My thoughts more specifically: - the data property is set -> an invalidation should occur. - a renderer is reused -> an invalidation should occur. - a renderer is scrolled within the view port -> no invalidation should occur, after its size is determined.
Or am i wrong? --- In [email protected], "Florian" <florian.saliho...@...> wrote: > > 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 <aharui@> 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.salihovic@> 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 > > >
