[Solved] RadSlideView pinchpan gestures conflict with nested RadImageEditor zoom and best practice for InteractionMode toggling?

[Andrey]

I have a RadSlideView where each slide's ItemTemplate hosts a RadImageEditor (toolbar hidden, used only for pan/zoom viewing). The intended behavior:

• Swipe between slides normally when the image isn't zoomed in
• Once the user pinch-zooms into the current image, RadImageEditor should take gesture priority, and slide-swiping should be suppressed until zoom returns to 100%

<telerik:RadSlideView
    x:Name="radSlideView"
    ItemsSource="{Binding Images}"
    CurrentItemChanged="OnCurrentItemChanged"
    InteractionMode="{Binding CurrentImage.IsZoomedIn, Converter={StaticResource IsZoomedInToInteractionModeConverter}}">
    <telerik:RadSlideView.ItemTemplate>
        <DataTemplate x:DataType="viewModels:SlideImageItem">
            <telerik:RadImageEditor
                Source="{Binding Source}"
                ZoomLevel="{Binding ZoomLevel, Mode=TwoWay}" />
        </DataTemplate>
    </telerik:RadSlideView.ItemTemplate>
</telerik:RadSlideView>

IsZoomedIn on SlideImageItem is computed from ZoomLevel != 100. A converter maps true to InteractionMode.None and false to InteractionMode.Pan, so RadSlideView should disable swiping once zoomed in.

Questions

1. Does RadImageEditor.ZoomLevel update reliably from user pinch gestures (not just programmatic sets), so a TwoWay binding like the one above correctly reflects live zoom state back to the view model?
2. Is toggling RadSlideView.InteractionMode at runtime via binding the supported approach for this kind of gesture conflict, or is there a recommended pattern for nesting a zoomable/pannable child inside RadSlideView without interference?
3. If dynamic InteractionMode switching isn't reliable, is there a built-in mechanism for RadSlideView to yield pan/swipe priority to an active child gesture automatically?

Any guidance, known limitations, or a working sample combining RadSlideView with per-slide pinch-zoom (e.g. via RadImageEditor) would be much appreciated — I wasn't able to find an existing example covering this combination in the docs.

[Didi]

Hi Andrey,

I have reviewed the case and here are my notes:

1. Does RadImageEditor.ZoomLevel update reliably

- Yes, the zoom level updates as expected, here is an image of the output window:

2. Is toggling RadSlideView.InteractionMode at runtime via binding the supported approach

- yes, the property is bindable. In the above image the interaction mode value changes as expected.

However, the case you observe includes gestures that are in conflict. So you have a slideview with swipe gesture and ImageEditor with pan and zoom gestures, these gestures are in a conflict.

You can try setting the SlideView InteractionMode to Pan and ImageEditor input transparent to true when the zoom level is 100. Setting input transparent to true will disable the gestures of the image editor. Another option is setting the interaction mode to none and use only the slideview buttons. 

Regards,
Didi
Progress Telerik