On 8/2/07, Bart van der Werf <[EMAIL PROTECTED]> wrote:
>
>
> only short strings all data is formatted on the serverside
>
> the base data has about 120 columns, but we're bringing it down to 10-20
> ish, but this still makes qx sluggish
>
> about 20000 rows, but we're using blocks so only about 200 rows are actually
> on the browser at anytime.
>
> on my screen i visually see about 30 rows, and 7 columns.
>
> this means that for every single row scroll it rerenders about 600 cells for
> a 20column table.which takes about 300ms

Hi Bart,

Yes, there are disadvantages as well as advantages to the virtual
table.  The time must be spent rendering at some point.  That means it
must be done either before the whole page is displayed (traditional
table) or as you scroll (virtual table).  The rendering speed is
*greatly* influenced by what browser you're using.  IE is painfully
slow at rendering; in fact, after using firefox with gmail for a
while, I recently had the displeasure of having to use IE to access my
email.  It was a thoroughly awful experience, due solely to the
slowness of rendering in IE.  Gmail isn't a qooxdoo application, but
the same issues apply.  Firefox is way, way faster than IE and I
understand, but have not had the opportunity to experience for myself,
that Webkit-based browsers such as Safari are much faster yet.

One area to experiment with would be pre-rendering the next and
previous "page" of data in the "background" so that scrolling is
merely a matter of making the new rows visible or moving them onscreen
or otherwise reversing whatever mechanism was used to hide them after
their background rendering.  The problem is that this could get in the
way of user interaction if not implemented properly, and it might add
quite a bit of complexity to the virtual table.

If you are using IE, please try your application using either Firefox
or a Webkit browser and let me know your results.  If you had been
using IE, I expect you'll be very pleasantly surprised.  (Then you get
to take on the unenviable job of convincing the users of your
application that they should switch to a reasonable browser...)

If you'd like to take a stab at modifying the table widget to
pre-render next and previous pages, I'll be glad to review your work
for inclusion.  It would need to provide enough benefit in "usability"
and perceived speed, while still having code that's easy enough to
maintain, but that may all be achievable.  Let me know!

Cheers,

Derrell

-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >>  http://get.splunk.com/
_______________________________________________
qooxdoo-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/qooxdoo-devel

Reply via email to