Hi Harbs,
That's fantastic !
That means, that I could use a normal DataGrid and "emulated" the infinite
behaviour ?
If you managed time to push the bead with a example of use, would be great
(when you have time).
But, don't forget that the user can grab the scroll bar and drop somewhere.
Harbs <harbs.li...@gmail.com> escreveu no dia quarta, 26/04/2023 à(s) 10:26:
> The way I handle performance in my app is with requestAnimationFrame.
>
> Stash an array of your data providers and add them i.e. 20 at a time:
>
> private function handleScrollEnd():void{
> for(var i:int=0;i<20;i++){
> if(pendingTags.length){
> // shift the first item and add it
> to tags
> tags.addItem(pendingTags.shift());
> } else {
> break;
> }
> }
> tagsList.dataProvider = tags;
> if(pendingTags.length){
> requestAnimationFrame(handleScrollEnd);
> }
> }
>
> This makes things very snappy.
>
> Another thing to look out for in terms of performance: Don’t create any
> unnecessary SVG elements (especially) in your itemRenderers. They are huge
> performance killers.
>
> Somewhat related:
>
> I recently learned about IntersectionObservers and it’s greatly improved
> my infinite scrolling code:
>
>
> private var gridObserver:Object;
> private var observedItem:DataItemRenderer;
> private function observeGridItem(lastIndex:int):void{
> if(!gridObserver){
> gridObserver = new
> window["IntersectionObserver"](handleGridItemIntersection, {
> root: view.images.element,
> rootMargin: "0px",
> threshold: 0.1
> });
> }
> unobserveGridItem();
> var dataContainerView:DataContainerView =
> prefUtils.treeLayout ? view.imageTree.view as DataContainerView :
> view.imageGrid.view as DataContainerView;
> observedItem =
> (dataContainerView).getItemRendererAt(lastIndex) as DataItemRenderer;
> if(observedItem && observedItem.element){
> gridObserver.observe(observedItem.element);
> }
> }
> private function unobserveGridItem():void{
> if(!observedItem){
> return;
> }
> if(!gridObserver){
> return;
> }
> gridObserver.unobserve(observedItem.element);
> observedItem = null;
> }
> private function
> handleGridItemIntersection(entries:Array):void{
> if(!entries.length){
> return;
> }
> var entry:Object = entries[0];
> if(entry.isIntersecting){
> unobserveGridItem();
> handleScrollEnd();
> }
> }
>
>
> In this class, handleScrollEnd makes a request for more data.
>
> When I have time, I should really create beads for both of these
> patterns...
>
> > On Apr 26, 2023, at 11:19 AM, Hugo Ferreira <hferreira...@gmail.com>
> wrote:
> >
> > Hi,
> >
> > File sent.
> >
> > Thanks for trying to improve virtualdatagrid.
> > It is far from perfect but for those who want to use it for an
> application with a lot of data, for now it is the solution (or use
> pagination).
> >
> > Regards,
> > Hugo.
> >
> > <cont...@cristallium.com <mailto:cont...@cristallium.com>> escreveu no
> dia quarta, 26/04/2023 à(s) 07:37:
> > Hi Hugo,
> >
> > Thank a lot for your reply and sharing.
> > I don't know if it's an issue with my webmail, I don't have an
> attachment. Could you send it directly on my email ? (contact at
> cristallium.com <http://cristallium.com/> )
> > I will try with latest build from source to have some of your fix and
> study your DataGrid.as
> > I will keep you in touch if I can do more improvements
> > Regards
> > Fred
> >
> > Le 2023-04-25 23:51, Hugo Ferreira a écrit :
> >
> >> Hi,
> >>
> >> DataGrid does not work good with a lot of data (as you saw).
> >> You can use pagination (the users hate this approach and it's not very
> mobile friendly but it's technically a simple way to solve this problem) or
> you can render on the screen only what is visible (the users love this
> approach, it's mobile friendly but technically it's hard).
> >> Think about a game with 1000 players on the screen that you hide what
> is not visible at a specific moment.
> >>
> >> VirtualDataGrid have this goal however there are many chalenges to be
> usable.
> >> I saw in action several issues, I was able to find what I fix the
> majority of them and push to Royale github (I recomend compile from the
> lastest source), I was able to fix 2 other problems in a ugly way and for
> that reason I have an extension of the VirtualDataGrid on my libraries (as
> soon I find better approach, I will exchange this local patches to Royale).
> >> You can find in attachment my DataGrid.as that extends from Royale
> VirtualDataGrid.as
> >> The 2 issues are commented in English (sorry for my bad English), so
> it's easy to understand the issues and what the pach does.
> >>
> >> I also recomend to create ItemRenderes to all your needs where you can
> have 2 states: reading and editing, exchaning from a Label to a TextInput
> for example.
> >>
> >> About your issue, I kwnow it and for now it's the only major issue with
> VirtualDataGrid that I'm aware and I was not able to find iet a stable fix,
> however I found a more or less workaround (you can find it on my
> DataGrid.as).
> >> I have created a bead DataGridScrollSpeed that I'm using on my
> DataGrid.as
> >> This slow a bit the scroll and the issue reduces for almost of the time
> unless you force several times.
> >> You can decrease even more the speed and reduce 99% the issue.
> >> It's not the correct fix but I was not able to find out a better
> approach.
> >> If someone can fix this for good, great !
> >>
> >> Regards,
> >> Hugo.
> >>
> >> <cont...@cristallium.com <mailto:cont...@cristallium.com>> escreveu no
> dia terça, 25/04/2023 à(s) 18:46:
> >> Hi All,
> >>
> >> I'm on a dev using Apache Royale with Jewel DataGrid tryng to show
> about
> >> 500 rows.
> >>
> >> But I have an issue when I set dataprovider : the application is
> hanging
> >> about 20 seconds... Then I saw that there is a VirtualDataGrid.
> >>
> >> Using it is very fast. But there is an issue with vertical scrollbar :
> >> when using it from bottom to upper, it's working right, but from upper
> >> to bottom the thumb goes away (on Chrome). The issue is visible on Tour
> >> de Jewel :
> >>
> >> https://royale.apache.org/tourdejewel/#!virtual_lists_panel <
> https://royale.apache.org/tourdejewel/#!virtual_lists_panel>
> >>
> >> (it's working is scrolling slow, but if I move down a little fast, then
> >> the thumb go away from mouse and go immediatly to the end at bottom of
> >> list)
> >>
> >> On Firefox : there is one scrollbar but when can't reach the end of
> list
> >> and on chrome there are 2 scrollbars, we can reach end of list but
> there
> >> is an issue on using scrollbar from top to bottom
> >>
> >> I saw a fix by Hugo, so I wanted to download last build on :
> >>
> >>
> http://apacheroyaleci2.westus2.cloudapp.azure.com:8080/job/royale-asjs_jsonly/lastSuccessfulBuild/artifact/out/
> <
> http://apacheroyaleci2.westus2.cloudapp.azure.com:8080/job/royale-asjs_jsonly/lastSuccessfulBuild/artifact/out/
> >
> >>
> >> Unfortunaly it's dead. Is there a way to download last build on other
> >> link ?
> >>
> >> Regards
> >>
> >> nb : I'm using sdk 0.9.10
> >
> > --
> > Frédéric Gilli
> > mob.0668542622
> > http://www.cristallium.com <http://www.cristallium.com/>
> > <http://www.cristallium.com/>
> >
>
>
