Re: [gtkmm] Two optional return values in pango functions: what to do?

[Naofumi Yasufuku <naofumi yasufuku net>]

At Fri, 6 Sep 2002 22:39:11 +0200,
Martin Schulze wrote:
> 
> So far only for one pango function this has been completely implemented in
> pangomm: There are three wrapper functions for 
> pango_font_get_glyph_extents:
> 
> 1) void Font::get_glyph_extents(Glyph glyph, Rectangle& ink_rect, 
> Rectangle& logical_rect)
> 2) void Font::get_glyph_extents_ink_rect_only (Glyph glyph, Rectangle& 
> ink_rect)
> 3) void Font::get_glyph_extents_logical_rect_only (Glyph glyph, Rectangle& 
> logical_rect)
> 
> So the return values are really optional here.
> 
> For other funtions, like GlyphString::extents(), that also return two
> rectangles we only have 1). Now, in my opinion, it would be an overkill to
> add 2) and 3) for every such function. E.g. GlyphString::extents() already
> has an overload because some parameters are optional. If we added 2) and 3)
> for both overloads, we would have 6 functions in the whole that wrap the 
> same
> single pango function.
> 
> On the other hand, if people agreed that it isn't desirable to add 2) and 
> 3)
> whereever possible, I would want to know whether anyone has some need for 
> the
> existing functions 2) and 3) in Pango::Font. Otherwise, I would just remove
> them to be consistent with the other wrapper functions that only have 1).
> 

I think pango_font_get_glyph_extents() means that

 I.   Programmers can get the ink extents of a glyph within a font.

    Rectangle Font::get_glyph_ink_extents(Glyph glyph)

 II.  Programmers can get the logical extents of a glyph within a font.

    Rectangle Font::get_glyph_logical_extents(Glyph glyph)

 III. Programmers can also get both extents at once.

    void Font::get_glyph_extents(Glyph glyph,
                                 Rectangle& ink_rect,
                                 Rectangle& logocal_rect)


Regards,
--Naofumi