[Bug] ScrollView ScrollOrientation.Neither not working properly

[mattleibow]

Description

ScrollView doesn't quite behave as expected when changing the orientation to Neither. I have a scroll view, with a stack layout that has 2 items (probably not important). One of the items is very tall.

By default, the big item causes the scroll view to scroll as expected.

If I set the orientation to neither in the page constructor or in XAML, Android goes weird and resizes my big view and my touch events are all mixed up for my canvas view. iOS does not resize my view, and my touch events are fine. It is almost as if the Android view is scrolling, but not actually :)

The other side of this is when I set the orientation later on, such as in a button click. Both platforms just ignore this change and still keep scrolling.

side bug: UWP scrollview padding is just plain evil. In fact, I think the scroll orientation seems to be affecting the padding on all platforms... This might need more testing and a new bug.

Steps to Reproduce

<ScrollView x:Name="scroller" Padding="20,60" BackgroundColor="Orange">
    <StackLayout>
        <Button Clicked="OnBtn" Text="Disable Scroll" BackgroundColor="Red" TextColor="Green" />
        <BoxView BackgroundColor="Green" WidthRequest="200" HeightRequest="3000" />
    </StackLayout>
</ScrollView>

private void OnBtn(object sender, EventArgs e)
{
	scroller.Orientation = ScrollOrientation.Neither;
}

Expected Behavior

ScrollView.Orientation = Neither always disables scroll, and does not resize contents.

Actual Behavior

Android:

• resizes contents when set in xaml and constructor
• does not stop scroll when set after rendered

iOS & UWP:

• does not stop scroll when set after rendered

Basic Information

• Version with issue: 4.3.0.947036
• Last known good version: N/A
• IDE: VS 2019 for Mac
• Platform Target Frameworks:
  • iOS: 12.3.1
  • Android: 10
  • UWP: Not tested yet
• Android Support Library Version:
• Nuget Packages:
• Affected Devices:

Screenshots

Android (late disable ignored)	iOS (late disable ignored)	UWP (late disable ignored)
Android (box height ignored)	iOS (box height respected)	UWP (box height respected)

Reproduction Link

[charlesroddie]

@AxelUser

[vchelaru]

I'd like to add a related bug here. If the ScrollView's Orientation is set to ScrollOrientation.Neither, I would expect that controls inside the ScrollView behave as if they are not in a scroll view at all. Specifically, for SKCanvasViews, that means that the SKTouchAction.Cancelled ActionType should not be raised, and the SKCanvasView should continue receiving Move actions when the user has moved vertically. However, currently the Cancel event is sent, and further Move events no longer get sent if the user moves too far horizontally.

This behavior makes it very difficult to add objects to a SKCanvasView which can scroll vertically, while the page can scroll horizontally.