Flickering Table

[Peter T]

Hello,

I have a table indicator which updates 5 times every second. During the
updates, I changes some of the cell's text values and background colors.
When I run my routine, the table flickers as it updates. If the table is
the slightest bit occluded by another control, it updates smoothly. How can
I prevent my table from flickering without clumbsily putting a control on
top of it?

Thanks,

Peter

[Greg_McKaskle2]

> I have a table indicator which updates 5 times every second. During the
> updates, I changes some of the cell's text values and background colors.
> When I run my routine, the table flickers as it updates. If the table is
> the slightest bit occluded by another control, it updates smoothly. How can
> I prevent my table from flickering without clumbsily putting a control on
> top of it?
>

The table control flicker is due to it drawing everything to the screen each
time. This allows you to see the various stages and gives a bit of a flicker.
Some of the controls, like the graph have a popup for smooth updates
that will
force them to draw everything offscreen, then copy to the screen. This can
slow down execution, but makes things flicker much less.

The
table doesn't have any such popup yet. As you noticed, if an object is
above the content rectangle of the table, the table will not draw to the
screen directly, but will do what we call an invalidation. If the Tools
Options menu is set to draw offscreen, then all of the flickering will
go away.
Another way to accomplish this is to make the table largely transparent.

If the table is just an indicator, the easiest approach is to place a decoration
over the table and make the decoration transparent. I think the hollow decorations
will do the same thing.

Greg McKaskle

[Peter T]

Thanks for the information. I did place a decoration over the table and
made it transparent. It works perfectly.

Thanks,

Peter


"Greg McKaskle" wrote in message
news:3B7331C6.BB4ACD12@austin.rr.com...
> > I have a table indicator which updates 5 times every second. During the
> > updates, I changes some of the cell's text values and background colors.
> > When I run my routine, the table flickers as it updates. If the table
is
> > the slightest bit occluded by another control, it updates smoothly. How
can
> > I prevent my table from flickering without clumbsily putting a control
on
> > top of it?
> >
>
> The table control flicker is due to it drawing everything to the screen
each
> time. This allows you to see the various stag
es and gives a bit of a
flicker.
> Some of the controls, like the graph have a popup for smooth updates
> that will
> force them to draw everything offscreen, then copy to the screen. This
can
> slow down execution, but makes things flicker much less.
>
> The table doesn't have any such popup yet. As you noticed, if an object
is
> above the content rectangle of the table, the table will not draw to the
> screen directly, but will do what we call an invalidation. If the Tools
> Options menu is set to draw offscreen, then all of the flickering will
> go away.
> Another way to accomplish this is to make the table largely transparent.
>
> If the table is just an indicator, the easiest approach is to place a
decoration
> over the table and make the decoration transparent. I think the hollow
decorations
> will do the same thing.
>
> Greg McKaskle

[Doug (CapeFl)]

I've had success with this by selecting one of blocked indicators or controls and selecting 'Move to back' or 'Move to front', as applicable.

[petrem]

I had a similar issue with a rapidly (50 times/sec) updating table.  Based on the suggestions in this tread I added a decoration frame at the edge of the table.  It worked like a charm - no flicker, scroll bars are still accessible, and it doesn't look half bad either.  Thanks to Greg for the helpful information.

[Leiyuan]

WOW! It really works!

[JÞB]

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@Leiyuan wrote:

WOW! It really works!

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Yes, but that is no longer the prefered solution!  (It is 14 years old afer all)

Better: Drop invoke nodes before and after the table value updates and select method "Defer FP Updates" Set True before and False after.

The help file will tell you more but essentially this forces any updates to the FP to happen, Stops updating the FP, Allows you to transfer a whole bunch of data to get ready for display and then makes all of the updates at the same time.

[Leiyuan]

For some reason, the deferfpupdate property does not work in my application. Only the decoration works.

[JÞB]

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@Leiyuan wrote:

For some reason, the deferfpupdate property does not work in my application. Only the decoration works.

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Lets see some code.... you might have other problems.  Feel free to start a new thread to address your issue.

[altenbach]

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@Leiyuan wrote:

For some reason, the deferfpupdate property does not work in my application. Only the decoration works.

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How often does the data change in the table and how often does it get updated? What is your loop rate?