Drop down list with scroll bar doesn't select correct item

[GeertvanHorrik]

I thought it was fixed in v5, but installing the prerelease still gives the same behavior:

.NET fx 4.0
Fluent.Ribbon 5.0.0 (stable, from AppVeyor)

Will try to find the cause and update this ticket.

[GeertvanHorrik]

Even with ClosePopupOnMouseDown set to false it picks the wrong item.

[GeertvanHorrik]

Basically the scrolling gets reset as soon as you focus the drop down content.

[GeertvanHorrik]

This seems to work in the demo app. Investigating why this isn't working in our component.

[GeertvanHorrik]

I can also reproduce strange scrolling behavior in the demo app. Note that I don't even click items here, just using the scroll buttons (hover only).

[GeertvanHorrik]

Found the cause. Whenever I use a StackPanel as ItemsPanelTemplate, this issue occurs. So this is reproducable in the app like this:

                    <Fluent:DropDownButton Header="Dropdown (auto close on click) g"
                                           ResizeMode="Both"
                                           Icon="pack://application:,,,/Fluent.Ribbon.Showcase;component/Icons/App.ico"
                                           LargeIcon="pack://application:,,,/Fluent.Ribbon.Showcase;component/Icons/App.ico"
                                           ClosePopupOnMouseDown="True"
                                           ClosePopupOnMouseDownDelay="250">
                        <Grid>
                            <ListBox ItemsSource="{Binding StringItems}">
                                <ItemsControl.ItemsPanel>
                                    <ItemsPanelTemplate>
                                        <StackPanel />
                                    </ItemsPanelTemplate>
                                </ItemsControl.ItemsPanel>

                                <ItemsControl.ItemTemplate>
                                    <DataTemplate>
                                        <MenuItem Header="{Binding}" Click="OnAutoCloseDropDownButtonMenuItemClick"/>
                                    </DataTemplate>
                                </ItemsControl.ItemTemplate>
                            </ListBox>
                        </Grid>
                    </Fluent:DropDownButton>

When I remove the custom ItemsPanelTemplate, it doesn't show this strange behavior.

[GeertvanHorrik]

For now I will close this issue since I can live without a custom ItemsPanelTemplate. Hopefully this ticket can be used as a reference for others bumping into this issue.

[batzen]

@GeertvanHorrik
The scrolling is intentional because of ClickMode="Hover".

The jumping selection is just the regular ScrollViewer in ScrollViewer problem.
Just set ScrollViewer.CanContentScroll="False" on your ListBox and everything is fine.
Scrolling by mouse still won't work that way.

I wonder why you even use a ListBox and don't rely on the DropDownButton already inheriting from MenuBase.

[GeertvanHorrik]

It's a control from an external lib which I am embedding into the ribbon. So in regular situations it would be perfect to have a ListBox inside the control.

I still find it strange that whenever I don't use an ItemsPanel, it works fine. Anyway, it's solved for now :)

And great work on v5, much appreciated!