[Lazarus] TMemo flicker
juergen.hestermann at gmx.de
Wed May 1 12:16:29 CEST 2013
Am 2013-04-30 20:45, schrieb Graeme Geldenhuys:
> If that is the case, then it is a bug in LCL. Even if there are nested
> Begin/EndUpdate calls, that should make no difference. As long as those
> calls are in pairs, and as soon as the last EndUpdate is called, then
> the whole component should refresh/repaint - that includes contents,
> scrollbar adjustment etc.
Yes, after thinking about it a bit more there should be an internal Begin/EndUpdate somewhere in the corresponding LCL routine. I first thought that each Begin/EndUpdate pair causes code generation but actually it is the opposite (if nesting is allowed).
> That's how it works in Delphi's VCL and in fpGUI. Nothing complicated or
> tricky. Before you populate any GUI component with large amounts of
> data, call BeginUpdate before and EndUpdate after.
Yes, if the *programmer* does multiple things to a GUI component. But here it was only a single assignment which should not require Begin/EndUpdate but this assignment seems to cause multiple things internally which make it flicker .
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