UPF Scrollbar flickers between two points in a texbox when scrolling.

[fireball87]

Using the same code as https://github.com/tlgkccampbell/ultraviolet/issues/129 meaning no scrollbar specific code at all and a very simple textbox when I scroll by clicking on the bar the scroll will often flicker between two points far above and far below where I've selected.

For my system info, Manjaro Linux running KDE Dotnet Core 3.1

A video showing the issue. https://youtu.be/1ur1A9AO4oo

[tlgkccampbell]

@fireball87 I'm having trouble tracking this one down; I can't seem to reproduce it locally. If you can send me an example program which reproduces the issue, that would help a lot.

[fireball87]

Replacing the screen xml in sample twelve with the following reproduces the issue for me (basically any textbox with a scrollbar does it, and honestly my gut is it's probably every scrollbar, give me a second to test that). It's likely Linux or even configuration specific, which if it is that makes it far lower priority for me at least.

<?xml version="1.0" encoding="utf-8" ?>
<UIPanelDefinition>
  <View ViewModelType="sample12_upf.UI.Screens.ExampleViewModel, sample12_upf">

    <Image Source="#Global:Textures:DefaultUIBackground 0 0 1161 685" VerticalAlignment="Stretch" HorizontalAlignment="Stretch"/>

    <TextBox Name="textbox" Grid.Row="0" Grid.Column="0" VerticalScrollBarVisibility="Visible" IsReadOnly="True">
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        </TextBox>
  </View>
</UIPanelDefinition>

[fireball87]

For note, replacing that text box with the following produces exactly the same behavior, so it's almost certainly every UV scrollbar on my system.

        <ListBox>
                        <ListBoxItem>ListBox Item #1</ListBoxItem>
            <ListBoxItem>ListBox Item #2</ListBoxItem>
            <ListBoxItem>ListBox Item #3</ListBoxItem>
                        {...100 more rows of this}
        </ListBox>

[tlgkccampbell]

As expected, this still does not reproduce locally for me. I'll set up a Linux VM and see if I can track it down.

[tlgkccampbell]

I believe I've identified the problem, and it should be fixed by 820856dcd10987afd80c3285b0186c8f7f8c8b91, which will be in the next release.