Re: [flexcoders] Horrible performance problems...Need some ideas on improving

[Adrian Williams]

Hi Doug,

   This makes sense.  It's staggering that the validateNow() is being 
called basically on every cell....

   In hope of avoiding recreating the wheel, would you be willing to 
share your extended code with me so I can give it a whirl and see if it 
remedies the problem?

Thanks!
Adrian

Doug McCune wrote:
There are a few places within the ADG code where the code loops over 
every single item renderer and needlessly (or at least excessively) 
calls validateNow() on each renderer. That forces the renderers to 
each relayout and draw themselves and does not allow the delayed 
layout processing that the framework is supposed to allow.

See the updateDisplayOfItemRenderer() method in AdvancedDataGridBase 
and you'll find this function:
protected function updateDisplayOfItemRenderer(r:IListItemRenderer):void
    {
        if (r is IInvalidating)
        {
            var ui:IInvalidating = IInvalidating(r);
            ui.invalidateDisplayList();
            ui.validateNow();
        }
    }

that gets run waaay too often.

Also see the drawCellItem() method of AdvancedDataGrid, which down at 
the bottom of the method has this call:

if (item is IFlexDisplayObject)
        {
            if (item is IInvalidating)
            {
                IInvalidating(item).invalidateDisplayList();
                IInvalidating(item).validateNow();
            }
        }

So basically every time your data grid is redrawing itself it takes 
way longer than it should. I created an extended version of ADG and 
overrode those two methods (had to copy/paste most of the drawCellItem 
method) and I removed the calls to validateNow, seemed to speed things 
up a lot.

Doug

On Thu, Sep 4, 2008 at 8:06 AM, Adrian Williams 
<[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>> wrote:

    All,

        I am seeing some incredible lag while using a couple of simple
    panels and a complex ADG.  While I love the flexibility and power
    of Flex/AS and the ADG,  I really need to overcome these
    performance problems or the project will sink.

        My ADG has approx. 100 columns with approx. 200 rows, in a
    grouping collection that contains approx 30 groups.

        I suspect the lag I am seeing has to do with the redrawing of
    the rows.  Whenever I scroll or collapse/expand the nodes, it
    takes between 1/2 to 1 second for the action to complete.  And
    this isn't even a very large dataset...we have some that have a
    few thousand rows. I haven't used any item rendering (yet) that
    would slow the speed down, though I have two columns that have
    style functions attached. All in all, this is about as close to
    display the raw data as I can get.

        I have spent some time with the profiler and performance
    monitor and it appears the the code is sound and without memory
    leaks.  I have also gone thru to refactor poorly designed code and
    remove unnecessary nestings.

        So my initial questions with this admittedly somewhat vague
    problem are:

        1.)  Is there a way to turn off the animations and would doing
    so help with the speed?
        2.)  Has anyone else faced this same dilemma and how did you
    overcome the problems?

    Thanks,
    Adrian