[SailfishDevel] Delegate creation on demand

Andrey Kozhevnikov coderusinbox at gmail.com
Sun Dec 15 20:05:46 UTC 2013


load model dynamically?

if you wont preload model before using it can solve many problems.
:)

On 16.12.2013 02:03, Hendrik Borghorst wrote:
> 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.lamb at 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" <hendrikborghorst at 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)
>>>
>>
>>
>>
>
>
> _______________________________________________
> SailfishOS.org Devel mailing list

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