playlist subsystem overhaul

[Ian Monroe]

On Tue, Oct 7, 2008 at 4:18 AM, Nikolaj Hald Nielsen
<nhnfreespirit at gmail.com> wrote:
>> I'm known to put great emphasis on graphical perfection, and as such I
>> have to say that the possibility of having proper animation in the
>> playlist is absolutely crucial. It has been a design goal of the
>> playlist from the beginning of Amarok 2 development. Even if we don't
>> get animation done until 2.0 anyway, what use would it be to switch to
>> a new system if we have to change it back later?
>>
>> So I would like to see proof for the feasibility of this before
>> agreeing to switching.
>
> To me at least, stuff like animation is completely secondary to having
> a playlist that actually works. And Sorens patch, although it has a
> ton of small and a few major issues, solves some very basic problems
> with the old version, such as how to drag and drop multiple disjoint
> items, dragging first track of an album seperately from the entire
> album and several other corner cases.

As a practical matter of landing the patch, there are some major
crashes it currently introduces. I haven't looked into why. But we're
on a pretty short schedule before beta3, so if its something
fundamentally wrong with the new implementations we wouldn't have
time. So I'd say either Soren should fix the crashes before committing
or at least assure us thats its details that would be fixed in a day
or two after committing  (this seems likely to me, btw, but I can't
say for sure).

Another issue to consider: Soren has two big changes here that are
only tangentially related: the refactor in the model and the new
listview.

> This is why I am for committing it and letting us have a got at
> getting the bugs out of it. Then we can evaluate whether we like it or
> not.
>
> As for feasibility, if the trolls can make animations work when
> expanding nodes in a QTreeView, it should be possible ( although
> likely non trivial ) to animate moves in the new playlist.

This doesn't say anything about feasibility. The Trolls wrote
QTreeView and QListView, the same way we wrote Playlist::GraphicsView.
If the Trolls had implemented animation in a subclass of QListView,
that would be interesting and relevant, but they haven't done that.
The system they have in place to customize QListView is the delegate
system, which unless something has changed since 2007 can't be
animated effectively.