Flickering TScrollbox
lazarus / 31-LCL

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kupferstecher · 2017-05-11 19:15

Hi,

there is flickering inside a TScrollbox when I set a quantity of
controls to visible:= false. Its reproducable, see the attached
example project. The flickering occurs on and near to the border of
the scrollbox.
DoubleBuffered:= true also doesn't help.

It seems to be fine for BorderStyle:= bsNone. But in the standard
configuration (bsSingle) there is this annoying flickering.

Does anyone know how to solve that?

Regards

PS: Same behaviour on Win Vista 32bit, Lazarus 1.6.4
and on Win7 64bit, Lazarus 1.6.

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Thaddy · 2017-05-11 19:38

Seems to be an off-by-one bug in the case of a border.

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kupferstecher · 2017-05-11 20:00

Hm, could be.
Now I also testet on Linux with qt, there the flickering doesn't
occur.

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ASerge · 2017-05-19 21:35

Quote from: kupferstecher on May 11, 2017, 09:15:02 pmthere is
flickering inside a TScrollbox when I set a quantity of controls to
visible:= false.
Framing with ScrollBox1.DisableAutoSizing and
ScrollBox1.EnableAutoSizing will help.

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kupferstecher · 2017-05-23 10:52

Hello ASerge,

now I tried that, for hiding the controls your solution works. But for
enabling the visibility there still is flicker.

For now I just use the scrollbox without frame.

Regards

Quote from: ASerge on May 19, 2017, 11:35:14 pmFraming with
ScrollBox1.DisableAutoSizing and ScrollBox1.EnableAutoSizing will
help.

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airpas · 2017-05-23 12:11

i got lot of flickering too with Splitters when it's linked with many
controls . i think the procedure TCustomSplitter.MoveSplitter is
unoptimized , there is alot of code inside this procedure .

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Handoko · 2017-06-08 05:43

I cannot reproduce the issue on Linux Gtk2.