forgot again to reply to all. If anyone ever considers changing the default settings of the list server, +1 from me.
---------- Forwarded message ---------- From: Robert Krüger <krue...@lesspain.de> Date: Wed, Jan 28, 2015 at 3:47 PM Subject: Re: TableView API, no lazy retrieval of visible cell content possible? To: Werner Lehmann <lehm...@media-interactive.de> On Wed, Jan 28, 2015 at 3:13 PM, Robert Krüger <krue...@lesspain.de> wrote: > > Hi, > > On Wed, Jan 28, 2015 at 1:59 PM, Werner Lehmann < > lehm...@media-interactive.de> wrote: > >> Robert, >> >> I think Tomas is right, load your thumbnails on demand when updateItem is >> called for an item with missing thumbnail. You say that the cell of a >> visible item gets reused for another item. If that is the case I guess that >> the item is "moved" to another cell. Wouldn't it be possible to have an >> image property on your items and the lazy loading is done on the item, >> triggered when the item is passed to updateItem of any cell? That > > > That is exactly what I have implemented but the problem is as described > above > - Too many non-visible images are loaded (I could probably live with that > for a while) > - I have yet to find a criterion to decide an image is no longer needed > and thus its loading job needs to be removed from the job stack (see below) > > >> should trigger the demand-loading and it would be robust against the >> tableview exchanging cells for individual items. >> > As to the question when to start or stop lazy loading for items, I would >> add the load-demands to a stack. Each time the image for a new item is >> requested it is put to the top of the stack and you have one or more >> threads processing items on the stack (LIFO). An an image is requested >> which is already on the stack move it to the top of the stack. If an item >> is removed from a cell remove it from the stack. That should do it. >> >> > That's what I am doing already. > To clarify: I am using the stack approach you describe and I remove it from the stack when updateItem for a table cell is called that already has a different item set. Then I remove the already set item from the stack but that never seems to happen in my example. > > > -- Robert Krüger Managing Partner Lesspain GmbH & Co. KG www.lesspain-software.com
