Subject Re: [IBO] IB_Grid and DoubleBuffered
Author Geoff Worboys
> I have the problem, when I set IB_Grid.DoubleBuffered:=true and
> the Grid is editable, I cannot scroll in the grid. Can anybody
> tell me, what the problem is ?

I just ran a small experiment here with IB_Grid.DoubleBuffered set to
true...

**IF** I have IB_Grid.AlwaysShowEditor = true then it appears that the
interactions between the grid and the inplace editor cause some sort
of continuous call to the paint routines - which resulted in high CPU
useage and slow or unreliable response from many aspects of the entire
application, including grid scrolling.

When I set IB_Grid.AlwaysShowEditor = false then the problem went away
and everything appeared to be normal (for the limited testing that I
did).

I could also cause the problem by dropping one of my Enh controls onto
IB_Grid with AutoLabel turned on - which is not desireable but does
point towards the cause of the problem. If a child control needs to
be painted as part of painting the parent you end up with a feedback
situation causing continuous painting.


Curiously the problem does not happen on an editable TStringGrid, so
it would seem that the problem results from code in the IBO grid or
inplace editor, however...

I suspect that this situation will be a difficult one to track down.
Once found it is even possible that it would not be fixable without
removing or restricting some other feature.

So I ask you how much trouble this is causing you? If you can find
some other way of working around the problem it would be preferrable,
this issue can then be put on a low priority for investigation in
IBO4.


Geoff Worboys
Telesis Computing