
> and AS)

> "Marco van de Voort" <mar...@toad.stack.nl> schreef in bericht
> news:slrnb5nkmu.1cif.marcov@toad.stack.nl...
> > In article <b3gf5i$60...@hyppo.gu.net>, RG RG wrote:
> > > Hm, what do you usually do if you want to type-cast, say, tview
> pointer as
> > > tdialog one?

> In fact you are telling the compiler not to check the type of parameter
> or object at a given location, but to consider it as the type specified
> by your typecasting.

> > tdialog(tview)

> > > I mean, tgroup.current returns pointer to active view (be it a
> window,
> > > dialog, whatever), which is declared as pview.
> > > How do I execute some method of tdialog, if active window is a
> dialog, and,
> > > therefore, pointer returned by tgroup.current points to
> > > an instance of tdialog object?

> > pdialog(tmygroup.current)^.method(param1,param2);

> > > I'm searching for a civilized way to do so:)) Would be very thankful
> for one
> > > who points thist way out.

> > There is some danger in this, because it doesn't check if it is a
> dialog. So if somehow
> > you cast the wrong pointer, you probably get a nice RTE 216.

> > But afaik there is no systematic way to check this in BP/TP. (Delphi
> has IS
> > and AS)

> Yes in BP/TP there is a possibility to check the type of an object by
> means of the typeof function.
> Something like
> if typeof (tgroup)=typeof(tmyobject) then.....

> I use this for determining the type in a tcollection filled with
> different types of objects

> --
> Femme

> "RG RG" <ragnar0ck_FORSPAMME...@ukr.net> schreef in bericht
> news:b3ip7l$lao$1@hyppo.gu.net...
> > There seems to be another way to check object types - pointers to
> > constructor init are all equal for every instance of an object.
> > Replies were very helpful, thank you.

> The typeof function gives you a pointer to the objects vitual method
> table.
> Other preferable method is to start with a mother type of object.
> Give it a virtual method of the common operation you want to do.
> All the objects that you work with, decend from the mother type, where
> every type defines its own unique virtual method for the operation you
> wanted to do.

> --
> Femme