Yes, i understand this aspect of the component model. But since nothing happens after the renderer references a new "data", why is there the invalidation of renderers which have a correct state already?
--- In [email protected], Alex Harui <aha...@...> wrote: > > When useVirtualLayout=true, renderers are being recycled so more invalidation > does go on. It pretty much has to. You might be able to block some of it, > depending on your scenario. > > > On 8/9/10 12:12 AM, "Florian" <florian.saliho...@...> wrote: > > > > > > > When scrolling my custom item renderer, which inherits from ItemRenderer, i > notice significant performance problems, when scrolling the list. It seems > like the list's layout is invalidating the component when the list is > scrolled. > > I configured the list's layout with the following parameters: > > <s:VerticalLayout gap="0" horizontalAlign="contentJustify" paddingBottom="0" > paddingLeft="0" paddingRight="0" paddingTop="0" rowHeight="82" > useVirtualLayout="true", variableRowHeight="false" /> > > I also overwrote the renderer's measuredWidth and measuredHeight properties: > > override public function set measuredHeight(value:Number):void > { > height = super.measuredHeight = value; > } > > override public function set measuredWidth(value:Number):void > { > width = super.measuredWidth = value; > } > > The question for me now popping up is, how to avoid those unnecessary > invalidation cycles? I'd expect the layout to be at least as smart as > handling size changes only when the item renderer's owner changes it's width, > since the rowHeight is set. > > Best regards > > > > > > > -- > Alex Harui > Flex SDK Team > Adobe System, Inc. > http://blogs.adobe.com/aharui >
