On 08/19/2014 03:24 PM, Alexander Larsson wrote: > On mån, 2014-08-18 at 18:09 +0200, Sébastien Wilmet wrote: >> On Mon, 2014-08-18 at 10:01 -0400, Jasper St. Pierre wrote: >>> Because every time we try to clean up GtkTreeView, we break some random >>> application. It's a widget that has twenty three gazillion use cases, and >>> so we have to keep it a mess, because removing the mess means removing one >>> use case, and we can't do that. >> So the problem is because GtkTreeView was developed as policy-free as >> possible. Now the new widgets are written with more policy, which makes >> the API easier to use, with a simpler implementation. > As I see it there are two fundamental problems with GtkTreeView. > > First of all it has a model-view split, but there is no way to save any > state in the view. For example, if the model has a "char *icon_name" > column, then every time we draw a row we read the icon name from the > column, set it as a property of the (one and only) pixbuf cell renderer, > and then ask the cell renderer to draw itself. Now, since the cell > renderer has no state it has to start from scratch each time, including > reading the icon from *disk*. A few releases ago we added a cache for > the icon theme, so we're not quite as bad as this any more, but it still > happens if you have more different icons than the size of the cache. > > This doesn't only affect pixbufs. For instance if you have a tree with a > lot of (mostly static) text you want to be able to cache pangolayouts > for things like rendering of visible rows.
This also affects the accessibility support, as at any point, the accessibility technologies would want to get info (text, status, etc) from a given cell. This leads to custom cell objects (in theory fly-weight objects) that maintain accessibility-related caches. And the accessibility implementation of GtkTreeView is also really complex and regression-prone. BR -- ---- Alejandro Piñeiro _______________________________________________ gtk-devel-list mailing list gtk-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-devel-list
