Re: Minutes of the GTK+ Team Meeting - 2010-12-14

[Tristan Van Berkom <tristanvb openismus com>]

On Fri, 2010-12-17 at 19:33 -0500, Matthias Clasen wrote:
> Tristan,
> 
> another thing (that I believe Cosimo already pointed out) is that the
> new cell area code seems to not quite get interaction between cell
> data functions and size allocation right.
> 
> You can see the resulting breakage in testappchooser. The treeview in
> the appchooser uses a separate cell renderer for the heading text, and
> uses a cell data function to make it visible only for rows that are
> supposed to be headings (this is a very common pattern, expect many
> things to break in similar ways). After the cellarea merge, the
> heading cell renderer seems to always get its size reserved, even in
> rows where it is invisible.

Ah interesting.

Currently this is happening because by default all cells are packed
with the "align" property set to true.

If we were to make the second cell appear "first" in the case the
first cell is invisible, it would be a lie to say that that cell
is "aligned" with adjacent cells.

Unaligning the cell following the invisible cell will make the
second cell cover the first cell's area when invisible, but not
following cells, maybe we need some different semantic for that
kind of thing (thinking...)

Cheers,
      -Tristan