Hey,
I noticed something and i’m not sure if it’s a bug. So i would like to hear someone else’s opinion.
Description:
The Scrollbars sometimes flicker or disappear completly for a few seconds when the table is loading data.
How to reproduce:
Go to
demo.vaadin.com/sampler/#ui/data-presentation/table . Already when you load the page and the table is rendering its data you can see the scrollbars flicker (sometimes more or less). Now select a row. scroll down a bit (i.e. by clicking below the scroller) and select a row again. The row will flicker sometimes after that. In the Vaadin Sampler this problem might not be visible as good but in my application where i have a table with 23 columns, 2 generated columns containing buttons, several styles attached to it and currently around 500-600 rows the scrollbars completly disappear for 2-3 seconds and the loading indicator pops up for a second even when i only scrolled about 12 rows (rows per page: 15 rows, row lazy loading: 30 rows).
Tested Browsers:
Google Chrome 23+29
FF 23
IE10: Sampler didn’t show flickering but table rows didn’t load properly when scrolling. When using my table, bug was visible as described
Vaadin Version: 7.1.2
I couldn’t see anything similar to this in Vaadin 6
Hope to hear if this is a known bug as it makes my Application behave really weird to a point where i don’t want to deploy it to the live server this way.
If i compare the performance of the table in my Vaadin 7 application with the same one from my Vaadin 6 app i can see quite a big difference. My V6 table takes around 2-3 seconds to load a full set of new rows while displaying the row indicator on the top.
My V7 table on the other hand takes 5 seconds to do the same thing followed by a Scrollbar and Loading indicator rave which freezes the app for about 1-2 seconds.
I know that in Vaadin 7.2. the Table Component will be completely rewritten which hopefully fixes the current performance problems but i wonder if i’m the only one having so much problem with it now and if there maybe is a way currently to at least make it a bit less frustrating to use.
just wanted to confirm that my general experience is that the Table in Vaadin 7 indeed does perform worse than in Vaadin 6. I don’t know about the reasons at all, but I think with ‘enough’ columns it is clearly noticeable. I can also confirm the scroll bar flicker.
I searched the Vaadin trac but could not find a bug ticket for the scroll bar flicker, maybe you could file one? Although I think it’s doubtful anything will be done about it due to the upcoming new table component (unless prioritized via pro account).
It feels good to know that i’m not the only one seeing this happening. I also found out that this was extremely visible in Firefox 29.
I created a Ticket
#12569 so that the Devs at least notice the problem. I sadly don’t have a Pro Account so i can’t increase the Priority but even when it won’t get fixed before the rewrite the Devs will know what not to do so that hopefully something like this won’t show up afterwards.
It seems like the main cause for this is adding a generated column. I made a test where without a generated column but with 16 non-generated columns it was running smoothly but when adding even one generated column the loading and the hanging starts again.
I have the same problem, caused by using icons in buttons embedded inside the table rows. When I was using plain buttons there was no flickering issue, but when I modified them with icons and style “link”, I got the flickering issue. I have attached my findings to ticket
http://dev.vaadin.com/ticket/12569