[Lazarus] testing virtual TListView in gtk2

[Paul Ishenin]

Seth Grover wrote:
> However, for the purposes of testing, I then increased the count to
> 1000000, since a major purpose of a virtual list view is so you don't
> have to eat up all your memory storing the items.
>
> To my dismay, when I ran the program, it ran correctly, but the memory
> usage of my program was huge compared to when I only had 10 items.
>
> I put some writeln's in the OnData method and also discovered that
> that the OnData routine was called, on startup of my program, for each
> of my million items.
>
> Am I doing something wrong? Is there some other way I'm supposed to
> set the number of items for my list rather than setting Items.Count? I
> tried looking at the revision changes
> (http://svn.freepascal.org/cgi-bin/viewvc.cgi?view=rev&root=lazarus&revision=22789)
> and didn't see any other way.
>   
ListViews on gtk can't be absolutely virtual - they need to have all the 
items. But captions, checks, etc are not stored in it (in the case of 
virtual) - they are requested before the drawing. So you should have 
some memory reduction in comparition with the real listview.

Only windows has real virtual listview. Other widgetsets have only 
compatible interface (your first test), not the implementation (storage 
organisation - your second test).

Best regards,
Paul Ishenin.