Composition: Snap points example not complete

[wldevries]

When following the "Snap points" example it seems several things are missing. It is not explained how to create the property set and set the snapDistance.

_propSet = ElementCompositionPreview.GetScrollViewerManipulationPropertySet(scrollPanel);
_propSet.InsertScalar("snapDistance", 400);

Another thing that is missing is what _root refers to. I take it that refers to the root visual of the page and not the ScrollViewers visual?

However after adding these to an example page with a ScrollViewer it only scrolls the entire page down including scrollbar, so I guess I'm animating the wrong visual and for some reason it won't scroll up either.

I've added the following statement to set _root:

_root = ElementCompositionPreview.GetElementVisual(scrollPanel);

And it seemd logical to increate the _tracker.MaxPosition:

_tracker.MaxPosition = new Vector3(scrollPanel.ActualSize.Y);

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Document Details

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• ID: a5380cd5-0823-c7a2-db3d-858eb9b05da0
• Version Independent ID: 19d0d893-9c2c-adfb-33ce-724b3d42c7a0
• Content: Use inertia modifiers to create snap points - UWP applications
• Content Source: windows-apps-src/composition/inertia-modifiers.md
• Product: uwp
• Technology: platform
• GitHub Login: @jwmsft
• Microsoft Alias: jimwalk

[wldevries]

Having this example fully working in WindowsCompositionSamples would be great.

microsoft/WindowsCompositionSamples#347