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Author Topic: ttrackbar flickering  (Read 501 times)

fcu

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ttrackbar flickering
« on: October 20, 2020, 03:47:44 pm »
Hi
seems ttrackbar is not benefit from DoubleBuffered option event if its explicitly turned on
its the only component that flickering when resizing the form , the rest of controls is fine
i am using lazarus 2.0.10 & fpc3.2 ( windows7 32bits )


jamie

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Re: ttrackbar flickering
« Reply #1 on: October 20, 2020, 11:01:34 pm »
I don't see that on the trunk nor the release., or even older ones I have installed.

This is tested on windows 10...

 the trackbar is a native control so native control so maybe the difference in os ?
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trev

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Re: ttrackbar flickering
« Reply #2 on: October 21, 2020, 12:51:49 am »
I seem to recall that there was another recent flickering thread about this or another component. Whether the flickering was noticed  depended on the speed of the individual's computer hardware.

Found it: see this thread.
o Lazarus 2.1 r64368 FPC 3.3.1 r48100 macOS 10.14.6 Xcode 11.3.1
o Lazarus 2.1 r64392 3.3.1 Jan 13 21:24 macOS 11.1 aarch64 Xcode 12.3
o Lazarus 2.1 r61574 3.3.1 r42318 FreeBSD 12.1 amd64 VMware VM
o Lazarus 2.1 r61574 3.0.4 Ubuntu 20.04 Parallels VM
o Lazarus 2.0.10 3.2.0 Win10 Parallels VM

jamie

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Re: ttrackbar flickering
« Reply #3 on: October 21, 2020, 01:59:16 am »
I think we need a strip down demo to show this effect.

it could be that it is anchored to other controls and things are going awry
The only true wisdom is knowing you know nothing

fcu

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Re: ttrackbar flickering
« Reply #4 on: October 21, 2020, 01:51:07 pm »
i recorded the issue
https://ibb.co/D5yrkjq

fcu

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Re: ttrackbar flickering
« Reply #5 on: October 21, 2020, 02:04:55 pm »
this is really weird
after adding a menu to the main form the trackbar stops flickering and the menu start flickering

https://ibb.co/99HMYtp

 

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