Hi Hendrik
My feeling is also that you have stumbled upon a bug.
Your update with the visible = false crossed mine.
My understanding was that all delegates are created when the ListView
is created / Loaded. I see no reason at all why the ListView should go
on a creation spree when it becomes INVISIBLE. That seems counter
intuitive to me.
It has been suggested that you use dynamic loading, but I don't think
that helps your problem. Just to be clear, I have used that technique
successfully in two ways.
1) in my app Landed overall startup time was poor. One of the reasons
was that all pages were being created on startup, and one was loading
the phone's ContactModel. Given that the user may never actually get
as far as the Page containing the ContactModel, I decided it would be
better to dynamically load the ContactModel if and when that page
becomes visible. So the app now starts fast, with the slight downside
that if a user choses to access the phone's contacts, he needs to wait
at at that point for the ContactModel to load.
2) Once the ContactModel was loaded (with several hundred contacts),
scrolling in the ListView was terrible. The solution here was to make
the delegate as lightweight as possible, and to dynamically load all
the bits required when the delegate is clicked.
However from the behaviour you describe, none of that will help you. I
need to do some thinking ...
bis bald
Chris
Zitat von "Hendrik Borghorst" <hendrikborgho...@gmail.com>:
Hello,
the problem isn't my delegate. It is quite minimal.
The problem is I think a bug in QML Listview. It goes absolutly crazy if
it is invisible and starts making delegate for around 50% of all items.
This causes the memory to run full.
A workaround I added is
model: visible ? modelVar : null
which works quite nicely. I think this bug could be an upstream qt bug?
greetings
Am Sonntag, den 15.12.2013, 10:01 +0100 schrieb
christopher.l...@thurweb.ch:
Hi Hendrik
Have you seen this? http://qt-project.org/wiki/Performance_tip_Lists
The general advice is to keep the delegates is lightweight as
possible, and to use Loaders for anything needed later (e.g. onClick)
Chris
Zitat von "Hendrik Borghorst" <hendrikborgho...@gmail.com>:
> Hello folks,
>
> I've got a problem with long lists (~25000 elements). All delegates are
> created at once which causes the memory usage to explode beyond the
> devices capability.
>
> I already tried setting "cacheBuffer: 0" in SiliciaListView but it
> doesn't change it.
>
> Is the something I'm doing wrong.
>
> You can see the actual page code here:
>
>
https://github.com/djselbeck/smpc/blob/master/pages/CurrentPlaylistPage.qml
>
> Shouldn't the delegates be constructed on demand? It is weird because my
> old n8 wasn't struggling with qml lists with this size.
>
> greetings and congrats on getting the devices to your customers (I'm
> very pleased)
>
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