Re: Bug in get_preferred_height_for_width() [was Re: Minimum height for minimum width]

[Havoc Pennington <hp pobox com>]

Hi,

On Fri, Oct 15, 2010 at 8:55 AM, Tristan Van Berkom
<tristanvb openismus com> wrote:
> The for_size fed to widget implementations additionally needs to
> strip the added padding that can happen in ->adjust_size_request()

Right, adjust_size_allocation should basically invert anything
adjust_size_request does so the widget is seeing things as if only the
widget itself had set the request.

By "padding" I don't just mean the margin properties, I mean anything
adjust_size_request adds (also the padding for fill alignment, the
container border width, etc.)

> However the bug I'm referring to is another one; the for_size also
> needs to be limited to the natural size in the case that the widget
> does not "fill" (i.e. not to compensate for pixels stripped in
> ->adjust_size_request(), but for pixels that will further be stripped
> in ->adjust_size_allocation(), in the case that the widget expanded).

Wouldn't it fix this to do adjust_size_allocation on the for_size?

> In the end the adjust_size_allocation() api/vfunc
> will look like this:
>
> void gtk_widget_adjust_allocated_size (GtkWidget *widget,
>                                       GtkOrientation orientation,
>                                       gint           proposed_size,
>                                       gint           natural_size,
>                                       gint          *offset,
>                                       gint          *adjusted_size);

If you have a for_size (which can be -1 for unset) then you could skip
the natural size and just call the size request API again, using the
for_size if >= 0. I think that would be better, because as you say:

> The part that feels weird here is that we are feeding in the
> natural_size, however it's important because come allocation time
> specifically; the 'natural_size' may be in context to a for_size
> in the other orientation (i.e. the widget cannot be expected to
> just "know" its natural size in this stage).

I think you should just call the request methods again. (Not the
wrappers of course, the vfuncs directly.) Instead of passing in a
natural size.

Havoc